PROVISION FOR INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Current Federal Tax Expense (Benefit) Related to Impact of Tax Cuts and Jobs Act		$ (9,700)	$ 37,500
U.S. and foreign components of income before income taxes [Abstract]
U.S. operations	$ 82,692	(6,529)	(6,944)
Foreign operations	139,722	66,293	67,243
INCOME BEFORE INCOME TAXES	222,414	59,764	60,299
Current provision:
Federal	18,293	(6,382)	35,311
State	184	4	4
Foreign	1,293	938	1,483
Current provision	19,770	(5,440)	36,798
Deferred provision (benefit):
Federal	9,683	(4,593)	(3,640)
State	0	0	0
Foreign	(507)	(187)	(468)
Deferred provision (benefit)	$ 9,176	$ (4,780)	$ (4,108)
Effective income tax rate reconciliation [Abstract]
Provision (benefit) computed at Federal statutory rate	21.00%	21.00%	35.00%
Business tax credits	(2.40%)	(9.10%)	(5.70%)
Stock-based compensation	(0.20%)	(2.20%)	(5.00%)
Foreign income taxed at different rate	(12.70%)	(25.00%)	(37.30%)
GILTI inclusion	6.20%	10.60%	0.00%
U.S. Tax Act - transition tax	0.10%	(16.20%)	54.10%
U.S. Tax Act - deferred tax asset and liability adjustment	0.00%	0.00%	8.10%
Valuation allowance	0.80%	2.80%	2.20%
Other	0.20%	1.00%	2.80%
Total	13.00%	(17.10%)	54.20%
Components of deferred income tax asset [Abstract]
Other reserves and accruals	$ 3,099	$ 3,695
Tax credit carry-forwards	18,968	18,052
Stock compensation	1,644	3,050
Capital losses	157	157
Net operating loss	899	3,144
Other	1,000	0
Valuation allowance	(20,822)	(19,955)
Deferred tax assets, net of valuation allowance	4,945	8,143
Depreciation	(2,273)	(1,423)
Other	0	(30)
Deferred tax liabilities	(2,273)	(1,453)
Net deferred tax asset	2,672	6,690
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits, Balance at beginning of period	18,607	16,683	$ 15,393
Gross Increase for Tax Positions of Current Year	1,379	1,994	1,699
Gross Decrease for Tax Positions of Prior Years	(937)	(70)	(409)
Unrecognized Tax Benefits, Balance at end of period	19,049	18,607	16,683
Unrecognized tax benefits [Abstract]
Unrecognized Tax Benefits, Balance at end of period	19,049	18,607	$ 16,683
Income tax benefit that would be recorded if unrecognized tax benefits are recognized	10,600
Income tax interest and penalties accrued		$ 100
State and Local Jurisdiction [Member] | California Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	24,600
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member] | California Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	27,500
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	700
Research Tax Credit Carryforward [Member] | Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 3,100
Earliest Tax Year [Member] | State and Local Jurisdiction [Member] | California Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2031
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 Carryforward, Expiration Date	Jan. 01, 2026
Earliest Tax Year [Member] | Research Tax Credit Carryforward [Member] | Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date	Jan. 01, 2030