Discontinued Operations - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense									$ 2,900	$ 22,737	$ 43,065
(Loss) income from discontinued operations, net of income tax	$ 0	$ 0	$ 0	$ (42,704)	$ 21,275	$ 20,164	$ 14,609	$ 10,209	(42,704)	66,257	104,228
Separation costs									500	2,500	200
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Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenues									58,215	682,185	629,440
Cost of net revenues									15,456	154,652	140,324
Gross margin									42,759	527,533	489,116
Research and development									9,108	93,892	83,018
Sales, marketing and services									20,881	209,475	189,560
General and administrative									7,636	63,270	50,068
Amortization of other intangible assets									1,176	14,097	11,254
Restructuring									3,189	3,721	1,750
Separation									40,573	54,084	6,173
Total operating expenses									82,563	438,539	341,823
(Loss) income from discontinued operations before income taxes									(39,804)	88,994	147,293
Income tax expense									2,900	22,737	43,065
(Loss) income from discontinued operations, net of income tax									$ (42,704)	$ 66,257	$ 104,228