Income Taxes (Additional Information) (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Provision for income taxes	$ 28,528,000	$ 24,682,000
Effective tax rate	27.30%	26.60%
Minimum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible change in unrecognized tax benefits over next 12 months	$ 0
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible change in unrecognized tax benefits over next 12 months	$ 2,400,000