Components of Other Operating Income (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Other Operating Income [Line Items]
Loan Service Fees		$ 59.1	$ 62.7	$ 61.9
Banking Service Fees		48.2	49.6	50.9
Other Income		139.8	41.2	53.7
Total Other Operating Income		247.1	$ 153.5	$ 166.5
Net gain on sale of certain loans and leases		25.9
Fair value adjustment on sale of certain loans and leases		(27.0)
Visa Class B
Components of Other Operating Income [Line Items]
Net gain on sale of derivative	$ 99.9	$ 99.9
Shares sold	1,000,000.0	1,000,000.0