Holdings of New GM Securities (Details Textual) (USD $)	Sep. 30, 2012	Mar. 31, 2012
Holdings of Securities for Trust Beneficiaries (Additional Textual) [Abstract]
Liquidating Distributions payable	$ 54,757,000	$ 31,720,000
New GM Securities reserved and set aside for projected GUC Trust fees, costs and expenses	52,700,000
New Gm securities set aside for potential taxes on distribution	$ 189,600,000
New GM Common Stock [Member]
Holdings of Securities for Trust Beneficiaries (Textual) [Abstract]
Number of securities pending distribution	1,279,688
Number of securities set aside from distribution	5,662,868
New GM Series A Warrants [Member]
Holdings of Securities for Trust Beneficiaries (Textual) [Abstract]
Number of warrants pending distribution	1,163,258
Number of warrants set aside from distribution	5,148,062
New GM Series B Warrants [Member]
Holdings of Securities for Trust Beneficiaries (Textual) [Abstract]
Number of warrants pending distribution	1,163,258
Number of warrants set aside from distribution	5,148,062