Fair Value Measurements - Nonrecurring (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Millions, unless otherwise specified	3 Months Ended						6 Months Ended				6 Months Ended				6 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2013 Segment, Geographical, Groups of Countries, Group One [Member]	Jun. 30, 2012 Segment, Geographical, Groups of Countries, Group One [Member]	Jun. 30, 2013 Segment, Geographical, Groups of Countries, Group One [Member] Retail [Member]	Jun. 30, 2012 Segment, Geographical, Groups of Countries, Group One [Member] Retail [Member]	Jun. 30, 2013 Segment, Geographical, Groups of Countries, Group One [Member] Dealer Loans [Member]	Jun. 30, 2012 Segment, Geographical, Groups of Countries, Group One [Member] Dealer Loans [Member]	Jun. 30, 2013 North America Segment [Member]	Jun. 30, 2012 North America Segment [Member]	Jun. 30, 2013 North America Segment [Member] Level 3 [Member]	Dec. 31, 2012 North America Segment [Member] Level 3 [Member]	Jun. 30, 2013 North America Segment [Member] Retail [Member]	Jun. 30, 2012 North America Segment [Member] Retail [Member]	Jun. 30, 2013 North America Segment [Member] Retail [Member] Level 3 [Member]	Dec. 31, 2012 North America Segment [Member] Retail [Member] Level 3 [Member]	Jun. 30, 2013 North America Segment [Member] Dealer Loans [Member]	Jun. 30, 2012 North America Segment [Member] Dealer Loans [Member]	Jun. 30, 2013 North America Segment [Member] Dealer Loans [Member] Level 3 [Member]	Dec. 31, 2012 North America Segment [Member] Dealer Loans [Member] Level 3 [Member]	Jun. 30, 2013 Segment, Geographical, Groups of Countries, Group Two [Member] Retail [Member]	Jun. 30, 2012 Segment, Geographical, Groups of Countries, Group Two [Member] Retail [Member]	Jun. 30, 2013 International Segment [Member] Retail [Member]	Jun. 30, 2012 International Segment [Member] Retail [Member]	Jun. 30, 2013 International Segment [Member] Retail [Member] Level 3 [Member]	Dec. 31, 2012 International Segment [Member] Retail [Member] Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing Receivable Fair Value Disclosure									$ 41	$ 54			$ 41	$ 52			$ 0	$ 2					$ 23	$ 26
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (2)	$ (7)	$ (2)	$ (7)	$ 0	$ 0	$ (16)	$ (15)			$ (16)	$ (15)			$ 0	$ 0			$ (2)	$ (5)	$ (5)	$ (10)