Income Taxes - Component of Income Taxes Expenses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Currently payable (refundable):
U.S. federal and state	$ 34.1	$ 87.3	$ 35.5
Non-U.S.	51.1	38.5	9.5
Total	85.2	125.8	45.0
Deferred income taxes (benefit):
U.S. federal and state	(145.5)	(96.9)	(29.1)
Non-U.S.	29.6	(148.9)	2.7
Total	(115.9)	(245.8)	(26.4)
Provision for income taxes (benefit)	$ (30.7)	$ (120.0)	$ 18.6