Segment and Related Information - Reconciliation of Operating Income from Segments to Consolidated (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	$ 40,048	$ 31,203	$ 76,910	$ 59,989
Amortization of acquired software	(5,680)	(456)	(11,139)	(912)
Amortization of customer and trade name intangibles	(3,453)	(1,151)	(6,815)	(2,303)
Other (expense) income, net	(720)	185	(1,187)	366
Income before income taxes	30,195	29,781	57,769	57,140
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Amortization of acquired software	(5,680)	(456)	(11,139)	(912)
Amortization of customer and trade name intangibles	(3,453)	(1,151)	(6,815)	(2,303)
Other (expense) income, net	$ (720)	$ 185	$ (1,187)	$ 366