Ally Financial (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended			9 Months Ended			3 Months Ended		3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Ally Financial [Member]	Mar. 31, 2012 Ally Financial [Member]	Sep. 30, 2011 Ally Financial [Member]	Sep. 30, 2012 Ally Financial [Member]	Sep. 30, 2011 Ally Financial [Member]	Dec. 31, 2011 Ally Financial [Member]	Dec. 31, 2011 Common Stock [Member] Ally Financial [Member]	Sep. 30, 2012 Common Stock [Member] Ally Financial [Member]	Mar. 31, 2011 Preferred Stock [Member] Ally Financial [Member]	Sep. 30, 2012 Residual support [Member] Ally Financial [Member]	Dec. 31, 2011 Residual support [Member] Ally Financial [Member]	Sep. 30, 2012 Risk sharing [Member] Ally Financial [Member]	Dec. 31, 2011 Risk sharing [Member] Ally Financial [Member]	Sep. 30, 2012 Vehicle repurchase obligations [Member] Ally Financial [Member]	Dec. 31, 2011 Vehicle repurchase obligations [Member] Ally Financial [Member]
Summary of Financial Statement Effects and Maximum Obligations [Abstract]
Market Incentive Programs, Liabilities(recievables) Recorded															$ 82,000,000	$ (6,000,000)	$ 2,000,000	$ 66,000,000
Market Incentive Programs, Maximum Obligation															87,000,000	40,000,000	4,000,000	88,000,000
Vehicle Repurchase, Maximum obligations																			20,771,000,000	19,779,000,000
Vehicle Repurchase, Fair value of guarantee																			16,000,000	17,000,000
Favorable Adjustments to Residual and Risk Sharing Liabilities									77,000,000	443,000,000
Marketing Incentive Program Payments and Fee Income [Abstract]
U.S. Marketing incentives and operating lease residual payments						509,000,000		192,000,000	1,320,000,000	1,162,000,000
Exclusivity fee income						16,000,000		25,000,000	54,000,000	71,000,000
Summary of Balance Sheet Effects [Abstract]
Accounts and Notes Receivable, Net						259,000,000			259,000,000		243,000,000
Accounts Payable						29,000,000			29,000,000		59,000,000
Short-term debt and current portion of long-term debt						933,000,000			933,000,000		1,068,000,000
Accrued Liabilities and other liabilities						766,000,000			766,000,000		650,000,000
Long-term Debt						4,000,000			4,000,000		8,000,000
Other Liabilities, Noncurrent	12,757,000,000		12,757,000,000		12,442,000,000	23,000,000			23,000,000		35,000,000
Summary of Income Statement Effects [Abstract]
Total Net Sales And Revenue	37,062,000,000	36,328,000,000	111,517,000,000	111,270,000,000		(530,000,000)		(335,000,000)	(1,815,000,000)	(952,000,000)
Automotive cost of sales and other automotive expenses						4,000,000		4,000,000	11,000,000	12,000,000
Interest income and other non-operating income, net	318,000,000	152,000,000	732,000,000	1,064,000,000		30,000,000		30,000,000	72,000,000	115,000,000
Automotive interest expense	128,000,000	101,000,000	356,000,000	405,000,000		15,000,000	(21,000,000)	16,000,000	23,000,000	53,000,000
Investment in Ally Financial [Abstract]
Total common equity ownership in investee						9.90%			9.90%		9.90%
Impairment charge on Ally Financial common stock												555,000,000
Carrying amount of investment Ally Financial common stock												403,000,000	404,000,000
Fair Value of investment in Ally Financial common stock												403,000,000	930,000,000
Proceeds from Sale of Ally Financial Preferred Stock														1,000,000,000
Gain on sale of Ally Financial preferred stock														$ 339,000,000