Changes in Allowance for Credit Losses by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at Beginning of Period	$ 303.5	$ 320.7	$ 307.9	$ 327.6
Charge-Offs	(8.6)	(11.6)	(27.9)	(39.8)
Recoveries	3.4	3.3	15.3	14.7
Net (Charge-Offs) Recoveries	(5.2)	(8.3)	(12.6)	(25.1)
Provision for Credit Losses		5.0	3.0	15.0
Effect of Foreign Exchange Rates		0.1
Balance at End of Period	298.3	317.5	298.3	317.5
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at Beginning of Period	168.7	184.1	168.0	194.2
Charge-Offs	(2.5)	(1.7)	(8.8)	(6.9)
Recoveries	1.9	1.7	10.7	8.1
Net (Charge-Offs) Recoveries	(0.6)		1.9	1.2
Provision for Credit Losses	1.0	(4.6)	(0.8)	(15.8)
Effect of Foreign Exchange Rates		0.1
Balance at End of Period	169.1	179.6	169.1	179.6
Personal
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at Beginning of Period	134.8	136.6	139.9	133.4
Charge-Offs	(6.1)	(9.9)	(19.1)	(32.9)
Recoveries	1.5	1.6	4.6	6.6
Net (Charge-Offs) Recoveries	(4.6)	(8.3)	(14.5)	(26.3)
Provision for Credit Losses	(1.0)	9.6	3.8	30.8
Balance at End of Period	$ 129.2	$ 137.9	$ 129.2	$ 137.9