Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$ 20.5	$ 18.5	$ 29.2	$ 25.5
Increase Decrease In Provision For Income Taxes	$ 2.0		$ 3.7
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%		35.00%