Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Tax benefit attributable to the remeasurement of tax assets and liabilities		$ 26,300
2017 transition tax benefit		21,900
Federal corporate tax rate reduction		4,400
Valuation allowance	$ (128,388)	(85,400)
Federal and state GILTI tax expense	3,800	12,800
Federal and state FDII tax benefit	3,800	5,400
Tax benefit from release of uncertain tax positions due to expiration of statute of limitations	20,098	8,436
Provisional income tax charge for transition tax on repatriation of deferred foreign income			$ 364,600
Provisional income tax charge for re-measurement of deferred tax assets and liabilities			64,800
Income tax charge to establish valuation allowance related to R&D credits			48,600
Tax benefit due to recognition of income tax effects related to stock based compensation		21,900
Unrecognized tax benefits	84,466	$ 89,906	$ 77,849
Accrued interest and penalties	3,200
Research
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	146,000
United States
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	159,000
Foreign jurisdictions
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	118,500
Swiss Federal Tax Administration (FTA)
Operating Loss Carryforwards [Line Items]
Income tax benefit due to remeasurement of Swiss deferred tax assets	99,900
Valuation allowance	(33,500)
Swiss Cantonal Tax Administration
Operating Loss Carryforwards [Line Items]
Deferred tax asset, attributable to impact of the Swiss TRAF	145,600
Income tax benefit due to remeasurement of Swiss deferred tax assets	112,100
Long-term Deferred Tax Assets
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits	$ 57,100