Goodwill and Long-Lived Intangible Assets - Schedule of Purchased Intangible Assets Resulting from Acquisitions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Purchased Identified Intangible Assets resulting from Acquisitions [Line Items]
Net carrying amount - Goodwill	$ 390,109	$ 403,278	$ 359,841
Weighted average useful life (years)	5 years 9 months 56 days
Gross carrying amount - Intangible assets	$ 340,010	364,992
Accumulated amortization	$ (265,288)	(241,984)
Weighted remaining average useful life (years)	2 years 9 months 6 days
Net carrying amount - Intangible assets	$ 74,722	123,008
Customer relationships and other
Purchased Identified Intangible Assets resulting from Acquisitions [Line Items]
Weighted average useful life (years)	5 years 10 months 8 days
Gross carrying amount - Intangible assets	$ 79,558	95,862
Accumulated amortization	$ (47,224)	(45,862)
Weighted remaining average useful life (years)	3 years 1 month 12 days
Net carrying amount - Intangible assets	$ 32,334	50,000
Existing technology
Purchased Identified Intangible Assets resulting from Acquisitions [Line Items]
Weighted average useful life (years)	4 years
Gross carrying amount - Intangible assets	$ 189,737	196,693
Accumulated amortization	$ (164,814)	(149,300)
Weighted remaining average useful life (years)	1 year
Net carrying amount - Intangible assets	$ 24,923	47,393
Trademarks and trade names
Purchased Identified Intangible Assets resulting from Acquisitions [Line Items]
Weighted average useful life (years)	10 years 10 months 8 days
Gross carrying amount - Intangible assets	$ 70,326	72,048
Accumulated amortization	$ (53,250)	(46,822)
Weighted remaining average useful life (years)	4 years 8 months 4 days
Net carrying amount - Intangible assets	$ 17,076	25,226
IPR&D
Purchased Identified Intangible Assets resulting from Acquisitions [Line Items]
Weighted average useful life (years)	3 years
Gross carrying amount - Intangible assets	$ 389	389
Net carrying amount - Intangible assets	$ 389	$ 389