Net Assets in Liquidation - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended			0 Months Ended
	Mar. 31, 2011 Trust	Mar. 31, 2015 Trust	Mar. 31, 2014 Trust	Mar. 31, 2013 Trust	Dec. 02, 2013 Trust	Oct. 21, 2013	Dec. 23, 2013
Loss Contingencies [Line Items]
Number of Trust Units issued per thousand dollars of allowed general unsecured claims	1
Amount required to issue one Trust Unit per contingent rights	$ 1,000
Distribution of trust units		10,326	1,644,941	274,604
New GM Common Stock [Member]
Loss Contingencies [Line Items]
Special excess distribution							6,735,070
New GM Series A Warrants [Member]
Loss Contingencies [Line Items]
Special excess distribution							6,122,789
New GM Series B Warrants [Member]
Loss Contingencies [Line Items]
Special excess distribution							6,122,789
Nova Scotia Matter [Member]
Loss Contingencies [Line Items]
Disputed General Unsecured Claims Allowed						$ 1,550,000,000
Distribution of trust units			1,550,000		1,550,000
Nova Scotia Matter [Member] | 8.375% guaranteed notes due December 7, 2015 [Member]
Loss Contingencies [Line Items]
Nova Scotia Claims guaranteed notes interest rate						8.375%
Nova Scotia Claims guaranteed notes maturity date						Dec. 07, 2015
Nova Scotia Matter [Member] | 8.875% guaranteed notes due July 10, 2023 [Member]
Loss Contingencies [Line Items]
Nova Scotia Claims guaranteed notes interest rate						8.875%
Nova Scotia Claims guaranteed notes maturity date						Jul. 10, 2023
Nova Scotia Matter [Member] | New GM Common Stock [Member]
Loss Contingencies [Line Items]
Settlement distribution					6,174,015
Nova Scotia Matter [Member] | New GM Series A Warrants [Member]
Loss Contingencies [Line Items]
Settlement distribution					5,612,741
Nova Scotia Matter [Member] | New GM Series B Warrants [Member]
Loss Contingencies [Line Items]
Settlement distribution					5,612,741