Components of Other Operating Expense (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Income and Expenses [Abstract]
Business Promotion	$ 93.2	$ 88.0	$ 91.6
FDIC Insurance Premiums	25.2	22.0	23.5
Staff Related	40.5	39.1	39.1
Other Intangibles Amortization	10.9	19.5	21.1
Other Expenses	158.2	103.5	138.9
Total Other Operating Expense	328.0	$ 272.1	314.2
Total NAV funds	$ (45.8)
Net Asset Value (in dollars per share)	$ 1.00
Legal settlement charge			$ 19.2