Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Effective tax rate, percentage	20.40%	37.50%	17.90%	27.10%
Earnings of foreign entities	$ 15.9	$ 7.3	$ 35.9	$ 31.6
Unrecognized tax benefit for uncertain tax positions	22.1		22.1			$ 14.8
Accrued interest and penalties related to income tax liabilities	$ 2.3		$ 2.3			$ 2.4
Decrease in unrecognized tax benefits due to expiration of statutes of limitations and settlement of various audits					$ 3.3