Plan of Liquidation - Additional Information (Detail) (USD $)	1 Months Ended	6 Months Ended	24 Months Ended
	Mar. 31, 2012	Sep. 30, 2013	Mar. 31, 2013	Dec. 15, 2011	Mar. 31, 2011
Class of Warrant or Right [Line Items]
Allowed General Unsecured Claims					$ 29,771,000,000
Disputed general unsecured claims		3,190,000,000			8,154,000,000
Total aggregate amount of general unsecured claims, both allowed and disputed inclusive of potential term loan avoidance action claims					39,425,000,000
Amount of term loan avoidance action					1,500,000,000
Allowed general unsecured claims threshold					35,000,000,000
Potential additional shares to be issued					30,000,000
Allowed general unsecured claims maximum excess amount					7,000,000,000
Additional shares issued					0
Contribution from MLC					52,700,000
Remaining GUC Trust Administrative Fund aggregated		15,600,000
Remaining Administrative Fund for governance and professionals' fees		7,000,000
Sales of New GM Securities aggregated			50,200,000
New GM Securities with an aggregate fair market value		67,800,000
New GM Securities reserved and set aside for potential Taxes on Distribution		572,700,000
Reduction in net deferred tax liability		411,600,000
Proceeds from liquidation of securities to fund avoidance action trust costs	13,700,000
Residual Wind-Down assets				42,800,000
Residual Wind-Down Assets Cash				40,000,000
Cash received to fund Avoidance Action Defense Costs				1,400,000
Residual wind-down assets transferred benefit in prepaid expenses				2,800,000
Residual Wind-Down Assets held by the GUC Trust aggregated		31,700,000
Remaining Avoidance Action Defense Costs funds		700,000
Remaining Residual Wind-Down Claims		12,800,000
Cash received for funding Indenture Trustee Fiscal and Paying Agent Costs and Reporting Costs				3,400,000
Cash received for funding Indenture Trustee Fiscal and Paying Agent Costs				1,400,000
Agents Costs held by the GUC Trust		$ 494,000
Common Stock [Member]
Class of Warrant or Right [Line Items]
Number of securities sold to fund costs and expenses			902,228
Number of securities sold to fund avoidance action trust costs	269,422
Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Number of securities sold to fund costs and expenses			820,205
Number of securities sold to fund avoidance action trust costs	244,929
Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Number of securities sold to fund costs and expenses			820,205
Number of securities sold to fund avoidance action trust costs	244,929
New GM Common Stock [Member]
Class of Warrant or Right [Line Items]
Distributable assets number of securities					150,000,000
Tax basis of securities held per security		$ 19.87
New GM Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Distributable assets number of securities called by warrants					136,363,635
Exercise price per share					$ 10.00
Tax basis of securities held per security		$ 11.38
New GM Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Distributable assets number of securities called by warrants					136,363,635
Exercise price per share					$ 18.33
Tax basis of securities held per security		$ 7.88