Segment and Related Information - Reconciliation of Operating Income from Segments to Consolidated (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	$ 156,367	$ 152,492	$ 162,758
Amortization of customer and trade name intangibles	(52,800)	(39,600)	(35,500)
Other income (expense), net	3,471	3,378	698
Income before income taxes	159,838	155,870	163,456
Operating Segments And Corporate Non Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	208,454	191,681	197,825
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Amortization of acquired software	(30,642)	(22,972)	(21,686)
Amortization of customer and trade name intangibles	(21,445)	(16,217)	(13,381)
Other income (expense), net	$ 3,471	$ 3,378	$ 698