Other Income, Net - Schedule of Components of Other Income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Securities earnings:
Dividends and interest	$ 6.7	$ 6.6
Securities transactions, net	0.1	0.1
Total	6.8	6.7
Currency transactions, net	2.3	1.6
Insurance recoveries	0.1	3.1
Business interruption insurance proceeds	2.0
Other, net	0.2	0.7
Total other income	$ 11.4	$ 12.1