Net Assets in Liquidation - Additional Information (Detail)		12 Months Ended
	Mar. 31, 2011 USD ($) Unit	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Net Assets in Liquidation [Line Items]
Distributable Assets		$ 464,300,000
Cash and cash equivalents and marketable securities		665,500,000	$ 68,400,000
Liquidating distributions payable in Distributable Cash for Excess GUC Trust Distributable Assets		4,300,000
Distributable Cash set aside for projected Trust fees, costs and expenses		47,100,000
Distributable Cash set aside for projected Dividend Taxes and Investment Income Taxes		2,300,000
Distributable Cash set aside for potential Taxes on Distribution		107,500,000
Distributable cash pending distribution or set aside and not available for distribution		160,800,000
Number of Trust Units issued per thousand dollars of allowed general unsecured claims | Unit	1
Amount required to issue one Trust Unit per contingent rights	$ 1,000
Avoidance Action Trust Proposed Agreement [Member]
Net Assets in Liquidation [Line Items]
Term loan avoidance action claims allowed		55,000
Liquidation Basis of Accounting [Member]
Net Assets in Liquidation [Line Items]
Liquidating distributions payable		$ 6,213,000	7,714,000
Accrued Dividends on Holdings of New GM Common Stock			26,524,000
Dividend Expected To Be Declared [Member] | Liquidation Basis of Accounting [Member]
Net Assets in Liquidation [Line Items]
Accrued Dividends on Holdings of New GM Common Stock			$ 22,400,000