Other Operating Expenses (Details Of Other Operating Expenses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Cost and Expense Disclosure, Operating [Abstract]
Total Charge Recorded Related to ResCap Bankruptcy	$ 1,192	$ 0	$ 0
Insurance Commissions	382	432	511
Communications and Information Technology	347	418	431
Lease and loan administration	315	168	143
Professional Fees	281	294	241
Marketing and Advertising Expense	150	168	137
Regulatory and licensing fees	119	127	115
Fines and Penalties	90	222	0
Depreciation, Nonproduction	83	81	70
Mortgage Representation And Warranty, Net	67	324	670
Occupancy, Net	58	72	72
Vehicle remarketing and repossession	52	84	123
State and local non-income taxes	15	49	42
Other Cost and Expense, Operating	347	497	523
Total other operating expenses	3,498	2,936	3,078
Impairment of Investment in ResCap	442
Cash Contribution to ResCap	$ 750