Income Taxes - Component of Income Taxes Expenses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Currently payable (refundable):
U.S. federal and state	$ 7.6	$ 7.4	$ 9.1
Non-U.S.	3.3	15.2	(1.2)
Total	10.9	22.6	7.9
Deferred income taxes (benefit):
U.S. federal and state	(58.5)	3.8	(57.9)
Non-U.S.	144.9	6.1	(41.0)
Total	86.4	9.9	(98.9)
Provision for income taxes (benefit)	$ 97.3	$ 32.5	$ (91.0)