Other Income, Net - Schedule of Components of Other Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Securities earnings:
Dividends and interest			$ 20.3	$ 19.8
Securities transactions, net			0.2	0.1
Total	$ 6.8	$ 6.5	20.5	19.9
Currency transactions, net			3.2	0.6
Insurance recoveries	0.1	0.1	0.4	3.5
Business interruption insurance proceeds			3.4
Other, net			0.8	1.4
Total other income	$ 6.2	$ 5.9	$ 28.3	$ 25.4