Restructuring And Other Initiatives (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended												9 Months Ended	3 Months Ended																								9 Months Ended	6 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2012 GMNA [Member]	Jun. 30, 2012 GMNA [Member]	Mar. 31, 2012 GMNA [Member]	Sep. 30, 2011 GMNA [Member]	Jun. 30, 2011 GMNA [Member]	Mar. 31, 2011 GMNA [Member]	Sep. 30, 2012 GMNA [Member]	Sep. 30, 2012 GME [Member]	Jun. 30, 2012 GME [Member]	Mar. 31, 2012 GME [Member]	Sep. 30, 2011 GME [Member]	Jun. 30, 2011 GME [Member]	Mar. 31, 2011 GME [Member]	Sep. 30, 2012 GMIO [Member]	Jun. 30, 2012 GMIO [Member]	Mar. 31, 2012 GMIO [Member]	Sep. 30, 2011 GMIO [Member]	Jun. 30, 2011 GMIO [Member]	Mar. 31, 2011 GMIO [Member]	Sep. 30, 2012 GMSA [Member]	Jun. 30, 2012 GMSA [Member]	Mar. 31, 2012 GMSA [Member]	Sep. 30, 2011 GMSA [Member]	Jun. 30, 2011 GMSA [Member]	Mar. 31, 2011 GMSA [Member]	Sep. 30, 2012 Dealer Wind-Down [Member] GMNA [Member]	Jun. 30, 2012 Dealer Wind-Down [Member] GMNA [Member]	Mar. 31, 2012 Dealer Wind-Down [Member] GMNA [Member]	Sep. 30, 2011 Dealer Wind-Down [Member] GMNA [Member]	Jun. 30, 2011 Dealer Wind-Down [Member] GMNA [Member]	Mar. 31, 2011 Dealer Wind-Down [Member] GMNA [Member]	Sep. 30, 2012 Voluntary Separation Program in Korea [Member] GMIO [Member]	Jun. 30, 2012 2012 Canada Auto Workers Union Labor Agreement [Member] GMNA [Member]	Sep. 30, 2011 2011 UAW Labor Agreement [Member] GMNA [Member]	Sep. 30, 2012 2011 UAW Labor Agreement [Member] GMNA [Member]	Sep. 30, 2011 2011 UAW Labor Agreement [Member] GMNA [Member]	Mar. 31, 2012 2011 UAW Labor Agreement [Member] GMNA [Member] employees	Sep. 30, 2012 Germany Separation Program [Member] GME [Member] employees	Sep. 30, 2011 Germany Separation Program [Member] GME [Member]	Jun. 30, 2012 Germany Separation Program [Member] GME [Member]	Sep. 30, 2012 Germany Separation Program [Member] GME [Member] employees	Sep. 30, 2011 Germany Separation Program [Member] GME [Member]	Sep. 30, 2012 Separation Program in Brazil [Member] GMSA [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment	$ (70)	$ (7)	$ (14)	$ 71	$ (8)	$ 7	$ (63)	$ 0	$ (12)	$ 71	$ (8)	$ 7		$ (6)	$ (7)	$ (2)	$ 0	$ 0	$ 0	$ (1)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ (1)	$ (4)	$ 0	$ (1)	$ (1)	$ (6)
Restructuring Reserve [Abstract]
Restructuring Reserve Beginning Balance	1,392	1,444	1,584	1,522	1,613	1,802	779	894	884	958	1,062	1,135	884	520	540	687	563	550	664	26	4	1	1	1	3	67	6	12	0	0	0	17	22	25	33	58	144
Additions	63	151	112	101	71	60	6	13	97	19	8	26		39	38	9	81	62	33	4	27	4	0	0	0	14	73	2	1	1	1							23			90								84
Interest accretion and other	17	21	24	30	22	31	3	3	3	5	6	7		14	18	22	25	16	24	0	0	(1)	0	0	0	0	0	0	0	0	0
Payments	(127)	(184)	(286)	(137)	(186)	(337)	(42)	(123)	(86)	(66)	(109)	(129)		(47)	(43)	(192)	(70)	(76)	(205)	(15)	(5)	0	0	0	(2)	(23)	(13)	(8)	(1)	(1)	(1)	(2)	(1)	(3)	(4)	(24)	(80)
Effect of foreign currency	24	(33)	24	(59)	10	50	15	(8)	8	(30)	(1)	16		8	(26)	16	(29)	11	34	1	0	0	0	0	0	0	1	0	0	0	0
Restructuring Reserve Ending Balance	1,299	1,392	1,444	1,528	1,522	1,613	698	779	894	957	958	1,062	698	528	520	540	570	563	550	15	26	4	1	1	1	58	67	6	0	0	0	14	17	22	28	33	58
Remaining Payments Including Temporary Layoffs Benefits							364			398			364
Restructuring Reserve, Period Decrease							54						(50)																											(95)		(141)			(106)			(241)
Restructuring and Related Activities, Completion Date																																												53		140
Restructuring and Related Activities [Abstract]
Number of Skilled Hourly Employees																																											1,400
Total Cost of Separation Programs																																									99						313
Additional Cost Expected to Incurr																																							$ 70								$ 100
Number of Employees Affected																																						154						1,900			1,900
Number Of Additional Employees Affected																																												350			350