Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Effective income tax rate	36.40%	27.20%
U.S. federal income tax rate	35.00%
Unrecognized tax benefits	$ 5.9
Recognized tax benefits	5.1
Accrued interest and penalties related to uncertain tax positions	$ 0.7