Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries	$ 65,300	$ 65,300
Unrecognized deferred tax liability related to undistributed foreign earnings	22,800	22,800
R&D tax credit	16,500	29,363	$ 18,655	$ 13,841
Deferred federal, state and local tax benefit		45,000
Income tax benefits attributable to the exercise of employee stock options		79,900	88,900	80,000
Unrecognized tax benefits	17,117	17,117	34,812	$ 68,231
Reduction in provision for income taxes due to impact of effective tax rate	13,500	13,500	$ 29,200
Tax reserves released	13,400
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount	44,100	44,100
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount	59,300	59,300
Tax credit carryforward not subject to expiration	58,800	58,800
Tax credit carryforward subject to expiration	500	500
Accrued Expenses [Member]
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits	3,600	3,600
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Deferred federal, state and local tax benefit		45,000
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	104,800	104,800
Internal Revenue Service (IRS) [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 237,000	$ 237,000