PDF Solutions (PDFS) 10-Q 4 May 15 2015 Q1 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	PDF SOLUTIONS INC
Document Type	10-Q
Current Fiscal Year End Date	-19
Entity Common Stock, Shares Outstanding		31,456,484
Amendment Flag	FALSE
Entity Central Index Key	1120914
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$131,880	$115,464
Accounts receivable, net of allowance of $299 and $381, respectively	29,193	37,725
Deferred tax assets - current portion	3,317	3,343
Prepaid expenses and other current assets	2,901	2,888
Total current assets	167,291	159,420
Property and equipment, net	9,895	8,832
Deferred tax assets - non-current portion	7,643	8,025
Other non-current assets	1,448	1,161
Total assets	186,277	177,438
Current liabilities:
Accounts payable	1,235	803
Accrued compensation and related benefits	3,988	6,112
Accrued and other current liabilities	1,588	1,733
Deferred revenues	5,265	3,740
Total current liabilities	12,076	12,388
Non-current liabilities	2,924	3,227
Total liabilities	15,000	15,615
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.00015 par value, 5,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $0.00015 par value, 70,000 shares authorized: shares issued 36,791 and 36,258, respectively; shares outstanding 31,449 and 31,116, respectively	5	5
Additional paid-in-capital	256,576	248,734
Treasury stock at cost, 5,342 and 5,142 shares, respectively	-37,655	-34,048
Accumulated deficit	-46,220	-52,187
Accumulated other comprehensive income	-1,429	-681
Total stockholders’ equity	171,277	161,823
Total liabilities and stockholders’ equity	$186,277	$177,438

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Per Share data, unless otherwise specified
Accounts receivable, allowance (in Dollars)	$299	$381
Preferred stock, par value (in Dollars per share)	$0.00	$0.00
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in Dollars per share)	$0.00	$0.00
Common stock, shares authorized	70,000	70,000
Common stock, shares issued	36,791	36,258
Common stock, shares outstanding	31,449	31,116
Treasury stock shares	5,342	5,142

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Design-to-silicon-yield solutions	$18,152	$14,919
Gainshare performance incentives	8,665	12,167
Total revenues	26,817	27,086
Costs of Design-to-silicon-yield solutions	8,804	9,705
Gross profit	18,013	17,381
Operating expenses:
Research and development	4,088	3,596
Selling, general and administrative	4,456	4,329
Amortization of other acquired intangible assets		18
Restructuring charges		57
Total operating expenses	8,544	8,000
Income from operations	9,469	9,381
Interest and other income (expense), net	51	-87
Income before income taxes	9,520	9,294
Income tax provision	3,553	3,039
Net income	5,967	6,255
Net income per share:
Basic (in Dollars per share)	$0.19	$0.21
Diluted (in Dollars per share)	$0.18	$0.20
Weighted average common shares:
Basic (in Shares)	31,336	30,477
Diluted (in Shares)	32,291	31,965
Net income	5,967	6,255
Other comprehensive income:
Foreign currency translation adjustments, net of tax	-748	-52
Comprehensive income	$5,219	$6,203

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating activities:
Net income	$5,967	$6,255
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	605	458
Stock-based compensation expense	2,199	1,660
Amortization of acquired intangible assets		18
Deferred taxes	416	1,886
Loss on sale/disposal of property and equipment		34
Purchases of treasury stock in connection with tax withholdings on restricted stock grants	-2	-8
Reversal of allowance for doubtful accounts	-82	-28
Unrealized loss on foreign currency forward contract	84	24
Tax benefit related to stock-based compensation expense	1,858	44
Excess tax benefit from stock-based compensation	-1,754	-41
Changes in operating assets and liabilities:
Accounts receivable	8,615	2,373
Prepaid expenses and other assets	-315	-264
Accounts payable	-988	-279
Accrued compensation and related benefits	-2,024	-2,386
Accrued and other liabilities	-415	-442
Deferred revenues	1,455	2,537
Billings in excess of recognized revenues		248
Net cash provided by operating activities	15,619	12,089
Investing activities:
Purchases of property and equipment	-1,145	-929
Net cash used in investing activities	-1,145	-929
Financing activities:
Proceeds from exercise of stock options	3,128	784
Proceeds from employee stock purchase plan	680	632
Excess tax benefit from stock-based compensation	1,754	41
Purchases of treasury stock	-3,605	-968
Net cash provided by financing activities	1,957	489
Effect of exchange rate changes on cash and cash equivalents	-15	-26
Net change in cash and cash equivalents	16,416	11,623
Cash and cash equivalents, beginning of period	115,464	89,371
Cash and cash equivalents, end of period	131,880	100,994
Cash paid during the period for:
Taxes	1,941	1,648
Property and equipment received and accrued in accounts payable and accrued and other liabilities	$749	$400

Note_1_Basis_of_Presentation

Note 1 - Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Disclosure Text Block [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. BASIS OF PRESENTATION
	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, 2014.
	The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries after the elimination of all significant intercompany balances and transactions.
	The condensed consolidated balance sheet at December 31, 2014, 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  —  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 revenue recognition for fixed-price solution implementation service contracts, stock-based compensation expense and accounting for income taxes. Actual results could differ from those estimates.
	Revenue Recognition  — The Company derives revenue from two sources: Design-to-silicon-yield solutions and Gainshare performance incentives.
	Design-to-Silicon-Yield Solutions — Revenue that is derived from Design-to-silicon-yield solutions comes from services and software licenses. The Company recognizes revenue 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. These contracts require reliable estimation of costs to perform obligations and the overall scope of each engagement. Revenue under project–based contracts for solution implementation services is recognized as services are performed using the cost-to-cost percentage of completion method of contract accounting. 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. Revenue under time and materials contracts for solution implementation services are recognized as the services are performed. On occasion, the Company licenses its software products as a component of its fixed-price service contracts. In such instances, the software products are licensed to customers over a specified term of the agreement with support and maintenance to be provided at each customer's option over the license term. The amount of product and service revenue recognized in a given period is affected by the Company’s judgment as to whether an arrangement includes multiple deliverables and, if so, the Company’s determination of the fair value of each deliverable. In general, vendor-specific objective evidence of selling price (“VSOE”) does not exist for the Company’s solution implementation services and software products and because the Company’s services and products include our unique technology, the Company is not able to determine third-party evidence of selling price (“TPE”). Therefore, in such circumstances the Company uses best estimated selling prices (“BESP”) in the allocation of arrangement consideration. In determining BESP, the Company applies significant judgment as the Company’s weighs a variety of factors, based on the facts and circumstances of the arrangement. The Company typically arrives at BESP for a product or service that is not sold separately by considering company-specific factors such as geographies, internal costs, gross margin objectives, pricing practices used to establish bundled pricing, and existing portfolio pricing and discounting. After fair value is established for each deliverable, the total transaction amount is allocated to each deliverable based upon its relative fair value. Fees allocated to solution implementation services are recognized using the cost-to-cost percentage of completion method of contract accounting. Fees allocated to software and related support and maintenance are recognized under software revenue recognition guidance. The Company defers certain pre-contract costs incurred for specific anticipated contracts. Deferred costs consist primarily of 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 persuasive evidence of contract arrangement assuming all other revenue recognition criteria are met. At the end of 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 no longer have future benefits and are no longer recoverable.
	The Company also licenses its software products separately from its solution implementations. For software license arrangements that do not require significant modification or customization of the underlying software, software license revenue is recognized under the residual method when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred, (3) the fee is fixed or determinable, (4) collectability is probable, and (5) the arrangement does not require services that are essential to the functionality of the software. When arrangements include multiple elements such as support and maintenance, consulting (other than for its fixed price solution implementations), installation, and training, revenue is allocated to each element of a transaction based upon its fair value as determined by the Company’s VSOE and such services are recorded as services revenue. VSOE for maintenance is generally established based upon negotiated renewal rates while VSOE for consulting, installation, and training services is established based upon the Company’s customary pricing for such services when sold separately. Revenue for software licenses with extended payment terms is not recognized in excess of amounts due. For software license arrangements that require significant modification or customization of the underlying software, the software license revenue is recognized as services are performed using the cost-to-cost percentage of completion method of contract accounting, and such revenue is recorded as services revenue.
	Gainshare Performance Incentives — When the Company enters into a contract to provide yield improvement services, the contract usually includes two components: (1) a fixed fee for performance by the Company of services delivered over a specific period of time; and (2) a Gainshare performance incentive component where the customer may pay a contingent variable fee, usually after the fixed fee period has ended. Revenue derived from Gainshare performance incentives represents profit sharing and performance incentives earned contingent upon the Company’s customers reaching certain defined operational levels established in related solution implementation service contracts. Gainshare performance incentives periods are usually subsequent to the delivery of all contractual services and therefore have no cost to the Company. Due to the uncertainties surrounding attainment of such operational levels, the Company recognizes Gainshare performance incentives revenue (to the extent of completion of the related solution implementation contract) upon receipt of performance reports or other related information from the customer supporting the determination of amounts and probability of collection.

Note_2_Recent_Accounting_Prono

Note 2 - Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	2. RECENT ACCOUNTING PRONOUNCEMENTS
	In May 2014, the Financial Accounting Standard Board ("FASB") issued ASU No. 2014-09, “Revenue from Contracts with Customers”. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. The updated standard will replace existing revenue recognition guidance under GAAP when it becomes effective. Early adoption is not permitted. The updated standard would be effective for the Company beginning January 1, 2017; however, in April 2015, the FASB agreed to propose a one-year deferral of the effective date. If the proposed deferral is approved, the new standard will become effective for the Company beginning January 1, 2018 and can be applied either the retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. The Company has not yet selected a transition method and is currently evaluating the impact of adopting this new accounting standard on its financial statements.
	In August 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-15, “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”. The new standard provides guidance around management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. Early adoption is permitted. The adoption of this standard is not expected to have a material impact on our financial statements.

Note_3_Balance_Sheet_Component

Note 3 - Balance Sheet Components	3 Months Ended
	Mar. 31, 2015
Disclosure Text Block Supplement [Abstract]
Supplemental Balance Sheet Disclosures [Text Block]	3. BALANCE SHEET COMPONENTS
	Accounts receivable include amounts that are unbilled at the end of the period. Unbilled accounts receivable are determined on an individual contract basis and were $9.2 million and $9.7 million as of March 31, 2015, and December 31, 2014, respectively.
	Property and equipment consists of (in thousands):
		March 31,			December 31,
		2015			2014
	Property and equipment, net:
	Computer equipment	$	8,678		$	9,817
	Software		1,898			3,369
	Furniture, fixtures and equipment		745			756
	Leasehold improvements		1,139			1,127
	Test equipment		6,677			6,401
	Construction-in-progress		3,287			2,405
			22,424			23,875
	Less: accumulated depreciation		(12,529	)		(15,043	)
	Total	$	9,895		$	8,832
	Depreciation and amortization expense was $0.6 million and $0.5 million for the three months ended March 31, 2015 and 2014, respectively.

Note_4_Stockholders_Equity

Note 4 - Stockholders' Equity	3 Months Ended
	Mar. 31, 2015
Disclosure Text Block Supplement [Abstract]
Shareholders' Equity and Share-based Payments [Text Block]	4. 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 expenses before taxes related to the Company’s stock plans and employee stock purchase plan were allocated as follows (in thousands):
		Three Months
		Ended March 31,
		2015			2014
	Cost of Design-to-silicon-yield solutions	$	887		$	724
	Research and development		491			371
	Selling, general and administrative		821			565
	Stock-based compensation expenses	$	2,199		$	1,660
	On March 31, 2015, the Company has in effect 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 first amended and restated at the 2013 annual meeting of stockholders on May 28, 2013, when the Company’s stockholders approved the First Amended and Restated 2011 Stock Incentive Plan and then subsequently amended at the 2014 annual meeting of stockholders on May 27, 2014, when the Company’s stockholders approved the Second Amended and Restated 2011 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 6,550,000 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 no 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.
	In 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 no 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.
	The Company estimated the fair value of share-based awards granted under the 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,
		2015			2014
	Expected life (in years)		4.51			4.58
	Volatility		46.48	%		43.35	%
	Risk-free interest rate		1.25	%		1.56	%
	Expected dividend		—			—
	Weighted average fair value per share of options granted during the period	$	6.38		$	7.75
	As of March 31, 2015, 7.0 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 0.4 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, 2015.  As of March 31, 2015, there were no outstanding awards that had been granted outside of the 2011, 2001 or the IDS Plans (collectively, the "Stock Plans").
	Stock option activity under the Company’s Stock Plans during the three months ended March 31, 2015, was as follows:
		Number of			Weighted			Weighted		Aggregate
		Options			Average			Average		Intrinsic
		(in			Exercise			Remaining		Value
		thousands)			Price			Contractual		(in
					per Share			Term		thousands)
								(years)
	Outstanding, January 1, 2015		2,352		$	7.65
	Granted (weighted average fair value of $6.38 per share)		12		$	16.12
	Exercised		(462	)	$	6.76
	Canceled		(10	)	$	10.41
	Expired		(1	)	$	13.08
	Outstanding, March 31, 2015		1,891		$	7.9			5.47	$	19,032
	Vested and expected to vest, March 31, 2015		1,874		$	7.87			5.45	$	18,918
	Exercisable, March 31, 2015		1,511		$	7.4			5	$	15,917
	The aggregate intrinsic value in the table above represents the total intrinsic value based on the Company’s closing stock price of $17.92 per share as of March 31, 2015. The total intrinsic value of options exercised during the three months ended March 31, 2015, was $5.2 million.
	As of March 31, 2015, there was $1.7 million of total unrecognized compensation cost related to unvested stock options. That cost is expected to be recognized over a weighted average period of 1.3 years. The total fair value of shares vested during the three months ended March 31, 2015, was $0.5 million.
	Nonvested restricted stock units activity during the three months ended March 31, 2015, was as follows:
		Shares			Weighted
		(in thousands)			Average
					Grant Date
					Fair Value Per
					Share
	Nonvested, January 1, 2015		941		$	17.38
	Granted		12		$	16.12
	Vested		(19	)	$	17.86
	Forfeited		(18	)	$	17.66
	Nonvested, March 31, 2015		916		$	17.35
	As of March 31, 2015, there was $12.5 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.
	Employee Stock Purchase Plan — In July 2001, the Company adopted a ten-year Employee Stock Purchase Plan (as amended, “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, the number of shares reserved for issuance will automatically increase by the lesser of (1) 675,000 shares, (2) 2% of the Company’s outstanding common stock on the last day of the immediately preceding year, or (3) 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,
		2015			2014
	Expected life (in years)		1.25			1.25
	Volatility		54.21	%		34.56	%
	Risk-free interest rate		0.26	%		0.18	%
	Expected dividend		—			—
	Weighted average fair value of purchase rights granted under the Purchase Plan	$	6.19		$	7.18
	During the three months ended March 31, 2015 and 2014, a total of 51,000 and 52,000 shares, respectively, were issued at a weighted-average purchase price of $13.32 and $12.10 per share. For both the three-month periods ended March 31, 2015 and 2014, the Purchase Plan compensation expense was $0.2 million. As of March 31, 2015, there was $1.5 million of unrecognized compensation cost related to the Purchase Plan. That cost is expected to be recognized over a weighted average period of 1.8 years. As of March 31, 2015, 2.8 million shares were available for future issuance under the Purchase Plan.
	Stock Repurchase Program —On October 21, 2014, 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, 2015, the Company repurchased 199,912 shares under this program. As of March 31, 2015, 199,912 shares had been repurchased at an average price of $18.03 per share under this program for a total purchase of $3.6 million, and $21.4 million remained available for future repurchases.

Note_5_Income_Taxes

Note 5 - Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	5. INCOME TAXES
	Income tax provision increased $0.5 million for the three months ended March 31, 2015, to $3.5 million as compared to an income tax provision of $3.0 million for the three months ended March 31, 2014. The Company’s effective tax rate was 37.3% and 32.7% for the three months ended March 31, 2015, and March 31, 2014, respectively.  The Company’s effective tax rate increased in the three months ended March 31, 2015, as compared to the same period in 2014, primarily due to the lower reversals of certain unrecognized tax benefits upon statute of limitation lapses and unfavorable changes to New York State Tax apportionment rules. The income tax provision for the three months ended March 31, 2014 was less than the provision at the statutory rate primarily due to changes in unrecognized tax benefits.
	The Company’s total amount of unrecognized tax benefits, excluding interest and penalties, as of March 31, 2015, was $10.3 million, of which $6.1 million, if recognized, would decrease the Company’s effective tax rate. The Company’s total amount of unrecognized tax benefits, excluding interest and penalties, as of December 31, 2014, was $10.4 million, of which $6.3 million, if recognized, would affect the Company's effective tax rate. As of March 31, 2015, the Company has recorded unrecognized tax benefits of $2.4 million, including interest and penalties, as long-term taxes payable in its condensed consolidated balance sheet. The remaining $8.4 million has been recorded net of our deferred tax assets, of which $4.2 million is subject to a full valuation allowance.
	As of March 31, 2015, the Company believes that its deferred tax assets are “more likely than not” to be realized with the exception of California R&D tax credits that have not met the “more likely than not” realization threshold criteria because on an annual basis and pursuant to current law, the Company generates more California credits than California tax. As a result, at March 31, 2015, the excess California R&D tax credits continue to be subject to a full valuation allowance. In the event the Company concludes at a future financial reporting period that there has been a change in its ability to realize the California R&D credit deferred tax assets, and it is at such time no longer “more likely than not” that the Company will realize the tax credits before applicable expiration dates, the Company’s tax provision will increase in the period in which the Company makes such determination.
	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 other of its major foreign subsidiaries’ jurisdictions.

Note_6_Net_Income_Per_Share

Note 6 - Net Income Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	6. 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. Under the treasury stock method, the amount that the employee must pay for exercising stock options, the amount of compensation cost for future service that the Company has not yet recognized, and the amount of the tax benefits that would be recorded in additional paid-in capital when the award becomes deductible are assumed to be used to repurchase shares.  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,
		2015		2014
	Numerator:
	Net income	$	5,967	$	6,255
	Denominator:
	Basic weighted-average shares outstanding		31,336		30,477
	Effect of dilutive options and restricted stock		955		1,488
	Diluted weighted average shares outstanding		32,291		31,965
	Net income per share - Basic	$	0.19	$	0.21
	Net income per share - Diluted	$	0.18	$	0.2
	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,
		2015		2014
	Outstanding options		55		19
	Nonvested restricted stock units		414		—
	Employee Stock Purchase Plan		264		48
	Total		733		67

Note_7_Customer_and_Geographic

Note 7 - Customer and Geographic Information	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	7. 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	2015			2014
	A		44	%		45	%
	B		28	%		13	%
	C		11	%		19	%
	The Company had gross accounts receivable from individual customers in excess of 10% of gross accounts receivable as follows:
	Customer	March 31,			December 31,
		2015			2014
	A		40	%		51	%
	C		27	%		21	%
	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,
		2015						2014
		Revenues			Percentage			Revenues		Percentage
					of					of
					Revenues					Revenues
	United States	$	10,315			38	%	$	11,399		42	%
	Germany		6,264			24			9,100		34
	South Korea		6,918			26			2,260		8
	Rest of the world		3,320			12			4,327		16
	Total revenue	$	26,817			100	%	$	27,086		100	%
	Long-lived assets, net by geographic area are as follows (in thousands):
		March 31,			December 31,
		2015			2014
	United States	$	9,319		$	8,240
	Rest of the world		576			592
	Total long-lived assets, net	$	9,895		$	8,832

Note_8_Fair_Value_Measurements

Note 8 - Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	8. 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 1 -	Inputs are quoted prices in active markets for identical assets or liabilities.
	Level 2 -	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 3 -	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, 2015, and the basis for that measurement (in thousands):
	Assets		Total		Quoted		Significant		Significant
					Prices		Other		Unobservable
					in		Observable		Inputs
					Active		Inputs		(Level 3)
					Markets		(Level 2)
					for
					Identical
					Assets
					(Level 1)
	Money market mutual funds		$	26,358	$	26,358	$	—	$	—
	The following table represents the Company’s assets measured at fair value on a recurring basis as of December 31, 2014, and the basis for that measurement (in thousands):
	Assets		Total		Quoted		Significant		Significant
					Prices		Other		Unobservable
					in		Observable		Inputs
					Active		Inputs		(Level 3)
					Markets		(Level 2)
					for
					Identical
					Assets
					(Level 1)
	Money market mutual funds		$	26,356	$	26,356	$	—	$	—
	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, 2015, the Company recognized a realized loss on the contracts of $0.7 million, which was recorded in other income (expense), net in the Company’s Statement of Operations and Comprehensive Income. For the three months ended March 31, 2014, the Company did not have gain/loss on foreign currency forward contracts.
	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 2 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, 2015, the Company had one outstanding forward contract with a notional amount of $6.5 million and recorded $134,000 other current liabilities associated with this outstanding forward contract.

Note_9_Commitments_and_Conting

Note 9 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	9. 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 2019. Rent expense was $0.5 million for each of the three months ended March 31, 2015 and 2014.
	Future minimum lease payments under noncancelable operating leases at March 31, 2015, are as follows (in thousands):
	Year Ending December 31,	Amount
	2015 (remaining nine months)	$	1,382
	2016		1,753
	2017		1,415
	2018		806
	2019		71
	Thereafter		79
	Total future minimum lease payments	$	5,506
	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. During the reported period, the Company was not party to any material legal proceedings, thus no loss was probable and no amount was accrued at March 31, 2015.

Accounting_Policies_by_Policy_

Accounting Policies, by Policy (Policies)	3 Months Ended
	Mar. 31, 2015
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, 2014.
	The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries after the elimination of all significant intercompany balances and transactions.
	The condensed consolidated balance sheet at December 31, 2014, 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 revenue recognition for fixed-price solution implementation service contracts, stock-based compensation expense and accounting for income taxes. Actual results could differ from those estimates.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition  — The Company derives revenue from two sources: Design-to-silicon-yield solutions and Gainshare performance incentives.
	Design-to-Silicon-Yield Solutions — Revenue that is derived from Design-to-silicon-yield solutions comes from services and software licenses. The Company recognizes revenue 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. These contracts require reliable estimation of costs to perform obligations and the overall scope of each engagement. Revenue under project–based contracts for solution implementation services is recognized as services are performed using the cost-to-cost percentage of completion method of contract accounting. 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. Revenue under time and materials contracts for solution implementation services are recognized as the services are performed. On occasion, the Company licenses its software products as a component of its fixed-price service contracts. In such instances, the software products are licensed to customers over a specified term of the agreement with support and maintenance to be provided at each customer's option over the license term. The amount of product and service revenue recognized in a given period is affected by the Company’s judgment as to whether an arrangement includes multiple deliverables and, if so, the Company’s determination of the fair value of each deliverable. In general, vendor-specific objective evidence of selling price (“VSOE”) does not exist for the Company’s solution implementation services and software products and because the Company’s services and products include our unique technology, the Company is not able to determine third-party evidence of selling price (“TPE”). Therefore, in such circumstances the Company uses best estimated selling prices (“BESP”) in the allocation of arrangement consideration. In determining BESP, the Company applies significant judgment as the Company’s weighs a variety of factors, based on the facts and circumstances of the arrangement. The Company typically arrives at BESP for a product or service that is not sold separately by considering company-specific factors such as geographies, internal costs, gross margin objectives, pricing practices used to establish bundled pricing, and existing portfolio pricing and discounting. After fair value is established for each deliverable, the total transaction amount is allocated to each deliverable based upon its relative fair value. Fees allocated to solution implementation services are recognized using the cost-to-cost percentage of completion method of contract accounting. Fees allocated to software and related support and maintenance are recognized under software revenue recognition guidance. The Company defers certain pre-contract costs incurred for specific anticipated contracts. Deferred costs consist primarily of 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 persuasive evidence of contract arrangement assuming all other revenue recognition criteria are met. At the end of 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 no longer have future benefits and are no longer recoverable.
	The Company also licenses its software products separately from its solution implementations. For software license arrangements that do not require significant modification or customization of the underlying software, software license revenue is recognized under the residual method when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred, (3) the fee is fixed or determinable, (4) collectability is probable, and (5) the arrangement does not require services that are essential to the functionality of the software. When arrangements include multiple elements such as support and maintenance, consulting (other than for its fixed price solution implementations), installation, and training, revenue is allocated to each element of a transaction based upon its fair value as determined by the Company’s VSOE and such services are recorded as services revenue. VSOE for maintenance is generally established based upon negotiated renewal rates while VSOE for consulting, installation, and training services is established based upon the Company’s customary pricing for such services when sold separately. Revenue for software licenses with extended payment terms is not recognized in excess of amounts due. For software license arrangements that require significant modification or customization of the underlying software, the software license revenue is recognized as services are performed using the cost-to-cost percentage of completion method of contract accounting, and such revenue is recorded as services revenue.
	Gainshare Performance Incentives — When the Company enters into a contract to provide yield improvement services, the contract usually includes two components: (1) a fixed fee for performance by the Company of services delivered over a specific period of time; and (2) a Gainshare performance incentive component where the customer may pay a contingent variable fee, usually after the fixed fee period has ended. Revenue derived from Gainshare performance incentives represents profit sharing and performance incentives earned contingent upon the Company’s customers reaching certain defined operational levels established in related solution implementation service contracts. Gainshare performance incentives periods are usually subsequent to the delivery of all contractual services and therefore have no cost to the Company. Due to the uncertainties surrounding attainment of such operational levels, the Company recognizes Gainshare performance incentives revenue (to the extent of completion of the related solution implementation contract) upon receipt of performance reports or other related information from the customer supporting the determination of amounts and probability of collection.

Note_3_Balance_Sheet_Component1

Note 3 - Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure Text Block Supplement [Abstract]
Property, Plant and Equipment [Table Text Block]		March 31,			December 31,
		2015			2014
	Property and equipment, net:
	Computer equipment	$	8,678		$	9,817
	Software		1,898			3,369
	Furniture, fixtures and equipment		745			756
	Leasehold improvements		1,139			1,127
	Test equipment		6,677			6,401
	Construction-in-progress		3,287			2,405
			22,424			23,875
	Less: accumulated depreciation		(12,529	)		(15,043	)
	Total	$	9,895		$	8,832

Note_4_Stockholders_Equity_Tab

Note 4 - Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure Text Block Supplement [Abstract]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]		Three Months
		Ended March 31,
		2015			2014
	Cost of Design-to-silicon-yield solutions	$	887		$	724
	Research and development		491			371
	Selling, general and administrative		821			565
	Stock-based compensation expenses	$	2,199		$	1,660
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]		Three Months
		Ended March 31,
		2015			2014
	Expected life (in years)		4.51			4.58
	Volatility		46.48	%		43.35	%
	Risk-free interest rate		1.25	%		1.56	%
	Expected dividend		—			—
	Weighted average fair value per share of options granted during the period	$	6.38		$	7.75
		Three Months
		Ended March 31,
		2015			2014
	Expected life (in years)		1.25			1.25
	Volatility		54.21	%		34.56	%
	Risk-free interest rate		0.26	%		0.18	%
	Expected dividend		—			—
	Weighted average fair value of purchase rights granted under the Purchase Plan	$	6.19		$	7.18
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]		Number of			Weighted			Weighted		Aggregate
		Options			Average			Average		Intrinsic
		(in			Exercise			Remaining		Value
		thousands)			Price			Contractual		(in
					per Share			Term		thousands)
								(years)
	Outstanding, January 1, 2015		2,352		$	7.65
	Granted (weighted average fair value of $6.38 per share)		12		$	16.12
	Exercised		(462	)	$	6.76
	Canceled		(10	)	$	10.41
	Expired		(1	)	$	13.08
	Outstanding, March 31, 2015		1,891		$	7.9			5.47	$	19,032
	Vested and expected to vest, March 31, 2015		1,874		$	7.87			5.45	$	18,918
	Exercisable, March 31, 2015		1,511		$	7.4			5	$	15,917
Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]		Shares			Weighted
		(in thousands)			Average
					Grant Date
					Fair Value Per
					Share
	Nonvested, January 1, 2015		941		$	17.38
	Granted		12		$	16.12
	Vested		(19	)	$	17.86
	Forfeited		(18	)	$	17.66
	Nonvested, March 31, 2015		916		$	17.35

Note_6_Net_Income_Per_Share_Ta

Note 6 - Net Income Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]		Three Months Ended March 31,
		2015		2014
	Numerator:
	Net income	$	5,967	$	6,255
	Denominator:
	Basic weighted-average shares outstanding		31,336		30,477
	Effect of dilutive options and restricted stock		955		1,488
	Diluted weighted average shares outstanding		32,291		31,965
	Net income per share - Basic	$	0.19	$	0.21
	Net income per share - Diluted	$	0.18	$	0.2
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]		Three Months Ended March 31,
		2015		2014
	Outstanding options		55		19
	Nonvested restricted stock units		414		—
	Employee Stock Purchase Plan		264		48
	Total		733		67

Note_7_Customer_and_Geographic1

Note 7 - Customer and Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]		Three Months Ended March 31,
	Customer	2015			2014
	A		44	%		45	%
	B		28	%		13	%
	C		11	%		19	%
Schedule of Receivables by Major Customers [Table Text Block]	Customer	March 31,			December 31,
		2015			2014
	A		40	%		51	%
	C		27	%		21	%
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]		Three Months Ended March 31,
		2015						2014
		Revenues			Percentage			Revenues		Percentage
					of					of
					Revenues					Revenues
	United States	$	10,315			38	%	$	11,399		42	%
	Germany		6,264			24			9,100		34
	South Korea		6,918			26			2,260		8
	Rest of the world		3,320			12			4,327		16
	Total revenue	$	26,817			100	%	$	27,086		100	%
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]		March 31,			December 31,
		2015			2014
	United States	$	9,319		$	8,240
	Rest of the world		576			592
	Total long-lived assets, net	$	9,895		$	8,832

Note_8_Fair_Value_Measurements1

Note 8 - Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	Assets	Total		Quoted		Significant		Significant
				Prices		Other		Unobservable
				in		Observable		Inputs
				Active		Inputs		(Level 3)
				Markets		(Level 2)
				for
				Identical
				Assets
				(Level 1)
	Money market mutual funds	$	26,358	$	26,358	$	—	$	—
	Assets	Total		Quoted		Significant		Significant
				Prices		Other		Unobservable
				in		Observable		Inputs
				Active		Inputs		(Level 3)
				Markets		(Level 2)
				for
				Identical
				Assets
				(Level 1)
	Money market mutual funds	$	26,356	$	26,356	$	—	$	—

Note_9_Commitments_and_Conting1

Note 9 - Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Year Ending December 31,	Amount
	2015 (remaining nine months)	$	1,382
	2016		1,753
	2017		1,415
	2018		806
	2019		71
	Thereafter		79
	Total future minimum lease payments	$	5,506

Note_3_Balance_Sheet_Component2

Note 3 - Balance Sheet Components (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Disclosure Text Block Supplement [Abstract]
Unbilled Receivables, Current	$9.20		$9.70
Depreciation, Depletion and Amortization, Nonproduction	$0.60	$0.50

Note_3_Balance_Sheet_Component3

Note 3 - Balance Sheet Components (Details) - Property and Equipment (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Property and equipment, net:
Property and Equipment, Net	$22,424	$23,875
Less: accumulated depreciation	-12,529	-15,043
Total	9,895	8,832
Computer Equipment [Member]
Property and equipment, net:
Property and Equipment, Net	8,678	9,817
Software and Software Development Costs [Member]
Property and equipment, net:
Property and Equipment, Net	1,898	3,369
Furniture and Fixtures [Member]
Property and equipment, net:
Property and Equipment, Net	745	756
Leasehold Improvements [Member]
Property and equipment, net:
Property and Equipment, Net	1,139	1,127
Equipment [Member]
Property and equipment, net:
Property and Equipment, Net	6,677	6,401
Construction in Progress [Member]
Property and equipment, net:
Property and Equipment, Net	$3,287	$2,405

Note_4_Stockholders_Equity_Det

Note 4 - Stockholders' Equity (Details) (USD $)	3 Months Ended		40 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Dec. 31, 2014	Oct. 21, 2014
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	6,550,000		6,550,000
Share Based Compensation Arrangement By Share Based Payment Award Shares Reserved Decrease Rate	1.33
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	10,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	1,891,000		1,891,000	2,352,000
Share Price (in Dollars per share)	$17.92		17.92
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value (in Dollars)	$500,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	51,000	52,000
Employee Stock Purchase Plan Weighted Average Purchase Price Of Shares Purchased (in Dollars per share)	$13.32	$12.10
Allocated Share-based Compensation Expense (in Dollars)	2,199,000	1,660,000
Stock Repurchased During Period, Shares	199,912
Stock Repurchsed During Period Average Per Share Price (in Dollars per share)	$18.03
Stock Repurchased During Period, Value (in Dollars)	3,600,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount (in Dollars)	21,400,000		21,400,000
Employee Stock Option [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value (in Dollars)	5,200,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options (in Dollars)	1,700,000		1,700,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 109 days
Number Of ESPP Shares Available For Future Issuance	2,800,000		2,800,000
Restricted Stock [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 146 days
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options (in Dollars)	12,500,000		12,500,000
Stock Repurchase Program Adopted in October 2014 [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Stock Repurchase Program, Authorized Amount (in Dollars)					25,000,000
Shares Previously Issued Under the 2001 Plan [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	3,500,000		3,500,000
2011 Stock Incentive Plan [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share Based Compensation Arrangement By Share Based Payment Award Expiration Term	10 years
Common Stock, Capital Shares Reserved for Future Issuance	7,000,000		7,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	4,000,000		4,000,000
IDS Plan [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share Based Compensation Arrangement By Share Based Payment Award Expiration Term	10 years
2001 Stock Incentive Plan [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period			400,000
Outside of the 2011, 2001, or IDS Plans [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	0		0
Employee Stock Purchase Plan [Member]
Note 4 - Stockholders' Equity (Details) [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 292 days
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options (in Dollars)	1,500,000		1,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	10.00%		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%
Allocated Share-based Compensation Expense (in Dollars)	$200,000	$200,000

Note_4_Stockholders_Equity_Det1

Note 4 - Stockholders' Equity (Details) - Allocation of Recognized Period Costs (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocation of Recognized Period Costs	$2,199	$1,660
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocation of Recognized Period Costs	887	724
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocation of Recognized Period Costs	491	371
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocation of Recognized Period Costs	$821	$565

Note_4_Stockholders_Equity_Det2

Note 4 - Stockholders' Equity (Details) - Stock Options, Valuation Assumptions (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Note 4 - Stockholders' Equity (Details) - Stock Options, Valuation Assumptions [Line Items]
Weighted Average Grant Date Fair Value (in Dollars per share)	$6.38
Employee Stock Option [Member]
Note 4 - Stockholders' Equity (Details) - Stock Options, Valuation Assumptions [Line Items]
Expected life (in years)	4 years 186 days	4 years 211 days
Volatility	46.48%	43.35%
Risk-free interest rate	1.25%	1.56%
Expected dividend	0.00%	0.00%
Weighted Average Grant Date Fair Value (in Dollars per share)	$6.38	$7.75
Employee Stock Purchase Plan [Member]
Note 4 - Stockholders' Equity (Details) - Stock Options, Valuation Assumptions [Line Items]
Expected life (in years)	1 year 3 months	1 year 3 months
Volatility	54.21%	34.56%
Risk-free interest rate	0.26%	0.18%
Weighted Average Grant Date Fair Value (in Dollars per share)	$6.19	$7.18

Note_4_Stockholders_Equity_Det3

Note 4 - Stockholders' Equity (Details) - Stock Options Activity (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015
Stock Options Activity [Abstract]
Outstanding - Number of Options	2,352
Outstanding - Weighted Average Exercise Price per Share	$7.65
Outstanding - Weighted Average Remaining Contractual Term	5 years 171 days
Vested and expected to vest, March 31, 2015	1,874
Vested and expected to vest, March 31, 2015	$7.87
Vested and expected to vest, March 31, 2015	5 years 164 days
Vested and expected to vest, March 31, 2015	$18,918
Exercisable, March 31, 2015	1,511
Exercisable, March 31, 2015	$7.40
Exercisable, March 31, 2015	5 years
Exercisable, March 31, 2015	15,917
Granted (weighted average fair value of $6.38 per share)	12
Granted (weighted average fair value of $6.38 per share)	$16.12
Exercised	-462
Exercised	$6.76
Canceled	-10
Canceled	$10.41
Expired	-1
Expired	$13.08
Outstanding - Number of Options	1,891
Outstanding - Weighted Average Exercise Price per Share	$7.90
Outstanding - Weighted Average Remaining Contractual Term	5 years 171 days
Outstanding - Aggregate Intrinsic Value	$19,032

Note_4_Stockholders_Equity_Det4

Note 4 - Stockholders' Equity (Details) - Stock Options Activity (Parentheticals) (USD $)	3 Months Ended
	Mar. 31, 2015
Stock Options Activity [Abstract]
Granted, weighted average fair value	$6.38

Note_4_Stockholders_Equity_Det5

Note 4 - Stockholders' Equity (Details) - Nonvested Restricted Stock Units Activity (Restricted Stock Units (RSUs) [Member], USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015
Restricted Stock Units (RSUs) [Member]
Note 4 - Stockholders' Equity (Details) - Nonvested Restricted Stock Units Activity [Line Items]
Nonvested, January 1, 2015	941
Nonvested, January 1, 2015	$17.38
Nonvested, March 31, 2015	916
Nonvested, March 31, 2015	$17.35
Granted	12
Granted	$16.12
Vested	-19
Vested	$17.86
Forfeited	-18
Forfeited	$17.66

Note_5_Income_Taxes_Details

Note 5 - Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Increase (Decrease) in Income Taxes	$500,000
Income Tax Expense (Benefit)	3,553,000	3,039,000
Effective Income Tax Rate Reconciliation, Percent	37.30%	32.70%
Unrecognized Tax Benefits	10,300,000		10,400,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	6,100,000		6,300,000
Unrecognized Tax Benefits In Long Term Liabilities	2,400,000
Unrecognized Tax Benefits In Deferred Tax Assets	8,400,000
Unrecognized Tax Benefits In Deferred Tax Asset Subject To Full Valuation Allowance	$4,200,000

Note_6_Net_Income_Per_Share_De

Note 6 - Net Income Per Share (Details) - Calculation of Earnings Per Share (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net income (in Dollars)	$5,967	$6,255
Denominator:
Basic weighted-average shares outstanding	31,336	30,477
Effect of dilutive options and restricted stock	955	1,488
Diluted weighted average shares outstanding	32,291	31,965
Net income per share - Basic (in Dollars per share)	$0.19	$0.21
Net income per share - Diluted (in Dollars per share)	$0.18	$0.20

Note_6_Net_Income_Per_Share_De1

Note 6 - Net Income Per Share (Details) - Antidilutive Securities	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	733	67
Equity Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	55	19
Restricted Stock Units (RSUs), Nonvested [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	414
Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	264	48

Note_7_Customer_and_Geographic2

Note 7 - Customer and Geographic Information (Details)	3 Months Ended
	Mar. 31, 2015
Note 7 - Customer and Geographic Information (Details) [Line Items]
Number of Operating Segments	1
Customer Concentration Risk [Member]
Note 7 - Customer and Geographic Information (Details) [Line Items]
Concentration Risk, Percentage	10.00%
Accounts Receivable [Member]
Note 7 - Customer and Geographic Information (Details) [Line Items]
Concentration Risk, Percentage	10.00%

Note_7_Customer_and_Geographic3

Note 7 - Customer and Geographic Information (Details) - Revenue Percentage by Major Customers (Customer Concentration Risk [Member])	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenue, Major Customer [Line Items]
Revenue Percentage by Major Customer	10.00%
Customer A [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Revenue Percentage by Major Customer	44.00%	45.00%
Customer B [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Revenue Percentage by Major Customer	28.00%	13.00%
Customer C [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Revenue Percentage by Major Customer	11.00%	19.00%

Note_7_Customer_and_Geographic4

Note 7 - Customer and Geographic Information (Details) - Receivables Percentage by Major Customers	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Customer A [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Note 7 - Customer and Geographic Information (Details) - Receivables Percentage by Major Customers [Line Items]
Receivables Percentage by Major Customer	40.00%	51.00%
Customer C [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Note 7 - Customer and Geographic Information (Details) - Receivables Percentage by Major Customers [Line Items]
Receivables Percentage by Major Customer	27.00%	21.00%
Customer Concentration Risk [Member]
Note 7 - Customer and Geographic Information (Details) - Receivables Percentage by Major Customers [Line Items]
Receivables Percentage by Major Customer	10.00%
Accounts Receivable [Member]
Note 7 - Customer and Geographic Information (Details) - Receivables Percentage by Major Customers [Line Items]
Receivables Percentage by Major Customer	10.00%

Note_7_Customer_and_Geographic5

Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area [Line Items]
Revenues	$26,817	$27,086
Geographic Concentration Risk [Member] | UNITED STATES | Sales Revenue, Net [Member]
Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area [Line Items]
Revenues	10,315	11,399
Concentration Risk Percentage	38.00%	42.00%
Geographic Concentration Risk [Member] | GERMANY | Sales Revenue, Net [Member]
Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area [Line Items]
Revenues	6,264	9,100
Concentration Risk Percentage	24.00%	34.00%
Geographic Concentration Risk [Member] | KOREA, REPUBLIC OF | Sales Revenue, Net [Member]
Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area [Line Items]
Revenues	6,918	2,260
Concentration Risk Percentage	26.00%	8.00%
Geographic Concentration Risk [Member] | Rest of the World [Member] | Sales Revenue, Net [Member]
Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area [Line Items]
Revenues	3,320	4,327
Concentration Risk Percentage	12.00%	16.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member]
Note 7 - Customer and Geographic Information (Details) - Revenues by Geographic Area [Line Items]
Revenues	$26,817	$27,086
Concentration Risk Percentage	100.00%	100.00%

Note_7_Customer_and_Geographic6

Note 7 - Customer and Geographic Information (Details) - Long-lived Assets by Geographic Area (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Note 7 - Customer and Geographic Information (Details) - Long-lived Assets by Geographic Area [Line Items]
Long-lived assets, net, by geographical area	$9,895	$8,832
North America [Member]
Note 7 - Customer and Geographic Information (Details) - Long-lived Assets by Geographic Area [Line Items]
Long-lived assets, net, by geographical area	9,319	8,240
Rest of the World [Member]
Note 7 - Customer and Geographic Information (Details) - Long-lived Assets by Geographic Area [Line Items]
Long-lived assets, net, by geographical area	$576	$592

Note_8_Fair_Value_Measurements2

Note 8 - Fair Value Measurements (Details) (Foreign Exchange Contract [Member], USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Note 8 - Fair Value Measurements (Details) [Line Items]
Derivative, Number of Instruments Held	1
Derivative Asset, Notional Amount	$6,500,000
Other Nonoperating Income (Expense) [Member]
Note 8 - Fair Value Measurements (Details) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	700,000	0
Other Current Liabilities [Member]
Note 8 - Fair Value Measurements (Details) [Line Items]
Derivative Liability, Current	$134,000

Note_8_Fair_Value_Measurements3

Note 8 - Fair Value Measurements (Details) - Fair Value, Assets Measured on Recurring Basis (Money Market Mutual Funds [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Note 8 - Fair Value Measurements (Details) - Fair Value, Assets Measured on Recurring Basis [Line Items]
Money market mutual funds	$26,358	$26,356
Fair Value, Inputs, Level 1 [Member]
Note 8 - Fair Value Measurements (Details) - Fair Value, Assets Measured on Recurring Basis [Line Items]
Money market mutual funds	$26,358	$26,356

Note_9_Commitments_and_Conting2

Note 9 - Commitments and Contingencies (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Operating Leases, Rent Expense, Net	$500,000	$500,000
Loss Contingency, Loss in Period	0
Loss Contingency Accrual	$0

Note_9_Commitments_and_Conting3

Note 9 - Commitments and Contingencies (Details) - Future Minimum Lease Payments Under Noncancelable Operating Leases (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Future Minimum Lease Payments Under Noncancelable Operating Leases [Abstract]
2015 (remaining nine months)	$1,382
2016	1,753
2017	1,415
2018	806
2019	71
Thereafter	79
Total future minimum lease payments	$5,506