Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 29,674,000	$ 24,134,000
Effective tax rate	28.50%	28.20%
Reasonably possible change in unrecognized tax benefits over next 12 months, lower range	0
Reasonably possible change in unrecognized tax benefits over next 12 months, upper range	$ 1,000,000