Net Assets in Liquidation - Additional Information (Detail)		3 Months Ended
	Mar. 31, 2011 USD ($)	Jun. 30, 2015 Trust	Mar. 31, 2015 USD ($)
Net Assets in Liquidation [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
GUC Trust Units outstanding | Trust		31,853,702
GUC Trust Units issued during the period | Trust		0
Liquidation Basis of Accounting [Member]
Net Assets in Liquidation [Line Items]
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