Amortization Expense Related to Intangible Assets (Detail) - 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
Finite Lived Intangible Assets [Line Items]
Amortization of software development and acquisition-related assets									$ 114,601	$ 88,631	$ 81,986
Amortization of intangible and acquisition-related assets	$ 10,414	$ 8,137	$ 7,891	$ 7,312	$ 10,903	$ 5,365	$ 5,417	$ 4,162	33,754	25,847	23,172
Total intangible amortization expense	$ 91,271				$ 71,204				91,271	71,204	58,316
Proprietary Technology [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of software development and acquisition-related assets									$ 57,517	$ 45,357	$ 35,144