Changes in Allowance for Credit Losses by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at Beginning of Period	$ 295.9	$ 307.9
Charge-Offs	(7.5)	(11.5)
Recoveries	2.9	10.0
Net (Charge-Offs) Recoveries	(4.6)	(1.5)
Provision for Credit Losses	(4.5)	3.0
Effect of Foreign Exchange Rates	(0.1)
Balance at End of Period	286.7	309.4
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at Beginning of Period	169.7	168.0
Charge-Offs	(2.7)	(4.2)
Recoveries	1.7	8.5
Net (Charge-Offs) Recoveries	(1.0)	4.3
Provision for Credit Losses	(4.3)	0.8
Effect of Foreign Exchange Rates	(0.1)
Balance at End of Period	164.3	173.1
Personal
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at Beginning of Period	126.2	139.9
Charge-Offs	(4.8)	(7.3)
Recoveries	1.2	1.5
Net (Charge-Offs) Recoveries	(3.6)	(5.8)
Provision for Credit Losses	(0.2)	2.2
Balance at End of Period	$ 122.4	$ 136.3