Power Integrations (POWI) 10-Q 7 May 20 2020 Q1 Quarterly report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION Document - shares	3 Months Ended
	Mar. 31, 2020	May 04, 2020
Document Information [Line Items]
Title of 12(b) Security	Common Stock
Entity Address, Address Line One	5245 Hellyer Avenue
Entity Address, City or Town	San Jose,
Entity Address, State or Province	CA
Entity Incorporation, State or Country Code	DE
Document Type	10-Q
Document Quarterly Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	000-23441
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Registrant Name	POWER INTEGRATIONS, INC.
Trading Symbol	POWI
Entity Central Index Key	0000833640
Entity Filer Category	Large Accelerated Filer
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		29,840,080
Entity Tax Identification Number	94-3065014
Entity Address, Postal Zip Code	95138
Security Exchange Name	NASDAQ
City Area Code	408
Local Phone Number	414-9200
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 190,459	$ 178,690
Short-term marketable securities	232,183	232,398
Accounts receivable, net	20,597	24,274
Inventories	96,633	90,380
Prepaid expenses and other current assets	20,570	15,597
Total current assets	560,442	541,339
PROPERTY AND EQUIPMENT, net	123,430	116,619
INTANGIBLE ASSETS, net	15,748	16,865
GOODWILL	91,849	91,849
DEFERRED TAX ASSETS	1,739	2,836
OTHER ASSETS	34,231	34,388
Total assets	827,439	803,896
CURRENT LIABILITIES:
Accounts payable	37,156	27,433
Accrued payroll and related expenses	10,921	13,408
Taxes payable	567	584
Other accrued liabilities	5,826	9,051
Total current liabilities	54,470	50,476
LONG-TERM INCOME TAXES PAYABLE	14,840	14,617
DEFERRED TAX LIABILITIES	162	164
OTHER LIABILITIES	14,137	14,093
Total liabilities	83,609	79,350
COMMITMENTS AND CONTINGENCIES (Notes 11, 12 and 13)
STOCKHOLDERS’ EQUITY:
Common stock	28	28
Additional paid-in capital	162,343	152,117
Accumulated other comprehensive loss	(4,314)	(3,130)
Retained earnings	585,773	575,531
Total stockholders’ equity	743,830	724,546
Total liabilities and stockholders’ equity	$ 827,439	$ 803,896

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
NET REVENUES		$ 109,664	$ 89,188
COST OF REVENUES		53,184	43,714
GROSS PROFIT		56,480	45,474
OPERATING EXPENSES:
Research and development		19,152	17,946
Sales and marketing		13,473	13,017
General and administrative		8,761	8,390
Total operating expenses		41,386	39,353
INCOME FROM OPERATIONS		15,094	6,121
OTHER INCOME		1,777	1,152
INCOME BEFORE INCOME TAXES		16,871	7,273
PROVISION FOR INCOME TAXES		985	40
NET INCOME		$ 15,886	$ 7,233
EARNINGS PER SHARE:
Basic (in dollars per share)		$ 0.54	$ 0.25
Diluted (in dollars per share)	[1]	$ 0.53	$ 0.25
SHARES USED IN PER SHARE CALCULATION:
Basic (in shares)		29,602	28,951
Diluted (in shares)		30,134	29,446
[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 excluded the shares underlying the outstanding performance-based awards in the 2020 and 2019 calculations as the shares were not contingently issuable as of the end of the reporting periods.

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 15,886	$ 7,233
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of $0 tax in each of the three months ended March 31, 2020 and 2019	(283)	(22)
Unrealized gain (loss) on marketable securities, net of $0 tax in each of the three months ended March 31, 2020 and 2019	(952)	334
Amortization of defined benefit pension items, net of tax of $31 and $5 in the three months ended March 31, 2020, and 2019, respectively	51	16
Total other comprehensive income (loss)	(1,184)	328
TOTAL COMPREHENSIVE INCOME	$ 14,702	$ 7,561

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Tax Effects - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$ 0	$ 0
Unrealized gain (loss) on marketable securities, tax	0	0
Amortization of defined benefit pension items, tax	$ 31	$ 5

STATEMENT OF STOCKHOLDERS' EQUI

STATEMENT OF STOCKHOLDERS' EQUITY Statement - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings
Beginning balance at Dec. 31, 2018		$ 28	$ 126,164	$ (1,689)	$ 402,569
Common stock issued under employee stock plans		0	4,500
Repurchase of common stock		0	(7,302)
Stock-based compensation			4,407
Other comprehensive income (loss)	$ 328			328
Net income	7,233
Payment of dividends to stockholders					(4,937)
Ending balance at Mar. 31, 2019	531,301	28	127,769	(1,361)	404,865
Beginning balance at Dec. 31, 2019	724,546	28	152,117	(3,130)	575,531
Common stock issued under employee stock plans		0	5,529
Repurchase of common stock	(2,000)	0	(2,013)
Stock-based compensation			6,710
Other comprehensive income (loss)	(1,184)			(1,184)
Net income	15,886
Payment of dividends to stockholders					(5,644)
Ending balance at Mar. 31, 2020	$ 743,830	$ 28	$ 162,343	$ (4,314)	$ 585,773

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 15,886	$ 7,233
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	5,488	4,610
Amortization of intangibles	1,117	1,255
Loss on disposal of property and equipment	30	96
Stock-based compensation expense	6,710	4,407
Amortization of premium (accretion of discount) on marketable securities	154	(110)
Deferred income taxes	1,095	1,161
Decrease in accounts receivable allowance for credit losses	(154)	(180)
Change in operating assets and liabilities:
Accounts receivable	3,831	(9,293)
Inventories	(6,253)	(4,223)
Prepaid expenses and other assets	(3,992)	(4,229)
Accounts payable	8,828	1,220
Taxes payable and accrued liabilities	(6,349)	(871)
Net cash provided by operating activities	26,391	1,076
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(11,603)	(3,459)
Acquisition of technology licenses	0	(214)
Purchases of marketable securities	(16,838)	(4,793)
Proceeds from sales and maturities of marketable securities	15,947	6,787
Net cash used in investing activities	(12,494)	(1,679)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	5,529	4,500
Repurchase of common stock	(2,013)	(7,302)
Payments of dividends to stockholders	(5,644)	(4,937)
Net cash used in financing activities	(2,128)	(7,739)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	11,769	(8,342)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	178,690	134,137
CASH AND CASH EQUIVALENTS AT END OF PERIOD	190,459	125,795
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	5,250	2,533
Unpaid technology licenses	0	100
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes, net	$ 305	$ 378

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION: The condensed consolidated financial statements include the accounts of Power Integrations, Inc., a Delaware corporation (the “Company”), and its wholly owned subsidiaries. Significant intercompany accounts and transactions have been eliminated in consolidation. While the financial information furnished is unaudited, the condensed consolidated financial statements included in this report reflect all adjustments (consisting only of normal recurring adjustments) that the Company considers necessary for the fair presentation of the results of operations for the interim periods covered and the financial condition of the Company at the date of the interim balance sheet in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The results for interim periods are not necessarily indicative of the results for the entire year. The condensed consolidated financial statements should be read in conjunction with the Power Integrations, Inc. consolidated financial statements and the notes thereto for the year ended December 31, 2019 , included in its Form 10-K filed on February 7, 2020

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS	3 Months Ended
	Mar. 31, 2020
Accounting Policies and Recent Accounting Pronouncements [Abstract]
Significant accounting policies and recent accounting pronouncements [Text Block]	SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS: Significant Accounting Policies and Estimates No material changes have been made to the Company’s significant accounting policies disclosed in Note 2, Significant Accounting Policies and Recent Accounting Pronouncements , in its Annual Report on Form 10-K, filed on February 7, 2020 , for the year ended December 31, 2019 . Adoption of New Accounting Standards In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), which modifies the measurement of expected credit losses on certain financial instruments. In addition, for available-for-sale debt securities, the standard eliminates the concept of other-than-temporary impairment and requires the recognition of an allowance for credit losses rather than reductions in the amortized cost of the securities. The Company adopted the new standard in the first quarter of 2020, effective January 1, 2020, using the modified-retrospective approach. For available-for-sale debt securities, the Company has made a policy election to present separately accrued interest receivable within prepaid expenses and other current assets on the condensed consolidated balance sheet. Upon adoption, there was no impact on the Company’s condensed consolidated financial statements.

COMPONENTS OF THE COMPANY'S CON

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS	3 Months Ended
	Mar. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Supplemental Balance Sheet Disclosures	3. COMPONENTS OF THE COMPANY’S CONDENSED CONSOLIDATED BALANCE SHEETS: Accounts Receivable (In thousands) March 31, 2020 December 31, 2019 Accounts receivable trade $ 64,232 $ 61,036 Allowance for ship and debit (40,332 ) (33,475 ) Allowance for stock rotation and rebate (2,694 ) (2,524 ) Allowance for credit losses (609 ) (763 ) Total $ 20,597 $ 24,274 The Company maintains an allowance for estimated credit losses resulting from the inability of customers to make required payments. This allowance is established using estimates formulated by the Company’s management based upon factors such as the composition of the accounts receivable aging, historical losses, changes in payments patterns, customer creditworthiness, and current economic trends. Receivables determined to be uncollectible are written off and deducted from the allowance. Allowance for Credit Losses Three Months Ended (In thousands) March 31, 2020 Beginning balance $ (763 ) Provision for credit loss expense — Receivables written off 154 Recoveries collected — Ending balance $ (609 ) Inventories (In thousands) March 31, 2020 December 31, 2019 Raw materials $ 41,413 $ 39,058 Work-in-process 33,809 25,982 Finished goods 21,411 25,340 Total $ 96,633 $ 90,380 Prepaid Expenses and Other Current Assets (In thousands) March 31, 2020 December 31, 2019 Prepaid legal fees $ 157 $ 16 Prepaid income tax 6,230 5,615 Prepaid maintenance agreements 1,318 819 Interest receivable 1,712 1,279 Advance to suppliers 4,204 3,579 Other 6,949 4,289 Total $ 20,570 $ 15,597 Intangible Assets March 31, 2020 December 31, 2019 (In thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Domain name $ 1,261 $ — $ 1,261 $ 1,261 $ — $ 1,261 Developed technology 37,960 (26,730 ) 11,230 37,960 (25,933 ) 12,027 Customer relationships 16,700 (15,025 ) 1,675 20,030 (18,098 ) 1,932 Technology licenses 1,926 (344 ) 1,582 1,926 (281 ) 1,645 Total $ 57,847 $ (42,099 ) $ 15,748 $ 61,177 $ (44,312 ) $ 16,865 The estimated future amortization expense related to finite-lived intangible assets at March 31, 2020 , is as follows: Fiscal Year Estimated Amortization (In thousands) 2020 (remaining nine months) $ 3,242 2021 3,494 2022 2,415 2023 2,173 2024 1,279 Thereafter 1,884 Total $ 14,487 Accumulated Other Comprehensive Loss Changes in accumulated other comprehensive loss for three months ended March 31, 2020 and 2019 , were as follows: Unrealized Gains and Losses on Marketable Securities Defined Benefit Pension Items Foreign Currency Items Total Three Months Ended Three Months Ended Three Months Ended Three Months Ended March 31, March 31, March 31, March 31, (In thousands) 2020 2019 2020 2019 2020 2019 2020 2019 Beginning balance $ 583 $ (266 ) $ (2,484 ) $ (712 ) $ (1,229 ) $ (711 ) $ (3,130 ) $ (1,689 ) Other comprehensive income (loss) before reclassifications (952 ) 334 — — (283 ) (22 ) (1,235 ) 312 Amounts reclassified from accumulated other comprehensive loss — — 51 (1) 16 (1) — — 51 16 Net-current period other comprehensive income (loss) (952 ) 334 51 16 (283 ) (22 ) (1,184 ) 328 Ending balance $ (369 ) $ 68 $ (2,433 ) $ (696 ) $ (1,512 ) $ (733 ) $ (4,314 ) $ (1,361 ) _______________ (1) This component of accumulated other comprehensive income (loss) is included in the computation of net periodic pension cost for the three months ended March 31, 2020 and 2019 .

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS: The FASB established 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 short-term marketable securities 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 fair-value hierarchy of the Company's cash equivalents and marketable securities at March 31, 2020 , and December 31, 2019 , was as follows: Fair Value Measurement at March 31, 2020 (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 217,314 $ — $ 217,314 Commercial paper 161,858 — 161,858 Money market funds 1,707 1,707 — Total $ 380,879 $ 1,707 $ 379,172 Fair Value Measurement at December 31, 2019 (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 232,398 $ — $ 232,398 Commercial paper 146,955 — 146,955 Money market funds 2,983 2,983 — Total $ 382,336 $ 2,983 $ 379,353 The Company did not transfer any investments between Level 1 and Level 2 of the fair-value hierarchy in the three months ended March 31, 2020 , and the twelve months ended December 31, 2019 .

MARKETABLE SECURITITES

MARKETABLE SECURITITES	3 Months Ended
	Mar. 31, 2020
Marketable Securities [Abstract]
Marketable Securities Disclosure	MARKETABLE SECURITIES: Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at March 31, 2020 , were as follows: Amortized Cost Gross Unrealized Estimated Fair Market Value (In thousands) Gains Losses Investments due in 3 months or less: Commercial paper $ 14,869 $ — $ — $ 14,869 Corporate securities 28,104 1 (21 ) 28,084 Total 42,973 1 (21 ) 42,953 Investments due in 4-12 months: Corporate securities 63,204 61 (159 ) 63,106 Total 63,204 61 (159 ) 63,106 Investments due in 12 months or greater: Corporate securities 126,375 145 (396 ) 126,124 Total 126,375 145 (396 ) 126,124 Total marketable securities $ 232,552 $ 207 $ (576 ) $ 232,183 Accrued interest receivable was $1.7 million at March 31, 2020 and was recorded within prepaid expenses and other current assets on the condensed consolidated balance sheet. Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2019 , were as follows: Amortized Cost Gross Unrealized Estimated Fair Market Value (In thousands) Gains Losses Investments due in 3 months or less: Corporate securities $ 15,934 $ 18 $ — $ 15,952 Total 15,934 18 — 15,952 Investments due in 4-12 months: Corporate securities 71,223 269 — 71,492 Total 71,223 269 — 71,492 Investments due in 12 months or greater: Corporate securities 144,658 302 — 144,954 Total 144,658 302 (6 ) 144,954 Total marketable securities $ 231,815 $ 589 $ (6 ) $ 232,398 Accrued interest receivable was $1.3 million at December 31, 2019 and was recorded within prepaid expenses and other current assets on the condensed consolidated balance sheet. The following table summarizes marketable securities classified as available-for-sale (excluding cash equivalents) in a continuous unrealized loss position for which an allowance for credit losses has not been recorded at March 31, 2020 and December 31, 2019 : Less Than 12 Months 12 Months or Longer Total (In thousands) Estimated Fair Market Value Gross Unrealized Losses Estimated Fair Market Value Gross Unrealized Losses Estimated Fair Market Value Gross Unrealized Losses March 31, 2020 Corporate securities $ 138,527 $ (576 ) $ — $ — $ 138,527 $ (576 ) Total marketable securities $ 138,527 $ (576 ) $ — $ — $ 138,527 $ (576 ) December 31, 2019 Corporate securities $ 13,069 $ (6 ) $ — $ — $ 13,069 $ (6 ) Total marketable securities $ 13,069 $ (6 ) $ — $ — $ 13,069 $ (6 ) In the three months ended March 31, 2020 , no unrealized losses on marketable securities were recognized in income. The Company does not intend to sell and it is unlikely that it will be required to sell the securities prior to their anticipated recovery. The issuers are high quality (investment grade) and the decline in fair value is largely due to changes in interest rates and other market conditions. Additionally, the issuers continue to make timely interest payments on the marketable securities with the fair value expected to recover as they reach maturity.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
STOCK PLANS AND SHARE-BASED COMPENSATION	STOCK-BASED COMPENSATION: The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the three months ended March 31, 2020 , and March 31, 2019 : Three Months Ended (In thousands) March 31, 2020 March 31, 2019 Cost of revenues $ 396 $ 271 Research and development 2,109 1,632 Sales and marketing 1,392 1,061 General and administrative 2,813 1,443 Total stock-based compensation expense $ 6,710 $ 4,407 Stock-based compensation expense in the three months ended March 31, 2020 , was approximately $6.7 million , comprising approximately $5.0 million related to restricted stock unit (RSU) awards, $1.3 million related to performance-based (PSU) awards and long-term performance-based (PRSU) awards and $0.4 million related to the Company’s employee stock purchase plan. Stock-based compensation expense in the three months ended March 31, 2019 , was approximately $4.4 million , comprising approximately $4.6 million related to RSUs, a reduction to expense of $0.6 million related to PSUs and PRSUs and $0.4 million related to the Company’s employee stock purchase plan. Stock Options A summary of stock options outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Exercise Price Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 167 $ 38.88 Granted — — Exercised (67 ) $ 38.07 Forfeited or expired — — Outstanding at March 31, 2020 100 $ 39.42 1.50 $ 4,893 Vested and exercisable at March 31, 2020 100 1.50 $ 4,893 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 income 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. In January 2020 , it was determined that approximately 61,000 shares subject to the PSUs granted in 2019 vested in aggregate; the shares were released to the Company’s employees and executives in the first quarter of 2020 . A summary of PSUs outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Grant Date Fair Value Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 61 $ 70.11 Granted 42 $ 100.23 Vested (61 ) $ 70.11 Forfeited — — Outstanding at March 31, 2020 42 $ 100.23 0.75 $ 3,728 Outstanding and expected to vest at March 31, 2020 42 0.75 $ 3,728 PRSU Awards The Company's PRSU program provides for the issuance of PRSUs which will vest based on the Company's performance measured against the PRSU program's established performance targets. PRSUs are 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 2018, 2019 and 2020 were based on the Company’s annual revenue growth over the respective three-year performance period. Expense associated with these awards, net of estimated forfeitures, is recorded throughout the year depending on the number of shares expected to vest based on progress toward the performance target. If the performance conditions are not achieved, no compensation cost is recognized and any previously recognized compensation is reversed. In January 2020 it was determined that no shares subject to the PRSUs granted in 2017 vested in aggregate; thus no shares were released to the Company’s executives in the first quarter of 2020. A summary of PRSUs outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Grant Date Fair Value Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 144 $ 64.05 Granted 73 $ 98.75 Vested — — Forfeited — — Outstanding at March 31, 2020 217 $ 75.70 1.75 $ 19,097 Outstanding and expected to vest at March 31, 2020 131 2.30 $ 11,564 RSU Awards A summary of RSUs outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Grant Date Fair Value Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 860 $ 62.66 Granted 70 $ 97.97 Vested (117 ) $ 58.12 Forfeited (3 ) $ 64.40 Outstanding at March 31, 2020 810 $ 66.39 2.02 $ 71,528 Outstanding and expected to vest at March 31, 2020 752 1.55 $ 66,443

SIGNIFICANT CUSTOMERS AND GEOGR

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES	3 Months Ended
	Mar. 31, 2020
Risks and Uncertainties [Abstract]
Concentration Risk Disclosure [Text Block]	SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES: 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 the 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. Customer Concentration The Company's top ten customers accounted for approximately 55% of net revenues for the three months ended March 31, 2020 , and approximately 52% of net revenues in the corresponding period of the previous year. 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 original equipment manufacturers, or OEMs, and merchant power supply manufacturers. Sales to distributors were $83.5 million and $69.8 million in the three months ended March 31, 2020 and 2019 , respectively. Direct sales to OEMs and power-supply manufacturers accounted for the remainder. In the three months ended March 31, 2020 , two customers, distributors of the Company's products, accounted for more than 10% of the Company’s net revenues. In the three months ended March 31, 2019 , one of the two customers accounted for more than 10% of the Company’s net revenues. The following table discloses the customers’ percentage of revenues for the respective periods: Three Months Ended Customer March 31, 2020 March 31, 2019 Avnet 11 % 13 % Powertech Distribution Ltd. 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 consist principally of cash investments and trade receivables. The Company does not have any off-balance-sheet credit exposure related to its customers. As of March 31, 2020 , and December 31, 2019 , 69% and 63% , respectively, of accounts receivable were concentrated with the Company’s top ten customers. The following customers represented 10% or more of accounts receivable: Customer March 31, 2020 December 31, 2019 Powertech Distribution Ltd. 16 % 10 % Avnet 13 % * Burnon International Ltd. 10 % * *Total customer accounts receivable was less than 10% of accounts receivable. 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, for the three months ended March 31, 2020 , and March 31, 2019 , were as follows: Three Months Ended (In thousands) March 31, 2020 March 31, 2019 United States of America $ 2,713 $ 2,672 Hong Kong/China 60,413 47,229 Taiwan 6,479 6,672 Korea 10,357 8,542 Western Europe (excluding Germany) 10,035 10,901 Japan 3,905 3,650 Germany 5,567 4,927 Other 10,195 4,595 Total net revenues $ 109,664 $ 89,188

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Stockholders' Equity [Text Block]	STOCKHOLDERS’ EQUITY: Common Stock Shares Outstanding Three Months Ended (In thousands) March 31, 2020 March 31, 2019 Beginning balance 29,431 28,889 Common stock issued under employee stock plans 284 342 Repurchased (24 ) (121 ) Ending balance 29,691 29,110 Common Stock Repurchases As of December 31, 2019, the Company had approximately $43.9 million remaining under its stock-repurchase program. In the three months ended March 31, 2020 , the Company repurchased approximately 24,000 shares of its common stock for approximately $2.0 million . As of March 31, 2020 , the Company had approximately $41.9 million remaining under its current repurchase program, which has no expiration date. Authorization of future 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, business conditions and other factors. Cash Dividends In January 2019, the Company’s board of directors declared four quarterly cash dividends in the amount of $0.17 per share to be paid to stockholders of record at the end of each quarter in 2019. In October 2019, the Company’s board of directors raised the cash dividends per share with the declaration of five cash dividends, consisting of (a) a dividend in the amount of $0.02 per share to be paid to stockholders of record at the end of the fourth quarter in 2019, which is in addition to the dividend in the amount of $0.17 per share to be paid to stockholders of record at the end of the fourth quarter in 2019 previously declared by the board in January 2019, and (b) a dividend in the amount of $0.19 per share to be paid to stockholders of record at the end of each quarter in 2020. In April 2020, the Company’s board of directors raised the cash dividends further with the declaration of three cash dividends in the amount of $0.21 per share (in lieu of the $0.19 per share previously announced) to be paid to stockholders of record at the end of each of the second, third and fourth quarter in 2020. For the three months ended March 31, 2020 , and 2019, cash dividends declared and paid were as follows: Three Months Ended (In thousands, except per share amounts) March 31, 2020 March 31, 2019 Dividends declared and paid $ 5,644 $ 4,937 Dividends declared per common share $ 0.19 $ 0.17

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
EARNINGS PER SHARE	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: Three Months Ended (In thousands, except per share amounts) March 31, 2020 March 31, 2019 Basic earnings per share: Net income $ 15,886 $ 7,233 Weighted-average common shares 29,602 28,951 Basic earnings per share $ 0.54 $ 0.25 Diluted earnings per share: (1) Net income $ 15,886 $ 7,233 Weighted-average common shares 29,602 28,951 Effect of dilutive awards: Employee stock plans 532 495 Diluted weighted-average common shares 30,134 29,446 Diluted earnings per share $ 0.53 $ 0.25 _______________ (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 excluded the shares underlying the outstanding performance-based awards in the 2020 and 2019 calculations as the shares were not contingently issuable as of the end of the reporting periods. In the three months ended March 31, 2020 and 2019 , no outstanding stock awards were determined to be anti-dilutive and therefore excluded from the computation of diluted earnings per share.

PROVISION FOR INCOME TAXES

PROVISION FOR INCOME TAXES	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
PROVISION FOR INCOME TAXES	PROVISION FOR INCOME TAXES: Income-tax expense includes a provision for federal, state and foreign taxes based on the annual estimated effective tax rate applicable to the Company and its subsidiaries, adjusted for certain discrete items which are fully recognized in the period they occur. Accordingly, the interim effective tax rate may not be reflective of the annual estimated effective tax rate. The Company's effective tax rates for the three months ended March 31, 2020 and 2019, were 5.8% and 0.5% , respectively. In the three months ended March 31, 2020 and 2019 , the effective tax rate was lower than the statutory federal income-tax rate of 21% due to the geographic distribution of the Company’s world-wide earnings in lower-tax jurisdictions, federal research tax credits and the recognition of excess tax benefits related to share-based payments. These benefits were partially offset by foreign income subject to U.S. tax, known as global intangible low-taxed income. The Company’s primary jurisdiction where foreign earnings are derived is the Cayman Islands, which is a non-taxing jurisdiction. Income earned in other foreign jurisdictions was not material. The Company has not been granted any incentivized tax rates and does not operate under any tax holidays in any jurisdiction. As of March 31, 2020 , the Company maintained a valuation allowance on its California deferred tax assets, New Jersey deferred tax assets, and capital losses for federal purposes, and a valuation allowance with respect to its deferred tax assets relating to tax credits in Canada. Determining the consolidated provision for income-tax expense, income-tax liabilities and deferred tax assets and liabilities involves judgment. The Company calculates and provides for income taxes in each of the tax jurisdictions in which it operates, which involves estimating current tax exposures as well as making judgments regarding the recoverability of deferred tax assets in each jurisdiction. The estimates used could differ from actual results, which may have a significant impact on operating results in future periods.

COMMITMENTS

COMMITMENTS	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS	COMMITMENTS: Supplier Agreements Under the terms of the Company's wafer-supply agreements with Seiko Epson Corporation ("Epson"), and ROHM Lapis Semiconductor Co., Ltd. ("Lapis") the wafers purchased from these suppliers are priced in U.S. dollars, with mutual sharing of the impact of fluctuations in the exchange rate between the Japanese yen and the U.S. dollar on future purchases. Each year, the Company's management and these two suppliers review and negotiate future pricing; the negotiated pricing is denominated in U.S. dollars but is subject to contractual exchange rate provisions. The fluctuation in the exchange rate is shared equally between the Company and each of these suppliers on future purchases.

LEGAL PROCEEDINGS AND CONTINGEN

LEGAL PROCEEDINGS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
LEGAL PROCEEDINGS AND CONTINGENCIES	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 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. On December 21, 2018, the Court granted the Company’s challenge to Opticurrent’s damages expert but denied the Company’s motion for summary judgment. Following a trial in February 2019, a jury issued a finding of direct infringement by the Company but found that the Company did not induce infringement, and awarded Opticurrent damages of $6.7 million . The Company challenged those findings in post-trial proceedings, and the Court granted one of the Company’s post-trial motions, reducing the damages award to $1.2 million . The Company believes it has strong defenses, and intends to vigorously defend itself against Opticurrent’s claims through appeals, which are currently under way, with briefing completed and oral argument to follow in the coming months. On June 19, 2019, Opticurrent, LLC filed a follow-on lawsuit accusing more of the Company’s products of infringing the same claim of the same patent asserted in the parties’ prior litigation, as described above. The Company believes it has strong defenses, and intends to vigorously defend itself against Opticurrent’s claims, with appeals to follow if necessary. On January 6, 2020, the Company filed a complaint against CogniPower LLC for infringement of two of the Company’s patents and seeking a declaration of non-infringement with respect to three patents that CogniPower had charged the Company’s customers with infringing. The case is in its preliminary stages, and no schedule has been set for the case at this time, but the Company believes it has strong claims and defenses, and intends to vigorously defend itself against CogniPower’s infringement claims, with appeals to follow if necessary. 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.

INDEMNIFICATIONS

INDEMNIFICATIONS	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
INDEMNIFICATIONS	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 March 31, 2020 . 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.

COMPONENTS OF THE COMPANY'S C_2

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS (Tables)	3 Months Ended
	Mar. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts Receivable	Accounts Receivable (In thousands) March 31, 2020 December 31, 2019 Accounts receivable trade $ 64,232 $ 61,036 Allowance for ship and debit (40,332 ) (33,475 ) Allowance for stock rotation and rebate (2,694 ) (2,524 ) Allowance for credit losses (609 ) (763 ) Total $ 20,597 $ 24,274
Accounts Receivable, Allowance for Credit Loss [Table Text Block]	The Company maintains an allowance for estimated credit losses resulting from the inability of customers to make required payments. This allowance is established using estimates formulated by the Company’s management based upon factors such as the composition of the accounts receivable aging, historical losses, changes in payments patterns, customer creditworthiness, and current economic trends. Receivables determined to be uncollectible are written off and deducted from the allowance. Allowance for Credit Losses Three Months Ended (In thousands) March 31, 2020 Beginning balance $ (763 ) Provision for credit loss expense — Receivables written off 154 Recoveries collected — Ending balance $ (609 )
Schedule of Inventory, Current	Inventories (In thousands) March 31, 2020 December 31, 2019 Raw materials $ 41,413 $ 39,058 Work-in-process 33,809 25,982 Finished goods 21,411 25,340 Total $ 96,633 $ 90,380
Schedule of Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets (In thousands) March 31, 2020 December 31, 2019 Prepaid legal fees $ 157 $ 16 Prepaid income tax 6,230 5,615 Prepaid maintenance agreements 1,318 819 Interest receivable 1,712 1,279 Advance to suppliers 4,204 3,579 Other 6,949 4,289 Total $ 20,570 $ 15,597
Schedule Of Intangible Assets	Intangible Assets March 31, 2020 December 31, 2019 (In thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Domain name $ 1,261 $ — $ 1,261 $ 1,261 $ — $ 1,261 Developed technology 37,960 (26,730 ) 11,230 37,960 (25,933 ) 12,027 Customer relationships 16,700 (15,025 ) 1,675 20,030 (18,098 ) 1,932 Technology licenses 1,926 (344 ) 1,582 1,926 (281 ) 1,645 Total $ 57,847 $ (42,099 ) $ 15,748 $ 61,177 $ (44,312 ) $ 16,865
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated future amortization expense related to finite-lived intangible assets at March 31, 2020 , is as follows: Fiscal Year Estimated Amortization (In thousands) 2020 (remaining nine months) $ 3,242 2021 3,494 2022 2,415 2023 2,173 2024 1,279 Thereafter 1,884 Total $ 14,487
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive loss for three months ended March 31, 2020 and 2019 , were as follows: Unrealized Gains and Losses on Marketable Securities Defined Benefit Pension Items Foreign Currency Items Total Three Months Ended Three Months Ended Three Months Ended Three Months Ended March 31, March 31, March 31, March 31, (In thousands) 2020 2019 2020 2019 2020 2019 2020 2019 Beginning balance $ 583 $ (266 ) $ (2,484 ) $ (712 ) $ (1,229 ) $ (711 ) $ (3,130 ) $ (1,689 ) Other comprehensive income (loss) before reclassifications (952 ) 334 — — (283 ) (22 ) (1,235 ) 312 Amounts reclassified from accumulated other comprehensive loss — — 51 (1) 16 (1) — — 51 16 Net-current period other comprehensive income (loss) (952 ) 334 51 16 (283 ) (22 ) (1,184 ) 328 Ending balance $ (369 ) $ 68 $ (2,433 ) $ (696 ) $ (1,512 ) $ (733 ) $ (4,314 ) $ (1,361 ) _______________ (1) This component of accumulated other comprehensive income (loss) is included in the computation of net periodic pension cost for the three months ended March 31, 2020 and 2019 .

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair value of marketable securities and investments	The fair-value hierarchy of the Company's cash equivalents and marketable securities at March 31, 2020 , and December 31, 2019 , was as follows: Fair Value Measurement at March 31, 2020 (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 217,314 $ — $ 217,314 Commercial paper 161,858 — 161,858 Money market funds 1,707 1,707 — Total $ 380,879 $ 1,707 $ 379,172 Fair Value Measurement at December 31, 2019 (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Corporate securities $ 232,398 $ — $ 232,398 Commercial paper 146,955 — 146,955 Money market funds 2,983 2,983 — Total $ 382,336 $ 2,983 $ 379,353

MARKETABLE SECURITITES (Tables)

MARKETABLE SECURITITES (Tables)	3 Months Ended
	Mar. 31, 2020
Marketable Securities [Abstract]
Available-for-sale Securities	Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at March 31, 2020 , were as follows: Amortized Cost Gross Unrealized Estimated Fair Market Value (In thousands) Gains Losses Investments due in 3 months or less: Commercial paper $ 14,869 $ — $ — $ 14,869 Corporate securities 28,104 1 (21 ) 28,084 Total 42,973 1 (21 ) 42,953 Investments due in 4-12 months: Corporate securities 63,204 61 (159 ) 63,106 Total 63,204 61 (159 ) 63,106 Investments due in 12 months or greater: Corporate securities 126,375 145 (396 ) 126,124 Total 126,375 145 (396 ) 126,124 Total marketable securities $ 232,552 $ 207 $ (576 ) $ 232,183 Accrued interest receivable was $1.7 million at March 31, 2020 and was recorded within prepaid expenses and other current assets on the condensed consolidated balance sheet. Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2019 , were as follows: Amortized Cost Gross Unrealized Estimated Fair Market Value (In thousands) Gains Losses Investments due in 3 months or less: Corporate securities $ 15,934 $ 18 $ — $ 15,952 Total 15,934 18 — 15,952 Investments due in 4-12 months: Corporate securities 71,223 269 — 71,492 Total 71,223 269 — 71,492 Investments due in 12 months or greater: Corporate securities 144,658 302 — 144,954 Total 144,658 302 (6 ) 144,954 Total marketable securities $ 231,815 $ 589 $ (6 ) $ 232,398
Available-for-sale Securities in an Unrealized Loss Position	The following table summarizes marketable securities classified as available-for-sale (excluding cash equivalents) in a continuous unrealized loss position for which an allowance for credit losses has not been recorded at March 31, 2020 and December 31, 2019 : Less Than 12 Months 12 Months or Longer Total (In thousands) Estimated Fair Market Value Gross Unrealized Losses Estimated Fair Market Value Gross Unrealized Losses Estimated Fair Market Value Gross Unrealized Losses March 31, 2020 Corporate securities $ 138,527 $ (576 ) $ — $ — $ 138,527 $ (576 ) Total marketable securities $ 138,527 $ (576 ) $ — $ — $ 138,527 $ (576 ) December 31, 2019 Corporate securities $ 13,069 $ (6 ) $ — $ — $ 13,069 $ (6 ) Total marketable securities $ 13,069 $ (6 ) $ — $ — $ 13,069 $ (6 )

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-based Compensation Expense	The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the three months ended March 31, 2020 , and March 31, 2019 : Three Months Ended (In thousands) March 31, 2020 March 31, 2019 Cost of revenues $ 396 $ 271 Research and development 2,109 1,632 Sales and marketing 1,392 1,061 General and administrative 2,813 1,443 Total stock-based compensation expense $ 6,710 $ 4,407
Summary of Option Activity Under the Plans	A summary of stock options outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Exercise Price Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 167 $ 38.88 Granted — — Exercised (67 ) $ 38.07 Forfeited or expired — — Outstanding at March 31, 2020 100 $ 39.42 1.50 $ 4,893 Vested and exercisable at March 31, 2020 100 1.50 $ 4,893
Performance Based Awards (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of PSUs outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Grant Date Fair Value Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 61 $ 70.11 Granted 42 $ 100.23 Vested (61 ) $ 70.11 Forfeited — — Outstanding at March 31, 2020 42 $ 100.23 0.75 $ 3,728 Outstanding and expected to vest at March 31, 2020 42 0.75 $ 3,728
Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of PRSUs outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Grant Date Fair Value Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 144 $ 64.05 Granted 73 $ 98.75 Vested — — Forfeited — — Outstanding at March 31, 2020 217 $ 75.70 1.75 $ 19,097 Outstanding and expected to vest at March 31, 2020 131 2.30 $ 11,564
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of RSUs outstanding as of March 31, 2020 , and activity during the three months then ended, is presented below: Shares (In thousands) Weighted- Average Grant Date Fair Value Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at January 1, 2020 860 $ 62.66 Granted 70 $ 97.97 Vested (117 ) $ 58.12 Forfeited (3 ) $ 64.40 Outstanding at March 31, 2020 810 $ 66.39 2.02 $ 71,528 Outstanding and expected to vest at March 31, 2020 752 1.55 $ 66,443

SIGNIFICANT CUSTOMERS AND GEO_2

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Tables)	3 Months Ended
	Mar. 31, 2020
Concentration Risk [Line Items]
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, for the three months ended March 31, 2020 , and March 31, 2019 , were as follows: Three Months Ended (In thousands) March 31, 2020 March 31, 2019 United States of America $ 2,713 $ 2,672 Hong Kong/China 60,413 47,229 Taiwan 6,479 6,672 Korea 10,357 8,542 Western Europe (excluding Germany) 10,035 10,901 Japan 3,905 3,650 Germany 5,567 4,927 Other 10,195 4,595 Total net revenues $ 109,664 $ 89,188
Revenue from Contract with Customer Benchmark [Member]
Concentration Risk [Line Items]
Schedules of Concentration of Risk, by Risk Factor	The following table discloses the customers’ percentage of revenues for the respective periods: Three Months Ended Customer March 31, 2020 March 31, 2019 Avnet 11 % 13 % Powertech Distribution Ltd. 11 % * *Total customer revenue was less than 10% of net revenues.
Accounts Receivable [Member]
Concentration Risk [Line Items]
Schedules of Concentration of Risk, by Risk Factor	The following customers represented 10% or more of accounts receivable: Customer March 31, 2020 December 31, 2019 Powertech Distribution Ltd. 16 % 10 % Avnet 13 % * Burnon International Ltd. 10 % * *Total customer accounts receivable was less than 10% of accounts receivable. No other customers accounted for 10% or more of the Company’s accounts receivable in the periods presented.

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Schedule of Common Stock [Table Text Block]	Three Months Ended (In thousands) March 31, 2020 March 31, 2019 Beginning balance 29,431 28,889 Common stock issued under employee stock plans 284 342 Repurchased (24 ) (121 ) Ending balance 29,691 29,110
Dividends Declared and Paid [Table Text Block]	Three Months Ended (In thousands, except per share amounts) March 31, 2020 March 31, 2019 Dividends declared and paid $ 5,644 $ 4,937 Dividends declared per common share $ 0.19 $ 0.17

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Earnings per share calculation	A summary of the earnings per share calculation is as follows: Three Months Ended (In thousands, except per share amounts) March 31, 2020 March 31, 2019 Basic earnings per share: Net income $ 15,886 $ 7,233 Weighted-average common shares 29,602 28,951 Basic earnings per share $ 0.54 $ 0.25 Diluted earnings per share: (1) Net income $ 15,886 $ 7,233 Weighted-average common shares 29,602 28,951 Effect of dilutive awards: Employee stock plans 532 495 Diluted weighted-average common shares 30,134 29,446 Diluted earnings per share $ 0.53 $ 0.25 _______________ (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 excluded the shares underlying the outstanding performance-based awards in the 2020 and 2019 calculations as the shares were not contingently issuable as of the end of the reporting periods.

COMPONENTS OF THE COMPANY'S C_3

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accounts receivable trade	$ 64,232	$ 61,036
Allowance for ship and debit	(40,332)	(33,475)
Allowance for stock rotation and rebate	(2,694)	(2,524)
Allowance for credit losses	(609)	(763)
Total	$ 20,597	$ 24,274

COMPONENTS OF THE COMPANY'S C_4

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 41,413	$ 39,058
Work-in-process	33,809	25,982
Finished goods	21,411	25,340
Total	$ 96,633	$ 90,380

COMPONENTS OF THE COMPANY'S C_5

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Prepaid legal fees	$ 157	$ 16
Prepaid income tax	6,230	5,615
Prepaid maintenance agreements	1,318	819
Interest receivable	1,712	1,279
Advance to suppliers	4,204	3,579
Other	6,949	4,289
Total	$ 20,570	$ 15,597

COMPONENTS OF THE COMPANY'S C_6

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Intangible Assets [Table] [Line Items]
Intangible Assets, Gross	$ 57,847	$ 61,177
Finite-Lived Intangible Assets, Accumulated Amortization	(42,099)	(44,312)
Total	15,748	16,865
Finite-Lived Intangible Assets, Net	14,487
Developed technology
Schedule of Intangible Assets [Table] [Line Items]
Finite-Lived Intangible Assets, Gross	37,960	37,960
Finite-Lived Intangible Assets, Accumulated Amortization	(26,730)	(25,933)
Finite-Lived Intangible Assets, Net	11,230	12,027
Customer relationships
Schedule of Intangible Assets [Table] [Line Items]
Finite-Lived Intangible Assets, Gross	16,700	20,030
Finite-Lived Intangible Assets, Accumulated Amortization	(15,025)	(18,098)
Finite-Lived Intangible Assets, Net	1,675	1,932
Technology licenses
Schedule of Intangible Assets [Table] [Line Items]
Finite-Lived Intangible Assets, Gross	1,926	1,926
Finite-Lived Intangible Assets, Accumulated Amortization	(344)	(281)
Finite-Lived Intangible Assets, Net	1,582	1,645
Internet Domain Names [Member]
Schedule of Intangible Assets [Table] [Line Items]
Indefinite-Lived Intangible Assets	$ 1,261	$ 1,261

COMPONENTS OF THE COMPANY'S C_7

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Future Amortization Expense (Details) $ in Thousands	Mar. 31, 2020USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2020 (remaining nine months)	$ 3,242
2021	3,494
2022	2,415
2023	2,173
2024	1,279
Thereafter	1,884
Total	$ 14,487

COMPONENTS OF THE COMPANY'S C_8

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (3,130)	$ (1,689)
Other comprehensive income (loss) before reclassifications	(1,235)	312
Amounts reclassified from accumulated other comprehensive loss	51	16
Net-current period other comprehensive income (loss)	(1,184)	328
Ending balance	(4,314)	(1,361)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	583	(266)
Other comprehensive income (loss) before reclassifications	(952)	334
Amounts reclassified from accumulated other comprehensive loss	0	0
Net-current period other comprehensive income (loss)	(952)	334
Ending balance	(369)	68
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,484)	(712)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	51	16
Net-current period other comprehensive income (loss)	51	16
Ending balance	(2,433)	(696)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,229)	(711)
Other comprehensive income (loss) before reclassifications	(283)	(22)
Amounts reclassified from accumulated other comprehensive loss	0	0
Net-current period other comprehensive income (loss)	(283)	(22)
Ending balance	$ (1,512)	$ (733)

COMPONENTS OF THE COMPANY'S C_9

COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accounts Receivable, Allowance for Credit Loss, Current	$ 609	$ 763
Provision for credit loss expense	0
Receivables written off	154
Recoveries collected	$ 0

FAIR VALUE MEASUREMENTS Fair Va

FAIR VALUE MEASUREMENTS Fair Value Measurement (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments at Fair Value	$ 380,879	$ 382,336
Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	217,314	232,398
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	161,858	146,955
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	1,707	2,983
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 at Fair Value	1,707	2,983
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	1,707	2,983
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments at Fair Value	379,172	379,353
Significant Other Observable Inputs (Level 2) | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	217,314	232,398
Significant Other Observable Inputs (Level 2) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	161,858	146,955
Significant Other Observable Inputs (Level 2) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	$ 0	$ 0

MARKETABLE SECURITITES Marketab

MARKETABLE SECURITITES Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Interest receivable	$ 1,712	$ 1,279
Amortized Cost	232,552	231,815
Gross Unrealized Gains	207	589
Gross Unrealized Losses	(576)	(6)
Estimated Fair Market Value	232,183	232,398
Investments due in 3 months or less:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	42,973	15,934
Gross Unrealized Gains	1	18
Gross Unrealized Losses	(21)	0
Estimated Fair Market Value	42,953	15,952
Investments due in 4-12 months:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	63,204	71,223
Gross Unrealized Gains	61	269
Gross Unrealized Losses	(159)	0
Estimated Fair Market Value	63,106	71,492
Investments due in 12 months or greater:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	126,375	144,658
Gross Unrealized Gains	145	302
Gross Unrealized Losses	(396)	(6)
Estimated Fair Market Value	126,124	144,954
Commercial paper | Investments due in 3 months or less:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	14,869
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Market Value	14,869
Corporate securities | Investments due in 3 months or less:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,104	15,934
Gross Unrealized Gains	1	18
Gross Unrealized Losses	(21)	0
Estimated Fair Market Value	28,084	15,952
Corporate securities | Investments due in 4-12 months:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	63,204	71,223
Gross Unrealized Gains	61	269
Gross Unrealized Losses	(159)	0
Estimated Fair Market Value	63,106	71,492
Corporate securities | Investments due in 12 months or greater:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	126,375	144,658
Gross Unrealized Gains	145	302
Gross Unrealized Losses	(396)	0
Estimated Fair Market Value	$ 126,124	$ 144,954

MARKETABLE SECURITITES Market_2

MARKETABLE SECURITITES Marketable Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 138,527	$ 13,069
Debt Securities, Available-for sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(576)	(6)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	138,527	13,069
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(576)	(6)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0
Corporate securities
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	138,527	13,069
Debt Securities, Available-for sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(576)	(6)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	138,527	13,069
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (576)	$ (6)

STOCK-BASED COMPENSATION Stock-

STOCK-BASED COMPENSATION Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	$ 6,710	$ 4,407
Performance Based Awards and Long Term Performance based Units
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	1,300	(600)
Restricted Stock Units (RSUs)
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	5,000	4,600
Employee Stock Purchase Plan
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	400	400
Cost of revenues
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	396	271
Research and development
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	2,109	1,632
Sales and marketing
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	1,392	1,061
General and administrative
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-Based Compensation Expense	$ 2,813	$ 1,443

STOCK-BASED COMPENSATION Option

STOCK-BASED COMPENSATION Option Activity (Details) - Stock Options $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)$ / sharesshares
Option activity under the Plans
Outstanding at January 1, 2020	167
Granted	0
Exercised	(67)
Forfeited or expired	0
Outstanding at March 31, 2020	100
Vested and exercisable at March 31, 2020	100
Weighted- Average Exercise Price (in dollars per share)
Outstanding at January 1, 2020 | $ / shares	$ 38.88
Granted | $ / shares	0
Exercised | $ / shares	38.07
Forfeited or expired | $ / shares	0
Outstanding at March 31, 2020 | $ / shares	$ 39.42
Weighted-Average Remaining Contractual Term (In years)
Outstanding, weighted-average remaining contractual term at period end	1 year 6 months
Exercisable, weighted-average remaining contractual term, at period-end	1 year 6 months
Aggregate Intrinsic Value [Abstract]
Outstanding, aggregate intrinsic value at period end | $	$ 4,893
Exercisable, aggregate intrinsic value, at period end | $	$ 4,893

STOCK-BASED COMPENSATION Perfor

STOCK-BASED COMPENSATION Performance-based Awards and Restricted Stock Units (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)$ / sharesshares
Restricted Stock Units (RSUs)
Shares
Outstanding at January 1, 2020	860,000
Granted	70,000
Vested	(117,000)
Forfeited	(3,000)
Outstanding at March 31, 2020	810,000
Outstanding and expected to vest at March 31, 2020	752,000
Weighted- Average Grant Date Fair Value Per Share (in dollars per share)
Outstanding at January 1, 2020 | $ / shares	$ 62.66
Granted | $ / shares	97.97
Vested | $ / shares	58.12
Forfeited | $ / shares	64.40
Outstanding at March 31, 2020 | $ / shares	$ 66.39
Weighted-Average Remaining Contractual Term (In years)
Outstanding at March 31, 2020	2 years 7 days
Outstanding and expected to vest at March 31, 2020	1 year 6 months 18 days
Aggregate Intrinsic Value (In thousands)
Outstanding at March 31, 2020 | $	$ 71,528
Outstanding and expected to vest at March 31, 2020 | $	$ 66,443
Long-Term Performance-Based Awards (PRSUs)
Shares
Outstanding at January 1, 2020	144,000
Granted	73,000
Vested	0
Forfeited	0
Outstanding at March 31, 2020	217,000
Outstanding and expected to vest at March 31, 2020	131,000
Weighted- Average Grant Date Fair Value Per Share (in dollars per share)
Outstanding at January 1, 2020 | $ / shares	$ 64.05
Granted | $ / shares	98.75
Vested | $ / shares	0
Forfeited | $ / shares	0
Outstanding at March 31, 2020 | $ / shares	$ 75.70
Weighted-Average Remaining Contractual Term (In years)
Outstanding at March 31, 2020	1 year 9 months
Outstanding and expected to vest at March 31, 2020	2 years 3 months 18 days
Aggregate Intrinsic Value (In thousands)
Outstanding at March 31, 2020 | $	$ 19,097
Outstanding and expected to vest at March 31, 2020 | $	$ 11,564
Performance Based Awards (PSUs)
Shares
Outstanding at January 1, 2020	61,000
Granted	42,000
Vested	(61,000)
Forfeited	0
Outstanding at March 31, 2020	42,000
Outstanding and expected to vest at March 31, 2020	42,000
Weighted- Average Grant Date Fair Value Per Share (in dollars per share)
Outstanding at January 1, 2020 | $ / shares	$ 70.11
Granted | $ / shares	100.23
Vested | $ / shares	70.11
Forfeited | $ / shares	0
Outstanding at March 31, 2020 | $ / shares	$ 100.23
Weighted-Average Remaining Contractual Term (In years)
Outstanding at March 31, 2020	9 months
Outstanding and expected to vest at March 31, 2020	9 months
Aggregate Intrinsic Value (In thousands)
Outstanding at March 31, 2020 | $	$ 3,728
Outstanding and expected to vest at March 31, 2020 | $	$ 3,728
Minimum [Member] | Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	0.00%
Minimum [Member] | Performance Based Awards (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	0.00%
Maximum [Member] | Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	200.00%
Maximum [Member] | Performance Based Awards (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	200.00%

SIGNIFICANT CUSTOMERS AND GEO_3

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Customer and Credit Risk Concentration (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020USD ($)Customer	Mar. 31, 2019USD ($)Customer	Dec. 31, 2019
Concentration Risk [Line Items]
NET REVENUES | $	$ 109,664	$ 89,188
Distributors [Member]
Concentration Risk [Line Items]
NET REVENUES | $	$ 83,500	$ 69,800
Revenue from Contract with Customer Benchmark [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers	2	1
Concentration risk percentage benchmark	10.00%	10.00%
Revenue from Contract with Customer Benchmark [Member] | Customer Concentration Risk [Member] | Avnet
Concentration Risk [Line Items]
Concentration risk, percentage of total net revenues	11.00%	13.00%
Revenue from Contract with Customer Benchmark [Member] | Customer Concentration Risk [Member] | Avnet
Concentration Risk [Line Items]
Concentration risk, percentage of total net revenues	11.00%
Revenue from Contract with Customer Benchmark [Member] | Customer Concentration Risk [Member] | Ten Customers
Concentration Risk [Line Items]
Number of major customers	10	10
Concentration risk, percentage of total net revenues	55.00%	52.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers	10
Concentration risk percentage benchmark for accounts receivable (more than)	10.00%		10.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Avnet
Concentration Risk [Line Items]
Concentration risk percentage benchmark	13.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Avnet
Concentration Risk [Line Items]
Concentration risk percentage benchmark	16.00%		10.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Ten Customers
Concentration Risk [Line Items]
Concentration risk percentage benchmark	69.00%		63.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Burnon [Member]
Concentration Risk [Line Items]
Concentration risk percentage benchmark	10.00%

SIGNIFICANT CUSTOMERS AND GEO_4

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES Geograpic Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue by Geography
Total net revenues	$ 109,664	$ 89,188
United States of America
Revenue by Geography
Total net revenues	2,713	2,672
Hong Kong/China
Revenue by Geography
Total net revenues	60,413	47,229
Taiwan
Revenue by Geography
Total net revenues	6,479	6,672
Korea
Revenue by Geography
Total net revenues	10,357	8,542
Western Europe (excluding Germany)
Revenue by Geography
Total net revenues	10,035	10,901
Japan
Revenue by Geography
Total net revenues	3,905	3,650
Germany
Revenue by Geography
Total net revenues	5,567	4,927
Other
Revenue by Geography
Total net revenues	$ 10,195	$ 4,595

STOCKHOLDERS' EQUITY Common Sto

STOCKHOLDERS' EQUITY Common Stock Shares Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Common Stock Shares Outstanding [Abstract]
Beginning balance	29,431,000	28,889,000
Common stock issued under employee stock plans	284,000	342,000
Repurchased	(24,000)	(121,000)
Ending balance	29,691,000	29,110,000

STOCKHOLDERS' EQUITY Common S_2

STOCKHOLDERS' EQUITY Common Stock Repurchases (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Stockholders' Equity Attributable to Parent [Abstract]
Repurchase of common stock	$ 2
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 41.9		$ 43.9
Stock Repurchased During Period, Shares	24,000	121,000

STOCKHOLDERS' EQUITY Cash Divid

STOCKHOLDERS' EQUITY Cash Dividends (Details) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended
	Apr. 30, 2020quarters$ / shares	Oct. 31, 2019quarters$ / shares	Jan. 31, 2019Quarter$ / shares	Mar. 31, 2020USD ($)$ / shares	Dec. 31, 2019$ / shares	Sep. 30, 2019$ / shares	Jun. 30, 2019$ / shares	Mar. 31, 2019USD ($)$ / shares
Dividends Declared and Paid [Line Items]
Payments of dividends to stockholders | $				$ 5,644				$ 4,937
Common Stock, Dividends, Per Share, Cash Paid		$ 0.19	$ 0.17	$ 0.19				$ 0.17
Common Stock, Dividends, Number of Quarterly Distributions Declared		5	4
Additional Common Stock, Dividends, Per Share, Declared		$ 0.02
Common Stock, Dividends, Per Share, Declared					$ 0.19	$ 0.17	$ 0.17
Subsequent Event [Member]
Dividends Declared and Paid [Line Items]
Common Stock, Dividends, Number of Quarterly Distributions Declared | quarters	3
Common Stock, Dividends Per Share Declared, Current Fiscal Year, Second Quarter	$ 0.21
Common Stock, Dividends Per Share Declared, Current Fiscal Year, Third Quarter	0.21
Common Stock, Dividends Per Share Declared, Current Fiscal Year, Fourth Quarter	$ 0.21

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Basic earnings per share:
NET INCOME		$ 15,886	$ 7,233
Weighted-average common shares		29,602,000	28,951,000
Basic earnings per share		$ 0.54	$ 0.25
Diluted earnings per share:
NET INCOME		$ 15,886	$ 7,233
Weighted-average common shares		29,602,000	28,951,000
Effect of dilutive awards:
Employee stock plans		532,000	495,000
Diluted weighted-average common shares		30,134,000	29,446,000
Diluted earnings per share	[1]	$ 0.53	$ 0.25
Stock awards excluded in the computation of diluted earnings per share		0	0
[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 excluded the shares underlying the outstanding performance-based awards in the 2020 and 2019 calculations as the shares were not contingently issuable as of the end of the reporting periods.

PROVISION FOR INCOME TAXES (Det

PROVISION FOR INCOME TAXES (Details)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory tax rate	21.00%	21.00%
Effective income tax rate	5.80%	0.50%

LEGAL PROCEEDINGS AND CONTING_2

LEGAL PROCEEDINGS AND CONTINGENCIES (Details) - Pending Litigation [Member] $ in Millions	Jan. 06, 2020patent	Apr. 01, 2016patent	Feb. 28, 2019USD ($)	Dec. 31, 2019USD ($)
Patent Infringement Claim One
Gain and Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number		1
Loss Contingency, Damages Awarded, Value | $			$ 6.7	$ 1.2
Patent Infringement Claim Two
Gain and Loss Contingencies [Line Items]
Gain Contingency, Patents Allegedly Infringed upon, Number	2
Patent Infringement Claim Two Counterclaim [Member]
Gain and Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number	3