Segment and Geographic Information Geographic Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Total revenue	$ 2,156	$ 2,083	$ 1,983	$ 1,960	$ 1,941	$ 1,888	$ 1,846	$ 1,905	$ 8,182	$ 7,580	$ 8,064
Income before income taxes									1,756	1,697	2,404
Net finance receivables and net investment in operating leases	99,913				88,616				99,913	88,616	82,043
United States
Segment Reporting Information [Line Items]
Total revenue									5,739	5,234	5,048
Income before income taxes									1,160	1,238	1,572
Net finance receivables and net investment in operating leases	70,513				62,299				70,513	62,299	55,485
Canada
Segment Reporting Information [Line Items]
Total revenue									909	898	1,058
Income before income taxes									127	176	296
Net finance receivables and net investment in operating leases	10,085				9,483				10,085	9,483	8,504
Europe
Segment Reporting Information [Line Items]
Total revenue									1,132	1,097	1,447
Income before income taxes									319	145	278
Net finance receivables and net investment in operating leases	15,674				14,349				15,674	14,349	15,519
All Other
Segment Reporting Information [Line Items]
Total revenue									402	351	511
Income before income taxes									150	138	258
Net finance receivables and net investment in operating leases	$ 3,641				$ 2,485				$ 3,641	$ 2,485	$ 2,535