Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	$ 1,222,000	$ 1,251,000
Change in deferred tax asset valuation allowance	(100,000)
Undistributed foreign earnings	224,000,000
Deferred income tax liability on undistributed foreign earnings	45,000,000
Income tax adjustment, expense increase (decrease)		3,600,000	5,300,000
Unrecognized tax benefits including accrued interest and penalties	41,100,000	30,600,000	26,900,000
Unrecognized tax benefits, income tax penalties and interest accrued	7,700,000	5,900,000	5,900,000
Income tax interest and penalties expense	1,800,000		1,200,000
Significant change in unrecognized tax benefits reasonably possible	4,300,000
Domestic country
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	26,100,000	30,700,000
Research and development tax credit carryforwards	30,500,000	10,000,000
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	45,000,000	59,000,000
Foreign country
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	300,000	2,400,000
Research and development tax credit carryforwards		$ 4,400,000