Intangible Assets and Estimated Useful Lives (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Intangible Assets [Line Items]
Amortized intangible assets, gross carrying amount	$ 626,095	$ 624,050
Amortized intangible assets, accumulated amortization	(453,833)	(403,854)
Unamortized intangible assets, gross carrying amount	357
Developed Software and Core Technologies
Intangible Assets [Line Items]
Amortized intangible assets, gross carrying amount	338,594	336,262
Amortized intangible assets, accumulated amortization	(275,130)	(251,201)
Customer Lists and Contract Backlog
Intangible Assets [Line Items]
Amortized intangible assets, gross carrying amount	159,549	159,885
Amortized intangible assets, accumulated amortization	(88,414)	(76,160)
Trade Names
Intangible Assets [Line Items]
Amortized intangible assets, gross carrying amount	127,952	127,903
Amortized intangible assets, accumulated amortization	(90,289)	(76,493)
Trade Names
Intangible Assets [Line Items]
Unamortized intangible assets, gross carrying amount	$ 357	$ 357