Fair Value Measurements (Tables)

12 Months Ended

Mar. 31, 2014

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table presents information about the GUC Trust’s assets and liabilities measured at fair value on a recurring basis at March 31, 2014 and 2013, and the valuation techniques used by the GUC Trust to determine those fair values.

	March 31, 2014
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	8,953	$	—	$	—	$	8,953
Marketable Securities:
Municipal commercial paper and demand notes		—		18,005		—		18,005
Corporate commercial paper		—		26,377		—		26,377
Holdings of New GM Securities
New GM Common Stock		526,533		—		—		526,533
New GM Warrants		587,545		—		—		587,545
Total Assets	$	1,123,031	$	44,382	$	—	$	1,167,413
Liabilities:
Liquidating distributions payable	$	42,111	$	—	$	—	$	42,111

	March 31, 2013
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	354	$	—	$	—	$	354
Marketable Securities:
Municipal commercial paper and demand notes		—		61,006		—		61,006
Corporate commercial paper		—		15,790		—		15,790
Holdings of New GM Securities
New GM Common Stock		798,848		—		—		798,848
New GM Warrants		792,262		—		—		792,262
Total Assets	$	1,591,464	$	76,796	$	—	$	1,668,260
Liabilities:
Liquidating distributions payable	$	16,555	$	—	$	—	$	16,555