Goodwill and Other Intangible Assets - Other Intangible Assets Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amortization of Intangible Assets [Line Items]
Amortization of intangible assets	$ 19,440	$ 19,920	$ 20,470
Cost of Sales [Member] | Technology and Other [Member]
Amortization of Intangible Assets [Line Items]
Amortization of intangible assets	4,900	5,340	5,680
Selling, General and Administrative Expenses [Member] | Customer Relationships [Member]
Amortization of Intangible Assets [Line Items]
Amortization of intangible assets	$ 14,540	$ 14,580	$ 14,790