Income Taxes (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax credit and operating loss carryforwards
Unrecognized tax benefits, reduction of long-term deferred tax assets, before federal tax benefit		$ 20,400	$ 19,700
Unrecognized tax benefits included in long-term income taxes payable		2,200	2,200
Portion of unrecognized tax benefits, which if recognized, would be recorded as an income tax benefit		2,200	2,200
Amount of potential unrecognized tax benefit		200
Reconciliation of the beginning and ending amounts of unrecognized income tax benefits
Balance at the beginning of the period	$ 22,652	21,925	20,836	$ 19,903
Tax positions related to current year:
Additions		1,083	1,225	1,186
Tax positions related to prior years:
Additions		16	256	0
Reductions		(372)	(171)	(35)
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		0	(221)	(218)
Balance at the end of the period		22,652	$ 21,925	$ 20,836
Undistributed earnings		$ 11,500
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Alternative Minimum Tax Credits
Tax credit and operating loss carryforwards
Tax credit carryforwards		$ 2,500
Foreign Tax Credit
Tax credit and operating loss carryforwards
Tax credit carryforwards		116,500
2017 U.S.Tax Reform Member [Member]
Tax positions related to prior years:
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		20,700
Federal | Research and Development as label
Tax credit and operating loss carryforwards
Tax credit carryforwards		38,000
Federal | Foreign Tax Credit
Tax credit and operating loss carryforwards
Tax Credit Carryforward, Subject To Expiration, Amount		54,900
State and Local Jurisdiction [Member]
Tax credit and operating loss carryforwards
Operating Loss Carryforwards		125,000
State and Local Jurisdiction [Member] | California Franchise Tax Board [Member]
Tax credit and operating loss carryforwards
Operating Loss Carryforwards		195,400
Operating Loss Carryforwards, Expired		67,100
Operating Loss Carryforwards, Expiring in the Future		21,500
State and Local Jurisdiction [Member] | Research and Development as label
Tax credit and operating loss carryforwards
Tax credit carryforwards		$ 27,000
Scenario, Forecast [Member]
Tax positions related to prior years:
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%