Operating Segments and Geographic Information - Reconciliations of Other Segment Measures to Consolidated Totals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total assets	$ 3,840,613	$ 3,806,803	$ 3,290,602
Cash and cash equivalents	561,108	848,116	216,751	$ 741,162
Goodwill	1,478,257	1,385,995	1,385,115
Intangible assets, less accumulated amortization	545,207	560,082	655,871
Deferred income taxes	42,549	33,706	34,295
Income tax receivable	0	0	3,787
Acquisition of property, plant and equipment	64,261	53,974	54,969
Reportable Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total assets	1,146,395	913,998	934,280
Acquisition of property, plant and equipment	62,759	53,582	53,572
Corporate assets [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total assets	67,097	64,906	60,503
Acquisition of property, plant and equipment	$ 1,502	$ 392	$ 1,397