Holdings of New GM Securities (Details Textual) (USD $)	Jun. 30, 2012	Mar. 31, 2012
Holdings of Securities For Trust Beneficiaries (Textual) [Abstract]
Liquidating Distributions Payable	$ 39,711,000	$ 31,720,000
New GM Securities reserved and set aside for projected GUC Trust fees, costs and expenses	42,900,000
New Gm securities set aside for potential taxes on distribution	$ 150,800,000
New GM Common Stock [Member]
Holdings of Securities For Trust Beneficiaries (Textual) [Abstract]
Number of securities pending distribution	1,106,095
Number of securities set aside from distribution	5,395,271
New GM Series A Warrants [Member]
Holdings of Securities For Trust Beneficiaries (Textual) [Abstract]
Number of warrants pending distribution	1,005,465
Number of warrants set aside from distribution	4,904,792
New GM Series B Warrants [Member]
Holdings of Securities For Trust Beneficiaries (Textual) [Abstract]
Number of warrants pending distribution	1,005,465
Number of warrants set aside from distribution	4,904,792