Segment and Related Information - Reconciliation of Operating Income from Segments to Consolidated (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	$ 46,001	$ 33,323	$ 122,911	$ 93,312
Amortization of acquired software	(5,598)	(552)	(16,737)	(1,464)
Amortization of customer and trade name intangibles	(3,458)	(1,282)	(10,273)	(3,585)
Other (expense) income, net	(526)	255	(1,713)	621
Income before income taxes	36,419	31,744	94,188	88,884
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Amortization of acquired software	(5,598)	(552)	(16,737)	(1,464)
Amortization of customer and trade name intangibles	(3,458)	(1,282)	(10,273)	(3,585)
Other (expense) income, net	$ (526)	$ 255	$ (1,713)	$ 621