Plan of Liquidation - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended	24 Months Ended	1 Months Ended
	Mar. 31, 2012	Dec. 31, 2014	Mar. 31, 2013	Jan. 31, 2015	Mar. 31, 2014	Dec. 15, 2011	Mar. 31, 2011	Jan. 14, 2015
Class of Warrant or Right [Line Items]
Allowed General Unsecured Claims							$ 29,771,000,000
Disputed General Unsecured Claims		39,500,000					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
Unsecured claims, previously disallowed by bankruptcy Court but subject to pending appeals		10,000,000
Amount of Term Loan Avoidance Action							1,500,000,000
Dividends received		17,200,000
Contribution from MLC							52,700,000
Remaining Administrative Fund for certain costs and liabilities of the GUC Trust		8,200,000
Remaining Administrative Fund for other Wind-Down Costs		200,000
Initial Reporting Cash							5,700,000
Proceeds from liquidation of securities to fund Avoidance Action Trust costs	13,700,000
Sales of New GM Securities aggregated			50,200,000
Aggregate Other Administrative Cash		6,000,000
New GM Securities with an aggregate fair market value		68,400,000
Dividend Cash set aside for projected Trust fees, costs and expenses		1,100,000
New GM Securities set aside for projected income taxes on dividends received on common stock fair market value		8,200,000
New GM Securities set aside for potential Taxes on Distribution		271,200,000
Dividend Cash set aside for potential Taxes on Distribution		4,400,000
Capital loss carryovers		189,300,000			185,400,000
Net operating loss carryovers		85,200,000			84,500,000
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
Avoidance action defense costs in excess of corresponding cash		3,000,000
Residual Wind-Down Assets held by the GUC Trust aggregated		28,900,000
Remaining Residual Wind-Down Claims		900,000
Cash received for funding Indenture Trustee Fiscal and Paying Agent Costs and Reporting Costs						3,400,000
Agents Costs held by the GUC Trust		400,000
Cash received for indenture trustee and paying agent costs						1,400,000
Cash received for reporting cash						2,000,000
Guc Trust [Member]
Class of Warrant or Right [Line Items]
Reserve for Disputed General Unsecured Claims		40,000,000
Cash and Cash Equivalents and Marketable Securities [Member]
Class of Warrant or Right [Line Items]
Remaining Administrative Fund aggregated		8,400,000
Residual Wind-Down Assets held by the GUC Trust aggregated		28,800,000
Other Assets And Deposits [Member]
Class of Warrant or Right [Line Items]
Residual Wind-Down Assets held by the GUC Trust aggregated		100,000
Subsequent Event [Member]
Class of Warrant or Right [Line Items]
Dividends declared per share for accrued dividend				$ 0.30
Accrued dividends record date				Mar. 11, 2015
Set aside New GM Securities and Dividend Cash to be Liquidated								$ 11,500,000
Common Stock [Member]
Class of Warrant or Right [Line Items]
Number of securities sold to fund costs and expenses			902,228
Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Number of securities sold to fund costs and expenses			820,205
Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Number of securities sold to fund costs and expenses			820,205
New GM Common Stock [Member]
Class of Warrant or Right [Line Items]
Distributable assets number of securities							150,000,000
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
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