Power Integrations (POWI) 10-K 14 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 09, 2018	Jun. 30, 2017
Document Information [Abstract]
Entity Registrant Name	POWER INTEGRATIONS INC
Entity Central Index Key	833,640
Trading Symbol	POWI
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		29,834,589
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,800

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 93,655	$ 62,134
Short-term marketable securities	189,236	188,323
Accounts receivable, net of allowance for doubtful accounts of $734 and $525 in 2017 and 2016, respectively	16,798	6,528
Inventories	57,087	52,564
Prepaid expenses and other current assets	7,758	8,715
Total current assets	364,534	318,264
PROPERTY AND EQUIPMENT, net	111,705	95,296
INTANGIBLE ASSETS, net	25,419	31,502
GOODWILL	91,849	91,849
DEFERRED TAX ASSETS	2,364	11,342
OTHER ASSETS	25,203	6,157
Total assets	621,074	554,410
CURRENT LIABILITIES:
Accounts payable	33,211	29,727
Accrued payroll and related expenses	12,064	10,756
Taxes payable	1,767	729
Other accrued liabilities	4,009	2,734
Total current liabilities	51,051	43,946
LONG-TERM INCOME TAXES PAYABLE	18,259	2,639
DEFERRED TAX LIABILITIES	138	820
OTHER LIABILITIES	3,944	3,921
Total liabilities	73,392	51,326
STOCKHOLDERS’ EQUITY:
Common stock, $0.001 par value Authorized - 140,000,000 shares Outstanding - 29,782,455 and 29,249,635 shares in 2017 and 2016, respectively	29	28
Additional paid-in capital	198,384	172,875
Accumulated other comprehensive loss	(2,139)	(2,710)
Retained earnings	351,408	332,891
Total stockholders’ equity	547,682	503,084
Total liabilities and stockholders’ equity	$ 621,074	$ 554,410

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 734	$ 525
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	140,000,000	140,000,000
Common stock, shares outstanding	29,782,455	29,249,635

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
NET REVENUES		$ 431,755	$ 389,668	$ 344,609
COST OF REVENUES		218,091	197,477	171,309
GROSS PROFIT		213,664	192,191	173,300
OPERATING EXPENSES:
Research and development		68,501	62,310	57,549
Sales and marketing		51,384	47,978	46,816
General and administrative		36,142	33,029	30,029
Total operating expenses		156,027	143,317	134,394
INCOME FROM OPERATIONS		57,637	48,874	38,906
OTHER INCOME		2,662	1,078	425
INCOME BEFORE INCOME TAXES		60,299	49,952	39,331
PROVISION FOR INCOME TAXES		32,690	1,054	179
NET INCOME		$ 27,609	$ 48,898	$ 39,152
EARNINGS PER SHARE:
Basic		$ 0.93	$ 1.69	$ 1.35
Diluted	[1]	$ 0.90	$ 1.65	$ 1.32
SHARES USED IN PER SHARE CALCULATION:
Basic		29,674	28,925	29,001
Diluted	[1]	30,545	29,619	29,696
[1]	The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2017, 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 27,609	$ 48,898	$ 39,152
Other comprehensive income:
Foreign currency translation adjustments, net of $0 tax in 2017, 2016 and 2015	79	(384)	(191)
Unrealized loss on marketable securities, net of $0 tax in 2017, 2016 and 2015	(207)	(123)	(180)
Unrealized actuarial gain (loss) on pension benefits, net of tax of ($194), $98 and $96 in 2017, 2016 and 2015, respectively	699	(352)	(344)
Total other comprehensive income (loss)	571	(859)	(715)
Total comprehensive income	28,180	48,039	38,437
Foreign currency translation adjustment, tax	0	0	0
Unrealized gain on marketable securities, tax	0	0	0
Unrealized actuarial gain (loss) on pension benefits, tax	$ (194)	$ 98	$ 96

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption | ASU 2014-09	$ 13,966				$ 13,966
Beginning Balance (in shares) at Dec. 31, 2014		29,208
Beginning Balance at Dec. 31, 2014	430,676	$ 29	$ 171,938	$ (1,136)	259,845
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock award plans (in shares)		578
Issuance of common stock under employee stock option and stock award plans	8,133		8,133
Repurchase of common stock (in shares)		(1,250)
Repurchase of common stock	(53,731)	$ (1)	(53,730)
Issuance of common stock under employee stock purchase plan (in shares)		117
Issuance of common stock under employee stock purchase plan	4,447		4,447
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	(189)		(189)
Stock-based compensation expense related to employee stock options and awards	13,562		13,562
Stock-based compensation expense related to employee stock purchases	1,205		1,205
Payment of dividends to stockholders	(13,916)				(13,916)
Unrealized actuarial gain (loss) on pension benefits	(344)			(344)
Unrealized gain (loss) on marketable securities,	(180)			(180)
Translation adjustment	(191)			(191)
Net income (loss)	39,152				39,152
Ending Balance (in shares) at Dec. 31, 2015		28,653
Ending Balance at Dec. 31, 2015	442,590	$ 28	145,366	(1,851)	299,047
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock award plans (in shares)		615
Issuance of common stock under employee stock option and stock award plans	8,479		8,479
Repurchase of common stock (in shares)		(146)
Repurchase of common stock	(6,435)		(6,435)
Issuance of common stock under employee stock purchase plan (in shares)		128
Issuance of common stock under employee stock purchase plan	4,580		4,580
Stock-based compensation expense related to employee stock options and awards	19,599		19,599
Stock-based compensation expense related to employee stock purchases	1,286		1,286
Payment of dividends to stockholders	(15,054)				(15,054)
Unrealized actuarial gain (loss) on pension benefits	(352)			(352)
Unrealized gain (loss) on marketable securities,	(123)			(123)
Translation adjustment	(384)			(384)
Net income (loss)	48,898				48,898
Ending Balance (in shares) at Dec. 31, 2016		29,250
Ending Balance at Dec. 31, 2016	503,084	$ 28	172,875	(2,710)	332,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption | ASU 2016-09	7,542				7,542
Issuance of common stock under employee stock option and stock award plans (in shares)		569
Issuance of common stock under employee stock option and stock award plans	5,087	$ 1	5,086
Repurchase of common stock (in shares)		(129)
Repurchase of common stock	(9,188)		(9,188)
Issuance of common stock under employee stock purchase plan (in shares)		92
Issuance of common stock under employee stock purchase plan	4,934		4,934
Stock-based compensation expense related to employee stock options and awards	23,337		23,337
Stock-based compensation expense related to employee stock purchases	1,340		1,340
Payment of dividends to stockholders	(16,634)				(16,634)
Unrealized actuarial gain (loss) on pension benefits	699			699
Unrealized gain (loss) on marketable securities,	(207)			(207)
Translation adjustment	79			79
Net income (loss)	27,609				27,609
Ending Balance (in shares) at Dec. 31, 2017		29,782
Ending Balance at Dec. 31, 2017	$ 547,682	$ 29	$ 198,384	$ (2,139)	$ 351,408

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 27,609	$ 48,898	$ 39,152
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	18,374	16,812	16,464
Amortization of intangibles	6,083	6,663	7,039
Loss on disposal of property and equipment	360	332	361
Stock-based compensation expense	24,677	20,885	14,767
Amortization of premium on marketable securities	1,100	555	1,063
Deferred income taxes	15,838	(638)	(5,508)
Increase in accounts receivable allowances	209	207	127
Tax shortfall associated with employee stock plans	0	0	(189)
Change in operating assets and liabilities:
Accounts receivable	(10,479)	751	4,144
Inventories	(4,523)	(630)	13,500
Prepaid expenses and other assets	(17,646)	(2,524)	3,342
Accounts payable	396	7,714	(2,000)
Taxes payable and accrued liabilities	20,041	(1,124)	(75)
Net cash provided by operating activities	82,039	97,901	92,187
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(32,496)	(12,198)	(11,359)
Payment for purchase of building (Note 14)	0	0	(10,389)
Payment for acquisition, net of cash acquired (Note 14)	0	0	(15,549)
Purchases of marketable securities	(151,663)	(188,654)	(29,748)
Proceeds from sales and maturities of marketable securities	149,443	83,423	59,309
Net cash used in investing activities	(34,716)	(117,429)	(7,736)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	10,020	13,059	12,580
Repurchase of common stock	(9,188)	(6,435)	(53,731)
Payments of dividends to stockholders	(16,634)	(15,054)	(13,916)
Proceeds from draw on line of credit	5,000	0	0
Payments on line of credit	(5,000)	0	0
Net cash used in financing activities	(15,802)	(8,430)	(55,067)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	31,521	(27,958)	29,384
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	62,134	90,092	60,708
CASH AND CASH EQUIVALENTS AT END OF PERIOD	93,655	62,134	90,092
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	4,913	1,825	1,472
Loan applied to CamSemi purchase price (Note 14)	0	0	6,600
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid (refund) for income taxes, net of refunds (Note 11)	$ (1,571)	$ 6,613	$ 473

THE COMPANY

THE COMPANY	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
THE COMPANY [Text Block]	THE COMPANY: Power Integrations, Inc. (“Power Integrations” or the “Company”), incorporated in California on March 25, 1988, and reincorporated in Delaware in December 1997, designs, develops, manufactures and markets analog and mixed-signal integrated circuits (ICs) and other electronic components and circuitry used in high-voltage power conversion. The Company’s products are used in power converters that convert electricity from a high-voltage source (typically 48 volts or higher) to the type of power required for a specified downstream use. A large percentage of the Company’s products are ICs used in AC-DC power supplies, which convert the high-voltage AC from a wall outlet to the low-voltage DC required by most electronic devices. Power supplies incorporating the Company’s products are used with all manner of electronic products including mobile phones, computing and networking equipment, appliances, electronic utility meters, power tools, industrial controls, lighting applications that utilize light-emitting diodes (LEDs), and “smart-home,” or “internet of things” applications such as networked thermostats, power strips and other building-automation and security devices. The Company also offers high-voltage gate drivers – either standalone ICs or circuit boards containing ICs, electrical isolation components and other circuitry – used to operate high-voltage switches such as insulated-gate bipolar transistors (IGBTs). These combinations of switches and drivers are used for power conversion in high-power applications (i.e., power levels ranging from a few kilowatts up to one gigawatt) such as industrial motors, solar- and wind-power systems, electric vehicles and high-voltage DC transmission systems.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUTING POLICIES [Text Block]	SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS: Significant Accounting Policies and Estimates Segment Reporting The Company is organized and operates as one reportable segment, the design, development, manufacture and marketing of integrated circuits and related components for use primarily in high-voltage power conversion market. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of making operating decisions and assessing financial performance. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of all intercompany transactions and balances. Estimates The preparation of financial statements in conformity with U.S. Generally Accepted Accounting Principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition and allowances for receivables and inventories. These estimates are based on historical facts and various other factors, which the Company believes to be reasonable at the time the estimates are made. However, as the effects of future events cannot be determined with precision, actual results could differ significantly from management’s estimates. Revenue Recognition The Company applies the provisions of Accounting Standards Codification (ASC) 606-10, Revenue from Contracts with Customers , and all related appropriate guidance. The Company recognizes revenue under the core principle to depict the transfer of control to the Company’s customers in an amount reflecting the consideration the Company expects to be entitled. In order to achieve that core principle, the Company applies the following five-step approach: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied. Product revenues consist of sales to original equipment manufacturers, or OEMs, merchant power supply manufacturers and distributors. The Company considers customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. In situations where sales are to a distributor, the Company has concluded that its contracts are with the distributor as the Company holds a contract bearing enforceable rights and obligations only with the distributor. As part of its consideration of the contract, the Company evaluates certain factors including the customer’s ability to pay (or credit risk). For each contract, the Company considers the promise to transfer products, each of which is distinct, to be the identified performance obligations. In determining the transaction price the Company evaluates whether the price is subject to refund or adjustment to determine the net consideration to which the Company expects to be entitled. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. The Company allocates the transaction price to each distinct product based on their relative standalone selling price. The product price as specified on the purchase order is considered the standalone selling price as it is an observable input which depicts the price as if sold to a similar customer in similar circumstances. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company’s performance obligation is satisfied), which typically occurs at shipment. Further, in determining whether control has transferred, the Company considers if there is a present right to payment and legal title, along with risks and rewards of ownership having transferred to the customer. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. As scheduled delivery dates are within one year, under the optional exemption provided by ASC 606-10-50-14 revenues allocated to future shipments of partially completed contracts are not disclosed. The Company has also elected the practical expedient under ASC 340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year. Sales to international customers that are shipped from the Company’s facility outside of the United States are pursuant to EX Works, or EXW, shipping terms, meaning that control of the product transfers to the customer upon shipment from the Company’s foreign warehouse. Sales to international customers that are shipped from the Company’s facility in California are pursuant to Delivered at Frontier, or DAF, shipping terms. As such, control of the product passes to the customer when the shipment reaches the destination country and revenue is recognized upon the arrival of the product in that country. Shipments to customers in the Americas are pursuant to Free on Board, or FOB, point of origin shipping terms meaning that control is passed to the customer upon shipment. Sales to most distributors are made under terms allowing certain price adjustments and limited rights of return (known as “stock rotation”) of the Company’s products held in their inventory or upon sale to their end customers. Revenue from sales to distributors is recognized upon the transfer of control to the distributor. Frequently, distributors need to sell at a price lower than the standard distribution price in order to win business. At the time the distributor invoices its customer or soon thereafter, the distributor submits a “ship and debit” price adjustment claim to the Company to adjust the distributor’s cost from the standard price to the pre-approved lower price. After the Company verifies that the claim was pre-approved, a credit memo is issued to the distributor for the ship and debit claim. In determining the transaction price, the Company considers ship and debit price adjustments to be variable consideration. Such price adjustments are estimated using the expected value method based on an analysis of actual ship and debit claims, at the distributor and product level, over a period of time considered adequate to account for current pricing and business trends. Historically, actual price adjustments for ship and debit claims relative to those estimated and included when determining the transaction price have not materially differed. Stock rotation rights grant the distributor the ability to return certain specified amounts of inventory. Stock rotation adjustments are an additional form of variable consideration and are also estimated using the expected value method based on historical return rates. Historically, distributor stock rotation adjustments have not been material. Sales to certain distributors are made under terms that do not include rights of return or price concessions after the product is shipped to the distributor. Accordingly, upon application of steps one through five above, product revenue is recognized upon shipment and transfer of control. The Company generally provides an assurance warranty that its products will substantially conform to the published specifications for twelve months from the date of shipment. The Company’s liability is limited to either a credit equal to the purchase price or replacement of the defective part. Returns under warranty have historically been immaterial. As such, the Company does not record a specific warranty reserve or consider activities related to such warranty, if any, to be a separate performance obligation. Inventories Inventories (which consist of costs associated with the purchases of wafers from domestic and offshore foundries and of packaged components from offshore assembly manufacturers, as well as internal labor and overhead associated with the testing of both wafers and packaged components) are stated at the lower of cost (first-in, first-out) or market. Provisions, when required, are made to reduce excess and obsolete inventories to their estimated net realizable values. Income Taxes Income-tax expense is an estimate of current income taxes payable or refundable in the current fiscal year based on reported income before income taxes. Deferred income taxes reflect the effect of temporary differences and carry-forwards that are recognized for financial reporting and income tax purposes. The Company accounts for income taxes under the provisions of ASC 740, Income Taxe s. Under the provisions of ASC 740, deferred tax assets and liabilities are recognized based on the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, utilizing the tax rates that are expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The Company recognizes valuation allowances to reduce any deferred tax assets to the amount that it estimates will more likely than not be realized based on available evidence and management’s judgment. The Company limits the deferred tax assets recognized related to certain officers’ compensation to amounts that it estimates will be deductible in future periods based upon Internal Revenue Code Section 162(m). In the event that the Company determines, based on available evidence and management judgment, that all or part of the net deferred tax assets will not be realized in the future, it would record a valuation allowance in the period the determination is made. In addition, the calculation of tax liabilities involves significant judgment in estimating the impact of uncertainties in the application of complex tax laws. Resolution of these uncertainties in a manner inconsistent with the Company’s expectations could have a material impact on the Company’s results of operations and financial position. Business Combinations The purchase price of an acquisition is allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. To the extent the purchase price exceeds the fair value of the net identifiable tangible and intangible assets acquired and liabilities assumed, such excess is allocated to goodwill. The Company determines the estimated fair values after review and consideration of relevant information, including discounted cash flows, quoted market prices and estimates made by management. The Company adjusts the preliminary purchase price allocation, as necessary, during the measurement period of up to one year after the acquisition closing date as it obtains more information as to facts and circumstances existing at the acquisition date impacting asset valuations and liabilities assumed. Acquisition-related costs are recognized separately from the acquisition and are expensed as incurred. Goodwill and Intangible Assets Goodwill and the Company's domain name are evaluated in accordance with ASC 350-10, Goodwill and Other Intangible Assets, and an impairment analysis is conducted on an annual basis, or sooner if indicators exist for a potential impairment. In accordance with ASC 360-10, Accounting for the Impairment or Disposal of Long-Lived Assets , long-lived assets, such as property and equipment and intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. Cash and Cash Equivalents The Company considers cash invested in highly liquid financial instruments with maturities of three months or less at the date of purchase to be cash equivalents. Marketable Securities The Company generally holds securities until maturity; however, they may be sold under certain circumstances including, but not limited to, when necessary for the funding of acquisitions and other strategic investments. As a result the Company classifies its investment portfolio as available-for-sale. The Company classifies all investments with a maturity date greater than three months at the date of purchase as short-term marketable securities in its consolidated balance sheet. As of December 31, 2017 , and December 31, 2016 , the Company’s marketable securities consisted primarily of commercial paper, corporate bonds, government securities and/or other high-quality commercial securities. Employee Benefits Plan The Company sponsors a 401(k) tax-deferred savings plan for all employees in the United States who meet certain eligibility requirements. Participants may contribute up to the amount allowable as a deduction for federal income tax purposes. The Company is not required to contribute; however, the Company contributes a certain percentage of employee annual salaries on a discretionary basis, not to exceed an established threshold. The Company provided for a contribution of approximately $1.2 million in 2017 and approximately $1.1 million in each of 2016 and 2015 . Retirement Benefit Obligations (Pension) The Company recognizes the over-funded or under-funded status of a defined benefit pension or post-retirement plan as an asset or liability in the accompanying consolidated balance sheets. Actuarial gains and losses are recorded in accumulated other comprehensive loss, a component of stockholders’ equity, and are amortized as a component of net periodic cost over the remaining estimated service period of participants. Foreign Currency Risk and Foreign Currency Translation As of December 31, 2017 , the Company’s primary transactional currency was U.S. dollars; in addition, the Company holds cash in Swiss francs and euros to fund the operations of the Company’s Swiss subsidiary. The foreign exchange rate fluctuation between the U.S. dollar versus the Swiss franc and euro is recorded in “other income” in the consolidated statements of income. Gains and losses arising from the remeasurement of non-functional currency balances are recorded in ''other income'' in the accompanying consolidated statements of income. For each of the years ended December 31, 2017 and 2016 the Company realized foreign exchange transaction losses of $0.1 million and $0.5 million in 2015 . The functional currencies of the Company’s other subsidiaries are the local currencies. Accordingly, all assets and liabilities are translated into U.S. dollars at the current exchange rates as of the applicable balance sheet date. Revenues and expenses are translated at the average exchange rate prevailing during the period. Cumulative gains and losses from the translation of the foreign subsidiaries’ financial statements have been included in stockholders’ equity. Warranty The Company generally warrants that its products will substantially conform to the published specifications for 12 months from the date of shipment. The Company’s liability is limited to either a credit equal to the purchase price or replacement of the defective part. Returns under warranty have historically been immaterial, and as a result, the Company does not record a specific warranty reserve. Advertising Advertising costs are expensed as incurred. In each of 2017 and 2016 advertising costs amounted to $1.3 million and $1.1 million in 2015 . Research and Development Research and development costs are expensed as incurred. Indemnifications The Company sells products to its distributors under contracts, collectively referred to as Distributor Sales Agreements (DSA). Each DSA contains the relevant terms of the contractual arrangement with the distributor, and generally includes certain provisions for indemnifying the distributor against losses, expenses, and liabilities from damages that may be awarded against the distributor in the event the Company’s products are found to infringe upon a patent, copyright, trademark, or other proprietary right of a third party (Customer Indemnification). The DSA generally limits the scope of and remedies for the Customer Indemnification obligations in a variety of industry-standard respects, including, but not limited to, limitations based on time and geography, and a right to replace an infringing product. The Company also, from time to time, has granted a specific indemnification right to individual customers. The Company believes its internal development processes and other policies and practices limit its exposure related to such indemnifications. In addition, the Company requires its employees to sign a proprietary information and inventions agreement, which assigns the rights to its employees' development work to the Company. To date, the Company has not had to reimburse any of its distributors or customers for any losses related to these indemnifications and no material claims were outstanding as of December 31, 2017 . For several reasons, including the lack of prior indemnification claims and the lack of a monetary liability limit for certain infringement cases, the Company cannot determine the maximum amount of potential future payments, if any, related to such indemnifications. Adoption of New Accounting Standards In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers , amending the existing accounting standards for revenue recognition. The Company elected to early adopt these standards, effective on January 1, 2017, using the full retrospective method, under which the amendments were applied to all prior periods presented. Under the new standards the Company recognizes all revenue on sales to distributors upon shipment and transfer of control (known as “sell-in” revenue recognition), rather than deferring recognition on sales to certain distributors until the distributors report that they have sold the products to their customers (known as “sell-through” revenue recognition). The impact of adoption on the Company’s previously reported consolidated financial statements were as follows: Consolidated Balance Sheet: December 31, 2016 (In thousands) As Reported Impact of Adoption As Adjusted Accounts receivable, net $ 6,961 $ (433 ) $ 6,528 Prepaid expenses and other current assets 8,520 195 8,715 Deferred tax assets 12,032 (690 ) 11,342 Deferred income on sales to distributors 16,207 (16,207 ) — Other accrued liabilities 2,434 300 2,734 Retained earnings $ 317,912 $ 14,979 $ 332,891 Year Ended December 31, Consolidated Statements of Income: 2016 2015 (In thousands, except per share) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted Net revenues $ 387,393 $ 2,275 $ 389,668 $ 343,989 $ 620 $ 344,609 Cost of revenues 196,232 1,245 197,477 170,602 707 171,309 Provision for income taxes 1,032 22 1,054 271 (92 ) 179 Net income $ 47,890 $ 1,008 $ 48,898 $ 39,147 $ 5 $ 39,152 Earnings per share Basic $ 1.66 $ 0.03 $ 1.69 $ 1.35 $ — $ 1.35 Diluted $ 1.62 $ 0.03 $ 1.65 $ 1.32 $ — $ 1.32 Year Ended December 31, Consolidated Statement of Cash Flows: 2016 2015 (In thousands) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted CASH FLOWS FROM OPERATING ACTIVITIES: Net income $ 47,890 $ 1,008 $ 48,898 $ 39,147 $ 5 $ 39,152 Deferred income taxes (660 ) 22 (638 ) (5,416 ) (92 ) (5,508 ) Accounts receivable 650 101 751 4,131 13 4,144 Prepaid expenses and other assets (2,499 ) (25 ) (2,524 ) 3,391 (49 ) 3,342 Taxes payable and accrued liabilities (1,124 ) — (1,124 ) (76 ) 1 (75 ) Deferred income on sales to distributors $ 1,106 $ (1,106 ) $ — $ (122 ) $ 122 $ — In March 2016, the FASB amended the existing accounting standards for stock-based compensation, ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09) . The amendments impact several aspects of accounting for share-based payment transactions, including the income tax consequences, forfeitures, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The manner of application varies by the various provisions of the guidance, with certain provisions applied on a retrospective or modified retrospective approach, while others are applied prospectively. The Company adopted the new standards in the first quarter of 2017, effective on January 1, 2017. Upon adoption, the Company recognized a windfall tax benefit of $7.5 million , as a cumulative effect adjustment to opening retained earnings, together with a corresponding increase in deferred tax assets. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350) . Under the amendments in this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The Company elected to early adopt the new standards in the fourth quarter of 2017 when the annual goodwill impairment test was performed. Recently Issued Accounting Pronouncements In February 2016, the FASB amended the existing accounting standards for leases, ASU 2016-02, Leases . The amendments require lessees to recognize, on the balance sheet, assets and liabilities for the rights and obligations created by leases of greater than twelve months. The accounting by lessors will remain largely unchanged from that applied under previous U.S. GAAP. The Company is required to adopt the amendments in the first quarter of fiscal 2019, with early adoption permitted. The amendments require a modified retrospective transition approach to recognize and measure leases at the beginning of the earliest period presented. The Company is currently evaluating the impact of these amendments and the transition alternatives on its consolidated financial statements.

COMPONENTS OF THE COMPANY'S CON

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Notes)	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Supplemental Balance Sheet Disclosures [Text Block]	COMPONENTS OF THE COMPANY’S CONSOLIDATED BALANCE SHEETS Accounts Receivable (in thousands) December 31, 2017 December 31, 2016 Accounts receivable trade $ 58,718 $ 46,849 Accrued ship and debit (39,486 ) (38,075 ) Allowance for stock rotation and rebate (1,700 ) (1,721 ) Allowance for doubtful accounts (734 ) (525 ) Total $ 16,798 $ 6,528 Inventories (in thousands) December 31, 2017 December 31, 2016 Raw materials $ 15,517 $ 14,610 Work-in-process 16,765 15,194 Finished goods 24,805 22,760 Total $ 57,087 $ 52,564 Prepaid Expenses and Other Current Assets (in thousands) December 31, 2017 December 31, 2016 Prepaid income tax $ 460 $ 2,431 Prepaid legal fees 213 212 Prepaid maintenance agreements 856 1,399 Advance to suppliers 1,211 69 Interest receivable 1,195 743 Other 3,823 3,861 Total $ 7,758 $ 8,715 Property and Equipment (in thousands) December 31, 2017 December 31, 2016 Land $ 20,288 $ 20,288 Construction-in-progress 15,353 6,880 Building and improvements 52,655 52,156 Machinery and equipment 151,269 132,162 Computer software and hardware and office furniture and fixtures 50,440 45,951 290,005 257,437 Accumulated depreciation (178,300 ) (162,141 ) Total $ 111,705 $ 95,296 Depreciation expense for property and equipment for fiscal years ended December 31, 2017 , 2016 and 2015 , was approximately $18.4 million , $16.8 million and $16.5 million , respectively, and was determined using the straight-line method over the following useful lives: Building and improvements 4-40 years Machinery and equipment 2-8 years Computer software and hardware and office furniture and fixtures 4-7 years Total property and equipment (excluding accumulated depreciation) located in the United States at December 31, 2017 , 2016 and 2015 , was approximately $159.5 million , $155.1 million and $150.1 million , respectively. In each of 2017 , 2016 and 2015, approximately 12% of total property and equipment (excluding accumulated depreciation) was held in Thailand by one of the Company’s subcontractors. No other country held 10% or more of total property and equipment in the periods presented. Accumulated Other Comprehensive Loss Changes in accumulated other comprehensive loss for the three years ended December 31, 2017 : (in thousands) Unrealized Gains and Losses on Available-for-Sale Securities Defined Benefit Pension Items Foreign Currency Items Total Balance at January 1, 2015 $ 83 $ (1,240 ) $ 21 $ (1,136 ) Other comprehensive loss before reclassifications (180 ) (469 ) (191 ) (840 ) Amounts reclassified from accumulated other comprehensive loss — 125 (1) — 125 Other comprehensive loss (180 ) (344 ) (191 ) (715 ) Balance at December 31, 2015 (97 ) (1,584 ) (170 ) (1,851 ) Other comprehensive loss before reclassifications (123 ) (505 ) (384 ) (1,012 ) Amounts reclassified from accumulated other comprehensive loss — 153 (1) — 153 Other comprehensive loss (123 ) (352 ) (384 ) (859 ) Balance at December 31, 2016 (220 ) (1,936 ) (554 ) (2,710 ) Other comprehensive income before reclassifications (207 ) 502 79 374 Amounts reclassified from accumulated other comprehensive loss — 197 (1) — 197 Other comprehensive income (207 ) 699 79 571 Balance at December 31, 2017 $ (427 ) $ (1,237 ) $ (475 ) $ (2,139 ) _______________ (1) This component of accumulated other comprehensive loss is included in the computation of net periodic pension cost for the years ended December 31, 2017 , 2016 and 2015 .

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS [Text Block]	FAIR VALUE MEASUREMENTS: ASC 820-10, Fair Value Measurements , clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, ASC 820-10 establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows: (Level 1) observable inputs such as quoted prices for identical assets in active markets; (Level 2) inputs other than the quoted prices in active markets that are observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. The Company’s cash equivalents and investment instruments are classified within Level 1 or Level 2 of the fair-value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The type of instrument valued based on quoted market prices in active markets primarily includes money market securities. This type of instrument is generally classified within Level 1 of the fair-value hierarchy. The types of instruments valued based on other observable inputs (Level 2 of the fair-value hierarchy) include investment-grade corporate bonds and government, state, municipal and provincial obligations. Such types of investments are valued by using a multi-dimensional relational model, the inputs are primarily benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications. The Company does not hold any instruments that would be classified within Level 3 of the fair-value hierarchy. The fair value hierarchy of the Company’s cash equivalents and marketable securities at December 31, 2017 , and December 31, 2016 , was as follows: Fair Value Measurement at December 31, 2017 (in thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 179,951 $ — $ 179,951 Commercial paper 51,122 — 51,122 Government securities 9,285 — 9,285 Money market funds 195 195 — Total $ 240,553 $ 195 $ 240,358 Fair Value Measurement at December 31, 2016 (in thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 132,141 $ — $ 132,141 Commercial paper 58,031 — 58,031 Money market funds 1,916 1,916 — Total $ 192,088 $ 1,916 $ 190,172 The Company did not transfer any investments between level 1 and level 2 of the fair value hierarchy in the years ended December 31, 2017 , and December 31, 2016 .

MARKETABLE SECURITIES (Notes)

MARKETABLE SECURITIES (Notes)	12 Months Ended
	Dec. 31, 2017
Marketable Securities [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	MARKETABLE SECURITIES: Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2017 , were as follows: Amortized Gross Unrealized Estimated Fair (in thousands) Cost Gains Losses Market Value Investments due in 3 months or less: Corporate securities $ 38,485 $ — $ (16 ) $ 38,469 Total 38,485 — (16 ) 38,469 Investments due in 4-12 months: Corporate securities 104,440 — (199 ) 104,241 Government securities 9,302 — (17 ) 9,285 Total 113,742 — (216 ) 113,526 Investments due in 12 months or greater: Corporate securities 37,436 — (195 ) 37,241 Total 37,436 — (195 ) 37,241 Total marketable securities $ 189,663 $ — $ (427 ) $ 189,236 Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2016 , were as follows: Amortized Gross Unrealized Estimated Fair (in thousands) Cost Gains Losses Market Value Investments due in 3 months or less: Commercial paper $ 36,996 $ — $ — $ 36,996 Corporate securities 9,342 2 (2 ) 9,342 Total 46,338 2 (2 ) 46,338 Investments due in 4-12 months: Commercial paper 19,186 — — 19,186 Corporate securities 59,714 15 (76 ) 59,653 Total 78,900 15 (76 ) 78,839 Investments due in 12 months or greater: Corporate securities 63,305 21 (180 ) 63,146 Total 63,305 21 (180 ) 63,146 Total marketable securities $ 188,543 $ 38 $ (258 ) $ 188,323 The weighted average interest rate of investments at December 31, 2017 and December 31, 2016 , was approximately 1.57% and 1.23% , respectively. As of December 31, 2017 and 2016 , there were no individual securities that had been in a continuous loss position for 12 months or greater.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS [Text Block]	GOODWILL AND INTANGIBLE ASSETS: Changes in the carrying amount of goodwill during the years ended December 31, 2017 and 2016, are as follows: (in thousands) Goodwill Balance at December 31, 2015 $ 91,849 Goodwill acquired during the period — Balance at December 31, 2016 91,849 Goodwill acquired during the period — Balance at December 31, 2017 $ 91,849 Intangible assets consist primarily of developed technology, acquired licenses, customer relationships, trade name, domain name, in-process R&D and patent rights, and are reported net of accumulated amortization. In January 2015, the Company acquired Cambridge Semiconductor Limited (CamSemi), a UK company, resulting in the addition of the following intangible assets: developed technology of $6.6 million , which is amortized over a period of three - seven years; and customer relationships of $2.4 million , which is amortized over a period of five years. In August 2015, the Company purchased a building with existing third-party leases, resulting in the addition of in-place lease intangible assets of $0.7 million which was amortized over a period of two years. The Company amortizes the cost of all intangible assets over the shorter of the estimated useful life or the term of the developed technology, acquired licenses, customer relationships, trade name, patent rights and in-place leases, which range from two to twelve years, with the exception of $4.7 million of in-process R&D and $1.3 million paid to acquire an internet domain name. In-process R&D is assessed for impairment until the development is completed and products are available for sale, at which time the Company will begin to amortize the in-process R&D. The Company does not expect the amortization of in-process R&D to begin in 2018. The Company acquired the rights to the internet domain name www.power.com , which is now the Company’s primary domain name; the cost to acquire the domain name has been recorded as an intangible asset and will not be amortized as it has an indefinite useful life. Amortization of acquired intangible assets was approximately $6.1 million , $6.7 million and $7.0 million in the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company does not believe there is any significant residual value associated with the following intangible assets: December 31, 2017 December 31, 2016 (in thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Domain name $ 1,261 $ — $ 1,261 $ 1,261 $ — $ 1,261 In-process research and development 4,690 — 4,690 4,690 — 4,690 Developed technology 33,270 (19,211 ) 14,059 33,270 (15,455 ) 17,815 Customer relationships 20,030 (14,621 ) 5,409 20,030 (12,474 ) 7,556 Technology licenses — — — 3,000 (3,000 ) — In-place leases 660 (660 ) — 660 (480 ) 180 Total intangible assets $ 59,911 $ (34,492 ) $ 25,419 $ 62,911 $ (31,409 ) $ 31,502 The estimated future amortization expense related to definite-lived intangible assets at December 31, 2017 , is as follows: Fiscal Year Estimated Amortization (in thousands) 2018 $ 5,152 2019 4,753 2020 3,528 2021 2,662 2022 1,584 Thereafter 1,789 Total (1) $ 19,468 _______________ (1) The total above excludes $4.7 million of in-process R&D which will be amortized upon completion of development over the estimated useful life of the technology.

STOCK PLANS AND SHARE BASED COM

STOCK PLANS AND SHARE BASED COMPENSATION	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK PLANS AND SHARE BASED COMPENSATION [Text Block]	STOCK PLANS AND SHARE BASED COMPENSATION: Stock Plans As of December 31, 2017 , the Company had three stock-based compensation plans (the “Plans”) which are described below. 2007 Equity Incentive Plan The 2007 Equity Incentive Plan (2007 Plan) was adopted by the board of directors on September 10, 2007, and approved by the stockholders on November 7, 2007, as an amendment and restatement of the 1997 Stock Option Plan (1997 Plan). The 2007 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit (RSU) awards, stock appreciation rights, performance-based (PSU) awards, long-term performance based (PRSU) awards and other stock awards to employees, directors and consultants. Pursuant to the 2007 Plan, the exercise price for incentive stock options and non-statutory stock options is generally at least 100% of the fair market value of the underlying shares on the date of grant. Options generally vest over 48 months measured from the date of grant. Options generally expire no later than ten years after the date of grant, subject to earlier termination upon an optionee’s cessation of employment or service. The 2007 Plan expired in September 2017 with no further grants to be made under this plan; however previous grants under this plan shall remain outstanding until they are exercised, vest, forfeited or expire. Beginning January 27, 2009, grants pursuant to the Directors Equity Compensation Program (which was adopted by the board of directors on January 27, 2009) to non-employee directors have been made primarily under the 2007 Plan. The Directors Equity Compensation Program provides for grants to outside directors as follows: effective annually, upon the first trading day of July, each outside director would receive a grant of an equity award with an aggregate value of $100,000 . At each outside director’s election, such award would consist entirely of RSUs or entirely of stock options. The quantity of options would be calculated by dividing $100,000 by the Black-Scholes value on the date of grant. The quantity of RSUs issued would be calculated by dividing $100,000 by the grant date fair value. Further, on the date of election of a new outside director, such new director would receive such grant as continuing outside directors receive on the first trading day of July; provided, however, that such grant is prorated for the portion of the year that such new outside director will serve until the next first trading day of July. The Directors Equity Compensation Program will remain in effect at the discretion of the board of directors or the compensation committee. 2016 Incentive Award Plan The 2016 Incentive Award Plan (2016 Plan) was adopted by the board of directors on March 17, 2016 and approved by the stockholders on May 13, 2016. The Plan provides for the grant of RSU awards, PSU awards and PRSU awards. No other forms of equity-based awards, including stock options and stock appreciation rights, may be granted under the Plan. As of December 31, 2017 , 35,000 awards have been issued and approximately 1.5 million shares of common stock remain available for future grant under the 2016 Plan. The 2016 Plan also provides for performance-based cash awards that qualify as “performance-based compensation” within the meaning of Section 162(m) of the Internal Revenue Code. 1997 Employee Stock Purchase Plan Under the 1997 Employee Stock Purchase Plan (Purchase Plan), eligible employees may apply accumulated payroll deductions, which may not exceed 15% of an employee’s compensation, to the purchase of shares of the Company’s common stock at periodic intervals. The purchase price of stock under the Purchase Plan is equal to 85% of the lower of (i) the fair market value of the Company’s common stock on the first day of each offering period, or (ii) the fair market value of the Company’s common stock on the purchase date (as defined in the Purchase Plan). Each offering period consists of one purchase period of approximately six months duration. An aggregate of 3.5 million shares of common stock were reserved for issuance to employees under the Purchase Plan. As of December 31, 2017 , of the shares reserved for issuance, 3.0 million shares had been purchased and 0.5 million shares were reserved for future issuance under the Purchase Plan. Shares Reserved As of December 31, 2017 , the Company had approximately 2.0 million shares of common stock reserved for future grant under all stock plans. Stock-Based Compensation The Company applies the provisions of ASC 718-10, Stock Compensation . Under the provisions of ASC 718-10, the Company recognizes the fair value of stock-based compensation in its financial statements over the requisite service period of the individual grants, which generally equals a four -year vesting period. The Company uses estimates of volatility, expected term, risk-free interest rate, dividend yield and forfeitures in determining the fair value of these awards and the amount of compensation expense to recognize. The Company uses the straight-line method to amortize all stock awards granted over the requisite service period of the award. The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, (in thousands) 2017 2016 2015 Cost of revenues $ 1,321 $ 1,148 $ 933 Research and development 8,496 7,309 5,255 Sales and marketing 5,197 4,489 3,644 General and administrative 9,663 7,939 4,935 Total stock-based compensation expense $ 24,677 $ 20,885 $ 14,767 The following table summarizes total compensation expense related to unvested awards not yet recognized, net of expected forfeitures, and the weighted average period over which it is expected to be recognized as of December 31, 2017 : Unrecognized Compensation Expense for Unvested Awards (in thousands) Weighted Average Remaining Recognition Period (in years) Long-term performance-based awards $ 3,519 1.36 Restricted stock units 35,132 3.73 Purchase plan 128 0.08 Total unrecognized compensation expense $ 38,779 Stock-based compensation expense in the year ended December 31, 2017 , was approximately $24.7 million (comprising approximately $8.2 million related to performance-based awards, $15.2 million related to restricted stock units and $1.3 million related to the Company’s Purchase Plan). Stock-based compensation expense in the year ended December 31, 2016 , was approximately $20.9 million (comprising approximately $0.2 million related to stock options, $6.4 million related to performance-based awards, $13.0 million related to restricted stock units and $1.3 million related to the Company’s Purchase Plan). Stock-based compensation expense in the year ended December 31, 2015 , was approximately $14.8 million (comprising approximately $0.7 million related to stock options, $0.3 million related to performance-based awards, $12.7 million related to restricted stock units and $1.2 million related to the Company’s Purchase Plan). The Company did not grant stock options in the years ended December 31, 2017 , 2016 and 2015 , and therefore no fair-value assumptions are reported. The fair value of employees’ stock purchase rights under the Purchase Plan was estimated using the Black-Scholes model with the following weighted-average assumptions used during the three years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, 2017 2016 2015 Risk-free interest rates 0.91% 0.44% 0.13% Expected volatility rates 30% 32% 29% Expected dividend yield 0.80% 0.96% 1.08% Expected term of purchase rights (in years) 0.50 0.50 0.50 Weighted-average estimated fair value of purchase rights $16.74 $12.23 $10.18 A summary of stock options outstanding as of December 31, 2017 , and activity during three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 1,344 $ 27.27 Granted — — Exercised (311 ) $ 26.11 Forfeited or expired (3 ) $ 37.97 Outstanding at December 31, 2015 1,030 $ 27.58 Granted — — Exercised (333 ) $ 25.41 Forfeited or expired — — Outstanding at December 31, 2016 697 $ 28.62 Granted — — Exercised (186 ) $ 27.48 Forfeited or expired — — Outstanding at December 31, 2017 511 $ 29.03 2.05 $ 22,770 Vested and Exercisable at December 31, 2017 511 2.05 $ 22,770 The total intrinsic value of options exercised during the year ended December 31, 2017 , 2016 and 2015 , was $8.9 million , $11.5 million and $7.0 million , respectively. The following table summarizes the stock options outstanding at December 31, 2017 : Options Outstanding Options Exercisable (shares in thousands) Range of Exercise Prices Options Outstanding Weighted Average Remaining Contractual Term (in years) Weighted Average Exercise Price Options Exercisable Weighted Average Exercise Price $17.75 - $24.21 263 1.26 $ 20.96 263 $ 20.96 $31.15 - $42.88 248 2.88 $ 37.56 248 $ 37.56 511 2.05 $ 29.03 511 $ 29.03 PSU Awards Under the performance-based awards program, the Company grants awards in the performance year in an amount equal to twice the target number of shares to be issued if the maximum performance metrics are met. The number of shares that are released at the end of the performance year can range from zero to 200% of the target number depending on the Company’s performance. The performance metrics of this program are annual targets consisting of a combination of net revenue, non-GAAP operating earnings and strategic goals. As the net revenue, non-GAAP operating income and strategic goals are considered performance conditions, expense associated with these awards, net of estimated forfeitures, is recognized over the service period based on an assessment of the achievement of the performance targets. The fair value of these PSUs is determined using the fair value of the Company’s common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest. If the performance conditions are not achieved, no compensation cost is recognized and any previously recognized compensation is reversed. A summary of PSU awards outstanding as of December 31, 2017 , and activity during the three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 — — Granted 89 $ 52.36 Vested — — Forfeited or canceled (78 ) $ 52.35 Outstanding at December 31, 2015 11 $ 52.35 Granted 101 $ 46.26 Vested (11 ) $ 52.35 Forfeited or canceled (2 ) $ 46.87 Outstanding at December 31, 2016 99 $ 46.25 Granted 88 $ 63.99 Vested (99 ) $ 46.25 Forfeited or canceled (9 ) $ 63.99 Outstanding at December 31, 2017 79 $ 63.99 0 $ 5,819 Outstanding and expected to vest at December 31, 2017 79 0 $ 5,819 The grant date fair value of PSU awards released, which were fully vested, in the years ended December 31, 2017 and 2016 were approximately $4.6 million and $0.6 million , respectively. There were no PSU awards released in the year ended December 31, 2015 (as the Company did not reach its minimum performance goals established for the 2014 PSUs). PRSU Awards (Long-term Performance Based) The Company's PRSU program provides for the issuance of PRSUs which will vest based on the Company's performance measured against the PRSU Plan's established revenue targets. The PRSUs were granted in an amount equal to twice the target number of shares to be issued if the maximum performance metrics are met. The actual number of shares the recipient receives is determined at the end of a three -year performance period based on results achieved versus the Company’s performance goals, and may range from zero to 200% of the target number. The performance goals for PRSUs granted in fiscal 2017 , 2016 and 2015 were based on the Company’s annual revenue growth over the respective three -year performance period. Recipients of a PRSU award generally must remain employed by the Company on a continuous basis through the end of the applicable three -year performance period in order to receive shares subject to that award. Expenses associated with these awards, net of estimated forfeitures, are recorded throughout the year depending on the number of shares expected to vest based on progress toward the performance target. The fair value of PRSU awards is determined using the fair value of the Company’s common stock on the grant date, reduced by the discounted present value of dividends expected to be declared before the awards vest. If the performance conditions are not achieved, no compensation cost is recognized and any previously recognized compensation is reversed. A summary of PRSU awards outstanding as of December 31, 2017 , and activity during the three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 61 $ 55.51 Granted 72 $ 52.47 Vested — — Forfeited or canceled (4 ) $ 57.76 Outstanding at December 31, 2015 129 $ 53.75 Granted 78 $ 43.26 Vested — — Forfeited or canceled (57 ) $ 55.35 Outstanding at December 31, 2016 150 $ 47.65 Granted 71 $ 63.00 Vested — — Forfeited or canceled (37 ) $ 51.59 Outstanding at December 31, 2017 184 $ 52.80 1.49 $ 13,547 Outstanding and expected to vest at December 31, 2017 164 1.28 $ 12,072 RSU Awards RSUs granted to employees typically vest ratably over a four -year period, and are converted into shares of the Company’s common stock upon vesting on a one-for-one basis subject to the employee’s continued service to the Company over that period. The fair value of RSUs is determined using the fair value of the Company’s common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest. Compensation expense is recognized on a straight-line basis over the requisite service period of each grant adjusted for estimated forfeitures. A summary of RSU awards outstanding as of December 31, 2017 , and activity during the three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 692 $ 43.86 Granted 319 $ 49.75 Vested (267 ) $ 42.49 Forfeited (63 ) $ 45.71 Outstanding at December 31, 2015 681 $ 46.98 Granted 331 $ 46.70 Vested (270 ) $ 45.13 Forfeited (24 ) $ 47.21 Outstanding at December 31, 2016 718 $ 47.54 Granted 558 $ 60.82 Vested (284 ) $ 46.52 Forfeited (44 ) $ 50.89 Outstanding at December 31, 2017 948 $ 55.51 1.97 $ 69,742 Outstanding and expected to vest at December 31, 2017 860 1.80 $ 63,289 The grant date fair value of RSUs vested in the years ended December 31, 2017 , 2016 and 2015 , was approximately $13.2 million , $12.2 million and $11.3 million , respectively.

SIGNIFICANT CUSTOMERS AND GEOGR

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
SIGNIFICANT CUSTOMERS AND EXPORT SALES [Text Block]	SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES: Customer Concentration The Company's top ten customers accounted for approximately 54% , 60% and 61% in 2017 , 2016 and 2015 , respectively. A significant portion of these revenues are attributable to sales of the Company’s products to distributors of electronic components. These distributors sell the Company’s products to a broad, diverse range of end users, including OEMs and merchant power supply manufacturers. Sales to distributors in 2017 , 2016 and 2015 were $330.9 million , $292.6 million and $261.4 million , respectively. Direct sales to OEMs and power-supply manufacturers accounted for the remainder. The following customers, distributors of the Company’s products, each accounted for 10% or more of total net revenues: Year Ended December 31, Customer 2017 2016 2015 Avnet 16 % 18 % 21 % Powertech Distribution Ltd. * 10 % 11 % _______________ * Total customer revenue was less than 10% of net revenues. No other customers accounted for 10% or more of the Company’s net revenues in the periods presented. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consisted principally of cash investments and trade receivables. The Company does not have any off-balance-sheet credit exposure related to its customers. As of December 31, 2017 and December 31, 2016 , 64% and 70% , respectively, of accounts receivable were concentrated with the Company’s top ten customers. The following customer, a distributor of the Company’s products, represented 10% or more of accounts receivable: Customer December 31, December 31, Avnet 18 % 24 % No other customers accounted for 10% or more of the Company’s accounts receivable in the periods presented. Geographic Net Revenues The Company markets its products globally through its sales personnel and a worldwide network of independent sales representatives and distributors. Geographic net revenues based on “bill to” customer locations were as follows: Year Ended December 31, (In thousands) 2017 2016 2015 United States of America $ 16,647 $ 14,948 $ 14,759 Hong Kong/China 227,335 198,858 173,202 Taiwan 50,307 50,324 47,279 Korea 38,012 41,996 34,264 Western Europe (excluding Germany) 48,230 41,214 38,028 Japan 20,769 19,767 16,994 Germany 11,558 7,563 7,802 Other 18,897 14,998 12,281 Total net revenues $ 431,755 $ 389,668 $ 344,609

COMMON STOCK REPURCHASES AND CA

COMMON STOCK REPURCHASES AND CASH DIVIDENDS (Notes)	12 Months Ended
	Dec. 31, 2017
Common Stock Repurchases and Cash Dividends [Abstract]
Common Stock Repurchase and Cash Dividends [Text Block]	COMMON STOCK REPURCHASES AND CASH DIVIDENDS: Common Stock Repurchases Over the years the Company’s board of directors has authorized the use of funds to repurchase shares of the Company’s common stock, including $60.0 million and $30.0 million in 2015 and 2017, respectively, with repurchases to be executed according to pre-defined price/volume guidelines. In 2015 , the Company purchased 1.3 million shares for approximately $53.7 million . In 2016 , the Company purchased 146,000 shares for approximately $6.4 million . In 2017 , the Company purchased 129,000 shares for approximately $9.2 million . As of December 31, 2017 , the Company had $44.4 million available for future stock repurchases, which has no expiration date. In January 2018, the Company’s board of directors authorized the use of an additional $30.0 million for the repurchase of the Company’s common stock, with repurchases to be executed according to pre-defined price/volume guidelines. Authorization of future stock repurchase programs is at the discretion of the board of directors and will depend on the Company’s financial condition, results of operations, capital requirements and business conditions as well as other factors. Common Stock Dividend The following table presents the quarterly dividends declared per share of the Company’s common stock for the periods indicated: Year Ended December 31, 2017 2016 2015 First Quarter $ 0.14 $ 0.13 $ 0.12 Second Quarter $ 0.14 $ 0.13 $ 0.12 Third Quarter $ 0.14 $ 0.13 $ 0.12 Fourth Quarter $ 0.14 $ 0.13 $ 0.12 The Company paid a total of approximately $16.6 million , $15.1 million and $13.9 million in cash dividends during 2017 , 2016 and 2015 , respectively. In January 2018, the Company’s board of directors declared a $0.16 per share quarterly dividend for each quarter in 2018. The declaration of any future cash dividend is at the discretion of the board of directors and will depend on the Company’s financial condition, results of operations, capital requirements, business conditions and other factors, as well as a determination that cash dividends are in the best interest of the Company’s stockholders.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
EARNINGS PER SHARE [Text Block]	EARNINGS PER SHARE: Basic earnings per share are calculated by dividing net income by the weighted-average shares of common stock outstanding during the period. Diluted earnings per share are calculated by dividing net income by the weighted-average shares of common stock and dilutive common equivalent shares outstanding during the period. Dilutive common equivalent shares included in this calculation consist of dilutive shares issuable upon the assumed exercise of outstanding common stock options, the assumed vesting of outstanding restricted stock units, the assumed issuance of awards under the stock purchase plan and contingently issuable performance-based awards, as computed using the treasury stock method. A summary of the earnings per share calculation is as follows: Year Ended December 31, (in thousands, except per share amounts) 2017 2016 2015 Basic earnings per share: Net income $ 27,609 $ 48,898 $ 39,152 Weighted-average common shares 29,674 28,925 29,001 Basic earnings per share $ 0.93 $ 1.69 $ 1.35 Diluted earnings per share (1) : Net income $ 27,609 $ 48,898 $ 39,152 Weighted-average common shares 29,674 28,925 29,001 Effect of dilutive securities: Employee stock plans 871 694 695 Diluted weighted-average common shares 30,545 29,619 29,696 Diluted earnings per share $ 0.90 $ 1.65 $ 1.32 _______________ (1) The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2017, 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods. In the years ended December 31, 2017 and 2016 , no outstanding stock awards were determined to be anti-dilutive and therefore were excluded from the computation of diluted earnings per share. In the years ended December 31, 2015 , approximately 8,000 outstanding stock awards were determined to be anti-dilutive and therefore were excluded from the computation of diluted earnings per share.

PROVISION FOR INCOME TAXES

PROVISION FOR INCOME TAXES	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
PROVISION FOR INCOME TAXES [Text Block]	PROVISION FOR INCOME TAXES: U.S. Tax Reform The Tax Cuts and Jobs Act (Tax Act) was enacted on December 22, 2017. The Act reduces the U.S. federal corporate tax rate from 35% to 21% , requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. As of December 31, 2017, the Company has not completed the accounting for the tax effects of enactment of the Tax Act; however, in certain cases, as described below, the Company has made a reasonable estimate of the effects on existing deferred tax balances and the one-time transition tax. In other cases, the Company has not been able to make a reasonable estimate and continues to account for those items based on the Company’s existing accounting policies and positions that were in effect immediately prior to enactment. The SEC staff issued Staff Accounting Bulletin 118 (SAB 118), which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. The items for which the Company was able to determine a reasonable estimate includes a provisional one-time transition tax of $35.3 million , which was included as a component of the income tax provision for the year-ended December 31, 2017. This one-time transition tax was based on the Company’s total post-1986 earnings and profits (E&P) previously deferred from U.S. income taxes. The Company has not yet completed the calculation of the total post-1986 E&P for these foreign subsidiaries. Further, the transition tax is based in part on the amount of those earnings held in cash and other specified assets. As of December 31, 2017, the Company has no undistributed foreign earnings that would be subject to the transition tax; although, this amount may change upon finalization of the total post-1986 foreign E&P balances and the amounts held in cash or other specified assets. The Company also re-measured certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in future periods, which is generally 21%. The Company recorded a provisional amount of $4.9 million related to the re-measurement of the Company’s deferred tax assets and liabilities. However, the Company is still analyzing certain aspects of the Tax Act and refining calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts. The Act also includes provisions for Global Intangible Low-Taxed Income (“GILTI”) wherein taxes on foreign income are imposed in excess of a deemed return on tangible assets of foreign corporations. Due to the complexity of the GILTI tax rules; the Company is continuing to evaluate this provision of the Tax Act and the application of ASC 740. The Company is allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into the Company’s measurement of deferred taxes (the “deferred method”). The Company’s selection of an accounting policy with respect to the new GILTI tax rules will depend, in part, on analyzing the Company’s global income to determine whether the Company expects to have future U.S. inclusions in taxable income related to GILTI and, if so, what the impact is expected to be. Whether the Company expects to have future U.S. inclusions in taxable income related to GILTI depends on not only the Company’s current structure and estimated future results of global operations but also the Company’s intent and ability to modify the Company’s structure and/or business. The Company is not yet able to reasonably estimate the effect of this provision of the Tax Act. Therefore, the Company has not made any adjustments related to potential GILTI tax in the Company’s financial statements and has not made a policy decision regarding whether to record deferred taxes on GILTI. Income Taxes The Company accounts for income taxes under the provisions of ASC 740, Income Taxes . Under the provisions of ASC 740, deferred tax assets and liabilities are recognized based on the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, utilizing the tax rates that are expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. U.S. and foreign components of income before income taxes were: Year Ended December 31, (in thousands) 2017 2016 2015 U.S. operations $ (6,944 ) $ (477 ) $ (2,246 ) Foreign operations 67,243 50,429 41,577 Total pretax income $ 60,299 $ 49,952 $ 39,331 The components of the provision for income taxes are as follows: Year Ended December 31, (in thousands) 2017 2016 2015 Current provision: Federal $ 35,311 $ — $ 443 State 4 — 83 Foreign 1,483 1,638 5,407 36,798 1,638 5,933 Deferred provision (benefit): Federal (3,640 ) (175 ) (1,791 ) State — (27 ) (57 ) Foreign (468 ) (382 ) (3,906 ) (4,108 ) (584 ) (5,754 ) Total $ 32,690 $ 1,054 $ 179 The Company is entitled to a deduction for federal and state tax purposes with respect to employees' stock option activity. The net reduction in taxes otherwise payable in excess of any amount credited to income tax expense has been reflected as an adjustment to the tax provision due to the adoption of ASU 2019-09, Compensation - Stock Compensation, effective January 1, 2017. For additional details on the adoption of ASU 2016-09, refer to Note 2, Significant Accounting Policies and Recent Accounting Pronouncements , in the Company’s Notes to Consolidated Financial Statements. Prior to the adoption of ASU 2016-09, the net reduction in taxes otherwise payable in excess of any amount credited to income tax expense has been reflected as an adjustment to additional paid-in capital. For 2015 , the deficiency arising from employee stock option activity that resulted in an adjustment to additional paid in capital was approximately $0.2 million . No adjustment was recorded in 2016 . The provision for income taxes differs from the amount that would result by applying the applicable federal income tax rate to income before provision for income taxes, as follows: Year Ended December 31, 2017 2016 2015 Provision computed at Federal statutory rate 35.0 % 35.0 % 35.0 % Business tax credits (5.7 ) (6.0 ) (6.8 ) Stock-based compensation (5.0 ) 2.2 0.8 Foreign income taxed at different rate (37.3 ) (33.1 ) (33.2 ) U.S. Tax Act - transition tax 54.1 — — U.S. Tax Act - deferred tax asset and liability adjustment 8.1 — — Valuation allowance 2.2 1.8 2.6 Other 2.8 2.2 2.1 Total 54.2 % 2.1 % 0.5 % The Company’s effective tax rate is impacted by the geographic distribution of the world-wide earnings in lower tax jurisdictions and the federal R&D tax credit. Additionally, in 2017 the Company’s effective tax rate is impacted by a $37.5 million charge resulting from the enactment of the Tax Act. The components of the net deferred income tax asset (liabilities) were as follows: December 31, (in thousands) 2017 (1) 2016 Deferred tax assets: Other reserves and accruals $ 979 $ 1,267 Tax credit carry-forwards 10,442 26,895 Stock compensation 4,064 5,760 Capital losses 163 10,585 Net operating loss 7,059 2,671 Other — 174 Valuation allowance (18,421 ) (27,489 ) 4,286 19,863 Deferred tax liabilities: Depreciation (1,965 ) (2,322 ) Unremitted earnings — (7,019 ) Other (95 ) — (2,060 ) (9,341 ) Net deferred tax asset $ 2,226 $ 10,522 _______________ (1) The reduction of deferred tax assets is primarily due to the utilization of tax attributes for transition tax related to the Tax Act as well as the reduction of the U.S. federal corporate tax rate from 35% to 21% beginning in 2018. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities and projected future taxable income. In the event that the Company determines, based on available evidence and management judgment, that all or part of the net deferred tax assets will not be realized in the future, the Company would record a valuation allowance in the period the determination is made. In addition, the calculation of tax liabilities involves significant judgment in estimating the impact of uncertainties in the application of complex tax laws. Resolution of these uncertainties in a manner inconsistent with the Company’s expectations could have a material impact on its results of operations and financial position. As of December 31, 2017 , the Company continues to maintain a valuation allowance primarily as a result of capital losses for federal purposes, and on its California deferred tax assets as the Company believes that it is not more likely than not that the deferred tax assets will be fully realized. In addition, the Company maintains a valuation allowance with respect to certain of its deferred tax assets relating to tax credits in Canada and the state of New Jersey. As of December 31, 2017 , due to the impact of the Tax Act, the Company expects to utilize all federal research and development tax credit carry-forwards and all net operating loss carry-forwards; California research and development tax credit carry-forwards of approximately $21.5 million (there is no expiration of research and development tax credit carry-forwards for the state of California) and California net operating losses of $46.6 million which will begin to expire in 2032 . As of December 31, 2017 , the Company had Canadian scientific research and experimental development tax credit carry-forwards of approximately $2.4 million and New Jersey research and experimental development tax credit carry-forwards of approximately $0.8 million , which will start to expire in 2030 and 2026 , respectively. Unrecognized Tax Benefits The Company applies the provisions of ASC 740-10, relating to accounting for uncertain income taxes. Reconciliation of the beginning and ending amount of unrecognized tax benefits: (in thousands) Unrecognized Tax Benefits Unrecognized Tax Benefits Balance at January 1, 2015 $ 11,160 Gross Increase for Tax Positions of Current Year 3,063 Gross Decrease for Tax Positions of Prior Years (663 ) Unrecognized Tax Benefits Balance at December 31, 2015 13,560 Gross Increase for Tax Positions of Current Year 1,856 Gross Decrease for Tax Positions of Prior Years (23 ) Unrecognized Tax Benefits Balance at December 31, 2016 15,393 Gross Increase for Tax Positions of Current Year 1,699 Gross Decrease for Tax Positions of Prior Years (409 ) Unrecognized Tax Benefits Balance at December 31, 2017 $ 16,683 The Company's total unrecognized tax benefits as of December 31, 2017 , 2016 and 2015 , were $16.7 million , $15.4 million and $13.6 million , respectively. An income tax benefit of $10.3 million , net of valuation allowance adjustments, would be recorded if these unrecognized tax benefits are recognized. The Company cannot reasonably estimate the amount of the unrecognized tax benefit that could be adjusted in the next twelve months. The Company’s continuing practice is to recognize interest and/or penalties related to income tax matters in income tax expense. The Company had accrued interest and penalties of $0.1 million as of both December 31, 2017 , and December 31, 2016 , which have been recorded in long-term income taxes payable in the accompanying consolidated balance sheets. As of December 31, 2017 , the Company has concluded all U.S. federal income tax matters for the years through 2012. However, due to tax attributes, the IRS may calculate tax adjustments for subsequent years for positions taken prior to 2012. There is currently no pending income tax audit. On July 27, 2015, in Altera Corp. v. Commissioner, the U.S. Tax Court issued an opinion related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. A final decision was issued by the Tax Court in December 2015. In February 2016, the Commissioner appealed the Tax Court decision. At this time, the U.S. Department of the Treasury has not withdrawn the requirement to include stock-based compensation expense from IRS cost-sharing regulations. The Company has reviewed this case and its impact and concluded that no adjustment to the consolidated financial statements is appropriate at this time. The Company will continue to monitor ongoing developments and potential impacts to the consolidated financial statements.

COMMITMENTS

COMMITMENTS	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS [Text Block]	COMMITMENTS: Facilities The Company owns its main executive, administrative, manufacturing and technical offices in San Jose, California. The Company also owns a research and development facility in New Jersey and a test facility in Biel, Switzerland. The Company leases administrative office space in Singapore and Switzerland, and R&D facilities in Canada and the United Kingdom, in addition to sales offices in various countries around the world. Future minimum lease payments under all non-cancelable operating lease agreements as of December 31, 2017 , are as follows: Fiscal Year (in thousands) 2018 $ 1,875 2019 1,057 2020 699 2021 286 2022 148 Thereafter 247 Total minimum lease payments $ 4,312 Total rent expense amounted to $2.0 million , $1.9 million and $2.0 million in the years ended December 31, 2017 , 2016 and 2015 , respectively. Purchase Obligations At December 31, 2017 , the Company had no non-cancelable purchase obligations that were due beyond one year.

LEGAL PROCEEDINGS AND CONTINGEN

LEGAL PROCEEDINGS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
LEGAL PROCEEDINGS AND CONTINGENCIES [Text Block]	LEGAL PROCEEDINGS AND CONTINGENCIES: From time to time in the ordinary course of business, the Company becomes involved in lawsuits, or customers and distributors may make claims against the Company. In accordance with ASC 450-10, Contingencies , the Company makes a provision for a liability when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. On October 20, 2004, the Company filed a complaint against Fairchild Semiconductor International, Inc. and Fairchild Semiconductor Corporation (referred to collectively as “Fairchild”) in the United States District Court for the District of Delaware. In its complaint, the Company alleged that Fairchild has and is infringing four of Power Integrations’ patents pertaining to pulse width modulation (PWM) integrated circuit devices. Fairchild denied infringement and asked for a declaration from the court that it does not infringe any Power Integrations patent and that the patents are invalid. The Court issued a claim construction order on March 31, 2006 which was favorable to the Company. The Court set a first trial on the issues of infringement, willfulness and damages for October 2, 2006. At the close of the first trial, on October 10, 2006, the jury returned a verdict in favor of the Company finding all asserted claims of all four patents-in-suit to be willfully infringed by Fairchild and awarding $34.0 million in damages. Fairchild raised defenses contending that the asserted patents are invalid or unenforceable, and the Court held a second trial on these issues beginning on September 17, 2007. On September 21, 2007, the jury returned a verdict in the Company’s favor, affirming the validity of the asserted claims of all four patents-in-suit. Fairchild submitted further materials on the issue of enforceability along with various other post-trial motions, and the Company filed post-trial motions seeking a permanent injunction and increased damages and attorneys’ fees, among other things. On September 24, 2008, the Court denied Fairchild’s motion regarding enforceability and ruled that all four patents are enforceable. On December 12, 2008, the Court ruled on the remaining post-trial motions, including granting a permanent injunction, reducing the damages award to $6.1 million , granting Fairchild a new trial on the issue of willful infringement in view of an intervening change in the law, and denying the Company’s motion for increased damages and attorneys’ fees with leave to renew the motion after the resolution of the issue of willful infringement. On December 22, 2008, at Fairchild’s request, the Court temporarily stayed the permanent injunction for 90 days. On January 12, 2009, Fairchild filed a notice of appeal challenging the Court’s refusal to enter a more permanent stay of the injunction, and Fairchild filed additional motions requesting that both the Federal Circuit and the District Court extend the stay of injunction. The District Court temporarily extended the stay pending the Federal Circuit ruling on Fairchild’s pending motion, but the Federal Circuit dismissed Fairchild’s appeal and denied its motion on May 5, 2009, and the District Court issued an order on May 13, 2009 confirming the reinstatement of the permanent injunction as originally entered in December 2008. On June 22, 2009, the Court held a brief bench re-trial on the issue of willful infringement. On July 22, 2010, the Court found that Fairchild willfully infringed all four of the asserted patents, and the Court also invited briefing on enhanced damages and attorneys’ fees. Fairchild also filed a motion requesting that the Court amend its findings regarding willfulness. On January 18, 2011, the Court denied Fairchild’s request to amend the findings regarding Fairchild’s willful infringement and doubled the damages award against Fairchild but declined to award attorneys’ fees. On February 3, 2011, the Court entered final judgment in favor of the Company for a total damages award of $12.9 million . Fairchild filed a notice of appeal challenging the final judgment and a number of the underlying rulings, and the Company filed a cross-appeal seeking to increase the damages award. The appeal was argued on January 11, 2012, and the Federal Circuit issued a mixed ruling on March 26, 2013, affirming Fairchild’s infringement of certain claims that support the basis for the permanent injunction while reversing, vacating, and remanding the findings with respect to other claims, including the Company’s claim for damages. The Company filed a petition seeking Supreme Court review of the Federal Circuit’s ruling on damages issues, and the Supreme Court called for a response from Fairchild but ultimately declined to review the case. On remand, the District Court reinstated the prior findings that Fairchild willfully infringed three of the Company’s patents; the Company intends to pursue its claim for financial compensation based on Fairchild’s infringement. On May 9, 2005, the Company filed a Complaint with the U.S. International Trade Commission (ITC) under section 337 of the Tariff Act of 1930, as amended, 19 U.S.C. Section 1337 against System General (SG). The Company filed a supplement to the complaint on May 24, 2005. The Company alleged infringement of its patents pertaining to PWM integrated circuit devices produced by SG, which are used in power conversion applications such as power supplies for computer monitors. The Commission instituted an investigation on June 8, 2005 in response to the Company’s complaint. SG filed a response to the ITC complaint asserting that the patents-in-suit were invalid and not infringed. The Company subsequently and voluntarily narrowed the number of patents and claims in suit, which proceeded to a hearing. The hearing on the investigation was held before the Administrative Law Judge (ALJ) from January 18 to January 24, 2006. Post-hearing briefs were submitted and briefing concluded February 24, 2006. The ALJ’s initial determination was issued on May 15, 2006. The ALJ found all remaining asserted claims valid and infringed, and recommended the exclusion of the infringing products as well as certain downstream products that contain the infringing products. After further briefing, on June 30, 2006, the Commission decided not to review the initial determination on liability, but did invite briefs on remedy, bonding and the public interest. On August 11, 2006, the Commission issued an order excluding from entry into the United States the infringing SG PWM chips, and any liquid-crystal-display (LCD) computer monitors, AC printer adapters and sample/demonstration circuit boards containing an infringing SG chip. The U.S. Customs Service is authorized to enforce the exclusion order. On October 11, 2006, the presidential review period expired without any action from the President, and the ITC exclusion order is now in full effect. SG appealed the ITC decision, and on November 19, 2007, the Federal Circuit affirmed the ITC’s findings in all respects. On October 27, 2008, SG filed a petition to modify the exclusion order in view of a recent Federal Circuit opinion in an unrelated case, and the Company responded to oppose any modification, but the Commission modified the exclusion order on February 27, 2009. Nevertheless, the exclusion order still prohibits SG and related entities from importing the infringing SG chips and any LCD computer monitors, AC printer adapters, and sample/demonstration circuit boards containing an infringing SG chip. On May 23, 2008, the Company filed a complaint against Fairchild Semiconductor International, Inc., Fairchild Semiconductor Corporation, and Fairchild’s wholly owned subsidiary System General Corporation (referred to collectively as “Fairchild”), in the United States District Court for the District of Delaware. In its complaint, the Company alleged that Fairchild has infringed and is infringing three patents pertaining to power supply controller integrated circuit devices. Fairchild answered the Company’s complaint on November 7, 2008, denying infringement and asking for a declaration from the Court that it does not infringe any Power Integrations patent and that the patents are invalid and unenforceable. Fairchild’s answer also included counterclaims accusing the Company of infringing three patents pertaining to primary side power conversion integrated circuit devices. Fairchild had earlier brought these same claims in a separate suit against the Company, also in Delaware, which Fairchild dismissed in favor of adding its claims to the Company’s already pending suit against Fairchild. The Company has answered Fairchild’s counterclaims, denying infringement and asking for a declaration from the Court that it does not infringe any Fairchild patent and that the Fairchild patents are invalid. Fairchild also filed a motion to stay the case, but the Court denied that motion on December 19, 2008. On March 5, 2009, Fairchild filed a motion for summary judgment to preclude any recovery for post-verdict sales of parts found to infringe in the parties’ other ongoing litigation, described above, and the Company filed its opposition and a cross-motion to preclude Fairchild from re-litigating the issues of infringement and damages for those same products. On June 26, 2009, the Court held a hearing on the parties’ motions, and on July 9, 2009 the Court issued an order denying the parties’ motions but staying proceedings with respect to the products that were found to infringe and which are subject to the injunction in the other Delaware case between the parties pending the entry of final judgment in that case; those products are expected to be addressed in the context of the parties’ remand proceedings following the appeal in their earlier litigation in Delaware, and the remainder of the case is proceeding. On December 18, 2009, the Court issued an order construing certain terms in the asserted claims of the Company’s and Fairchild’s patents in suit. Following the Court’s ruling on claim construction, Fairchild withdrew its claim related to one of its patents and significantly reduced the number of claims asserted for the remaining two patents. The parties thereafter filed and argued a number of motions for summary judgment, and the Court denied the majority of the parties’ motions but granted the Company’s motion to preclude Fairchild from re-arguing validity positions that were rejected in the prior case between the parties. Because the assigned Judge retired at the end of July 2010, the case was re-assigned to a different Judge, and the Court vacated the trial schedule and had the parties provide their input on the appropriate course of action. The Court thereafter set a trial schedule with the jury trial on infringement and validity to begin in July 2011. On April 18, 2011, the Court rescheduled the trial to begin in January 2012, and on June 2, 2011, the Court moved the trial date to April 2012 to permit the parties to address another patent the Company accused Fairchild of infringing. Following a trial in April 2012, the jury returned a verdict finding that Fairchild infringes two of the Company’s patents, that Fairchild has induced others to infringe the Company’s patents, and also upheld the validity of the infringed patents. Of the two remaining counterclaim patents Fairchild asserted in the case, one was found not to be infringed, but the jury found the second patent to be infringed by a limited number of the Company’s products, although the jury further found the Company did not induce infringement by any customers, including customers outside the United States. On March 29, 2013, the District Court denied most of the parties’ post-trial motions on liability but granted the Company’s motion for judgment as a matter of law finding that Fairchild infringed another of the Company’s patents. On April 25, 2013, the Court denied both parties’ motions regarding the unenforceability of each other’s patents. The Company challenged adverse findings on appeal; nevertheless, the Company estimated that even if the verdict on Fairchild’s patent had ultimately been upheld, the sales potentially impacted would have amounted to less than 0.5% of the Company’s revenues. The Company requested an injunction preventing further infringement of its own patents by Fairchild, and Fairchild requested an injunction as well. Following a hearing on the issue in June 2014, the Court denied Fairchild’s request for an injunction against the Company and granted the Company’s request for an injunction against Fairchild. On January 13, 2015, the District Court entered final judgment on the liability and validity issues discussed above, and both parties filed appeals with the Federal Circuit. After briefing was completed, oral argument on the appeal took place in early July 2016, and on December 12, 2016, the Federal Circuit issued its opinion in the appeal, overturning the lone infringement verdict against the Company, finding one of the Company’s patents invalid, and overturning the District Court’s jury instruction on inducement. In view of the Federal Circuit’s rejection of the District Court’s jury instruction on inducement, the Court also vacated the inducement findings and associated injunction against Fairchild and remanded the case for a retrial on inducement, but the underlying validity and infringement findings against Fairchild on those two patents remain intact. On remand, the Company will also be seeking financial damages as well as enhanced damages for Fairchild’s willful infringement. On June 28, 2004, the Company filed a complaint for patent infringement in the U.S. District Court, Northern District of California, against SG Corporation, a Taiwanese company, and its U.S. subsidiary. The Company’s complaint alleged that certain integrated circuits produced by SG infringed and continue to infringe certain of its patents. On June 10, 2005, in response to the initiation of the International Trade Commission (ITC) investigation discussed above, the District Court stayed all proceedings. Subsequent to the completion of the ITC proceedings, the District Court temporarily lifted the stay and scheduled a case management conference. On December 6, 2006, SG filed a notice of appeal of the ITC decision as discussed above. In response, and by agreement of the parties, the District Court vacated the scheduled case management conference and renewed the stay of proceedings pending the outcome of the Federal Circuit appeal of the ITC determination. On November 19, 2007, the Federal Circuit affirmed the ITC’s findings in all respects, and SG did not file a petition for review. The parties subsequently filed a motion to dismiss the District Court case without prejudice. On November 4, 2009, the Company re-filed its complaint for patent infringement against SG and its parent corporations, Fairchild Semiconductor International, Inc. and Fairchild Semiconductor Corporation, to address their continued infringement of patents at issue in the original suit that recently emerged from SG requested reexamination proceedings before the U.S. Patent and Trademark Office (USPTO). The Company seeks, among other things, an order enjoining SG and Fairchild from infringing the Company’s patents and an award of damages resulting from the alleged infringement. Fairchild has denied infringement and asked for a declaration from the Court that it does not infringe any Power Integrations patent, that the patents are invalid, and that one of the two of the Company’s patents now at issue in the case is unenforceable. On May 5, 2010, SG and Fairchild filed an amended answer including counterclaims accusing the Company of infringing two patents, and since that time Fairchild has withdrawn its claim for infringement of one of the patents it originally asserted against the Company but added another patent to the case over the Company’s objections; the Company contests these claims vigorously. Both parties filed summary judgment motions and challenges to each other’s experts’ testimony, and the Court granted the Company’s motion for summary judgment of non-infringement with respect to one of Fairchild’s two patents. Following a trial on the remaining claims in February 2014, the jury returned a verdict in the Company’s favor, affirming the validity of the asserted claims of the Company’s patents-in-suit, finding that SG and Fairchild infringed the Company’s asserted patents and induced infringement by others, and awarding $105.0 million in damages. The Jury also rejected Fairchild’s remaining counterclaims for infringement against the Company. Fairchild challenged these rulings in post-trial motions, but the judge confirmed the jury’s determinations on infringement and damages, although the Court declined to find Fairchild’s infringement willful. Fairchild also pressed its unenforceability claim with respect to one of the two patents it was found to infringe in post-trial briefing, but the Court rejected Fairchild’s unenforceability claim. Fairchild also requested reconsideration of the damages determinations, and the Court granted a new trial with respect to damages but none of the other issues addressed in the previous trial, with the retrial scheduled for December 2015. Thereafter, the parties completed pretrial proceedings challenging each other’s experts, and the Court granted portions of each party’s motions limiting the scope of expert testimony for purposes of the damages retrial, but neither party was successful in their efforts to prevent the other side’s experts from testifying at trial. Following a retrial on the issue of damages in December 2015, the jury returned a verdict in the Company’s favor, finding that the Company’s patented technology created the basis for customer demand for the infringing Fairchild products and awarding $139.8 million in damages. Although the jury awarded damages, at this stage of the proceedings the Company cannot state the amount, if any, it might ultimately recover from Fairchild, and no benefits have been recorded in the Company’s consolidated financial statements as a result of the damages verdict. Fairchild filed post-trial motions challenging the verdict, but the Court rejected Fairchild’s motions challenging the damages verdict in August 2016. The Company also filed motions requesting enhanced damages and attorney fees and reinstatement of the willfulness finding against Fairchild in view of an intervening change of law; on January 13, 2017, the District Court reinstated the finding that Fairchild’s infringement was willful but declined to enhance damages or award fees. In January 2017, Fairchild filed a further challenge to the verdict, but the Court rejected Fairchild’s motion and entered a final judgment of $146.5 million after factoring in pre-judgment interest. Fairchild’s appeal on the merits is under way, with briefing now completed and oral argument expected in the coming months and a ruling to follow thereafter. In February 2010, Fairchild and System General (SG) filed suits for patent infringement against the Company, Power Integrations Netherlands B.V., and representative offices of Power Integrations Netherlands in Shanghai and Shenzhen with the Suzhou Intermediate Court in the People’s Republic of China. The suits asserted four Chinese patents and sought an injunction and damages of approximately $19.0 million . Power Integrations Netherlands filed invalidation proceedings for all four asserted SG patents in the People’s Republic of China Patent Reexamination Board (PRB) of the State Intellectual Property Office (SIPO), and all four challenges were accepted by the PRB, with hearings conducted in September 2010. In early January 2012, the Company received rulings from the PRB invalidating the majority of the claims Fairchild asserted in litigation. The Suzhou Court conducted evidentiary hearings in 2012 and issued rulings in late December 2012, finding that the Company did not infringe any of the asserted patents. Fairchild filed appeals challenging the Suzhou Court’s non-infringement rulings, and the appeals court in Nanjing held further hearings in the infringement proceedings in late 2014, but Fairchild has since dismissed its appeals, bringing the infringement proceedings to a close in the first quarter of 2015. On July 11, 2011, the Company filed a complaint in the U.S. District Court, District of Columbia, against David Kappos in his capacity as Director of the United States Patent and Trademark Office (PTO) as part of the ongoing reexamination proceedings related to one of the patents asserted against Fairchild and SG in the Delaware litigation described above. The Company filed a motion for summary judgment on a preliminary jurisdictional issue, and the PTO filed a cross-motion to dismiss on this same issue; briefing on those motions was completed in October, 2011. On November 18, 2013, the Court granted the PTO’s motion and transferred the case to the Federal Circuit, where additional briefing took place. Following a hearing in May 2015, the Federal Circuit ruled in the Company’s favor on August 12, 2015, overturning the PTO’s claim construction and remanding the case for further proceedings. On remand, the PTO ignored the Federal Circuit’s guidance, so the Company has filed another appeal to the Federal Circuit; briefing and oral argument on the second appeal are now complete, with a ruling expected in the coming months. On May 1, 2012, Fairchild Semiconductor Corporation and Fairchild's wholly owned subsidiary, System General Corporation (referred to collectively as “Fairchild”), filed a complaint against the Company in the United States District Court for the District of Delaware. In its complaint, Fairchild alleged that the Company has infringed and is infringing four patents pertaining to power conversion integrated circuit devices. The Company answered Fairchild’s complaint, denying infringement and asking for a declaration from the Court that it does not infringe any Fairchild patent and that the Fairchild patents are invalid, and the Company also asserted counterclaims against Fairchild for infringement of five of the Company’s patents. Fairchild withdrew its claim for infringement of one of the patents it asserted against the Company after the Company’s preliminary challenge. The parties streamlined their contentions in view of the Court’s pretrial rulings, and following a trial in late May and early June 2015, a jury returned a verdict finding that Fairchild infringed one of the Company’s patents, that Fairchild has induced and contributed to others’ infringement of the Company’s patent, and that the Company induced infringement of a Fairchild patent that was previously found infringed in the 2012 trial described above, with a damages award of $2.4 million in favor of Fairchild. Both parties filed post-trial motions and challenges to various portions of the jury verdicts, and the Court addressed the first wave of post-trial motions, denying each side’s challenges to the verdict and denying Fairchild’s request for an injunction. In parallel proceedings, the Federal Circuit overturned the underlying finding of infringement against the Company on the Fairchild patent-in-suit, and the Company moved to vacate the inducement and damages judgment against the Company, a motion that Fairchild did not oppose. Further proceedings and an appeal of the outstanding issues are expected in the coming months. On October 21, 2015, the Company filed a complaint for patent infringement against Fairchild Semiconductor Corporation, Fairchild Semiconductor International, Inc., and wholly-owned subsidiary Fairchild (Taiwan) Corporation (referred to collectively as “Fairchild”) to address Fairchild’s continued infringement of two patents Fairchild was previously found to infringe in the three District Court cases the Company brought against Fairchild discussed above. In each of the three prior cases, Fairchild was found to infringe one of the patents at issue in the latest complaint, and Fairchild’s challenges to the validity of the patents were rejected during the course of the prior lawsuits as well. Fairchild has answered the Company’s complaint, denying infringement and asking for a declaration from the Court that it does not infringe any Power Integrations patent and that the patents are invalid. Fairchild’s answer also included counterclaims accusing the Company of infringing four patents pertaining to power conversion integrated circuit devices, including one patent the Company was found not to infringe in prior litigation. The Company has answered Fairchild’s counterclaims, denying infringement and asking for a declaration from the Court that it does not infringe any Fairchild patent and that the Fairchild patents are invalid. On December 15, 2016, the Court stayed the case pending resolution of the parties’ inter partes review (IPR) and reexamination proceedings regarding the patents-in-suit. On March 10, 2016, Silver Star Capital, LLC filed a petition with the U.S. Patent & Trademark Office (PTO) requesting that the PTO conduct an IPR of the validity of the Company’s U.S. Patent No. 6,212,079 (the ’079 patent), which the Company has asserted against Fairchild Semiconductor in the California litigation initiated in 2004, as discussed above. The Company’s ’079 patent is also asserted in the Company’s most recent lawsuits against Fairchild filed in October 2015 and against ON Semiconductor filed in November 2016, also discussed herein. On March 29, 2016, ON Semiconductor Corporation filed another petition requesting inter partes review of the Company’s ‘079 patent. Since that time, ON Semiconductor filed eleven more IPR petitions requesting review of various patents that the Company previously asserted against Fairchild as described above, and another three IPR petitions requesting review of various patents that the Company asserted against ON Semiconductor as described herein. The PTO denied Silver Star Capital’s IPR petition on the ‘079 patent but instituted IPR proceedings with respect to ON Semiconductor’s petition directed to the ‘079 patent. On September 22, 2017, the PTO rejected as obvious the claims of the Company’s ‘079 patent that were asserted in litigation and which form the basis for the $146.5 million judgment against Fairchild; an appeal to reverse the PTO’s adverse findings is expected in the coming months. The PTO also instituted IPR proceedings in response to eight of ON Semiconductor’s eleven other petitions challenging patents previously asserted against Fairchild, denying institution in three cases, and the PTO has rejected a number of claims in the context of these ongoing proceedings. In one case, the PTO rejected as anticipated the claims of the Company’s U.S. Patent No. 6,538,908 that were asserted in litigation against Fairchild; an appeal is expected in the coming months, and further proceedings and the PTO’s initial rulings on other IPRs are expected in the coming months as well. Although the validity of many of the Company’s challenged patents has previously been confirmed in the Company’s District Court litigation with Fairchild and in many cases in prior PTO reexamination proceedings as well, and though the Company intends to vigorously defend the validity of its patents, the outcome of the IPR proceedings is uncertain. On April 1, 2016, Opticurrent, LLC filed a complaint against the Company in the United States District Court for the Eastern District of Texas. In its complaint, Opticurrent alleges that the Company has infringed and is infringing one patent pertaining to transistor switch devices. The Company filed a motion to transfer the case to California, which the Court granted, and the case was assigned to a new judge in San Francisco following the transfer. Further proceedings and summary judgment briefing are expected over the course of the coming months, with trial scheduled for February 2019. The Company intends to vigorously defend itself against Opticurrent’s claims. On August 11, 2016, ON Semiconductor filed a complaint against the Company in the United States District Court for the District of Arizona. In its complaint, ON Semiconductor alleged that the Company has infringed and is infringing six patents and requested injunctive relief. The Company filed a motion to transfer the case to the Northern District of California, which the Court granted, and the case has been consolidated with the Company’s affirmative case against ON Semiconductor in the Northern District of California, as discussed below. The Company believes it has valid defenses and intends to vigorously defend itself against ON Semiconductor’s claims. On November 1, 2016, the Company filed a lawsuit against ON Semiconductor in the United States District Court for the Northern District of California to address ON Semiconductor’s infringement of six patents. The court denied ON Semiconductor’s motion requesting that the case be transferred to Arizona and scheduled trial for December of 2019, with interim deadlines for hearing claim construction and dispositive motions. In consolidating the pleadings from the California and Arizona cases following the transfer of ON Semiconductor’s case from Arizona, ON Semiconductor asserted two additional patents, bringing the total number of patents asserted against the Company to eight in this case, and ON Semiconductor’s amended complaint also seeks a declaration of non-infringement with respect to another of the Company’s patents that was previously asserted against Fairchild Semiconductor. Further proceedings and discovery will take place over the coming months. On December 27, 2016, ON Semiconductor filed a complaint against the Company in the United States District Court for the Eastern District of Texas. In its complaint, ON Semiconductor alleges that the Company has infringed and is infringing six patents and requests injunctive relief. On March 9, 2017, ON Semiconductor dismissed its Texas complaint and re-filed a substantially similar complaint in the District of Delaware. After the Company filed a motion to dismiss, ON Semiconductor filed an amended complaint; the Company has answered ON Semiconductor’s complaint and asserted claims for infringement of seven of the Company’s patents. Trial has been scheduled for February of 2020, with interim deadlines for discovery and claim construction, and the Company believes it has valid defenses and intends to vigorously defend itself against ON Semiconductor’s claims. In November 2017, ON Semiconductor filed suit against the Company in Taiwan charging the Company with infringing three Taiwanese patents and seeking an injunction and damages of approximately $1.0 million . No schedule has been set for the case at this preliminary stage, but the Company believes it has valid defenses and intends to vigorously defend itself against ON Semiconductor’s claims. The Company is unable to predict the outcome of legal proceedings with certainty, and there can be no assurance that Power Integrations will prevail in the above-mentioned unsettled litigations. These litigations, whether or not determined in Power Integrations’ favor or settled, will be costly and will divert the efforts and attention of the Company’s management and technical personnel from normal business operations, potentially causing a material adverse effect on the business, financial condition and operating results. Currently, the Company is not able to estimate a loss or a range of loss for the ongoing litigation disclosed above, however adverse determinations in litigation could result in monetary losses, the loss of proprietary rights, subject the Company to significant liabilities, require Power Integrations to seek licenses from third parties or prevent the Company from licensing the technology, any of which could have a material adverse effect on the Company’s business, financial condition and operating results.

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
ACQUISITIONS [Text Block]	ACQUISITIONS: Cambridge Semiconductor Limited On January 2, 2015, the Company acquired 100% of the shares outstanding of Cambridge Semiconductor Limited (CamSemi) for total consideration of approximately $23.3 million , of which $16.7 million was paid in cash and $6.6 million was applied against an outstanding loan owed to the Company. The acquisition-related costs for the purchase of CamSemi totaled $1.0 million , with $0.8 million recognized in 2014 and $0.2 million recognized in 2015. CamSemi was acquired to accelerate the Company’s product development efforts for the low-power market. The acquisition also broadens the Company’s technology and product portfolio for low-power applications, particularly in the mobility and LED lighting markets. The purchase price allocated to goodwill in the acquisition (as noted in the purchase price allocation below) is related largely to synergies and economies of scale expected from combining the operations of CamSemi with those of the Company. The following table summarizes the purchase price and estimated fair values of the assets acquired and the liabilities assumed as of January 2, 2015, the completion of the acquisition of CamSemi: (in thousands) Total Amount Assets Acquired Cash $ 1,134 Accounts receivable 1,891 Inventories 1,409 Prepaid expenses and other current assets 408 Tax receivable 1,093 Intangible assets: Developed technology 6,600 Customer relationships 2,420 Goodwill 11,250 Total assets acquired 26,205 Liabilities Assumed Current liabilities 1,832 Taxes payable 1,090 Total liabilities assumed 2,922 Total purchase price $ 23,283 The following table represents details of the purchased intangible assets: Fair Value Amount (in thousands) Estimated Useful Life (in years) Developed technology $ 6,600 3 - 7 Customer relationships 2,420 5 Total acquired CamSemi intangibles $ 9,020 The fair value of the identifiable intangible assets were determined based on the following approach. Developed Technology. The income approach was used to value the acquired developed technology. Revenue attributable to the Company’s technology was estimated based on expected evolution of the technology over time. Expenses were assumed to reflect the costs necessary to support the developed technology. The present value was capitalized as developed technology as of the acquisition date and is being amortized using a straight-line method to cost of revenues over the estimated life of 3 - 7 years. Customer Relationships. An intangible customer relationship asset was recognized to the extent that the Company was expected to benefit from future revenues reasonably anticipated given the historical customer relationships and operating practices of CamSemi. In order to determine the fair value of the customer relationships, the Company’s analysis assumed that the Company would immediately benefit from the economics generated by CamSemi’s existing customer relationships. This amount was reduced by the potential impact given no past customer relationships and the assumption that the Company could reacquire the customer relationships and ramp up to a similar level of revenue within two years. The fair value of customer relationships was capitalized as of the acquisition date and is being amortized on a straight line basis to sales and marketing expenses over the estimated life of 5 years. Pro forma results of operations for this acquisition have not been presented because it is not material to the Company’s consolidated financial statements. Corporate Headquarters Building In August 2015, the Company purchased a building adjacent to its corporate headquarters in San Jose, California to support the continued growth of the business. The purchase has been accounted for using the acquisition method of accounting in accordance with ASC 805, Business Combinations , as the building had existing rental income resulting from in-place lease agreements with third-party tenants. The aggregate purchase price of $10.4 million , funded with cash on hand, was allocated as follows: $3.5 million for land, $6.3 million for building and improvements, $0.7 million for in-place leases and $(0.1) million for liabilities assumed. The building and improvements are being depreciated on a straight-line basis over an estimated useful life of up to 30 years. Additionally, as a result of the purchase, the Company acquired existing third-party leases that were valued as in-place lease intangible assets and are being amortized over the weighted average estimated life of two years. The valuation of the acquired in-place leases were estimated by the Company based on the amount of avoided cash outflows necessary to originate such leases. Acquisition-related costs in connection with the building purchase were included in other income in the consolidated statements of income and were not material for the periods presented. Rental income from third-party leases, and the proportionate share of building expenses for those leases, are included in other income in the consolidated statements of income from the date of acquisition. These amounts were not material for the periods presented.

RETIREMENT PLANS

RETIREMENT PLANS	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
RETIREMENT PLANS [Text Block]	RETIREMENT PLANS: The Company sponsors a defined benefit pension plan (Pension Plan) for its Swiss subsidiary in accordance with the legal requirements of Switzerland. The plan assets, which provide benefits in the event of an employee’s retirement, death or disability, are held in legally autonomous trustee-administered funds that are subject to Swiss law. Benefits are based on the employee’s age, years of service and salary, and the plan is financed by contributions by both the employee and the Company. The net periodic benefit cost of the Pension Plan was not material to the Company's financial statements during the years ended December 31, 2017 , 2016 and 2015 . At December 31, 2017 , the projected benefit obligation was $10.6 million , the plan assets were $6.8 million and the net pension liability was $3.8 million . As of December 31, 2016 , the projected benefit obligation was $11.8 million , the plan assets were $7.9 million , and the net pension liability was $3.9 million . The Company has recorded the unfunded amount as a liability in its consolidated balance sheet at December 31, 2017 and 2016 , under the other liabilities caption. The Company expects to make contributions to the Pension Plan of approximately $0.3 million during 2018. The unrealized actuarial loss on pension benefits, net of tax at December 31, 2017 , 2016 and 2015 was $1.2 million , $1.9 million and $1.6 million , respectively. These amounts were reflected in Note 3 above under the caption “accumulated other comprehensive loss.” In accordance with the Compensation-Retirement Benefits Topic of ASC 715-20, Defined Benefits Plan , the Company recognizes the over-funded or under-funded status of its defined post-retirement plan as an asset or liability in its statement of financial position. The company measured the plan assets and benefit obligations as of the date of the fiscal year-end.

BANK LINE OF CREDIT

BANK LINE OF CREDIT	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
BANK LINE OF CREDIT [Text Block]	BANK LINE OF CREDIT: On July 27, 2016, the Company entered into a credit agreement with a bank (the "Credit Agreement") that provides the Company with a $75.0 million revolving line of credit to use for general corporate purposes with a $20.0 million sub-limit for the issuance of standby and trade letters of credit. The Company’s ability to borrow under the revolving line of credit is conditioned upon the Company’s compliance with specified covenants, including reporting and financial covenants, primarily a minimum cash requirement and a debt to earnings ratio. The Credit Agreement terminates on July 26, 2019; all advances under the revolving line of credit will become due on such date, or earlier in the event of a default. As of December 31, 2017 , the Company was compliant with all covenants and had no amount outstanding under the Credit Agreement.

SELECTED QUARTERLY INFORMATION

SELECTED QUARTERLY INFORMATION	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY INFORMATION (Unaudited) [Text Block]	SELECTED QUARTERLY INFORMATION (Unaudited): The following tables set forth certain data from the Company's consolidated statements of income for each of the quarters in the years ended December 31, 2017 and 2016 . The unaudited quarterly consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements contained herein and include all adjustments that the Company considers necessary for a fair presentation of such information when read in conjunction with the Company’s annual audited consolidated financial statements and notes thereto appearing elsewhere in this report. The operating results for any quarter are not necessarily indicative of the results for any subsequent period or for the entire fiscal year. Three Months Ended (unaudited) Dec. 31, Sept. 30, June 30, Mar. 31, Dec. 31, Sept. 30, June 30, Mar. 31, (in thousands, except per share data) 2017 2017 2017 2017 2016 2016 2016 2016 Net revenues $ 108,249 $ 111,255 $ 107,563 $ 104,688 $ 102,436 $ 101,625 $ 97,571 $ 88,036 Gross profit 54,028 55,713 53,447 50,476 50,076 49,842 47,785 44,488 Net income (loss) (1) $ (16,898 ) $ 16,506 $ 13,902 $ 14,099 $ 14,303 $ 12,809 $ 11,407 $ 10,379 Earnings (loss) per share Basic $ (0.57 ) $ 0.55 $ 0.47 $ 0.48 $ 0.49 $ 0.44 $ 0.40 $ 0.36 Diluted $ (0.57 ) $ 0.54 $ 0.46 $ 0.47 $ 0.48 $ 0.43 $ 0.39 $ 0.35 Shares used in per share calculation Basic 29,759 29,759 29,720 29,456 29,196 28,972 28,850 28,679 Diluted 29,759 30,614 30,454 30,248 29,914 29,625 29,422 29,244 _______________ (1) In December 2017 the U.S. governme nt enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Refer to Note 11, Provision for Income Taxes , in the Notes to Consolidated Financial Statements).

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts [Text Block]	Schedule II Valuation and Qualifying Accounts The Company maintains an allowance for the distributors’ ship and debit credits relating to the sell-through of the Company’s products. This reserve is established using the Company’s historical ship and debit amounts and levels of inventory in the distributor channels. The following is a summary of the activity in the allowance for ship and debit credits: (in thousands) Balance at Beginning of Period Charged to Costs and Expenses Deductions (1) Balance at End of Period Allowance for ship and debit credits: Year ended December 31, 2015 $ 27,425 $ 195,669 $ (188,679 ) $ 34,415 Year ended December 31, 2016 34,415 262,501 (258,841 ) 38,075 Year ended December 31, 2017 $ 38,075 $ 273,492 $ (272,081 ) $ 39,486 _______________ (1) Deductions relate to ship and debit credits issued which adjust the sell-in price from the standard distribution price to the pre-approved lower price. Refer to Note 2, Significant Accounting Policies and Recent Accounting Pronouncements , for the Company’s revenue recognition policy, including the Company’s accounting for ship and debit claims.

SIGNIFICANT ACCOUNTING POLICI26

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Significant Accounting Policies and Estimates (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Segment Reporting [Policy Text Block]	Segment Reporting The Company is organized and operates as one reportable segment, the design, development, manufacture and marketing of integrated circuits and related components for use primarily in high-voltage power conversion market. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of making operating decisions and assessing financial performance.
Principles of Consolidation [Policy Text Block]	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of all intercompany transactions and balances.
Estimates [Policy Text Block]	Estimates The preparation of financial statements in conformity with U.S. Generally Accepted Accounting Principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition and allowances for receivables and inventories. These estimates are based on historical facts and various other factors, which the Company believes to be reasonable at the time the estimates are made. However, as the effects of future events cannot be determined with precision, actual results could differ significantly from management’s estimates.
Revenue Recognition [Policy Text Block]	Revenue Recognition The Company applies the provisions of Accounting Standards Codification (ASC) 606-10, Revenue from Contracts with Customers , and all related appropriate guidance. The Company recognizes revenue under the core principle to depict the transfer of control to the Company’s customers in an amount reflecting the consideration the Company expects to be entitled. In order to achieve that core principle, the Company applies the following five-step approach: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied. Product revenues consist of sales to original equipment manufacturers, or OEMs, merchant power supply manufacturers and distributors. The Company considers customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. In situations where sales are to a distributor, the Company has concluded that its contracts are with the distributor as the Company holds a contract bearing enforceable rights and obligations only with the distributor. As part of its consideration of the contract, the Company evaluates certain factors including the customer’s ability to pay (or credit risk). For each contract, the Company considers the promise to transfer products, each of which is distinct, to be the identified performance obligations. In determining the transaction price the Company evaluates whether the price is subject to refund or adjustment to determine the net consideration to which the Company expects to be entitled. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. The Company allocates the transaction price to each distinct product based on their relative standalone selling price. The product price as specified on the purchase order is considered the standalone selling price as it is an observable input which depicts the price as if sold to a similar customer in similar circumstances. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company’s performance obligation is satisfied), which typically occurs at shipment. Further, in determining whether control has transferred, the Company considers if there is a present right to payment and legal title, along with risks and rewards of ownership having transferred to the customer. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. As scheduled delivery dates are within one year, under the optional exemption provided by ASC 606-10-50-14 revenues allocated to future shipments of partially completed contracts are not disclosed. The Company has also elected the practical expedient under ASC 340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year. Sales to international customers that are shipped from the Company’s facility outside of the United States are pursuant to EX Works, or EXW, shipping terms, meaning that control of the product transfers to the customer upon shipment from the Company’s foreign warehouse. Sales to international customers that are shipped from the Company’s facility in California are pursuant to Delivered at Frontier, or DAF, shipping terms. As such, control of the product passes to the customer when the shipment reaches the destination country and revenue is recognized upon the arrival of the product in that country. Shipments to customers in the Americas are pursuant to Free on Board, or FOB, point of origin shipping terms meaning that control is passed to the customer upon shipment. Sales to most distributors are made under terms allowing certain price adjustments and limited rights of return (known as “stock rotation”) of the Company’s products held in their inventory or upon sale to their end customers. Revenue from sales to distributors is recognized upon the transfer of control to the distributor. Frequently, distributors need to sell at a price lower than the standard distribution price in order to win business. At the time the distributor invoices its customer or soon thereafter, the distributor submits a “ship and debit” price adjustment claim to the Company to adjust the distributor’s cost from the standard price to the pre-approved lower price. After the Company verifies that the claim was pre-approved, a credit memo is issued to the distributor for the ship and debit claim. In determining the transaction price, the Company considers ship and debit price adjustments to be variable consideration. Such price adjustments are estimated using the expected value method based on an analysis of actual ship and debit claims, at the distributor and product level, over a period of time considered adequate to account for current pricing and business trends. Historically, actual price adjustments for ship and debit claims relative to those estimated and included when determining the transaction price have not materially differed. Stock rotation rights grant the distributor the ability to return certain specified amounts of inventory. Stock rotation adjustments are an additional form of variable consideration and are also estimated using the expected value method based on historical return rates. Historically, distributor stock rotation adjustments have not been material. Sales to certain distributors are made under terms that do not include rights of return or price concessions after the product is shipped to the distributor. Accordingly, upon application of steps one through five above, product revenue is recognized upon shipment and transfer of control. The Company generally provides an assurance warranty that its products will substantially conform to the published specifications for twelve months from the date of shipment. The Company’s liability is limited to either a credit equal to the purchase price or replacement of the defective part. Returns under warranty have historically been immaterial. As such, the Company does not record a specific warranty reserve or consider activities related to such warranty, if any, to be a separate performance obligation.
Inventories [Policy Text Block]	Inventories Inventories (which consist of costs associated with the purchases of wafers from domestic and offshore foundries and of packaged components from offshore assembly manufacturers, as well as internal labor and overhead associated with the testing of both wafers and packaged components) are stated at the lower of cost (first-in, first-out) or market. Provisions, when required, are made to reduce excess and obsolete inventories to their estimated net realizable values.
Income Taxes [Policy Text Block]	Income Taxes Income-tax expense is an estimate of current income taxes payable or refundable in the current fiscal year based on reported income before income taxes. Deferred income taxes reflect the effect of temporary differences and carry-forwards that are recognized for financial reporting and income tax purposes. The Company accounts for income taxes under the provisions of ASC 740, Income Taxe s. Under the provisions of ASC 740, deferred tax assets and liabilities are recognized based on the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, utilizing the tax rates that are expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The Company recognizes valuation allowances to reduce any deferred tax assets to the amount that it estimates will more likely than not be realized based on available evidence and management’s judgment. The Company limits the deferred tax assets recognized related to certain officers’ compensation to amounts that it estimates will be deductible in future periods based upon Internal Revenue Code Section 162(m). In the event that the Company determines, based on available evidence and management judgment, that all or part of the net deferred tax assets will not be realized in the future, it would record a valuation allowance in the period the determination is made. In addition, the calculation of tax liabilities involves significant judgment in estimating the impact of uncertainties in the application of complex tax laws. Resolution of these uncertainties in a manner inconsistent with the Company’s expectations could have a material impact on the Company’s results of operations and financial position.
Business Combinations [Policy Text Block]	Business Combinations The purchase price of an acquisition is allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. To the extent the purchase price exceeds the fair value of the net identifiable tangible and intangible assets acquired and liabilities assumed, such excess is allocated to goodwill. The Company determines the estimated fair values after review and consideration of relevant information, including discounted cash flows, quoted market prices and estimates made by management. The Company adjusts the preliminary purchase price allocation, as necessary, during the measurement period of up to one year after the acquisition closing date as it obtains more information as to facts and circumstances existing at the acquisition date impacting asset valuations and liabilities assumed. Acquisition-related costs are recognized separately from the acquisition and are expensed as incurred.
Goodwill and Intangible Assets [Policy Text Block]	Goodwill and Intangible Assets Goodwill and the Company's domain name are evaluated in accordance with ASC 350-10, Goodwill and Other Intangible Assets, and an impairment analysis is conducted on an annual basis, or sooner if indicators exist for a potential impairment. In accordance with ASC 360-10, Accounting for the Impairment or Disposal of Long-Lived Assets , long-lived assets, such as property and equipment and intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset.
Cash and Cash Equivalents [Policy Text Block]	Cash and Cash Equivalents The Company considers cash invested in highly liquid financial instruments with maturities of three months or less at the date of purchase to be cash equivalents.
Marketable Securities [Policy Text Block]	Marketable Securities The Company generally holds securities until maturity; however, they may be sold under certain circumstances including, but not limited to, when necessary for the funding of acquisitions and other strategic investments. As a result the Company classifies its investment portfolio as available-for-sale. The Company classifies all investments with a maturity date greater than three months at the date of purchase as short-term marketable securities in its consolidated balance sheet. As of December 31, 2017 , and December 31, 2016 , the Company’s marketable securities consisted primarily of commercial paper, corporate bonds, government securities and/or other high-quality commercial securities.
Employee Benefits Plan [Policy Text Block]	Employee Benefits Plan The Company sponsors a 401(k) tax-deferred savings plan for all employees in the United States who meet certain eligibility requirements. Participants may contribute up to the amount allowable as a deduction for federal income tax purposes. The Company is not required to contribute; however, the Company contributes a certain percentage of employee annual salaries on a discretionary basis, not to exceed an established threshold. The Company provided for a contribution of approximately $1.2 million in 2017 and approximately $1.1 million in each of
Retirement Benefit Obligations (Pension) [Policy Text Block]	Retirement Benefit Obligations (Pension) The Company recognizes the over-funded or under-funded status of a defined benefit pension or post-retirement plan as an asset or liability in the accompanying consolidated balance sheets. Actuarial gains and losses are recorded in accumulated other comprehensive loss, a component of stockholders’ equity, and are amortized as a component of net periodic cost over the remaining estimated service period of participants.
Foreign Currency Risk and Foreign Currency Translations [Policy Text Block]	Foreign Currency Risk and Foreign Currency Translation As of December 31, 2017 , the Company’s primary transactional currency was U.S. dollars; in addition, the Company holds cash in Swiss francs and euros to fund the operations of the Company’s Swiss subsidiary. The foreign exchange rate fluctuation between the U.S. dollar versus the Swiss franc and euro is recorded in “other income” in the consolidated statements of income. Gains and losses arising from the remeasurement of non-functional currency balances are recorded in ''other income'' in the accompanying consolidated statements of income. For each of the years ended December 31, 2017 and 2016 the Company realized foreign exchange transaction losses of $0.1 million and $0.5 million in 2015 . The functional currencies of the Company’s other subsidiaries are the local currencies. Accordingly, all assets and liabilities are translated into U.S. dollars at the current exchange rates as of the applicable balance sheet date. Revenues and expenses are translated at the average exchange rate prevailing during the period. Cumulative gains and losses from the translation of the foreign subsidiaries’ financial statements have been included in stockholders’ equity.
Warranty [Policy Text Block]	Warranty The Company generally warrants that its products will substantially conform to the published specifications for 12 months from the date of shipment. The Company’s liability is limited to either a credit equal to the purchase price or replacement of the defective part. Returns under warranty have historically been immaterial, and as a result, the Company does not record a specific warranty reserve.
Advertising [Policy Text Block]	Advertising Advertising costs are expensed as incurred. In each of 2017 and 2016 advertising costs amounted to $1.3 million and $1.1 million in 2015 .
Research and Development [Policy Text Block]	Research and Development Research and development costs are expensed as incurred.
Indemnifications [Policy Text Block]	Indemnifications The Company sells products to its distributors under contracts, collectively referred to as Distributor Sales Agreements (DSA). Each DSA contains the relevant terms of the contractual arrangement with the distributor, and generally includes certain provisions for indemnifying the distributor against losses, expenses, and liabilities from damages that may be awarded against the distributor in the event the Company’s products are found to infringe upon a patent, copyright, trademark, or other proprietary right of a third party (Customer Indemnification). The DSA generally limits the scope of and remedies for the Customer Indemnification obligations in a variety of industry-standard respects, including, but not limited to, limitations based on time and geography, and a right to replace an infringing product. The Company also, from time to time, has granted a specific indemnification right to individual customers. The Company believes its internal development processes and other policies and practices limit its exposure related to such indemnifications. In addition, the Company requires its employees to sign a proprietary information and inventions agreement, which assigns the rights to its employees' development work to the Company. To date, the Company has not had to reimburse any of its distributors or customers for any losses related to these indemnifications and no material claims were outstanding as of December 31, 2017 . For several reasons, including the lack of prior indemnification claims and the lack of a monetary liability limit for certain infringement cases, the Company cannot determine the maximum amount of potential future payments, if any, related to such indemnifications.
Fair Value of Financial Instruments, Policy [Policy Text Block]	The Company’s cash equivalents and investment instruments are classified within Level 1 or Level 2 of the fair-value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The type of instrument valued based on quoted market prices in active markets primarily includes money market securities. This type of instrument is generally classified within Level 1 of the fair-value hierarchy. The types of instruments valued based on other observable inputs (Level 2 of the fair-value hierarchy) include investment-grade corporate bonds and government, state, municipal and provincial obligations. Such types of investments are valued by using a multi-dimensional relational model, the inputs are primarily benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications.
Share-based Compensation [Policy Text Block]	Stock-Based Compensation The Company applies the provisions of ASC 718-10, Stock Compensation . Under the provisions of ASC 718-10, the Company recognizes the fair value of stock-based compensation in its financial statements over the requisite service period of the individual grants, which generally equals a four -year vesting period. The Company uses estimates of volatility, expected term, risk-free interest rate, dividend yield and forfeitures in determining the fair value of these awards and the amount of compensation expense to recognize. The Company uses the straight-line method to amortize all stock awards granted over the requisite service period of the award.

SIGNIFICANT ACCOUNTING POLICI27

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Adjustments for New Accounting Pronouncements (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	The impact of adoption on the Company’s previously reported consolidated financial statements were as follows: Consolidated Balance Sheet: December 31, 2016 (In thousands) As Reported Impact of Adoption As Adjusted Accounts receivable, net $ 6,961 $ (433 ) $ 6,528 Prepaid expenses and other current assets 8,520 195 8,715 Deferred tax assets 12,032 (690 ) 11,342 Deferred income on sales to distributors 16,207 (16,207 ) — Other accrued liabilities 2,434 300 2,734 Retained earnings $ 317,912 $ 14,979 $ 332,891 Year Ended December 31, Consolidated Statements of Income: 2016 2015 (In thousands, except per share) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted Net revenues $ 387,393 $ 2,275 $ 389,668 $ 343,989 $ 620 $ 344,609 Cost of revenues 196,232 1,245 197,477 170,602 707 171,309 Provision for income taxes 1,032 22 1,054 271 (92 ) 179 Net income $ 47,890 $ 1,008 $ 48,898 $ 39,147 $ 5 $ 39,152 Earnings per share Basic $ 1.66 $ 0.03 $ 1.69 $ 1.35 $ — $ 1.35 Diluted $ 1.62 $ 0.03 $ 1.65 $ 1.32 $ — $ 1.32 Year Ended December 31, Consolidated Statement of Cash Flows: 2016 2015 (In thousands) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted CASH FLOWS FROM OPERATING ACTIVITIES: Net income $ 47,890 $ 1,008 $ 48,898 $ 39,147 $ 5 $ 39,152 Deferred income taxes (660 ) 22 (638 ) (5,416 ) (92 ) (5,508 ) Accounts receivable 650 101 751 4,131 13 4,144 Prepaid expenses and other assets (2,499 ) (25 ) (2,524 ) 3,391 (49 ) 3,342 Taxes payable and accrued liabilities (1,124 ) — (1,124 ) (76 ) 1 (75 ) Deferred income on sales to distributors $ 1,106 $ (1,106 ) $ — $ (122 ) $ 122 $ —

COMPONENTS OF THE COMPANY'S C28

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Tables)	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts Receivable [Table Text Block]	Accounts Receivable (in thousands) December 31, 2017 December 31, 2016 Accounts receivable trade $ 58,718 $ 46,849 Accrued ship and debit (39,486 ) (38,075 ) Allowance for stock rotation and rebate (1,700 ) (1,721 ) Allowance for doubtful accounts (734 ) (525 ) Total $ 16,798 $ 6,528
Schedule of Inventory, Current [Table Text Block]	Inventories (in thousands) December 31, 2017 December 31, 2016 Raw materials $ 15,517 $ 14,610 Work-in-process 16,765 15,194 Finished goods 24,805 22,760 Total $ 57,087 $ 52,564
Schedule of Prepaid Expenses and Other Current Assets [Table Text Block]	Prepaid Expenses and Other Current Assets (in thousands) December 31, 2017 December 31, 2016 Prepaid income tax $ 460 $ 2,431 Prepaid legal fees 213 212 Prepaid maintenance agreements 856 1,399 Advance to suppliers 1,211 69 Interest receivable 1,195 743 Other 3,823 3,861 Total $ 7,758 $ 8,715
Property and Equipment [Table Text Block]	Property and Equipment (in thousands) December 31, 2017 December 31, 2016 Land $ 20,288 $ 20,288 Construction-in-progress 15,353 6,880 Building and improvements 52,655 52,156 Machinery and equipment 151,269 132,162 Computer software and hardware and office furniture and fixtures 50,440 45,951 290,005 257,437 Accumulated depreciation (178,300 ) (162,141 ) Total $ 111,705 $ 95,296
Property and Equipment Useful Lives [Table Text Block]	Building and improvements 4-40 years Machinery and equipment 2-8 years Computer software and hardware and office furniture and fixtures 4-7 years
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Accumulated Other Comprehensive Loss Changes in accumulated other comprehensive loss for the three years ended December 31, 2017 : (in thousands) Unrealized Gains and Losses on Available-for-Sale Securities Defined Benefit Pension Items Foreign Currency Items Total Balance at January 1, 2015 $ 83 $ (1,240 ) $ 21 $ (1,136 ) Other comprehensive loss before reclassifications (180 ) (469 ) (191 ) (840 ) Amounts reclassified from accumulated other comprehensive loss — 125 (1) — 125 Other comprehensive loss (180 ) (344 ) (191 ) (715 ) Balance at December 31, 2015 (97 ) (1,584 ) (170 ) (1,851 ) Other comprehensive loss before reclassifications (123 ) (505 ) (384 ) (1,012 ) Amounts reclassified from accumulated other comprehensive loss — 153 (1) — 153 Other comprehensive loss (123 ) (352 ) (384 ) (859 ) Balance at December 31, 2016 (220 ) (1,936 ) (554 ) (2,710 ) Other comprehensive income before reclassifications (207 ) 502 79 374 Amounts reclassified from accumulated other comprehensive loss — 197 (1) — 197 Other comprehensive income (207 ) 699 79 571 Balance at December 31, 2017 $ (427 ) $ (1,237 ) $ (475 ) $ (2,139 ) _______________ (1) This component of accumulated other comprehensive loss is included in the computation of net periodic pension cost for the years ended December 31, 2017 , 2016 and 2015 .

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Of Marketable Securities and Investments [Table Text Block]	The fair value hierarchy of the Company’s cash equivalents and marketable securities at December 31, 2017 , and December 31, 2016 , was as follows: Fair Value Measurement at December 31, 2017 (in thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 179,951 $ — $ 179,951 Commercial paper 51,122 — 51,122 Government securities 9,285 — 9,285 Money market funds 195 195 — Total $ 240,553 $ 195 $ 240,358 Fair Value Measurement at December 31, 2016 (in thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 132,141 $ — $ 132,141 Commercial paper 58,031 — 58,031 Money market funds 1,916 1,916 — Total $ 192,088 $ 1,916 $ 190,172

MARKETABLE SECURITIES (Tables)

MARKETABLE SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Marketable Securities [Abstract]
Available-for-sale Securities [Table Text Block]	Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2017 , were as follows: Amortized Gross Unrealized Estimated Fair (in thousands) Cost Gains Losses Market Value Investments due in 3 months or less: Corporate securities $ 38,485 $ — $ (16 ) $ 38,469 Total 38,485 — (16 ) 38,469 Investments due in 4-12 months: Corporate securities 104,440 — (199 ) 104,241 Government securities 9,302 — (17 ) 9,285 Total 113,742 — (216 ) 113,526 Investments due in 12 months or greater: Corporate securities 37,436 — (195 ) 37,241 Total 37,436 — (195 ) 37,241 Total marketable securities $ 189,663 $ — $ (427 ) $ 189,236 Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2016 , were as follows: Amortized Gross Unrealized Estimated Fair (in thousands) Cost Gains Losses Market Value Investments due in 3 months or less: Commercial paper $ 36,996 $ — $ — $ 36,996 Corporate securities 9,342 2 (2 ) 9,342 Total 46,338 2 (2 ) 46,338 Investments due in 4-12 months: Commercial paper 19,186 — — 19,186 Corporate securities 59,714 15 (76 ) 59,653 Total 78,900 15 (76 ) 78,839 Investments due in 12 months or greater: Corporate securities 63,305 21 (180 ) 63,146 Total 63,305 21 (180 ) 63,146 Total marketable securities $ 188,543 $ 38 $ (258 ) $ 188,323

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table Text Block]	(in thousands) Goodwill Balance at December 31, 2015 $ 91,849 Goodwill acquired during the period — Balance at December 31, 2016 91,849 Goodwill acquired during the period — Balance at December 31, 2017 $ 91,849
Schedule of intangible assets [Table Text Block]	The Company does not believe there is any significant residual value associated with the following intangible assets: December 31, 2017 December 31, 2016 (in thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Domain name $ 1,261 $ — $ 1,261 $ 1,261 $ — $ 1,261 In-process research and development 4,690 — 4,690 4,690 — 4,690 Developed technology 33,270 (19,211 ) 14,059 33,270 (15,455 ) 17,815 Customer relationships 20,030 (14,621 ) 5,409 20,030 (12,474 ) 7,556 Technology licenses — — — 3,000 (3,000 ) — In-place leases 660 (660 ) — 660 (480 ) 180 Total intangible assets $ 59,911 $ (34,492 ) $ 25,419 $ 62,911 $ (31,409 ) $ 31,502
Schedule of expected amortization expense [Table Text Block]	The estimated future amortization expense related to definite-lived intangible assets at December 31, 2017 , is as follows: Fiscal Year Estimated Amortization (in thousands) 2018 $ 5,152 2019 4,753 2020 3,528 2021 2,662 2022 1,584 Thereafter 1,789 Total (1) $ 19,468 _______________ (1) The total above excludes $4.7 million of in-process R&D which will be amortized upon completion of development over the estimated useful life of the technology.

STOCK PLANS AND SHARE BASED C32

STOCK PLANS AND SHARE BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of stock-based compensation expense [Table Text Block]	The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, (in thousands) 2017 2016 2015 Cost of revenues $ 1,321 $ 1,148 $ 933 Research and development 8,496 7,309 5,255 Sales and marketing 5,197 4,489 3,644 General and administrative 9,663 7,939 4,935 Total stock-based compensation expense $ 24,677 $ 20,885 $ 14,767
Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]	The following table summarizes total compensation expense related to unvested awards not yet recognized, net of expected forfeitures, and the weighted average period over which it is expected to be recognized as of December 31, 2017 : Unrecognized Compensation Expense for Unvested Awards (in thousands) Weighted Average Remaining Recognition Period (in years) Long-term performance-based awards $ 3,519 1.36 Restricted stock units 35,132 3.73 Purchase plan 128 0.08 Total unrecognized compensation expense $ 38,779
Fair value assumptions for employees' stock purchase rights under the Purchase Plan [Table Text Block]	The fair value of employees’ stock purchase rights under the Purchase Plan was estimated using the Black-Scholes model with the following weighted-average assumptions used during the three years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, 2017 2016 2015 Risk-free interest rates 0.91% 0.44% 0.13% Expected volatility rates 30% 32% 29% Expected dividend yield 0.80% 0.96% 1.08% Expected term of purchase rights (in years) 0.50 0.50 0.50 Weighted-average estimated fair value of purchase rights $16.74 $12.23 $10.18
Summary of option activity under the Plans [Table Text Block]	A summary of stock options outstanding as of December 31, 2017 , and activity during three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 1,344 $ 27.27 Granted — — Exercised (311 ) $ 26.11 Forfeited or expired (3 ) $ 37.97 Outstanding at December 31, 2015 1,030 $ 27.58 Granted — — Exercised (333 ) $ 25.41 Forfeited or expired — — Outstanding at December 31, 2016 697 $ 28.62 Granted — — Exercised (186 ) $ 27.48 Forfeited or expired — — Outstanding at December 31, 2017 511 $ 29.03 2.05 $ 22,770 Vested and Exercisable at December 31, 2017 511 2.05 $ 22,770
Summary of stock options outstanding by exercise price range [Table Text Block]	The following table summarizes the stock options outstanding at December 31, 2017 : Options Outstanding Options Exercisable (shares in thousands) Range of Exercise Prices Options Outstanding Weighted Average Remaining Contractual Term (in years) Weighted Average Exercise Price Options Exercisable Weighted Average Exercise Price $17.75 - $24.21 263 1.26 $ 20.96 263 $ 20.96 $31.15 - $42.88 248 2.88 $ 37.56 248 $ 37.56 511 2.05 $ 29.03 511 $ 29.03
Summary of restricted stock units outstanding [Table Text Block]	A summary of RSU awards outstanding as of December 31, 2017 , and activity during the three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 692 $ 43.86 Granted 319 $ 49.75 Vested (267 ) $ 42.49 Forfeited (63 ) $ 45.71 Outstanding at December 31, 2015 681 $ 46.98 Granted 331 $ 46.70 Vested (270 ) $ 45.13 Forfeited (24 ) $ 47.21 Outstanding at December 31, 2016 718 $ 47.54 Granted 558 $ 60.82 Vested (284 ) $ 46.52 Forfeited (44 ) $ 50.89 Outstanding at December 31, 2017 948 $ 55.51 1.97 $ 69,742 Outstanding and expected to vest at December 31, 2017 860 1.80 $ 63,289
Performance Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of performance-based awards outstanding [Table Text Block]	A summary of PSU awards outstanding as of December 31, 2017 , and activity during the three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 — — Granted 89 $ 52.36 Vested — — Forfeited or canceled (78 ) $ 52.35 Outstanding at December 31, 2015 11 $ 52.35 Granted 101 $ 46.26 Vested (11 ) $ 52.35 Forfeited or canceled (2 ) $ 46.87 Outstanding at December 31, 2016 99 $ 46.25 Granted 88 $ 63.99 Vested (99 ) $ 46.25 Forfeited or canceled (9 ) $ 63.99 Outstanding at December 31, 2017 79 $ 63.99 0 $ 5,819 Outstanding and expected to vest at December 31, 2017 79 0 $ 5,819
Long-Term Performance-based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of performance-based awards outstanding [Table Text Block]	A summary of PRSU awards outstanding as of December 31, 2017 , and activity during the three years then ended, is presented below: (shares and intrinsic value in thousands) Shares Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at January 1, 2015 61 $ 55.51 Granted 72 $ 52.47 Vested — — Forfeited or canceled (4 ) $ 57.76 Outstanding at December 31, 2015 129 $ 53.75 Granted 78 $ 43.26 Vested — — Forfeited or canceled (57 ) $ 55.35 Outstanding at December 31, 2016 150 $ 47.65 Granted 71 $ 63.00 Vested — — Forfeited or canceled (37 ) $ 51.59 Outstanding at December 31, 2017 184 $ 52.80 1.49 $ 13,547 Outstanding and expected to vest at December 31, 2017 164 1.28 $ 12,072

SIGNIFICANT CUSTOMERS AND GEO33

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Tables)	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Customers accounted for 10% or more of total net revenues [Table Text Block]	The following customers, distributors of the Company’s products, each accounted for 10% or more of total net revenues: Year Ended December 31, Customer 2017 2016 2015 Avnet 16 % 18 % 21 % Powertech Distribution Ltd. * 10 % 11 %
Customers representing 10% or more of accounts receivable [Table Text Block]	The following customer, a distributor of the Company’s products, represented 10% or more of accounts receivable: Customer December 31, December 31, Avnet 18 % 24 %
Geographic net revenues	The Company markets its products globally through its sales personnel and a worldwide network of independent sales representatives and distributors. Geographic net revenues based on “bill to” customer locations were as follows: Year Ended December 31, (In thousands) 2017 2016 2015 United States of America $ 16,647 $ 14,948 $ 14,759 Hong Kong/China 227,335 198,858 173,202 Taiwan 50,307 50,324 47,279 Korea 38,012 41,996 34,264 Western Europe (excluding Germany) 48,230 41,214 38,028 Japan 20,769 19,767 16,994 Germany 11,558 7,563 7,802 Other 18,897 14,998 12,281 Total net revenues $ 431,755 $ 389,668 $ 344,609

COMMON STOCK REPURCHASES AND 34

COMMON STOCK REPURCHASES AND CASH DIVIDENDS (Tables)	12 Months Ended
	Dec. 31, 2017
Common Stock Repurchases and Cash Dividends [Abstract]
Dividends Declared [Table Text Block]	The following table presents the quarterly dividends declared per share of the Company’s common stock for the periods indicated: Year Ended December 31, 2017 2016 2015 First Quarter $ 0.14 $ 0.13 $ 0.12 Second Quarter $ 0.14 $ 0.13 $ 0.12 Third Quarter $ 0.14 $ 0.13 $ 0.12 Fourth Quarter $ 0.14 $ 0.13 $ 0.12

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings per share calculation [Table Text Block]	A summary of the earnings per share calculation is as follows: Year Ended December 31, (in thousands, except per share amounts) 2017 2016 2015 Basic earnings per share: Net income $ 27,609 $ 48,898 $ 39,152 Weighted-average common shares 29,674 28,925 29,001 Basic earnings per share $ 0.93 $ 1.69 $ 1.35 Diluted earnings per share (1) : Net income $ 27,609 $ 48,898 $ 39,152 Weighted-average common shares 29,674 28,925 29,001 Effect of dilutive securities: Employee stock plans 871 694 695 Diluted weighted-average common shares 30,545 29,619 29,696 Diluted earnings per share $ 0.90 $ 1.65 $ 1.32 _______________ (1) The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2017, 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.

PROVISION FOR INCOME TAXES (Tab

PROVISION FOR INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S. and foreign components of income before income taxes [Table Text Block]	U.S. and foreign components of income before income taxes were: Year Ended December 31, (in thousands) 2017 2016 2015 U.S. operations $ (6,944 ) $ (477 ) $ (2,246 ) Foreign operations 67,243 50,429 41,577 Total pretax income $ 60,299 $ 49,952 $ 39,331
Components of provision for income taxes [Table Text Block]	The components of the provision for income taxes are as follows: Year Ended December 31, (in thousands) 2017 2016 2015 Current provision: Federal $ 35,311 $ — $ 443 State 4 — 83 Foreign 1,483 1,638 5,407 36,798 1,638 5,933 Deferred provision (benefit): Federal (3,640 ) (175 ) (1,791 ) State — (27 ) (57 ) Foreign (468 ) (382 ) (3,906 ) (4,108 ) (584 ) (5,754 ) Total $ 32,690 $ 1,054 $ 179
Effective income tax rate reconciliation [Table Text Block]	The provision for income taxes differs from the amount that would result by applying the applicable federal income tax rate to income before provision for income taxes, as follows: Year Ended December 31, 2017 2016 2015 Provision computed at Federal statutory rate 35.0 % 35.0 % 35.0 % Business tax credits (5.7 ) (6.0 ) (6.8 ) Stock-based compensation (5.0 ) 2.2 0.8 Foreign income taxed at different rate (37.3 ) (33.1 ) (33.2 ) U.S. Tax Act - transition tax 54.1 — — U.S. Tax Act - deferred tax asset and liability adjustment 8.1 — — Valuation allowance 2.2 1.8 2.6 Other 2.8 2.2 2.1 Total 54.2 % 2.1 % 0.5 %
Components of net deferred income tax asset [Table Text Block]	The components of the net deferred income tax asset (liabilities) were as follows: December 31, (in thousands) 2017 (1) 2016 Deferred tax assets: Other reserves and accruals $ 979 $ 1,267 Tax credit carry-forwards 10,442 26,895 Stock compensation 4,064 5,760 Capital losses 163 10,585 Net operating loss 7,059 2,671 Other — 174 Valuation allowance (18,421 ) (27,489 ) 4,286 19,863 Deferred tax liabilities: Depreciation (1,965 ) (2,322 ) Unremitted earnings — (7,019 ) Other (95 ) — (2,060 ) (9,341 ) Net deferred tax asset $ 2,226 $ 10,522
Unrecognized tax benefits rollforward [Table Text Block]	The Company applies the provisions of ASC 740-10, relating to accounting for uncertain income taxes. Reconciliation of the beginning and ending amount of unrecognized tax benefits: (in thousands) Unrecognized Tax Benefits Unrecognized Tax Benefits Balance at January 1, 2015 $ 11,160 Gross Increase for Tax Positions of Current Year 3,063 Gross Decrease for Tax Positions of Prior Years (663 ) Unrecognized Tax Benefits Balance at December 31, 2015 13,560 Gross Increase for Tax Positions of Current Year 1,856 Gross Decrease for Tax Positions of Prior Years (23 ) Unrecognized Tax Benefits Balance at December 31, 2016 15,393 Gross Increase for Tax Positions of Current Year 1,699 Gross Decrease for Tax Positions of Prior Years (409 ) Unrecognized Tax Benefits Balance at December 31, 2017 $ 16,683

COMMITMENTS (Tables)

COMMITMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Future minimum lease payments under all non-cancelable operating lease agreements as of December 31, 2017 , are as follows: Fiscal Year (in thousands) 2018 $ 1,875 2019 1,057 2020 699 2021 286 2022 148 Thereafter 247 Total minimum lease payments $ 4,312

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following table summarizes the purchase price and estimated fair values of the assets acquired and the liabilities assumed as of January 2, 2015, the completion of the acquisition of CamSemi: (in thousands) Total Amount Assets Acquired Cash $ 1,134 Accounts receivable 1,891 Inventories 1,409 Prepaid expenses and other current assets 408 Tax receivable 1,093 Intangible assets: Developed technology 6,600 Customer relationships 2,420 Goodwill 11,250 Total assets acquired 26,205 Liabilities Assumed Current liabilities 1,832 Taxes payable 1,090 Total liabilities assumed 2,922 Total purchase price $ 23,283
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	The following table represents details of the purchased intangible assets: Fair Value Amount (in thousands) Estimated Useful Life (in years) Developed technology $ 6,600 3 - 7 Customer relationships 2,420 5 Total acquired CamSemi intangibles $ 9,020

SELECTED QUARTERLY INFORMATION

SELECTED QUARTERLY INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	The following tables set forth certain data from the Company's consolidated statements of income for each of the quarters in the years ended December 31, 2017 and 2016 . The unaudited quarterly consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements contained herein and include all adjustments that the Company considers necessary for a fair presentation of such information when read in conjunction with the Company’s annual audited consolidated financial statements and notes thereto appearing elsewhere in this report. The operating results for any quarter are not necessarily indicative of the results for any subsequent period or for the entire fiscal year. Three Months Ended (unaudited) Dec. 31, Sept. 30, June 30, Mar. 31, Dec. 31, Sept. 30, June 30, Mar. 31, (in thousands, except per share data) 2017 2017 2017 2017 2016 2016 2016 2016 Net revenues $ 108,249 $ 111,255 $ 107,563 $ 104,688 $ 102,436 $ 101,625 $ 97,571 $ 88,036 Gross profit 54,028 55,713 53,447 50,476 50,076 49,842 47,785 44,488 Net income (loss) (1) $ (16,898 ) $ 16,506 $ 13,902 $ 14,099 $ 14,303 $ 12,809 $ 11,407 $ 10,379 Earnings (loss) per share Basic $ (0.57 ) $ 0.55 $ 0.47 $ 0.48 $ 0.49 $ 0.44 $ 0.40 $ 0.36 Diluted $ (0.57 ) $ 0.54 $ 0.46 $ 0.47 $ 0.48 $ 0.43 $ 0.39 $ 0.35 Shares used in per share calculation Basic 29,759 29,759 29,720 29,456 29,196 28,972 28,850 28,679 Diluted 29,759 30,614 30,454 30,248 29,914 29,625 29,422 29,244 _______________ (1) In December 2017 the U.S. governme nt enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Refer to Note 11, Provision for Income Taxes , in the Notes to Consolidated Financial Statements).

Schedule II - Valuation and Q40

Schedule II - Valuation and Qualifying Accounts Schedule II - Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule of Allowance for Ship and Debit [Table Text Block]	ollowing is a summary of the activity in the allowance for ship and debit credits: (in thousands) Balance at Beginning of Period Charged to Costs and Expenses Deductions (1) Balance at End of Period Allowance for ship and debit credits: Year ended December 31, 2015 $ 27,425 $ 195,669 $ (188,679 ) $ 34,415 Year ended December 31, 2016 34,415 262,501 (258,841 ) 38,075 Year ended December 31, 2017 $ 38,075 $ 273,492 $ (272,081 ) $ 39,486 _______________ (1) Deductions relate to ship and debit credits issued which adjust the sell-in price from the standard distribution price to the pre-approved lower price. Refer to Note 2, Significant Accounting Policies and Recent Accounting Pronouncements , for the Company’s revenue recognition policy, including the Company’s accounting for ship and debit claims.

SIGNIFICANT ACCOUNTING POLICI41

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Segment Reporting (Details)	12 Months Ended
	Dec. 31, 2017segments
Segment Reporting [Abstract]
Number of Reportable Segments	1

SIGNIFICANT ACCOUNTING POLICI42

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Benefits Plan
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 1.2	$ 1.1	$ 1.1
Foreign Exchange Transactions
Foreign Currency Transaction Gain (Loss), before Tax	$ (0.1)	(0.1)	(0.5)
Warranty
Product Warranty Period	12 months
Advertising Expense
Advertising Expense	$ 1.3	$ 1.3	$ 1.1

SIGNIFICANT ACCOUNTING POLICI43

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Prior Period Balance Sheet Adjustments, Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, net	$ 16,798	$ 6,528
Prepaid expenses and other current assets	7,758	8,715
DEFERRED TAX ASSETS	2,364	11,342
Deferred income on sales to distributors		0
Other accrued liabilities	4,009	2,734
Retained earnings	$ 351,408	332,891
As Reported
Accounts receivable, net		6,961
Prepaid expenses and other current assets		8,520
DEFERRED TAX ASSETS		12,032
Deferred income on sales to distributors		16,207
Other accrued liabilities		2,434
Retained earnings		317,912
Adjustments for Accounting Standards Update 2014-09 [Member]
Accounts receivable, net		(433)
Prepaid expenses and other current assets		195
DEFERRED TAX ASSETS		(690)
Deferred income on sales to distributors		(16,207)
Other accrued liabilities		300
Retained earnings		$ 14,979

SIGNIFICANT ACCOUNTING POLICI44

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Prior Period Statements of Income Adjustments, Adoption of ASU 2014-09 (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
NET REVENUES		$ 108,249		$ 111,255	$ 107,563	$ 104,688	$ 102,436	$ 101,625	$ 97,571	$ 88,036	$ 431,755	$ 389,668	$ 344,609
COST OF REVENUES											218,091	197,477	171,309
PROVISION FOR INCOME TAXES											32,690	1,054	179
Net income		$ (16,898)	[1]	$ 16,506	$ 13,902	$ 14,099	$ 14,303	$ 12,809	$ 11,407	$ 10,379	$ 27,609	$ 48,898	$ 39,152
Basic		$ (0.57)		$ 0.55	$ 0.47	$ 0.48	$ 0.49	$ 0.44	$ 0.40	$ 0.36	$ 0.93	$ 1.69	$ 1.35
Diluted	[2]	$ (0.57)		$ 0.54	$ 0.46	$ 0.47	$ 0.48	$ 0.43	$ 0.39	$ 0.35	$ 0.90	$ 1.65	$ 1.32
As Reported
NET REVENUES												$ 387,393	$ 343,989
COST OF REVENUES												196,232	170,602
PROVISION FOR INCOME TAXES												1,032	271
Net income												$ 47,890	$ 39,147
Basic												$ 1.66	$ 1.35
Diluted												$ 1.62	$ 1.32
Adjustments for Accounting Standards Update 2014-09 [Member]
NET REVENUES												$ 2,275	$ 620
COST OF REVENUES												1,245	707
PROVISION FOR INCOME TAXES												22	(92)
Net income												$ 1,008	$ 5
Basic												$ 0.03	$ 0
Diluted												$ 0.03	$ 0
[1]	In December 2017 the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Refer to Note 11, Provision for Income Taxes, in the Notes to Consolidated Financial Statements).
[2]	The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2017, 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.

SIGNIFICANT ACCOUNTING POLICI45

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Prior Period Statements of Cash Flows Adjustments, Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2017	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ (16,898)		$ 16,506	$ 13,902	$ 14,099	$ 14,303	$ 12,809	$ 11,407	$ 10,379	$ 27,609	$ 48,898	$ 39,152
Deferred income taxes										15,838	(638)	(5,508)
Accounts receivable										(10,479)	751	4,144
Prepaid expenses and other assets										(17,646)	(2,524)	3,342
Taxes payable and accrued liabilities										$ 20,041	(1,124)	(75)
Increase (Decrease) in Deferred Income											0	0
As Reported
Net income											47,890	39,147
Deferred income taxes											(660)	(5,416)
Accounts receivable											650	4,131
Prepaid expenses and other assets											(2,499)	3,391
Taxes payable and accrued liabilities											(1,124)	(76)
Increase (Decrease) in Deferred Income											1,106	(122)
Adjustments for Accounting Standards Update 2014-09 [Member]
Net income											1,008	5
Deferred income taxes											22	(92)
Accounts receivable											101	13
Prepaid expenses and other assets											(25)	(49)
Taxes payable and accrued liabilities											0	1
Increase (Decrease) in Deferred Income											$ (1,106)	$ 122
[1]	In December 2017 the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Refer to Note 11, Provision for Income Taxes, in the Notes to Consolidated Financial Statements).

SIGNIFICANT ACCOUNTING POLICI46

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Balance Sheet Adjustments, Adoption of ASU 2016-09 (Details) - Accounting Standards Update 2016-09 $ in Millions	Jan. 01, 2017USD ($)
Deferred Tax Asset [Member]
Consolidated Balance Sheet Statements
Cumulative Effect Adjustment	$ 7.5
Retained Earnings [Member]
Consolidated Balance Sheet Statements
Cumulative Effect Adjustment	$ 7.5

COMPONENTS OF THE COMPANY'S C47

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS Components of Consolidated Balanec Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable
Accounts receivable trade	$ 58,718	$ 46,849
Accrued ship and debit	(39,486)	(38,075)
Allowance for stock rotation and rebate	(1,700)	(1,721)
Allowance for doubtful accounts	(734)	(525)
Total	16,798	6,528
Inventory, Net [Abstract]
Raw materials	15,517	14,610
Work-in-process	16,765	15,194
Finished goods	24,805	22,760
Total	57,087	52,564
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid income tax	460	2,431
Prepaid legal fees	213	212
Prepaid maintenance agreements	856	1,399
Advance to suppliers	1,211	69
Interest receivable	1,195	743
Other	3,823	3,861
Total	$ 7,758	$ 8,715

COMPONENTS OF THE COMPANY'S C48

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 290,005	$ 257,437
Depreciation	18,374	16,812	$ 16,464
Accumulated depreciation	$ 178,300	$ 162,141
Property and Equipment [Member] | Geographic Concentration Risk [Member]
Property, Plant and Equipment [Line Items]
Concentration Risk, Percentage	10.00%	10.00%	10.00%
Property and Equipment [Member] | Geographic Concentration Risk [Member] | United States of America
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 159,500	$ 155,100	$ 150,100
Property and Equipment [Member] | Geographic Concentration Risk [Member] | THAILAND
Property, Plant and Equipment [Line Items]
Concentration Risk, Percentage	12.00%	12.00%	12.00%
Land
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 20,288	$ 20,288
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	15,353	6,880
Building and improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	52,655	52,156
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	151,269	132,162
Computer software and hardware and office furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 50,440	$ 45,951
Minimum [Member] | Building and improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	4 years
Minimum [Member] | Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	2 years
Minimum [Member] | Computer software and hardware and office furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	4 years
Maximum [Member] | Building and improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	40 years
Maximum [Member] | Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	8 years
Maximum [Member] | Computer software and hardware and office furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	7 years

COMPONENTS OF THE COMPANY'S C49

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		$ (2,139)	$ (2,710)	$ (1,851)	$ (1,136)
Other comprehensive loss before reclassifications		374	(1,012)	(840)
Amounts reclassified from accumulated other comprehensive loss		197	153	125
Other Comprehensive Income (Loss), Net of Tax		571	(859)	(715)
Unrealized Gains and Losses on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		(427)	(220)	(97)	83
Other comprehensive loss before reclassifications		(207)	(123)	(180)
Amounts reclassified from accumulated other comprehensive loss		0	0	0
Other Comprehensive Income (Loss), Net of Tax		(207)	(123)	(180)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		(1,237)	(1,936)	(1,584)	(1,240)
Other comprehensive loss before reclassifications		502	(505)	(469)
Amounts reclassified from accumulated other comprehensive loss	[1]	197	153	125
Other Comprehensive Income (Loss), Net of Tax		699	(352)	(344)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		(475)	(554)	(170)	$ 21
Other comprehensive loss before reclassifications		79	(384)	(191)
Amounts reclassified from accumulated other comprehensive loss		0	0	0
Other Comprehensive Income (Loss), Net of Tax		$ 79	$ (384)	$ (191)
[1]	This component of accumulated other comprehensive loss is included in the computation of net periodic pension cost for the years ended December 31, 2017, 2016 and 2015.

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments as Fair Value	$ 240,553	$ 192,088
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments as Fair Value	195	1,916
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments as Fair Value	240,358	190,172
Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	179,951	132,141
Corporate securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0	0
Corporate securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	179,951	132,141
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	51,122	58,031
Commercial paper | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0	0
Commercial paper | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	51,122	58,031
Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	9,285
Government securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0
Government securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	9,285
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	195	1,916
Money market funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	195	1,916
Money market funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	$ 0	$ 0

MARKETABLE SECURITIES (Details)

MARKETABLE SECURITIES (Details) Securities in Thousands, $ in Thousands	Dec. 31, 2017USD ($)Securities	Dec. 31, 2016USD ($)Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 189,663	$ 188,543
Gross Unrealized Gains	0	38
Gross Unrealized Losses	(427)	(258)
Estimated Fair Market Value	$ 189,236	$ 188,323
Weighted Average Interest Rate on Investments	1.57%	1.23%
Investments due in 3 months or less:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 38,485	$ 46,338
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(16)	(2)
Estimated Fair Market Value	38,469	46,338
Investments due in 4-12 months:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	113,742	78,900
Gross Unrealized Gains	0	15
Gross Unrealized Losses	(216)	(76)
Estimated Fair Market Value	113,526	78,839
Investments due in 12 months or greater:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	37,436	63,305
Gross Unrealized Gains	0	21
Gross Unrealized Losses	(195)	(180)
Estimated Fair Market Value	$ 37,241	$ 63,146
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | Securities	0	0
Commercial paper | Investments due in 3 months or less:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		$ 36,996
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Market Value		36,996
Commercial paper | Investments due in 4-12 months:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		19,186
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Market Value		19,186
Corporate securities | Investments due in 3 months or less:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 38,485	9,342
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(16)	(2)
Estimated Fair Market Value	38,469	9,342
Corporate securities | Investments due in 4-12 months:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	104,440	59,714
Gross Unrealized Gains	0	15
Gross Unrealized Losses	(199)	(76)
Estimated Fair Market Value	104,241	59,653
Corporate securities | Investments due in 12 months or greater:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	37,436	63,305
Gross Unrealized Gains	0	21
Gross Unrealized Losses	(195)	(180)
Estimated Fair Market Value	37,241	$ 63,146
Government securities | Investments due in 4-12 months:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,302
Gross Unrealized Gains	0
Gross Unrealized Losses	(17)
Estimated Fair Market Value	$ 9,285

GOODWILL AND INTANGIBLE ASSET52

GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 02, 2015
Intangible Assets, Net[Abstract]
Total intangible assets, Gross		$ 59,911	$ 62,911
Accumulated amortization		(34,492)	(31,409)
Total Finite Lived Intangible Assets, Net	[1]	19,468
Total Intangible Assets, Net		25,419	31,502
Amortization of intangibles		$ 6,083	6,663	$ 7,039
Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Intangible assets					$ 9,020
Minimum [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		2 years
Maximum [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		12 years
Developed technology
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		$ 33,270	33,270
Accumulated amortization		(19,211)	(15,455)
Total Finite Lived Intangible Assets, Net		$ 14,059	17,815
Developed technology | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Intangible assets					6,600
Developed technology | Minimum [Member] | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		3 years
Developed technology | Maximum [Member] | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		7 years
Customer relationships [Member]
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		$ 20,030	20,030
Accumulated amortization		(14,621)	(12,474)
Total Finite Lived Intangible Assets, Net		$ 5,409	7,556
Customer relationships [Member] | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Intangible assets					$ 2,420
Useful life (in years)		5 years
Technology licenses [Member]
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		$ 0	3,000
Accumulated amortization		0	(3,000)
Total Finite Lived Intangible Assets, Net		0	0
Leases, Acquired-in-Place [Member]
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		660	660
Accumulated amortization		(660)	(480)
Total Finite Lived Intangible Assets, Net		0	180
Domain name
Intangible Assets, Net[Abstract]
Indefinite-lived intangible assets		1,261	1,261
In-process research and development
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		4,690	4,690
Total Finite Lived Intangible Assets, Net		4,690	$ 4,690
In-process research and development | Early Stage Research And Developement Company [Member]
Intangible Assets and Goodwill [Line Items]
Finite-lived intangible assets		$ 4,690
[1]	The total above excludes $4.7 million of in-process R&D which will be amortized upon completion of development over the estimated useful life of the technology.

GOODWILL AND INTANGIBLE ASSET53

GOODWILL AND INTANGIBLE ASSETS (Intangible Assets Amortization Expense) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles		$ 6,083	$ 6,663	$ 7,039
Finite-Lived Intangible Assets, Accumulated Amortization		34,492	31,409
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2,018		5,152
2,019		4,753
2,020		3,528
2,021		2,662
2,022		1,584
Thereafter		1,789
Total Finite Lived Intangible Assets, Net	[1]	19,468
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		660	660
Finite-Lived Intangible Assets, Accumulated Amortization		660	480
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total Finite Lived Intangible Assets, Net		0	180
Developed technology
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		33,270	33,270
Finite-Lived Intangible Assets, Accumulated Amortization		19,211	15,455
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total Finite Lived Intangible Assets, Net		14,059	17,815
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		20,030	20,030
Finite-Lived Intangible Assets, Accumulated Amortization		14,621	12,474
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total Finite Lived Intangible Assets, Net		$ 5,409	$ 7,556
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)		2 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)		12 years
Cambridge Semiconductor Limited [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)		5 years
Cambridge Semiconductor Limited [Member] | Minimum [Member] | Developed technology
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)		3 years
Cambridge Semiconductor Limited [Member] | Maximum [Member] | Developed technology
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)		7 years
[1]	The total above excludes $4.7 million of in-process R&D which will be amortized upon completion of development over the estimated useful life of the technology.

GOODWILL AND INTANGIBLE ASSET54

GOODWILL AND INTANGIBLE ASSETS Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 91,849	$ 91,849	$ 91,849
Goodwill, Acquired During Period	$ 0	$ 0

STOCK PLANS AND SHARE BASED C55

STOCK PLANS AND SHARE BASED COMPENSATION (Details)	12 Months Ended
	Dec. 31, 2017USD ($)planspurchaseperiodsshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans | plans	3
Number of shares available for future issuance | shares	2,000,000
Stock-based compensation expense | $	$ 24,677,000	$ 20,900,000	$ 14,800,000
2016 Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance under stock option and stock purchase plans | shares	1,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number | shares	35,000
Incentive Stock Options [Member] | 2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of stock options as percentage of fair market value on date of grant, minimum	100.00%
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Stock-based compensation expense | $	$ 15,200,000	13,000,000	12,700,000
Restricted Stock Units (RSUs) [Member] | Directors Equity Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Factor used to determine the number of options/units to be granted | $	$ 100,000
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of employee's compensation eligible for payroll deductions	15.00%
Purchase price of the purchase plan as percentage of the lower of the fair market value on the first day of each offering period or on the purchase date	85.00%
Number of purchase period in each offering period | purchaseperiods	1
Duration of each purchase period in each offering period	6 months
Shares reserved for issuance | shares	3,500,000
Number of shares purchased | shares	3,000,000
Common stock reserved for future issuance under stock option and stock purchase plans | shares	500,000
Stock-based compensation expense | $	$ 1,300,000	$ 1,300,000	$ 1,200,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | shares	511,000	697,000	1,030,000	1,344,000
Stock-based compensation expense | $		$ 200,000	$ 700,000
Stock Options [Member] | 2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	48 months
Awards expiration period, maximum	10 years
Stock Options [Member] | Directors Equity Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Factor used to determine the number of options/units to be granted | $	$ 100,000
Stock Options and Restricted Stock Units (RSUs) [Member] | Directors Equity Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Factor used to determine the number of options/units to be granted | $	$ 100,000

STOCK PLANS AND SHARE BASED C56

STOCK PLANS AND SHARE BASED COMPENSATION (Stock-Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 24,677	$ 20,900	$ 14,800
Unrecognized compensation costs	38,779
Cost of revenues [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	1,321	1,148	933
Research and Development Expense [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	8,496	7,309	5,255
Selling and Marketing Expense [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	5,197	4,489	3,644
General and Administrative Expense [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 9,663	7,939	4,935
Stock Options [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Awards vesting period	4 years
Stock-based compensation expense		200	700
Performance Based Awards [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 8,200	6,400	300
Long-Term Performance-based Awards [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	$ 3,519
Unrecognized compensation costs, period of recognition (in years)	1 year 4 months 10 days
Restricted Stock Units (RSUs) [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Awards vesting period	4 years
Stock-based compensation expense	$ 15,200	13,000	12,700
Unrecognized compensation costs	$ 35,132
Unrecognized compensation costs, period of recognition (in years)	3 years 8 months 22 days
Employee Stock [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 1,300	$ 1,300	$ 1,200
Unrecognized compensation costs	$ 128
Unrecognized compensation costs, period of recognition (in years)	1 month

STOCK PLANS AND SHARE BASED C57

STOCK PLANS AND SHARE BASED COMPENSATION (Fair Value Assumptions) (Details) - Employee Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rates	0.91%	0.44%	0.13%
Expected volatility rates	30.00%	32.00%	29.00%
Expected dividend yield	0.80%	0.96%	1.08%
Expected term of purchase rights (in years)	6 months	6 months	6 months
Weighted-average estimated fair value of purchase rights	$ 16.74	$ 12.23	$ 10.18

STOCK PLANS AND SHARE BASED C58

STOCK PLANS AND SHARE BASED COMPENSATION (Option Activity) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Option activity under the Plans
Outstanding, shares, beginning of period	697	1,030	1,344
Outstanding, weighted-average exercise price, beginning of period (per share)	$ 28.62	$ 27.58	$ 27.27
Granted, shares	0	0	0
Granted, weighted-average exercise price (per share)	$ 0	$ 0	$ 0
Exercised, shares	(186)	(333)	(311)
Exercised, weighted-average exercise price (per share)	$ 27.48	$ 25.41	$ 26.11
Forfeited or expired, shares	0	0	(3)
Forfeited or expired, weighted-average exercise price (per share)	$ 0	$ 0	$ 37.97
Outstanding, shares, end of period	511	697	1,030
Outstanding, weighted-average exercise price, end of period (per share)	$ 29.03	$ 28.62	$ 27.58
Outstanding, weighted-average remaining contractual term (in years)	2 years 17 days
Outstanding, aggregate intrinsic value	$ 22,770
Vested and Exercisable, shares	511
Exercisable, weighted-average remaining contractual term (in years)	2 years 17 days
Exercisable, aggregate intrinsic value	$ 22,770
Total intrinsic value of options exercised	$ 8,900	$ 11,500	$ 7,000

STOCK PLANS AND SHARE BASED C59

STOCK PLANS AND SHARE BASED COMPENSATION (Options by Exercise Price Range) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number Outstanding | shares	511
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 17 days
Options Outstanding, Weighted Average Exercise Price (per share)	$ 29.03
Options Vested and Exercisable, Number Vested | shares	511
Options Vested and Exercisable, Weighted Average Exercise Price (per share)	$ 29.03
$17.75 - $24.21
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit	17.75
Options Outstanding, Exercise Price Range, Upper Range Limit	$ 24.21
Options Outstanding, Number Outstanding | shares	263
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	1 year 3 months 5 days
Options Outstanding, Weighted Average Exercise Price (per share)	$ 20.96
Options Vested and Exercisable, Number Vested | shares	263
Options Vested and Exercisable, Weighted Average Exercise Price (per share)	$ 20.96
$31.15 - $42.88
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit	31.15
Options Outstanding, Exercise Price Range, Upper Range Limit	$ 42.88
Options Outstanding, Number Outstanding | shares	248
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 10 months 17 days
Options Outstanding, Weighted Average Exercise Price (per share)	$ 37.56
Options Vested and Exercisable, Number Vested | shares	248
Options Vested and Exercisable, Weighted Average Exercise Price (per share)	$ 37.56

STOCK PLANS AND SHARE BASED C60

STOCK PLANS AND SHARE BASED COMPENSATION (Performance-based Awards and Restricted Stock Units) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Performance Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based awards shares released as a percentage of target number, minimum	0.00%
Number of performance-based awards shares released as a percentage of target number, maximum	200.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Outstanding, shares	79,000	99,000	11,000	0
Granted, shares	88,000	101,000	89,000
Vested, shares	(99,000)	(11,000)	0
Forfeited or expired, shares	(9,000)	(2,000)	(78,000)
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 46.25	$ 52.35	$ 0
Granted, weighted-average grant date fair value per share	63.99	46.26	52.36
Vested, weighted-average grant date fair value per share	46.25	52.35	0
Forfeited or expired, weighted-average grant date fair value per share	63.99	46.87	52.35
Outstanding, weighted-average grant date fair value per share, end of period	$ 63.99	$ 46.25	$ 52.35
Outstanding, weighted-average remaining contractual term (in years)	0 years
Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Outstanding, Aggregate Intrinsic Value	$ 5,819
Outstanding and expected to vest, shares	79,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	0 years
Outstanding and expected to vest, aggregate intrinsic value	$ 5,819
Grant date fair value of awards released	$ 4,600	$ 600
Long-Term Performance-based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based awards shares released as a percentage of target number, minimum	0.00%
Number of performance-based awards shares released as a percentage of target number, maximum	200.00%
Performance based period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Outstanding, shares	184,000	150,000	129,000	61,000
Granted, shares	71,000	78,000	72,000
Vested, shares	0	0	0
Forfeited or expired, shares	(37,000)	(57,000)	(4,000)
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 47.65	$ 53.75	$ 55.51
Granted, weighted-average grant date fair value per share	63	43.26	52.47
Vested, weighted-average grant date fair value per share	0	0	0
Forfeited or expired, weighted-average grant date fair value per share	51.59	55.35	57.76
Outstanding, weighted-average grant date fair value per share, end of period	$ 52.80	$ 47.65	$ 53.75
Outstanding, weighted-average remaining contractual term (in years)	1 year 5 months 25 days
Outstanding, aggregate intrinsic value	$ 13,547
Outstanding and expected to vest, shares	164,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	1 year 3 months 10 days
Outstanding and expected to vest, aggregate intrinsic value	$ 12,072
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Outstanding, shares	948,000	718,000	681,000	692,000
Granted, shares	558,000	331,000	319,000
Vested, shares	(284,000)	(270,000)	(267,000)
Forfeited or expired, shares	(44,000)	(24,000)	(63,000)
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 47.54	$ 46.98	$ 43.86
Granted, weighted-average grant date fair value per share	60.82	46.70	49.75
Vested, weighted-average grant date fair value per share	46.52	45.13	42.49
Forfeited or expired, weighted-average grant date fair value per share	50.89	47.21	45.71
Outstanding, weighted-average grant date fair value per share, end of period	$ 55.51	$ 47.54	$ 46.98
Outstanding, weighted-average remaining contractual term (in years)	1 year 11 months 20 days
Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Outstanding, Aggregate Intrinsic Value	$ 69,742
Outstanding and expected to vest, shares	860,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	1 year 9 months 20 days
Outstanding and expected to vest, aggregate intrinsic value	$ 63,289
Grant date fair value of awards released	$ 13,200	$ 12,200	$ 11,300

SIGNIFICANT CUSTOMERS AND GEO61

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Customer and Credit Risk Concentration) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)customers	Dec. 31, 2016USD ($)customers	Dec. 31, 2015USD ($)customers
Concentration Risk [Line Items]
NET REVENUES | $	$ 108,249	$ 111,255	$ 107,563	$ 104,688	$ 102,436	$ 101,625	$ 97,571	$ 88,036	$ 431,755	$ 389,668	$ 344,609
Distributors [Member]
Concentration Risk [Line Items]
NET REVENUES | $									$ 330,900	$ 292,600	$ 261,400
Credit Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk percentage benchmark for total accounts receivable	10.00%				10.00%				10.00%	10.00%
Number of major customers | customers									10	10
Concentration Risk, Percentage									64.00%	70.00%
Credit Concentration Risk | Accounts Receivable | Avnet
Concentration Risk [Line Items]
Concentration Risk, Percentage									18.00%	24.00%
Customer Concentration Risk | Net Revenues
Concentration Risk [Line Items]
Number of major customers | customers									10	10	10
Concentration Risk, Percentage									10.00%	10.00%	10.00%
Concentration risk percentage of net revenue									54.00%	60.00%	61.00%
Customer Concentration Risk | Net Revenues | Avnet
Concentration Risk [Line Items]
Concentration risk percentage of net revenue									16.00%	18.00%	21.00%
Customer Concentration Risk | Net Revenues | Powertech Distribution Ltd.
Concentration Risk [Line Items]
Concentration risk percentage of net revenue										10.00%	11.00%

SIGNIFICANT CUSTOMERS AND GEO62

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geographic Net Revevnues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Revenues by Geography [Line Items]
NET REVENUES	$ 108,249	$ 111,255	$ 107,563	$ 104,688	$ 102,436	$ 101,625	$ 97,571	$ 88,036	$ 431,755	$ 389,668	$ 344,609
United States of America
Schedule of Revenues by Geography [Line Items]
NET REVENUES									16,647	14,948	14,759
Hong Kong/China
Schedule of Revenues by Geography [Line Items]
NET REVENUES									227,335	198,858	173,202
Taiwan
Schedule of Revenues by Geography [Line Items]
NET REVENUES									50,307	50,324	47,279
Korea
Schedule of Revenues by Geography [Line Items]
NET REVENUES									38,012	41,996	34,264
Western Europe (excluding Germany)
Schedule of Revenues by Geography [Line Items]
NET REVENUES									48,230	41,214	38,028
Japan
Schedule of Revenues by Geography [Line Items]
NET REVENUES									20,769	19,767	16,994
Germany
Schedule of Revenues by Geography [Line Items]
NET REVENUES									11,558	7,563	7,802
Other
Schedule of Revenues by Geography [Line Items]
NET REVENUES									$ 18,897	$ 14,998	$ 12,281

COMMON STOCK REPURCHASES AND 63

COMMON STOCK REPURCHASES AND CASH DIVIDENDS Common Stock Repurchases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 30, 2018
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ 9,188	$ 6,435	$ 53,731
Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 30,000		$ 60,000
Stock Repurchased and Retired During Period, Shares	129,000	146,000	1,300,000
Stock Repurchased and Retired During Period, Value	$ 9,200	$ 6,400	$ 53,700
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 44,400
Subsequent Event [Member] | Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 30,000

COMMON STOCK REPURCHASES AND 64

COMMON STOCK REPURCHASES AND CASH DIVIDENDS Cash Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands

1 Months Ended

3 Months Ended

12 Months Ended

Jan. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Dividends Declared and Paid [Line Items]

Common Stock, Dividends, Per Share, Declared

$ 0.14

$ 0.14

$ 0.14

$ 0.14

$ 0.13

$ 0.13

$ 0.13

$ 0.13

$ 0.12

$ 0.12

$ 0.12

$ 0.12

Payments of Dividends

$ 16,634

$ 15,054

$ 13,916

Subsequent Event [Member]

Dividends Declared and Paid [Line Items]

Common Stock Dividends Declared, Per Share, Payable 1st Quarter 2018

$ 0.16

Common Stock Dividends Declared, Per Share, Payable 2nd Quarter 2018

0.16

Common Stock Dividends Declared, Per Share, Payable 3rd Quarter 2018

0.16

Common Stock Dividends Declared, Per Share, Payable 4th Quarter 2018

$ 0.16

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic earnings per share:
Net income		$ (16,898)	[1]	$ 16,506	$ 13,902	$ 14,099	$ 14,303	$ 12,809	$ 11,407	$ 10,379	$ 27,609	$ 48,898	$ 39,152
Weighted-average common shares		29,759,000		29,759,000	29,720,000	29,456,000	29,196,000	28,972,000	28,850,000	28,679,000	29,674,000	28,925,000	29,001,000
Basic earnings per share		$ (0.57)		$ 0.55	$ 0.47	$ 0.48	$ 0.49	$ 0.44	$ 0.40	$ 0.36	$ 0.93	$ 1.69	$ 1.35
Diluted earnings per share:
Net income		$ (16,898)	[1]	$ 16,506	$ 13,902	$ 14,099	$ 14,303	$ 12,809	$ 11,407	$ 10,379	$ 27,609	$ 48,898	$ 39,152
Weighted-average common shares		29,759,000		29,759,000	29,720,000	29,456,000	29,196,000	28,972,000	28,850,000	28,679,000	29,674,000	28,925,000	29,001,000
Effect of dilutive securities:
Employee stock plans	[2]										871,000	694,000	695,000
Diluted weighted average common shares	[2]	29,759,000		30,614,000	30,454,000	30,248,000	29,914,000	29,625,000	29,422,000	29,244,000	30,545,000	29,619,000	29,696,000
Diluted earnings per share	[2]	$ (0.57)		$ 0.54	$ 0.46	$ 0.47	$ 0.48	$ 0.43	$ 0.39	$ 0.35	$ 0.90	$ 1.65	$ 1.32
Antidilutive shares attributable to stock-based awards outstanding excluded from computation of diluted earnings per share											0	0	8,000
[1]	In December 2017 the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Refer to Note 11, Provision for Income Taxes, in the Notes to Consolidated Financial Statements).
[2]	The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2017, 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.

PROVISION FOR INCOME TAXES (Det

PROVISION FOR INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net				$ (189)
U.S. and foreign components of income before income taxes [Abstract]
U.S. operations	$ (6,944)		$ (477)	(2,246)
Foreign operations	67,243		50,429	41,577
INCOME BEFORE INCOME TAXES	60,299		49,952	39,331
Current provision:
Federal	35,311		0	443
State	4		0	83
Foreign	1,483		1,638	5,407
Current provision	36,798		1,638	5,933
Deferred provision (benefit):
Federal	(3,640)		(175)	(1,791)
State	0		(27)	(57)
Foreign	(468)		(382)	(3,906)
Deferred provision (benefit)	(4,108)		(584)	(5,754)
Total	$ 32,690		$ 1,054	$ 179
Effective income tax rate reconciliation [Abstract]
Provision computed at Federal statutory rate	35.00%		35.00%	35.00%
Business tax credits	(5.70%)		(6.00%)	(6.80%)
Stock-based compensation	(5.00%)		2.20%	0.80%
Foreign income taxed at different rate	(37.30%)		(33.10%)	(33.20%)
IRS audit settlement	54.10%		0.00%	0.00%
U.S. Tax Act - deferred tax asset and liability adjustment	8.10%		0.00%	0.00%
Valuation allowance	2.20%		1.80%	2.60%
Other	2.80%		2.20%	2.10%
Total	54.20%		2.10%	0.50%
Components of deferred income tax asset [Abstract]
Other reserves and accruals	$ 979		$ 1,267
Tax credit carry-forwards	10,442		26,895
Stock compensation	4,064		5,760
Capital losses	163		10,585
Net operating loss	7,059		2,671
Deferred Tax Assets, Other	0		174
Valuation allowance	(18,421)		(27,489)
Deferred tax assets, net of valuation allowance	4,286		19,863
Depreciation	(1,965)		(2,322)
Unremitted earnings	0		(7,019)
Other	(95)		0
Deferred tax liabilities	(2,060)		(9,341)
Net deferred tax asset	2,226	[1]	10,522
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits, Balance at beginning of period	15,393		13,560	$ 11,160
Gross Increase for Tax Positions of Current Year	1,699		1,856	3,063
Gross Decrease for Tax Positions of Prior Years	(409)		(23)	(663)
Unrecognized Tax Benefits, Balance at end of period	16,683		15,393	13,560
Unrecognized tax benefits [Abstract]
Unrecognized Tax Benefits, Balance at end of period	16,683		15,393	$ 13,560
Income tax benefit that would be recorded if unrecognized tax benefits are recognized	10,300
Income tax interest and penalties accrued	100		$ 100
U.S. Tax Cuts and Jobs Act [Abstract]
Provisional One-Time Transition Tax Related to Tax Cuts and Jobs Act	$ 35,300
Future Effective Federal Income Tax Rate Percent	21.00%
Provisional Net Adjustment of Deferred Tax Assets and Liabilities Related to Tax Cuts and Jobs Act	$ 4,900
Current Federal Tax Expense Related to Impact of Tax Cuts and Jobs Act	37,500
State and Local Jurisdiction [Member] | California Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	46,600
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member] | California Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	21,500
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member] | New Jersey Division of Taxation [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	800
Research Tax Credit Carryforward [Member] | Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 2,400
Earliest Tax Year [Member] | State and Local Jurisdiction [Member] | California Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 1, 2032
Earliest Tax Year [Member] | Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member] | New Jersey Division of Taxation [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforwards, Expiration Date	Jan. 1, 2026
Earliest Tax Year [Member] | Research Tax Credit Carryforward [Member] | Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforwards, Expiration Date	Jan. 1, 2030
[1]	The reduction of deferred tax assets is primarily due to the utilization of tax attributes for transition tax related to the Tax Act as well as the reduction of the U.S. federal corporate tax rate from 35% to 21% beginning in 2018.

COMMITMENTS (Details)

COMMITMENTS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 1,875,000
2,019	1,057,000
2,020	699,000
2,021	286,000
2,022	148,000
Thereafter	247,000
Total minimum lease payments	4,312,000
Rent expense, net	2,000,000	$ 1,900,000	$ 2,000,000
Non-cancelable purchase obligations	$ 0

LEGAL PROCEEDINGS AND CONTING68

LEGAL PROCEEDINGS AND CONTINGENCIES (Details) $ in Millions

Sep. 22, 2017patents

Dec. 27, 2016patent

Dec. 12, 2016patents

Nov. 01, 2016patent

Aug. 11, 2016patent

Apr. 01, 2016patent

Oct. 21, 2015patents

May 01, 2012USD ($)patents

Feb. 03, 2011USD ($)

May 05, 2010patents

Dec. 18, 2009patents

Nov. 04, 2009patentspatent

Dec. 22, 2008

Dec. 12, 2008USD ($)

Nov. 07, 2008patents

May 23, 2008patents

Oct. 10, 2006USD ($)

Oct. 20, 2004patents

Nov. 30, 2017USD ($)

Mar. 31, 2017patent

Jan. 31, 2017USD ($)

Dec. 31, 2015USD ($)

Jun. 30, 2015patent

Feb. 28, 2014USD ($)patentspatent

Dec. 31, 2012patents

Apr. 30, 2012patents

May 31, 2010patents

Feb. 28, 2010USD ($)patents

Dec. 31, 2017patents

Patent Inter Partes Review Petition Request One [Domain]

Gain and Loss Contingencies [Line Items]

Number of Patents in Inter Partes Review Petition Request

11

Counterclaims [Member] | Patent Infringement Claim Three Counterclaim [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Patents Allegedly Infringed, Number

2

1

Counterclaims [Member] | Patent Infringment Claim Five [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Damages Awarded, Value | $

$ 2.4

Gain Contingency, Patents Allegedly Infringed upon, Number

5

Judicial Ruling [Member] | Patent Infringement Claim Two [Member]

Gain and Loss Contingencies [Line Items]

Gain Contingency, Patents Found Infringed upon, Number

2

Judicial Ruling [Member] | Patent Infringement Claim Two Counterclaim [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Patents Found Not Infringed, Number

1

Number of Patents Found Invalid

1

Judicial Ruling [Member] | Patent Infringement Claim Four [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Patents Found Not Infringed, Number

4

Judicial Ruling [Member] | Patent Infringment Claim Five [Member]

Gain and Loss Contingencies [Line Items]

Gain Contingency, Patents Found Infringed upon, Number | patent

1

Judicial Ruling [Member] | Patent Inter Partes Review Petition Request One [Domain]

Gain and Loss Contingencies [Line Items]

Number of Patents Denied Inter Partes Review Proceedings

3

Number of Patents in Inter Partes Review Proceedings

8

Pending Litigation [Member] | Patent Infringement Claim One [Member]

Gain and Loss Contingencies [Line Items]

Period for petition for further stay of permanent injunction

90 days

Pending Litigation [Member] | Patent Infringement Claim Two [Member]

Gain and Loss Contingencies [Line Items]

Gain Contingency, Patents Allegedly Infringed upon, Number

3

Pending Litigation [Member] | Patent Infringement Claim Two Counterclaim [Member]

Gain and Loss Contingencies [Line Items]

Number of patents withdrawn from infringement claims

1

Number of patents remaining in infringement claims

2

2

2

Percent of revenue impacted by patents involved in litigation

0.50%

Loss Contingency, Patents Allegedly Infringed, Number

3

Pending Litigation [Member] | Patent Infringement Claim Three Counterclaim [Member]

Gain and Loss Contingencies [Line Items]

Number of patents withdrawn from infringement claims

1

Pending Litigation [Member] | Patent Infringement Claim Four [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Damages Sought, Value | $

$ 19

Loss Contingency, Patents Allegedly Infringed, Number

4

Pending Litigation [Member] | Patent Infringment Claim Five [Member]

Gain and Loss Contingencies [Line Items]

Number of patents withdrawn from infringement claims

1

Loss Contingency, Patents Allegedly Infringed, Number

4

Pending Litigation [Member] | Patent Infringment Claim Six [Member]

Gain and Loss Contingencies [Line Items]

Gain Contingency, Patents Found Infringed upon, Number

2

Pending Litigation [Member] | Patent Infringement Claim Seven [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Patents Allegedly Infringed, Number | patent

1

Pending Litigation [Member] | Patent Infringement Claim Eight [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Patents Allegedly Infringed, Number | patent

6

Pending Litigation [Member] | Patent Infringement Claim Nine [Member]

Gain and Loss Contingencies [Line Items]

Gain Contingency, Patents Allegedly Infringed upon, Number | patent

6

Pending Litigation [Member] | Patent Infringement Claim Ten [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Patents Allegedly Infringed, Number | patent

6

7

Pending Litigation [Member] | Patent Infringement Claim Eleven [Member]

Gain and Loss Contingencies [Line Items]

Loss Contingency, Damages Sought, Value | $

$ 1

Positive Outcome of Litigation [Member] | Patent Infringement Claim One [Member]

Gain and Loss Contingencies [Line Items]

Gain Contingency, Patents Found Infringed upon, Number

4

Litigation Settlement, Amount | $

$ 12.9

$ 6.1

$ 34

Positive Outcome of Litigation [Member] | Patent Infringement Claim Three [Member]

Gain and Loss Contingencies [Line Items]

Litigation Settlement, Amount | $

$ 146.5

$ 139.8

$ 105

Number of Patents in Infringement Case, Unenforceable | patent

1

1

Gain Contingency, Patents Allegedly Infringed upon, Number

2

Loss Contingency, Patents Allegedly Infringed, Number

2

ACQUISITIONS (Cambridge Semicon

ACQUISITIONS (Cambridge Semiconductor Limited) (Details) - Cambridge Semiconductor Limited [Member] - USD ($) $ in Millions	Jan. 02, 2015	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
CamSemi Purchase Price	$ 23.3
Payments to Acquire Businesses, Gross	16.7
Consideration applied against outstanding loan	6.6
Business Combination, Accumulated Acquisition Related Costs	$ 1
Business Combination, Acquisition Related Costs		$ 0.2	$ 0.8

ACQUISITIONS (Purchase Price an

ACQUISITIONS (Purchase Price and Estimated Fair Values) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 02, 2015
Assets Acquired
Goodwill	$ 91,849	$ 91,849	$ 91,849
Cambridge Semiconductor Limited [Member]
Assets Acquired
Cash				$ 1,134
Accounts receivable				1,891
Inventories				1,409
Prepaid expenses and other current assets				408
Tax receivable				1,093
Intangible assets				9,020
Goodwill				11,250
Total assets acquired				26,205
Liabilities Assumed
Current liabilities				1,832
Taxes payable				1,090
Total liabilities assumed				2,922
Total purchase price				23,283
Developed technology | Cambridge Semiconductor Limited [Member]
Assets Acquired
Intangible assets				6,600
Customer relationships [Member] | Cambridge Semiconductor Limited [Member]
Assets Acquired
Intangible assets				$ 2,420

ACQUISITIONS Building (Details)

ACQUISITIONS Building (Details) - Building [Member] - USD ($) $ in Millions	Aug. 31, 2015	Dec. 31, 2017
Business Acquisition [Line Items]
Intangible Asset Useful life (in years)		2 years
Payments to Acquire Businesses, Gross	$ 10.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land	3.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings	6.3
Intangible assets	0.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	$ 0.1
Property and Equipment, Useful Life		30 years

RETIREMENT PLANS (Details)

RETIREMENT PLANS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation	$ 3.8	$ 3.9
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	6.8	7.9
Business Acquisition, Purchase Price Allocation, Projected Benefit Obligation (Asset), Net of Plan Assets Acquired	10.6	11.8
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	0.3
Defined Benefit Pension Items
Defined Benefit Plan Disclosure [Line Items]
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	$ 1.2	$ 1.9	$ 1.6

BANK LINE OF CREDIT (Details)

BANK LINE OF CREDIT (Details) - USD ($) $ in Millions	Dec. 31, 2017	Jul. 27, 2016
Line of Credit Facility [Line Items]
Credit Agreement, maximum borrowing capacity		$ 75
Line of credit, amount outstanding	$ 0
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Credit Agreement, maximum borrowing capacity		$ 20

SELECTED QUARTERLY INFORMATIO74

SELECTED QUARTERLY INFORMATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
NET REVENUES		$ 108,249		$ 111,255	$ 107,563	$ 104,688	$ 102,436	$ 101,625	$ 97,571	$ 88,036	$ 431,755	$ 389,668	$ 344,609
Gross Profit		54,028		55,713	53,447	50,476	50,076	49,842	47,785	44,488	213,664	192,191	173,300
Net income (loss)		$ (16,898)	[1]	$ 16,506	$ 13,902	$ 14,099	$ 14,303	$ 12,809	$ 11,407	$ 10,379	$ 27,609	$ 48,898	$ 39,152
Earnings per share
Basic		$ (0.57)		$ 0.55	$ 0.47	$ 0.48	$ 0.49	$ 0.44	$ 0.40	$ 0.36	$ 0.93	$ 1.69	$ 1.35
Diluted	[2]	$ (0.57)		$ 0.54	$ 0.46	$ 0.47	$ 0.48	$ 0.43	$ 0.39	$ 0.35	$ 0.90	$ 1.65	$ 1.32
Shares used in per share calculation
Basic		29,759		29,759	29,720	29,456	29,196	28,972	28,850	28,679	29,674	28,925	29,001
Diluted	[2]	29,759		30,614	30,454	30,248	29,914	29,625	29,422	29,244	30,545	29,619	29,696
[1]	In December 2017 the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Refer to Note 11, Provision for Income Taxes, in the Notes to Consolidated Financial Statements).
[2]	The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2017, 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.

Schedule II - Valuation and Q75

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Ship and Debit Credits [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 38,075	$ 34,415	$ 27,425
Charged to Costs and Expenses		273,492	262,501	195,669
Deductions	[1]	(272,081)	(258,841)	(188,679)
Balance at End of Period		$ 39,486	$ 38,075	$ 34,415
[1]	Deductions relate to ship and debit credits issued which adjust the sell-in price from the standard distribution price to the pre-approved lower price. Refer to Note 2, Significant Accounting Policies and Recent Accounting Pronouncements, for the Company’s revenue recognition policy, including the Company’s accounting for ship and debit claims.