Goodwill and Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule Of Goodwill And Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,242,917	$ 1,242,642
Accumulated Amortization	(879,480)	(863,561)
Intangible Assets, Net	363,437	379,081
Registered trademarks	52,000	52,000
Goodwill	1,373,996	1,373,744
Total	1,425,996	1,425,744
Proprietary Technology [Member]
Schedule Of Goodwill And Intangible Assets [Line Items]
Gross Carrying Amount	537,952	537,834
Accumulated Amortization	(410,154)	(401,093)
Intangible Assets, Net	127,798	136,741
Customer Contracts and Relationships [Member]
Schedule Of Goodwill And Intangible Assets [Line Items]
Gross Carrying Amount	704,965	704,808
Accumulated Amortization	(469,326)	(462,468)
Intangible Assets, Net	$ 235,639	$ 242,340