Holdings of New GM Securities (Details Textual) (USD $)	Jun. 30, 2013	Mar. 31, 2013
Holdings of Securities for Trust Beneficiaries (Textual) [Abstract]
Liquidating distributions payable	$ 25,046,000	$ 16,555,000
Liquidating distributions payable in cash	600,000
New GM Securities reserved and set aside for projected GUC Trust fees, costs and expenses	25,600,000
New GM securities set aside for potential taxes on distribution	$ 581,300,000
New GM Common Stock [Member]
Holdings of Securities for Trust Beneficiaries (Additional Textual) [Abstract]
Number of warrants or shares pending distribution	349,789
Number of securities set aside from distribution	8,670,493
New GM Series A Warrants [Member]
Holdings of Securities for Trust Beneficiaries (Additional Textual) [Abstract]
Number of warrants or shares pending distribution	317,941
Number of warrants set aside from distribution	7,882,237
New GM Series B Warrants [Member]
Holdings of Securities for Trust Beneficiaries (Additional Textual) [Abstract]
Number of warrants or shares pending distribution	317,941
Number of warrants set aside from distribution	7,882,237