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Revenue from Contract with Customer [Text Block]

REVENUE RECOGNITION

January 1, 2018,

the Company adopted Topic

606,

using the modified retrospective transition method applied to those contracts which were

not

completed as of

January 1, 2018.

Under this method, the Company evaluated contracts that were in effect at the beginning of fiscal

2018

as if those contracts had been accounted for under Topic

606

from the beginning of their terms. Upon adoption, the Company recognized the cumulative effect of adopting this guidance as an adjustment to accumulated deficit on the date of initial application. The comparative information in prior periods has

not

been restated and continues to be reported under the accounting standards in effect for those periods.

The Company also considered the impact of subtopic ASC

340

40.

Prior to the adoption of Topic

606,

the Company expensed commission costs and related fringe benefits as incurred. Under ASC

340

40,

the Company is required to capitalize and amortize incremental costs of obtaining or fulfilling a contract over the period of the expected benefit. Incremental costs of obtaining and fulfilling a contract are recognized as an asset if the costs are expected to be recovered.

The most significant impacts of the adoption of Topic

606

are as follows:

●

At the adoption date, the Company recorded a net decrease of

$4.4

million to accumulated deficit related to the acceleration of revenue required by the adoption of Topic

606

using the modified retrospective method and the capitalization of incremental sales commission costs, net of related deferred tax impact. Under the modified retrospective method, a portion of revenue for uncompleted contracts, which would have been recognized in future periods under Topic

605,

was accelerated and recognized as an adjustment to accumulated deficit as of the date of adoption. As a result, the beginning balance of accounts receivable increased by

$0.8

million, contract assets were established at

$1.9

million and deferred revenue decreased by

$2.5

million. The Company capitalized

$0.5

million of incremental sales commission costs at the adoption date directly related to obtaining customer contracts and will amortize these costs over the lives of the contracts for which such commissions are paid.

●

For fiscal

2018,

revenue generated under Topic

606

is expected to be slightly lower than revenue would have been under Topic

605.

This is the result of a combination of factors, including the reduction of deferred revenue that under Topic

605

would continue to be recognized into revenue in

2018

and beyond, as well as changes in the timing of revenue recognition as discussed below. The actual effect on revenue recognized for the

first

quarter of fiscal

2018

was

not

significant; and

The adoption of Topic

606

impacted the Company’s accounting for certain commercial software multi-element arrangements (“MEA”) that combine software-related deliverables, which

may

include software contracts with varying terms and service elements. Topic

605

required establishing vendor specific objective evidence of fair value or, VSOE, for undelivered elements to recognize revenue separately for each of the different elements. Topic

606

requires the Company to allocate consideration to each separate different performance obligation through the use of stand-alone selling prices (“SSPs”) and to recognize the revenue as if those performance obligations had been sold on a standalone basis, either at a point-in-time or over time. The most significant impact of this change relates to the Company’s accounting for software license revenue. For the Company’s Exensio big data solution software licensed under time-based license model, the Company will recognize a portion of revenue on these types of contracts at the time of delivery rather than ratably over the term of the license. For perpetual software license contracts, the Company will allocate consideration to the different performance obligations based on their SSPs rather than using the VSOE for undelivered elements as required under Topic

605.

In addition, under the Company’s previous accounting practices, revenue was recognized from Gainshare performance incentive agreements in the period of receipt of related Gainshare acknowledgement reports, generally

one

quarter in arrears from the period in which the underlying sales (usage) occurred. Under Topic

606,

the Company is now required to record Gainshare revenue in the same period in which the usage occurs. Because the Company generally does

not

Under Topic

605,

the Company recognized revenue for professional services, including revenue from fixed price solution implementation service contracts, either on a percentage of completion method or time and materials method. Under Topic

606

revenue related to these professional services will remain substantially unchanged.

The following table summarizes the effects of adopting Topic

606

on the Company’s condensed consolidated balance sheet as of

March

31,

2018:


	As reported under Topic 606			Adjustments			Balances under Topic 605
					(In thousands)
Accounts receivable, net of allowance	$	58,436		$	764		$	59,200
Prepaid expenses and other current assets		9,654			(3,959	)		5,695
Deferred tax assets		15,896			316			16,212
Other non-current assets		9,752			(289	)		9,463
Deferred revenues – current portion		8,474			1,348			9,822
Long-term income taxes payable		4,824			(1,032	)		3,792
Other non-current liabilities		1,122			899			2,021
Accumulated deficit		(23,160	)		(4,383	)		(27,543	)

The impact of adopting Topic

606

to revenues, cost of revenues and net income for the

three

months ended

March

31,

2018

was

not

significant. There was

significant impact to the basic and diluted net income (loss) per share.

The Company’s net cash provided by operating activities for the

three

months ended

March

31,

2018

did

not

change due to the adoption of Topic

606.

The following table summarizes the effects of adopting Topic

606

on the financial statement line items of the Company’s condensed consolidated statement of cash flows for the

three

months ended

March

31,

2018:

	As reported under Topic 606			Adjustments			Balances under Topic 605
	(In thousands)
Net income	$	(424	)	$	(30	)	$	(454	)
Changes in operating assets and liabilities:
Accounts receivable, net of allowance		(80	)		(1,556	)		(1,636	)
Prepaid expenses and other current assets		(2,183	)		1,569			(614	)
Other non-current assets		798			288			1,086
Deferred revenue		1,906			(271	)		1,635

The Company derives revenue from

two

sources: Design-to-silicon-yield solutions and Gainshare performance incentives.

Revenue is recognized when control of products or services is transferred to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those promised products or services.

The Company determines revenue recognition through the following

five

steps:

●

Identification of the contract, or contracts, with a customer

●

Identification of the performance obligations in the contract

●

Determination of the transaction price

●

Allocation of the transaction price to the performance obligations in the contract

●

Recognition of revenue when, or as, performance obligations are satisfied

The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable.

The Company enters into contracts that can include various combinations of licenses, products and services, some of which are distinct and are accounted for as separate performance obligations. For contracts with multiple performance obligations, the Company allocates the transaction price of the contract to each performance obligation, generally on a relative basis using its standalone selling price.

Nature of Products and Services

Design-to-silicon-yield solutions — The Company recognizes revenue for each element of Design-to-silicon-yield solutions as follows:

The Company generates a significant portion of its Design-to-silicon-yield solutions revenue from fixed-price solution implementation service contracts delivered over a specific period of time. Revenue under project–based contracts for solution implementation services is recognized as services are performed using a percentage of completion method based on costs or labor-hours inputs, whichever is the most appropriate measure of the progress towards completion of the contract. Due to the nature of the work performed in these arrangements, the estimation of costs or hours at completion is complex, subject to many variables and requires significant judgment. Key factors reviewed by the Company to estimate costs to complete each contract are future labor and product costs and expected productivity efficiencies. If circumstances arise that change the original estimates of revenues, costs, or extent of progress toward completion, revisions to the estimates are made. These revisions

may

result in increases or decreases in estimated revenues or costs. Losses on fixed-price solution implementation contracts are recognized in the period when they become probable. Revisions in profit estimates are reflected in the period in which the conditions that require the revisions become known and can be estimated (cumulative catch-up method).

On occasion, the Company includes its products as a component of its fixed-price service contracts. In such instances, the Company determines whether the services performed and products included, are distinct. In most cases, the arrangement is a single performance obligation and therefore follows the pattern of transfer as the service is provided. The Company applies a measure of progress (typically hours-to-hours or cost-to-cost) to any fixed consideration. As a result, revenue is generally recognized over the period the services are performed using percentage of completion method. This results in revenue recognition that corresponds with the value to the client of the services transferred to date relative to the remaining services promised.

The Company also license our Design-for-Inspection (DFI) system as a separate component of fixed-price service contracts. The Company allocates revenue to all deliverables based on their standalone selling prices, or SSP. In such instances, the Company applies judgment to estimate the range of SSPs for each performance obligation.

The Company licenses some of its software products separately from solution implementations, primarily its Exensio big data platform and related products. The majority of these products are delivered as on-premise software licenses, while others can be delivered entirely or partially through Software-as-a-Service (SaaS) or cloud delivery models. Revenue from perpetual (

one

-time charge) license software is recognized at a point in time at the inception of the arrangement when control transfers to the client, if the software license is distinct from the services offered by the Company. Revenue from post-contract support subscription is recognized over the contract term on a straight-line basis, because the Company is providing a service of standing ready to provide support, when-and-if needed, and is providing unspecified software upgrades on a when-and-if available basis over the contract term. Revenue from time-based license software is allocated to each performance obligation and is recognized either at a point in time or over time. The license component is recognized at a point in time, at the delivery of the software license, with the post-contract support subscription component being recognized ratably over for the committed term of the contract. Revenue from software hosting or SaaS arrangements that allow for the use of a hosted software product or service over a contractually determined period of time without taking possession of software are accounted for as subscriptions and recognized as revenue ratably, on a straight-line basis, over the coverage period beginning on the date the service is made available to customers.

Gainshare Performance Incentives — When the Company enters into a contract to provide yield improvement services, the contract usually includes

two

components: (

) a fixed fee for performance by the Company of services delivered over a specific period of time; and (

) a Gainshare performance incentive component where the customer pays a variable fee, usually after the fixed fee period has ended, related to the usage of the Company's intellectual property. Revenue derived from Gainshare performance incentives is contingent upon the Company’s customers reaching certain defined production yield levels. Gainshare performance incentive periods are usually subsequent to the delivery of all contractual services and performance obligations. The Company recorded Gainshare revenue as a usage-based royalty based on customers' usage of intellectual property and recorded in the same period in which the usage occurs.

Disaggregation of revenue

In accordance with ASC

606

50,

the Company disaggregates revenue from contracts with customers into geographical regions, major contract performance obligations and timing of transfer of goods and services. The Company determined that disaggregating revenue into these categories achieves the disclosure objective to depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors.

The following table shows the revenues from contracts with customers by the nature of transactions for the

three

months ended

March 31, 2018:

	March 31 , 2018

Product and licenses	$	7,487
Support and Services		16,989
Other		261
Total	$	24,737

Product and licenses include a portion of time-based software, perpetual software which is recognized in the period and Gainshare performance incentives. The remaining portions of revenue from these contracts correspond to services or other types of performance obligations are reported as either services revenue or other revenue.

Under Topic

606,

the Company’s performance obligations are satisfied either over-time or at a point-in-time. Revenue from performance obligations satisfied over time and at a point-in-time accounted for approximately

69%

and

31%,

respectively, of the Company’s total revenue for the

three

months ended

March

31,

2018.

International revenues accounted for approximately

59%

of our total revenues for the

three

months ended

March 31, 2018

as compared to

53%

for the

three

months ended

March 31, 2017.

See Note

Customer and Geographic Information.

Significant Judgments

More judgments and estimates are required under Topic

606

than were required under Topic

605.

Due to the complexity of certain contracts, the actual revenue recognition treatment required under Topic

606

for the Company’s arrangements

may

be dependent on contract-specific terms and

may

vary in some instances.

In services arrangements, the Company typically satisfies the performance obligation and recognizes revenue over time. In Design-to-silicon-yield service arrangements, the performance obligation is satisfied over time either because the client controls the asset as it is created (e.g., when the asset is built at the customer site) or because the Company’s performance does

not

create an asset with an alternative use and the Company has an enforceable right to payment plus a reasonable profit for performance completed to date. In most other services arrangements, the performance obligation is satisfied over time because the client simultaneously receives and consumes the benefits provided as the Company performs the services.

For revenue under project–based contracts for fixed-price solution implementation services, revenue is recognized as services are performed using a percentage-of-completion method based on costs or labor-hours input method, whichever is the most appropriate measure of the progress towards completion of the contract. Due to the nature of the work performed in these arrangements, the estimation of percentage of completion method is complex, subject to many variables and requires significant judgment. Key factors reviewed by the Company to estimate costs to complete each contract are future labor and product costs and expected productivity efficiencies. If circumstances arise that change the original estimates of revenues, costs, or extent of progress toward completion, revisions to the estimates are made. These revisions

may

result in increases or decreases in estimated revenues or costs, and such revisions are reflected in revenue on a cumulative catch-up basis in the period in which the circumstances that gave rise to the revision become known.

The Company’s contracts with customers often include promises to transfer products, licenses and services, including professional services, technical support services, and rights to unspecified updates to a customer. Determining whether products, licenses and services are distinct performance obligations that should be accounted for separately, or

not

distinct and thus accounted for together, requires significant judgment. The Company rarely licenses or sells products on a standalone basis, so the Company is required to estimate the range of SSPs for each performance obligation. In instances where SSP is

not

directly observable because the Company does

not

sell the license, product or service separately, the Company determines the SSP using information that

may

include market conditions and other observable inputs. The Company, in some cases, has more than

one

SSP for individual performance obligations. In these instances, the Company

may

use information such as the size of the customer and geographic region of the customer in determining the SSP.

The Company is required to record Gainshare royalty revenue in the same period in which the usage occurs. Because the Company generally does

not

receive the acknowledgment reports during a given quarter within the time frame necessary to adequately review the reports and include the actual amounts in quarterly results for such quarter, the Company accrues the related revenue based on estimates of customer's underlying sales achievement. The Company estimation process can be based on historical data, trends, seasonality, changes in the contract rate, knowledge of the changes in the industry and changes in the customer’s manufacturing environment learned through discussions with customers and sales personnel. As a result of accruing revenue for the quarter based on such estimates, adjustments will be required in the following quarter to true-up revenue to the actual amounts reported.

Contract Balances

The Company performs its obligation under a contract with a customer by transferring products or services in exchange for consideration from the customer. The timing of the Company’s performance often differs from the timing of the customer’s payment, which results in the recognition of a receivable, a contract asset or a contract liability. The Company classifies the right to consideration in exchange for products or services transferred to a client as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional as compared to a contract asset which is a right to consideration that is conditional upon factors other than the passage of time. The majority of the Company’s contract assets represent unbilled amounts related to fixed-price solution implementation service contracts when the costs or labor-hours input method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the client, and the right to consideration is subject to milestone completion or client acceptance. The contract assets are generally classified as current and are recorded on a net basis with deferred revenue (i.e., contract liabilities) at the contract level. The contract assets is included in prepaid expenses and other in the condensed consolidated balance sheets. At

March 31, 2018

and

January 1, 2018,

contract assets of

$3.7

million and

$1.9

million, respectively, are included in prepaid expenses and other current assets in the condensed consolidated balance sheets. Deferred revenues consist substantially of amounts invoiced in advance of revenue recognition and is recognized as the revenue recognition criteria are met. Deferred revenues that will be recognized during the succeeding

twelve

month period is recorded as current deferred revenues and the remaining portion is recorded as non- current deferred revenues. This balance was recorded in the other non-current liabilities in the accompanying condensed consolidated balance sheets. Non-current portion of deferred revenue was

$0.5

million and

$0.9

million, respectively, as of

March 31, 2018

and

January 1, 2018.

During the

three

months ended

March

31,

2018,

the Company recognized

$2.6

million of revenue that was included in the deferred revenue balance, as adjusted for Topic

606,

at the beginning of the period.

March 31, 2018,

the aggregate amount of the transaction price allocated to the remaining performance obligations related to customer contracts that were unsatisfied or partially unsatisfied was approximately

$45.0

million. Given the applicable contract terms, the majority of this amount is expected to be recognized as revenue over the next

years, with the remainder in the following

years. This amount does

not

include contracts to which the customer is

not

committed, nor contracts with original expected lengths of

one

year or less, nor contracts for which we recognize revenue equal to the amount we have the right to invoice for services performed, or future sales-based or usage-based royalty payments in exchange for a license of intellectual property. This amount is subject change due to future revaluations of variable consideration, terminations, other contract modifications, or currency adjustments. The estimated timing of the recognition remaining unsatisfied performance obligations is subject to change and are affected by changes to the scope, change in timing of delivery of products and services, or contract modifications.

Payment terms and conditions vary by contract type, although terms generally include a requirement of payment within

days. In instances where the timing of revenue recognition differs from the timing of invoicing, the Company has determined that its contracts generally do

not

include a significant financing component. The primary purpose of invoicing terms is to provide customers with simplified and predictable ways of purchasing the Company’s products and services, and

not

to facilitate financing arrangements.

The amount of revenue recognized in the

three

months ended

March

31,

2018

from performance obligations satisfied (or partially satisfied) in previous periods was

$0.5

million. This amount primarily represents changes in estimated on percentage-of –completion based contracts and changes in estimated Gainshare performance incentives for those customers that reported actual Gainshare revenue with some time lag.

Costs

to obtain or fulfill a contract

The Company capitalizes the incremental costs to obtain or fulfill a contract with a customer, including direct sales commissions and related fees, when it expects to recover those costs. As a result, these costs will need to be capitalized and amortized over an appropriate period, which

may

exceed the initial contract term. The incremental costs of obtaining a contract are costs that would

not

have been incurred if the contract had

not

been obtained. The Company uses the portfolio method to recognize the amortization expense related to these capitalized costs related to initial contracts and renewals and such expense is recognized over the period associated with the revenue of the related portfolio. Total capitalized direct sales commission costs as of

March 31, 2018

were

$0.5

million and the amortization of these assets were

$0.1

million during the

three

months ended

March 31, 2018.

There was

impairment loss in relation to the costs capitalized for the periods presented. Certain eligible initial project costs are capitalized when the costs relate directly to the contract, the costs generate or enhance resources of the company that will be used in satisfying the performance obligation in the future, and the costs are expected to be recovered. These costs primarily consist of transition and set-up costs related to the installation of systems and processes and other deferred fulfillment costs eligible for capitalization. Capitalized costs are amortized consistent with the transfer to the client of the services to which the asset relates and recorded as a component of cost of revenues. The Company also incurred certain direct costs to provide solution implementation services in relation to the specific anticipated contracts. The Company recognizes such costs as a component of cost of revenues, the timing of which is dependent upon identification of a contract arrangement. The Company also defers costs from arrangements that required us to defer the revenues, typically due to the pattern of transfer of the performance obligations in the contract. These costs are recognized in proportion to the related revenue. At the end of the reporting period, the Company evaluates its deferred costs for their probable recoverability. The Company recognizes impairment of deferred costs when it is determined that the costs

longer have future benefits and are

longer recoverable. Deferred costs balance was

$0.5

million and

$0.6

million as of

March 31, 2018

and

December 31, 2017,

respectively. The balance was included in prepaid expenses and other current assets and other non-current assets in the accompanying condensed consolidated balance sheets.

Note 3 - Balance Sheet Components

3 Months Ended

Mar. 31, 2018

Supplemental Balance Sheet Disclosures [Text Block]

. BALANCE SHEET COMPONENTS

Accounts receivable include amounts that are unbilled at the end of the period that are expected to be billed and collected within

-month period. Unbilled accounts receivable, included in accounts receivable, totaled

$23.1

million and

$22.2

million as of

March 31, 2018,

and

December 31, 2017,

respectively. Unbilled accounts receivable that are

not

expected to be billed and collected during the succeeding

-month period are recorded in other non-current assets and totaled

$7.7

million and

$8.6

million as of

March 31, 2018,

and

December 31, 2017,

respectively.

Property and equipment, net consists of (in thousands):

	March 31 , 201 8			December 31, 2017
Property and equipment, net:
Computer equipment	$	10,725		$	10,729
Software		3,391			3,348
Furniture, fixtures and equipment		4,102			3,676
Leasehold improvements		2,025			1,980
Test equipment		14,209			13,796
Construction-in-progress		13,761			12,527
		48,213			46,056
Less: accumulated depreciation		(21,677	)		(20,670	)
Total	$	26,536		$	25,386

Test equipment includes DFI assets at customer sites that are contributing to DFI solution revenues. The construction-in-progress balance as of

March 31, 2018

and

December 31, 2017

was primarily related to construction of DFI assets. Depreciation and amortization expense was

$1.3

million and

$1.1

million for the

three

months ended

March 31, 2018

and

2017,

respectively.

As of both

March 31, 2018,

and

December 31, 2017,

the carrying amount of goodwill was

$1.9

million.

Intangible assets balance was

$5.8

million and

$6.1

million as of

March 31, 2018,

and

December 31, 2017,

respectively. Intangible assets as of

March 31, 2018

and

December 31, 2017

consist of the following (in thousands):

				March 31, 2018							December 31, 2017
	Amortization Period (Years)			Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Acquired identifiable intangibles:
Customer relationships	1	-	9	$	6,740	$	(4,237	)	$	2,503	$	6,740	$	(4,145	)	$	2,595
Developed technology	4	-	6		15,820		(12,974	)		2,846		15,820		(12,829	)		2,991
Tradename	2	-	4		790		(628	)		162		790		(622	)		168
Backlog		1			100		(100	)		-		100		(100	)		-
Patent	7	-	10		1,800		(1,490	)		310		1,800		(1,480	)		320
Other acquired intangibles		4			255		(255	)		-		255		(255	)		-
Total				$	25,505	$	(19,684	)	$	5,821	$	25,505	$	(19,431	)	$	6,074

The weighted average amortization period for acquired identifiable intangible assets was

6.52

years as of

March 31, 2018.

For the

three

months ended

March 31, 2018,

and

2017,

intangible asset amortization expense was

$0.3

million and

$0.2

million, respectively. The Company expects annual amortization of acquired identifiable intangible assets to be as follows (in thousands):

Year ending December 31 ,	Amount
2018 (remaining nine months)	$	757
2019		1,009
2020		1,009
2021		833
2022		626
2023 and thereafter		1,587
Total future amortization expense	$	5,821

Intangible assets are amortized over their useful lives unless these lives are determined to be indefinite. Intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group

may

not

be recoverable. During the

three

months ended

March 31, 2018,

there were

indicators of impairment related to the Company’s intangible assets.

Note 4 - Stockholders' Equity

3 Months Ended

Mar. 31, 2018

Shareholders' Equity and Share-based Payments [Text Block]

. STOCKHOLDERS’ EQUITY

Stock-based compensation is estimated at the grant date based on the award’s fair value and is recognized on a straight-line basis over the vesting periods, generally

four

years

Stock-based compensation expense before taxes related to the Company’s stock plans and employee stock purchase plan was allocated as follows (in thousands):

	Three Months Ended March 31,
	2018		2017
Cost of Design-to-silicon-yield solutions	$	1,014	$	1,192
Research and development		879		834
Selling, general and administrative		963		858
Stock-based compensation expenses	$	2,856	$	2,884

March 31, 2018,

the Company had the following stock-based compensation plans:

Stock Plans —

At the annual meeting of stockholders on

November 16, 2011,

the Company’s stockholders approved the

2011

Stock Incentive Plan, which was amended and restated at the

2017

annual meeting of stockholders on

May 31, 2017,

when the Company’s stockholders approved the

third

amended and restated

2011

Stock Incentive Plan (as amended, the

“2011

Plan”). Under the

2011

Plan, the Company

may

award stock options, stock appreciation rights, stock grants or stock units covering shares of the Company's common stock to employees, directors, non-employee directors and contractors. The aggregate number of shares reserved for awards under this plan is

7,800,000

shares, plus up to

3,500,000

shares previously issued under the

2001

Plan that are forfeited or repurchased by the Company or shares subject to awards previously issued under the

2001

Plan that expire or that terminate without having been exercised or settled in full on or after

November 16, 2011.

In case of awards other than options or stock appreciation rights, the aggregate number of shares reserved under the plan will be decreased at a rate of

1.33

shares issued pursuant to such awards. The exercise price for stock options must generally be at prices

less than the fair market value at the date of grant. Stock options generally expire

ten

years from the date of grant and become vested and exercisable over a

four

-year period.

2001,

the Company adopted a

2001

Stock Plan (the

“2001

Plan”). In

2003,

in connection with its acquisition of IDS Systems Inc., the Company assumed IDS’

2001

Stock Option / Stock Issuance Plan (the “IDS Plan”). Both of the

2001

and the IDS Plans expired in

2011.

Stock options granted under the

2001

and IDS Plans generally expire

ten

years from the date of grant and become vested and exercisable over a

four

-year period. Although

new awards

may

be granted under the

2001

or IDS Plans, awards made under the

2001

and IDS Plans that are currently outstanding remain subject to the terms of each such plan.

As of

March 31, 2018,

9.6

million shares of common stock were reserved to cover stock-based awards under the

2011

Plan, of which

4.0

million shares were available for future grant. The number of shares reserved and available under the

2011

Plan includes

0.5

million shares that were subject to awards previously made under the

2001

Plan and were forfeited, expired or repurchased by the Company after adoption of the

2011

Plan through

March 31, 2018.

As of

March 31, 2018,

there were

outstanding awards that had been granted outside of the

2011,

2001

or the IDS Plans (collectively, the "Stock Plans").

The Company estimated the fair value of share-based awards granted under the

2011

Stock Plan during the period using the Black-Scholes-Merton option-pricing model with the following weighted average assumptions, resulting in the following weighted average fair values:

	Three Months Ended March 31,
	2018			2017
Expected life (in years)		4.43			4.41
Volatility		42.22	%		40.57	%
Risk-free interest rate		2.52	%		1.87	%
Expected dividend		—			—
Weighted average fair value per share of options granted during the period	$	4.28		$	7.85

Stock option activity under the Company’s Stock Plans during the

three

months ended

March 31, 2018,

was as follows:

	Number of Options (in thousands)			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in thousands)
Outstanding, January 1, 2018		1,045		$	9.65
Granted (weighted average fair value of $4.28 per share)		10		$	11.26
Exercised		(8	)	$	4.86
Canceled		(4	)	$	13.77
Expired		(1	)	$	20.39
Outstanding, March 31, 2018		1,042		$	9.67		4.69	$	3,398
Vested and expected to vest, March 31, 2018		1,024		$	9.56		4.61	$	3,396
Exercisable, March 31, 2018		831		$	8.17		3.60	$	3,378

The aggregate intrinsic value in the table above represents the total intrinsic value based on the Company’s closing stock price of

$11.66

per share as of

March 31, 2018.

The total intrinsic value of options exercised during the

three

months ended

March 31, 2018,

was

$0.1

million.

As of

March 31, 2018,

there was

$1.0

million of total unrecognized compensation cost related to unvested stock options. That cost is expected to be recognized over a weighted average period of

3.1

years. The total fair value of shares vested during the

three

months ended

March 31, 2018,

was

$0.1

million.

Nonvested restricted stock units activity during the

three

months ended

March 31, 2018,

was as follows:

	Shares (in thousands)			Weighted Average Grant Date Fair Value Per Share
Nonvested, January 1, 2018		1,617		$	15.66
Granted		10		$	11.26
Vested		(110	)	$	14.41
Forfeited		(48	)	$	15.62
Nonvested, March 31, 2018		1,469		$	15.73

As of

March 31, 2018,

there was

$17.9

million of total unrecognized compensation cost related to nonvested restricted stock units. That cost is expected to be recognized over a weighted average period of

2.4

years. Restricted stock units do

not

have rights to dividends prior to vesting.

Employee Stock Purchase Plan

— In

July 2001,

the Company adopted a

ten

-year Employee Stock Purchase Plan (as amended, the “Purchase Plan”) under which eligible employees can contribute up to

10%

of their compensation, as defined in the Purchase Plan, towards the purchase of shares of PDF common stock at a price of

85%

of the lower of the fair market value at the beginning of the offering period or the end of the purchase period. The Purchase Plan consists of

twenty-four

-month offering periods with

four six

-month purchase periods in each offering period. Under the Purchase Plan, on

January 1

of each year, starting with

2002,

the number of shares reserved for issuance will automatically increase by the lesser of (

)

675,000

shares, (

)

of the Company’s outstanding common stock on the last day of the immediately preceding year, or (

) the number of shares determined by the board of directors. At the annual meeting of stockholders on

May 18, 2010,

the Company’s stockholders approved an amendment to the Purchase Plan to extend it through

May 17, 2020.

The Company estimated the fair value of purchase rights granted under the Purchase Plan during the period using the Black-Scholes-Merton option-pricing model with the following weighted average assumptions, resulting in the following weighted average fair values:

	Three Months Ended March 31,
	2018			2017
Expected life (in years)		1.25			1.25
Volatility		37.23	%		33.32	%
Risk-free interest rate		1.93	%		0.93	%
Expected dividend		—			—
Weighted average fair value per share of options granted during the period	$	4.32		$	6.78

During the

three

months ended

March 31, 2018

and

2017,

a total of

108,000

and

100,000

shares, respectively, were issued at a weighted-average purchase price of

$9.29

and

$9.13

per share, respectively. As of

March 31, 2018,

there was

$1.7

million of unrecognized compensation cost related to the Purchase Plan. That cost is expected to be recognized over a weighted average period of

1.83

years. As of

March 31, 2018,

4.3

million shares were available for future issuance under the Purchase Plan.

Stock Repurchase Program

- On

October 25, 2016,

the Board of Directors adopted a program, effective immediately, to repurchase up to

$25.0

million of the Company’s common stock both on the open market and in privately negotiated transactions over the next

two

years. During the

three

months ended

March 31, 2018,

the Company repurchased

338,207

shares under this program. As of

March 31, 2018,

1,180,389

shares had been repurchased at an average price of

$14.86

per share under this program for a total purchase of

$17.5

million, and

$7.5

million remained available for future repurchases.

Note 5 - Income Taxes	3 Months Ended
Note 5 - Income Taxes	Mar. 31, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	5. INCOME TAXES Income tax benefit decreased $0.8 million for the three months ended March 31, 2018, to a $0.4 million income tax benefit as compared to an income tax benefit of $1.2 million for the three months ended March 31, 2017. The Company’s effective tax rate benefit was 47% and 180% for the three months ended March 31, 2018 and 2017, respectively. The Company’s effective tax rate benefit decreased in the three months ended March 31, 2018, as compared to the same period in 2017, primarily due to lower excess tax benefits related to employee stock compensation and impacts of the recently enacted U.S. Tax Cuts and Jobs Act ("Tax Act"), such as, a decrease in the maximum federal tax rate from 35% to 21%, global intangible low-taxed income (“GILTI”), and foreign derived intangible income (“FDII”). The Company’s total amount of unrecognized tax benefits, excluding interest and penalties, as of March 31, 2018, was $13.4 million, of which $7.9 million, if recognized, would affect the Company’s effective tax rate. The Company’s total amount of unrecognized tax benefits, excluding interest and penalties, as of December 31, 2017, was $12.9 million, of which $7.7 million, if recognized, would affect the Company's effective tax rate. As of March 31, 2018, the Company has recorded unrecognized tax benefits of $3.0 million, including interest and penalties, as long-term taxes payable in its condensed consolidated balance sheet. The remaining $10.4 million has been recorded net of our deferred tax assets, of which $5.5 million is subject to a full valuation allowance. The valuation allowance was approximately $9.0 million and $9.1 million as of March 31, 2018, and December 31, 2017, respectively, which was related to California R&D tax credits and California net operating losses related to our acquisition of Syntricity that we currently do not believe are more likely than not to be ultimately realized. In December 2017, the SEC issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118 ), which allows companies to record provisional amounts during a measurement period not to extend more than one year beyond the Tax Act enactment date. Since the Tax Act was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation are expected during the year, we consider the accounting for deferred tax remeasurements, the impact of the transition of U.S. international taxation from a worldwide tax system to a territorial system and other provisions to be incomplete. There have been no material changes to the provisional adjustments disclosed in our 2017 Form 10 -K. The Company is continuing to evaluate the estimates used to record and disclose the effects of the Tax Act. Effective January 1, 2018, the Tax Act creates a new requirement to include in U.S. income global intangible low-taxed income (“GILTI”) earned by controlled foreign corporations (“CFCs”). The GILTI must be included currently in the gross income of the CFCs’ U.S. shareholder. Under U.S. GAAP, we are allowed to make an accounting policy choice of either ( 1 ) treating taxes due on future U.S. inclusions related to GILTI as a current-period expense when incurred (the “period cost method”) or ( 2 ) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). During the first quarter of 2018, the Company selected the period cost method in recording the tax effects of GILTI in its financial statements. The Company conducts business globally and, as a result, files numerous consolidated and separate income tax returns in the U.S. federal, various state and foreign jurisdictions. Because the Company used some of the tax attributes carried forward from previous years to tax years that are still open, statutes of limitation remain open for all tax years to the extent of the attributes carried forward into tax year 2002 for federal and California tax purposes. The Company is not subject to income tax examinations in any of its major foreign subsidiaries’ jurisdictions.

Note 6 - Net Income Per Share

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Text Block]

. NET INCOME PER SHARE

Basic net income per share is computed by dividing net income by weighted average number of common shares outstanding for the period (excluding outstanding stock options and shares subject to repurchase). Diluted net income per share is computed using the weighted-average number of common shares outstanding for the period plus the potential effect of dilutive securities which are convertible into common shares (using the treasury stock method), except in cases in which the effect would be anti-dilutive. The following is a reconciliation of the numerators and denominators used in computing basic and diluted net income per share (in thousands except per share amount):

	Three Months Ended March 31,
	2018			2017
Numerator:
Net income (loss)	$	(424	)	$	517
Denominator:
Basic weighted-average shares outstanding		32,168			31,991
Effect of dilutive options and restricted stock		-			1,603
Diluted weighted average shares outstanding		32,168			33,594

Net income (loss) per share - Basic	$	(0.01	)	$	0.02
Net income (loss) per share - Diluted	$	(0.01	)	$	0.02

For the period ended

March 31, 2018,

there are

potential dilutive common shares included in the computation of diluted net income per share because there was a net loss for the period.

The following table sets forth potential shares of common stock that are

not

included in the diluted net income per share calculation above because to do so would be anti-dilutive for the periods indicated (in thousands):

	Three Months Ended March 31,
	2018		2017
Outstanding options		-		40
Nonvested restricted stock units		-		-
Employee Stock Purchase Plan		-		30
Total		-		70

Note 7 - Customer and Geographic Information

3 Months Ended

Mar. 31, 2018

Segment Reporting Disclosure [Text Block]

. CUSTOMER AND GEOGRAPHIC INFORMATION

Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or group, in deciding how to allocate resources and in assessing performance.

The Company’s chief operating decision maker, the chief executive officer, reviews discrete financial information presented on a consolidated basis for purposes of regularly making operating decisions and assessing financial performance. Accordingly, the Company considers itself to be in

one

operating segment, specifically the licensing and implementation of yield improvement solutions for companies designing and/or manufacturing integrated circuits.

The Company had revenues from individual customers in excess of

10%

of total revenues as follows:

	Three Months Ended March 31,
Customer	2018			2017
A		38	%		48	%

The Company had gross accounts receivable from individual customers in excess of

10%

of gross accounts receivable as follows:

Customer	March 31, 2018			December 31, 2017
A		39	%		41	%
B		17	%		15	%

Revenues from customers by geographic area based on the location of the customers’ work sites are as follows (in thousands):

	Three Months Ended March 31 ,
	2018					2017
	Revenues		Percentage of Revenues			Revenues		Percentage of Revenues
United States	$	10,083		41	%	$	11,634		47	%
China		5,182		21			1,686		7
Taiwan		2,135		9			3,837		16
Germany		1,544		6			2,308		10
Rest of the world		5,793		23			4,824		20
Total revenue	$	24,737		100	%	$	24,289		100	%

Long-lived assets, net by geographic area are as follows (in thousands):

	March 31 , 2018		December 31, 2017
United States	$	26,068	$	24,883
Rest of the world		468		503
Total long-lived assets, net	$	26,536	$	25,386

Note 8 - Fair Value Measurements

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Text Block]

. FAIR VALUE MEASUREMENTS

Fair value is the exit price, or the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The multiple assumptions used to value financial instruments are referred to as inputs, and a hierarchy for inputs used in measuring fair value is established, that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity’s pricing based upon its own market assumptions. These inputs are ranked according to a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into

three

broad levels.

Level

Inputs are quoted prices in active markets for identical assets or liabilities.

Level

Inputs are quoted prices for similar assets or liabilities in an active market, quoted prices for identical or similar assets or liabilities in markets that are

not

active, inputs other than quoted prices that are observable and market-corroborated inputs which are derived principally from or corroborated by observable market data.

Level

Inputs are derived from valuation techniques in which

one

or more significant inputs or value drivers are unobservable.

The following table represents the Company’s assets measured at fair value on a recurring basis as of

March 31, 2018,

and the basis for that measurement (in thousands):

Assets		Total				Quoted Prices in Active Markets for Identical Assets (Level 1)				Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
Money market mutual funds		$	26,713			$	26,713			$	—			$	—

The following table represents the Company’s assets measured at fair value on a recurring basis as of

December 31, 2017,

and the basis for that measurement (in thousands):

Assets		Total				Quoted Prices in Active Markets for Identical Assets (Level 1)				Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
Money market mutual funds		$	26,638			$	26,638			$	—			$	—

The Company enters into foreign currency forward contracts to reduce the exposure to foreign currency exchange rate fluctuations on certain foreign currency denominated monetary assets and liabilities, primarily on

third

-party accounts payables and intercompany balances. The primary objective of the Company’s hedging program is to reduce volatility of earnings related to foreign currency exchange rate fluctuations. The counterparty to these foreign currency forward contracts is a large global financial institution that the Company believes is creditworthy, and therefore, the Company believes the credit risk of counterparty nonperformance is

not

significant. These foreign currency forward contracts are

not

designated for hedge accounting treatment. Therefore, the change in fair value of these contracts is recorded into earnings as a component of other income (expense), net, and offsets the change in fair value of the foreign currency denominated assets and liabilities, which is also recorded in other income (expense), net. For the

three

months ended

March 31, 2018

and

2017,

the Company recognized a realized loss of

$46,000

and a realized gain

$0.1

million on the contracts, respectively, which was recorded in other income (expense), net in the Company’s Statements of Operations and Comprehensive Income.

The Company carries these derivatives financial instruments on its Consolidated Balance Sheets at their fair values. The Company’s foreign currency forward contracts are classified as Level

because it is

not

actively traded and the valuation inputs are based on quoted prices and market observable data of similar instruments. As of

March 31, 2018,

the Company had

one

outstanding forward contract with a notional amount of

$8.6

million and recorded

$46,000

other current liabilities associated with this outstanding forward contract. As of

December 31, 2017,

the Company had

one

outstanding forward contract with a notional amount of

$8.2

million and recorded

$12,000

other current assets associated with the outstanding forward contract.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Note 9 - Commitments and Contingencies

3 Months Ended

Mar. 31, 2018

Commitments and Contingencies Disclosure [Text Block]

. COMMITMENTS AND CONTINGENCIES

Leases

The Company leases administrative and sales offices and certain equipment under noncancelable operating leases, which contain various renewal options and, in some cases, require payment of common area costs, taxes and utilities. These operating leases expire at various times through

2024.

Rent expense was

$0.6

million and

$0.5

million for the

three

months ended

March 31, 2018

and

2017,

respectively.

Future minimum lease payments under noncancelable operating leases at

March 31, 2018,

are as follows (in thousands):

Year ending December 31 ,	Amount
2018 (remaining nine months)	$	1,363
2019		800
2020		726
2021		645
2022		389
2023 and thereafter		51
Total future minimum lease payments	$	3,974

As of

March 31, 2018,

the Company leases approximately

28,600

square feet for its principal executive offices located in San Jose, California. The lease terminates

September 2018.

April 2018,

the Company entered into a new approximately

20,800

square foot lease, located in Santa Clara, California. The term of the new lease is approximately

ten

years and is expected to commence on or around

July 1, 2018.

Total lease obligation over the new lease term is approximately

$7.0

million, less a lease abatement allowance of approximately

$0.4

million. The terms of the new lease include a tenant improvement allowance of approximately

$1.3

million.

Indemnifications

— The Company generally provides a warranty to its customers that its software will perform substantially in accordance with documented specifications typically for a period of

days following initial delivery of its products. The Company also indemnifies certain customers from

third

-party claims of intellectual property infringement relating to the use of its products. Historically, costs related to these guarantees have

not

been significant. The Company is unable to estimate the maximum potential impact of these guarantees on its future results of operations.

Purchase obligations

— The Company has purchase obligations with certain suppliers for the purchase of goods and services entered in the ordinary course of business. As of

March 31, 2018,

total outstanding purchase obligations were

$14.7

million, which are primarily due within the next

months.

Indemnification of Officers and Directors

— As permitted by the Delaware general corporation law, the Company has included a provision in its certificate of incorporation to eliminate the personal liability of its officers and directors for monetary damages for breach or alleged breach of their fiduciary duties as officers or directors, other than in cases of fraud or other willful misconduct.

In addition, the Bylaws of the Company provide that the Company is required to indemnify its officers and directors even when indemnification would otherwise be discretionary, and the Company is required to advance expenses to its officers and directors as incurred in connection with proceedings against them for which they

may

be indemnified. The Company has entered into indemnification agreements with its officers and directors containing provisions that are in some respects broader than the specific indemnification provisions contained in the Delaware general corporation law. The indemnification agreements require the Company to indemnify its officers and directors against liabilities that

may

arise by reason of their status or service as officers and directors other than for liabilities arising from willful misconduct of a culpable nature, to advance their expenses incurred as a result of any proceeding against them as to which they could be indemnified, and to obtain directors’ and officers’ insurance if available on reasonable terms. The Company has obtained directors’ and officers’ liability insurance in amounts comparable to other companies of the Company’s size and in the Company’s industry. Since a maximum obligation of the Company is

not

explicitly stated in the Company’s Bylaws or in its indemnification agreements and will depend on the facts and circumstances that arise out of any future claims, the overall maximum amount of the obligations cannot be reasonably estimated.

Litigation

— From time to time, the Company is subject to various claims and legal proceedings that arise in the ordinary course of business. The Company accrues for losses related to litigation when a potential loss is probable and the loss can be reasonably estimated in accordance with FASB requirements. As of

March 31, 2018,

the Company was

not

party to any material legal proceedings, thus

loss was probable and

amount was accrued.

Significant Accounting Policies (Policies)	3 Months Ended
Significant Accounting Policies (Policies)	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation — The interim unaudited condensed consolidated financial statements included herein have been prepared by PDF Solutions, Inc. (the “Company”) pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), including the instructions to the Quarterly Report on Form 10 -Q and Article 10 of Regulation S- X. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted. The interim unaudited condensed consolidated financial statements reflect, in the opinion of management, all adjustments necessary (consisting only of normal recurring adjustments), to present a fair statement of results for the interim periods presented. The operating results for any interim period are not necessarily indicative of the results that may be expected for other interim periods or the full fiscal year. The accompanying interim unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto in the Company’s Annual Report on Form 10 -K for the year ended December 31, 2017. The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries after the elimination of all intercompany balances and transactions. The condensed consolidated balance sheet at December 31, 2017, has been derived from the audited consolidated financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates — The preparation of financial statements in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates in these financial statements include significant estimates and judgments made in recognizing revenue, accounting for goodwill and intangible assets, stock-based compensation expense and accounting for income taxes. Actual results could differ from those estimates. For a discussion of significant estimates and judgments made in recognizing revenue under the new revenue standard, see Note 2. Revenue Recognition.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements – Recently Adopted Accounting Standards In May 2014, the Financial Accounting Standards Board (or FASB) issued ASU No. 2014 - 09, Revenue from Contracts with Customers (Topic 606 ), which supersedes the revenue recognition requirements in “Revenue Recognition (Topic 605 ).” Subsequently, the FASB has issued several amendments to the standard, including clarification on accounting for licenses of intellectual property and identifying performance obligations. Under Topic 606, the new revenue recognition standard provides a five -step analysis of transactions to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to reflect the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company adopted this new standard on the first day of the first fiscal quarter of fiscal 2018. The Company chose to adopt the standard using the modified retrospective transition method. See Note 2. Revenue recognition, below for further information, including further discussion on the impact of adoption and changes in accounting policies relating to revenue recognition. In August 2016, the FASB issued ASU No. 2016 - 15, Statement of Cash Flows (Topic 230 ): Classification of Certain Cash Receipts and Cash Payments. The purpose of this standard is to clarify the treatment of several cash flow categories. This update is effective for annual periods beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted this standard on January 1, 2018 and it did not have a material impact on its financial statements and footnote disclosures. In November 2016, the FASB issued ASU No. 2016 - 18, Statement of Cash Flows (Topic 230 ): Restricted Cash, that will require that the amounts generally described as restricted cash and restricted cash equivalents would be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period amounts shown on the statement of cash flows. The new guidance also requires certain disclosures to supplement the statement of cash flows. This update is effective for annual periods beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted this standard on January 1, 2018, and it did not have a material impact on our financial statements and footnote disclosures. In January 2017, the FASB issued ASU No. 2017 - 01, Business Combinations: Clarifying the Definition of a Business, which narrows the existing definition of a business and provides a framework for evaluating whether a transaction should be accounted for as an acquisition (or disposal) of assets or a business. The guidance is effective for fiscal years beginning after December 15, 2017. The Company adopted this standard on January 1, 2018, and it did not have a material impact on its financial statements and footnote disclosures. In May 2017, the FASB issued ASU No. 2017 - 09, Compensation-Stock Compensation (Topic 718 ) Scope of Modification Accounting. This standard clarifies which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The standard is effective for interim and annual reporting periods beginning after December 15, 2017. The Company adopted this standard on January 1, 2018, and it did not have a material impact on our financial statements and footnote disclosures. Accounting Standards Not Yet Effective In February 2016, the FASB issued ASU No. 2016 - 02, Leases (Topic 842 ). The update requires that most leases, including operating leases, be recorded on the balance sheet as an asset and a liability, initially measured at the present value of the lease payments. Subsequently, the lease asset will be amortized generally on a straight-line basis over the lease term, and the lease liability will bear interest expense and be reduced for lease payments. The amendments in this update are effective for public companies’ financial statements issued for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is still in the process of evaluating the impact of adopting this new accounting standard on its consolidated financial statements and footnote disclosures. In January 2017, the FASB issued ASU No. 2017 - 04, Intangibles - Goodwill and Other (Topic 350 ). This standard eliminates step 2 from the annual goodwill impairment test. This update is effective for annual periods beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted, and is to be applied on a prospective basis. The Company does not anticipate that the adoption of this standard will have a significant impact on its consolidated financial statements or the related disclosures. In February 2018, the FASB issued ASU No. 2018 - 02, Income Statement – Reporting Comprehensive Income (Topic 220 ): Reclassification of Certain Tax Effect from Accumulated Other Comprehensive Income. This update allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Job Act enacted in December 2017. This update will be effective for the Company for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption is permitted. The Company does not anticipate that the adoption of this standard will have a significant impact on its consolidated financial statements or the related disclosures. In March 2018, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2018 - 05, "Income Taxes (Topic 740 ): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118". The staff of the U.S. Securities and Exchange Commission (SEC) recognized the complexity of reflecting the impacts of the Tax Cuts Job Act (TCJA), and on December 22, 2017 issued guidance in Staff Accounting Bulletin 118 (SAB 118 ), which clarifies accounting for income taxes under Accounting Standards Codification (ASC) 740 if information is not yet available or complete and provides for up to a one year period in which to complete the required analysis and accounting (the measurement period). Refer to Note 5, Income Taxes, for further discussion regarding the impact of this standard to the Company's consolidated financial statements.

Note 2 - Revenue Recognition (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]


	As reported under Topic 606			Adjustments			Balances under Topic 605
					(In thousands)
Accounts receivable, net of allowance	$	58,436		$	764		$	59,200
Prepaid expenses and other current assets		9,654			(3,959	)		5,695
Deferred tax assets		15,896			316			16,212
Other non-current assets		9,752			(289	)		9,463
Deferred revenues – current portion		8,474			1,348			9,822
Long-term income taxes payable		4,824			(1,032	)		3,792
Other non-current liabilities		1,122			899			2,021
Accumulated deficit		(23,160	)		(4,383	)		(27,543	)

	As reported under Topic 606			Adjustments			Balances under Topic 605
	(In thousands)
Net income	$	(424	)	$	(30	)	$	(454	)
Changes in operating assets and liabilities:
Accounts receivable, net of allowance		(80	)		(1,556	)		(1,636	)
Prepaid expenses and other current assets		(2,183	)		1,569			(614	)
Other non-current assets		798			288			1,086
Deferred revenue		1,906			(271	)		1,635

Disaggregation of Revenue [Table Text Block]

	March 31 , 2018

Product and licenses	$	7,487
Support and Services		16,989
Other		261
Total	$	24,737

Note 3 - Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2018

Property, Plant and Equipment [Table Text Block]

	March 31 , 201 8			December 31, 2017
Property and equipment, net:
Computer equipment	$	10,725		$	10,729
Software		3,391			3,348
Furniture, fixtures and equipment		4,102			3,676
Leasehold improvements		2,025			1,980
Test equipment		14,209			13,796
Construction-in-progress		13,761			12,527
		48,213			46,056
Less: accumulated depreciation		(21,677	)		(20,670	)
Total	$	26,536		$	25,386

Schedule of Finite-Lived Intangible Assets [Table Text Block]

				March 31, 2018							December 31, 2017
	Amortization Period (Years)			Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Acquired identifiable intangibles:
Customer relationships	1	-	9	$	6,740	$	(4,237	)	$	2,503	$	6,740	$	(4,145	)	$	2,595
Developed technology	4	-	6		15,820		(12,974	)		2,846		15,820		(12,829	)		2,991
Tradename	2	-	4		790		(628	)		162		790		(622	)		168
Backlog		1			100		(100	)		-		100		(100	)		-
Patent	7	-	10		1,800		(1,490	)		310		1,800		(1,480	)		320
Other acquired intangibles		4			255		(255	)		-		255		(255	)		-
Total				$	25,505	$	(19,684	)	$	5,821	$	25,505	$	(19,431	)	$	6,074

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

Year ending December 31 ,	Amount
2018 (remaining nine months)	$	757
2019		1,009
2020		1,009
2021		833
2022		626
2023 and thereafter		1,587
Total future amortization expense	$	5,821

Note 4 - Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Three Months Ended March 31,
	2018		2017
Cost of Design-to-silicon-yield solutions	$	1,014	$	1,192
Research and development		879		834
Selling, general and administrative		963		858
Stock-based compensation expenses	$	2,856	$	2,884

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Three Months Ended March 31,
	2018			2017
Expected life (in years)		4.43			4.41
Volatility		42.22	%		40.57	%
Risk-free interest rate		2.52	%		1.87	%
Expected dividend		—			—
Weighted average fair value per share of options granted during the period	$	4.28		$	7.85

	Three Months Ended March 31,
	2018			2017
Expected life (in years)		1.25			1.25
Volatility		37.23	%		33.32	%
Risk-free interest rate		1.93	%		0.93	%
Expected dividend		—			—
Weighted average fair value per share of options granted during the period	$	4.32		$	6.78

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of Options (in thousands)			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in thousands)
Outstanding, January 1, 2018		1,045		$	9.65
Granted (weighted average fair value of $4.28 per share)		10		$	11.26
Exercised		(8	)	$	4.86
Canceled		(4	)	$	13.77
Expired		(1	)	$	20.39
Outstanding, March 31, 2018		1,042		$	9.67		4.69	$	3,398
Vested and expected to vest, March 31, 2018		1,024		$	9.56		4.61	$	3,396
Exercisable, March 31, 2018		831		$	8.17		3.60	$	3,378

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

	Shares (in thousands)			Weighted Average Grant Date Fair Value Per Share
Nonvested, January 1, 2018		1,617		$	15.66
Granted		10		$	11.26
Vested		(110	)	$	14.41
Forfeited		(48	)	$	15.62
Nonvested, March 31, 2018		1,469		$	15.73

Note 6 - Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended March 31,
	2018			2017
Numerator:
Net income (loss)	$	(424	)	$	517
Denominator:
Basic weighted-average shares outstanding		32,168			31,991
Effect of dilutive options and restricted stock		-			1,603
Diluted weighted average shares outstanding		32,168			33,594

Net income (loss) per share - Basic	$	(0.01	)	$	0.02
Net income (loss) per share - Diluted	$	(0.01	)	$	0.02

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Three Months Ended March 31,
	2018		2017
Outstanding options		-		40
Nonvested restricted stock units		-		-
Employee Stock Purchase Plan		-		30
Total		-		70

Note 7 - Customer and Geographic Information (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

	Three Months Ended March 31,
Customer	2018			2017
A		38	%		48	%

Receivables by Major Customers [Table Text Block]

Customer	March 31, 2018			December 31, 2017
A		39	%		41	%
B		17	%		15	%

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	Three Months Ended March 31 ,
	2018					2017
	Revenues		Percentage of Revenues			Revenues		Percentage of Revenues
United States	$	10,083		41	%	$	11,634		47	%
China		5,182		21			1,686		7
Taiwan		2,135		9			3,837		16
Germany		1,544		6			2,308		10
Rest of the world		5,793		23			4,824		20
Total revenue	$	24,737		100	%	$	24,289		100	%

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

	March 31 , 2018		December 31, 2017
United States	$	26,068	$	24,883
Rest of the world		468		503
Total long-lived assets, net	$	26,536	$	25,386

Note 8 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

Assets		Total				Quoted Prices in Active Markets for Identical Assets (Level 1)				Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
Money market mutual funds		$	26,713			$	26,713			$	—			$	—

Assets		Total				Quoted Prices in Active Markets for Identical Assets (Level 1)				Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
Money market mutual funds		$	26,638			$	26,638			$	—			$	—

Note 9 - Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

Year ending December 31 ,	Amount
2018 (remaining nine months)	$	1,363
2019		800
2020		726
2021		645
2022		389
2023 and thereafter		51
Total future minimum lease payments	$	3,974

Note 2 - Revenue Recognition (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Retained Earnings (Accumulated Deficit), Ending Balance	$ (23,160)			$ (27,089)
Capitalized Contract Cost, Net, Total			$ 500
Contract with Customer, Liability, Noncurrent	500		900
Contract with Customer, Liability, Revenue Recognized	2,600
Revenue, Remaining Performance Obligation, Amount	45,000
Contract with Customer, Performance Obligation Satisfied in Previous Period	500
Capitalized Contract Cost, Amortization	100
Capitalized Contract Cost, Impairment Loss	0
Prepaid Expenses and Other Current Assets [Member]
Contract with Customer, Asset, Net, Current, Total	3,700		1,900
Prepaid Expenses and Other Current Assets and Other Non-current Assets [Member]
Deferred Costs, Total	$ 500			$ 600
Sales Revenue, Net [Member] \| Customer Concentration Risk [Member] \| Transferred over Time [Member]
Concentration Risk, Percentage	69.00%
Sales Revenue, Net [Member] \| Customer Concentration Risk [Member] \| Transferred at Point in Time [Member]
Concentration Risk, Percentage	31.00%
Sales Revenue, Net [Member] \| Geographic Concentration Risk [Member]
Concentration Risk, Percentage	100.00%	100.00%
Sales Revenue, Net [Member] \| Geographic Concentration Risk [Member] \| Countries other than the United States [Member]
Concentration Risk, Percentage	59.00%	53.00%
Accounting Standards Update 2014-09 [Member]
Retained Earnings (Accumulated Deficit), Ending Balance			(4,400)
Accounts Receivable, Net, Total			800
Contract with Customer, Asset, Net, Total			1,900
Contract with Customer, Liability, Total			$ (2,500)

Note 2 - Revenue Recognition - Adoption of ASC 606 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Accounts receivable, net of allowance	$ 58,436			$ 57,564
Prepaid expenses and other current assets	9,654			5,069
Deferred tax assets	15,896			16,348
Other non-current assets	9,752			10,545
Deferred revenues – current portion	8,474			7,981
Long-term income taxes payable	4,824			3,902
Other non-current liabilities	1,122			2,269
Accumulated deficit	(23,160)			$ (27,089)
Net income (loss)	(424)	$ 517
Accounts receivable, net of allowance	(80)	(1,931)
Prepaid expenses and other current assets	(2,183)	(1,395)
Other non-current assets	798	$ (1,977)
Deferred revenue	1,906
Accounting Standards Update 2014-09 [Member]
Accumulated deficit			$ (4,400)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] \| Accounting Standards Update 2014-09 [Member]
Accounts receivable, net of allowance	764
Prepaid expenses and other current assets	(3,959)
Deferred tax assets	316
Other non-current assets	(289)
Deferred revenues – current portion	1,348
Long-term income taxes payable	(1,032)
Other non-current liabilities	899
Accumulated deficit	(4,383)
Net income (loss)	(30)
Accounts receivable, net of allowance	(1,556)
Prepaid expenses and other current assets	1,569
Other non-current assets	288
Deferred revenue	(271)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Accounts receivable, net of allowance	59,200
Prepaid expenses and other current assets	5,695
Deferred tax assets	16,212
Other non-current assets	9,463
Deferred revenues – current portion	9,822
Long-term income taxes payable	3,792
Other non-current liabilities	2,021
Accumulated deficit	(27,543)
Net income (loss)	(454)
Accounts receivable, net of allowance	(1,636)
Prepaid expenses and other current assets	(614)
Other non-current assets	1,086
Deferred revenue	$ 1,635

Note 2 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Product and licenses	$ 24,737	$ 24,289
License [Member]
Product and licenses	7,487
Service [Member]
Product and licenses	16,989
Product and Service, Other [Member]
Product and licenses	$ 261

Note 3 - Balance Sheet Components (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Unbilled Receivables, Current	$ 23,100		$ 22,200
Unbilled Receivables, Not Billable, Amount Expected to be Collected after Next Twelve Months	7,700		8,600
Depreciation, Depletion and Amortization, Nonproduction, Total	1,300	$ 1,100
Goodwill, Ending Balance	1,923		1,923
Finite-Lived Intangible Assets, Net, Ending Balance	$ 5,821		$ 6,074
Finite-Lived Intangible Assets, Remaining Amortization Period	6 years 189 days
Amortization of Intangible Assets, Total	$ 253	$ 188
Impairment of Intangible Assets, Finite-lived	$ 0

Note 3 - Balance Sheet Components - Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property and equipment, gross	$ 48,213	$ 46,056
Less: accumulated depreciation	(21,677)	(20,670)
Total	26,536	25,386
Computer Equipment [Member]
Property and equipment, gross	10,725	10,729
Software and Software Development Costs [Member]
Property and equipment, gross	3,391	3,348
Furniture and Fixtures [Member]
Property and equipment, gross	4,102	3,676
Leasehold Improvements [Member]
Property and equipment, gross	2,025	1,980
Test Equipment [Member]
Property and equipment, gross	14,209	13,796
Construction in Progress [Member]
Property and equipment, gross	$ 13,761	$ 12,527

Note 3 - Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Gross Carrying Amount	$ 25,505	$ 25,505
Accumulated Amortization	(19,684)	(19,431)
Intangible assets, net	5,821	6,074
Customer Relationships [Member]
Gross Carrying Amount	6,740	6,740
Accumulated Amortization	(4,237)	(4,145)
Intangible assets, net	$ 2,503	2,595
Customer Relationships [Member] \| Minimum [Member]
Amortization Period (Year)	1 year
Customer Relationships [Member] \| Maximum [Member]
Amortization Period (Year)	9 years
Developed Technology Rights [Member]
Gross Carrying Amount	$ 15,820	15,820
Accumulated Amortization	(12,974)	(12,829)
Intangible assets, net	$ 2,846	2,991
Developed Technology Rights [Member] \| Minimum [Member]
Amortization Period (Year)	4 years
Developed Technology Rights [Member] \| Maximum [Member]
Amortization Period (Year)	6 years
Trade Names [Member]
Gross Carrying Amount	$ 790	790
Accumulated Amortization	(628)	(622)
Intangible assets, net	$ 162	168
Trade Names [Member] \| Minimum [Member]
Amortization Period (Year)	2 years
Trade Names [Member] \| Maximum [Member]
Amortization Period (Year)	4 years
Order or Production Backlog [Member]
Amortization Period (Year)	1 year
Gross Carrying Amount	$ 100	100
Accumulated Amortization	(100)	(100)
Intangible assets, net
Patents [Member]
Gross Carrying Amount	1,800	1,800
Accumulated Amortization	(1,490)	(1,480)
Intangible assets, net	$ 310	320
Patents [Member] \| Minimum [Member]
Amortization Period (Year)	7 years
Patents [Member] \| Maximum [Member]
Amortization Period (Year)	10 years
Other Intangible Assets [Member]
Amortization Period (Year)	4 years
Gross Carrying Amount	$ 255	255
Accumulated Amortization	(255)	(255)
Intangible assets, net

Note 3 - Balance Sheet Components - Annual Amortization of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
2018 (remaining nine months)	$ 757
2019	1,009
2020	1,009
2021	833
2022	626
2023 and thereafter	1,587
Total future amortization expense	$ 5,821	$ 6,074

Note 4 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	3 Months Ended		12 Months Ended	17 Months Ended
	May 31, 2017	Oct. 25, 2016	Jul. 31, 2001	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2001	Mar. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period				4,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance				1,042,000			1,042,000	1,045,000
Share Price				$ 11.66			$ 11.66
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value				$ 0.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value				$ 0.1
Stock Repurchase Program, Authorized Amount		$ 25.0
Stock Repurchase Program, Period in Force		2 years
Treasury Stock, Shares, Acquired				338,207			1,180,389
Treasury Stock Acquired, Average Cost Per Share							$ 14.86
Treasury Stock, Value, Acquired, Cost Method							$ 17.5
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 7.5			7.5
Employee Stock Option [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total				$ 1.0			1.0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition				3 years 36 days
Restricted Stock Units (RSUs) [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total				$ 17.9			$ 17.9
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition				2 years 146 days
Twenty Eleven Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	7,800,000
Share Based Compensation Arrangement By Share Based Payment Award Shares Reserved Decrease Rate	1.33
Common Stock, Capital Shares Reserved for Future Issuance				9,600,000			9,600,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant				4,000,000			4,000,000
Twenty Eleven Stock Incentive Plan [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Shares Previously Issued Under the 2001 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized						3,500,000
IDS Plan [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period						10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period						4 years
Two Thousand One Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period				500,000
Outside of the 2011, 2001 or IDS Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance				0			0
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period			10 years
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total				$ 1.7			$ 1.7
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition				1 year 302 days
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate			10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent			85.00%
ESPP Maximum Annual Share Replenishment			675,000
ESPP Maximum Annual Share Replenishment Percentage of Prior Year Outstanding Company Common Stock			2.00%
Stock Issued During Period, Shares, Employee Stock Purchase Plans				108,000	100,000
Employee Stock Purchase Plan Weighted Average Purchase Price of Shares Purchased				$ 9.29	$ 9.13
Number Of ESPP Shares Available For Future Issuance				4,300,000			4,300,000

Note 4 - Stockholders' Equity - Allocation of Recognized Period Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allocation of recognized period costs	$ 2,856	$ 2,884
Cost of Sales [Member]
Allocation of recognized period costs	1,014	1,192
Research and Development Expense [Member]
Allocation of recognized period costs	879	834
Selling, General and Administrative Expenses [Member]
Allocation of recognized period costs	$ 963	$ 858

Note 4 - Stockholders' Equity - Stock Options, Valuation Assumptions (Details) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Weighted average fair value (in dollars per share)	$ 4.28
Stock Plans [Member]
Expected life (Year)	4 years 156 days	4 years 149 days
Volatility	42.22%	40.57%
Risk-free interest rate	2.52%	1.87%
Expected dividend	0.00%	0.00%
Weighted average fair value (in dollars per share)	$ 4.28	$ 7.85
Employee Stock Purchase Plan [Member]
Expected life (Year)	1 year 91 days	1 year 91 days
Volatility	37.23%	33.32%
Risk-free interest rate	1.93%	0.93%
Expected dividend	0.00%	0.00%
Weighted average fair value (in dollars per share)	$ 4.32	$ 6.78

Note 4 - Stockholders' Equity - Stock Options Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) $ / shares shares
Outstanding (in shares)	1,045
Outstanding, weighted average exercise price (in dollars per share) \| $ / shares	$ 9.65
Granted (in shares)	10
Exercised (in shares)	(8)
Exercised, weighted average exercise price (in dollars per share) \| $ / shares	$ 4.86
Canceled (in shares)	(4)
Canceled, weighted average exercise price (in dollars per share) \| $ / shares	$ 13.77
Expired (in shares)	(1)
Expired, weighted average exercise price (in dollars per share) \| $ / shares	$ 20.39
Outstanding (in shares)	1,042
Outstanding, weighted average exercise price (in dollars per share) \| $ / shares	$ 9.67
Outstanding, weighted average remaining term (Year)	4 years 251 days
Outstanding, intrinsic value \| $	$ 3,398
Vested and expected to vest, March 31, 2018 (in shares)	1,024
Vested and expected to vest, weighted average exercise price (in dollars per share) \| $ / shares	$ 9.56
Vested and expected to vest, weighted average remaining term (Year)	4 years 222 days
Vested and expected to vest, intrinsic value \| $	$ 3,396
Exercisable, March 31, 2018 (in shares)	831
Exercisable, weighted average exercise price (in dollars per share) \| $ / shares	$ 8.17
Exercisable, weighted average remaining term (Year)	3 years 219 days
Exercisable, intrinsic value \| $	$ 3,378

Note 4 - Stockholders' Equity - Stock Options Activity (Details) (Parentheticals)	3 Months Ended
	Mar. 31, 2018 $ / shares
Weighted average fair value (in dollars per share)	$ 4.28

Note 4 - Stockholders' Equity - Nonvested Restricted Stock Units Activity (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Nonvested, Balance (in shares) \| shares	1,617
Nonvested, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 15.66
Granted (in shares) \| shares	10
Granted, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 11.26
Vested (in shares) \| shares	(110)
Vested, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 14.41
Forfeited (in shares) \| shares	(48)
Forfeited, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 15.62
Nonvested, Balance (in shares) \| shares	1,469
Nonvested, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 15.73

Note 5 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Income Taxes	$ 800
Income Tax Expense (Benefit), Total	$ (381)	$ (1,162)
Effective Income Tax Rate Reconciliation, Percent, Total	47.00%	180.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent				35.00%
Unrecognized Tax Benefits, Ending Balance	$ 13,400			$ 12,900
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	7,900			7,700
Unrecognized Tax Benefits In Long Term Liabilities	3,000
Unrecognized Tax Benefits In Deferred Tax Assets	10,400
Unrecognized Tax Benefits In Deferred Tax Asset Subject To Full Valuation Allowance	5,500
Deferred Tax Assets, Valuation Allowance, Total	$ 9,000			$ 9,100
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%

Note 6 - Net Income Per Share - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income (loss)	$ (424)	$ 517
Basic weighted-average shares outstanding (in shares)	32,168	31,991
Effect of dilutive options and restricted stock (in shares)		1,603
Diluted weighted average shares outstanding (in shares)	32,168	33,594
Net income (loss) per share - Basic (in dollars per share)	$ (0.01)	$ 0.02
Net income (loss) per share - Diluted (in dollars per share)	$ (0.01)	$ 0.02

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-URI http://asc.fasb.org/extlink&oid=114873790&loc=SL114874131-224263

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109260490&loc=d3e1337-109256

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI http://asc.fasb.org/extlink&oid=109256448&loc=d3e4984-109258

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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