Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]
Liquidation Basis of Accounting	*Liquidation Basis of Accounting* The GUC Trust exists solely for the purposes described above in Note 1 and has a finite life. Accordingly, the GUC Trust has prepared the accompanying financial statements on the liquidation basis of accounting in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). Under the liquidation basis of accounting as prescribed by the Financial Accounting Standards Board (FASB) Accounting Standards Codification, assets are stated at their estimated net realizable value, which is the non-discounted amount of cash into which an asset is expected to be converted during the liquidation period, while liabilities continue to be recognized at the amount required by other U.S. GAAP, and are not remeasured to reflect any anticipation that an entity will be legally released from an obligation. Additionally, under the liquidation basis of accounting, a reserve is established for estimated costs expected to be incurred during the liquidation period. Such costs are accrued when there is a reasonable basis for estimation. These estimates are periodically reviewed and adjusted as appropriate. The valuation of assets at net realizable value, reserves for residual wind-down claims and reserves for expected liquidation costs represent estimates, based on present facts and circumstances known to the GUC Trust Administrator, and are subject to change. As described above, the beneficiaries of the GUC Trust are future and, to the extent their liquidating distributions have not yet been paid to them, current holders of Allowed General Unsecured Claims and future and current holders of GUC Trust Units (“Trust Beneficiaries”). As Disputed General Unsecured Claims are resolved and allowed and thereby become Allowed General Unsecured Claims, the holders thereof become entitled to receive liquidating distributions of New GM Securities (and the related Dividend Cash) and GUC Trust Units pro rata by the amount of such Claims and, upon such occurrence, the GUC Trust incurs an obligation to distribute such securities. Accordingly, liquidating distributions payable are recorded (at the fair value of such New GM Securities and the related Dividend Cash) as of the end of the period in which the Disputed General Unsecured Claims are resolved as Allowed General Unsecured Claims. Similarly, to the extent potential Term Loan Avoidance Action Claims (as defined below) were to arise (and would become allowed) in the manner described in Note 2, liquidating distributions payable would be recorded for the New GM Securities and the related Dividend Cash (at fair value) that would become distributable to holders of Term Loan Avoidance Action Claims upon such occurrence. Prior to the resolution and allowance of Disputed General Unsecured Claims (or potential Term Loan Avoidance Action Claims), liabilities are not recorded for the conditional obligations associated with Disputed General Unsecured Claims. Rather, the beneficial interests of Trust Beneficiaries in the residual assets of the GUC Trust are reflected in Net Assets in Liquidation of the GUC Trust in the accompanying financial statements. Under the liquidation basis of accounting, the GUC Trust presents two principal financial statements: a Statement of Net Assets in Liquidation and a Statement of Changes in Net Assets in Liquidation. In addition, although not required under the liquidation basis of accounting, the GUC Trust also presents a Statement of Cash Flows, in accordance with the requirements of the GUC Trust Agreement.
Fiscal Year	*Fiscal Year* The GUC Trust’s fiscal year begins on April 1 and ends on the following March 31. As the GUC Trust was created on March 30, 2011 and the Effective Date of the Plan was March 31, 2011, for financial reporting purposes, the GUC Trust is assumed to have been established as of April 1, 2011 and received its initial funding on or about April 1, 2011.
Cash and Cash Equivalents	*Cash and Cash Equivalents* Cash and cash equivalents consist of amounts held in bank accounts or money market funds.
Marketable Securities	*Marketable Securities* Marketable securities consist of short term investments in corporate commercial paper and municipal government commercial paper and variable demand notes. The GUC Trust has valued these securities at fair value based on carrying value for municipal and corporate commercial paper where carrying value approximates fair value and par value for variable demand notes where par value equals fair value.
Holdings of New GM Securities and Dividends Received on New GM Common Stock	*Holdings of New GM Securities and Dividends Received on New GM Common Stock* Holdings of New GM Securities represent the GUC Trust’s holdings of New GM Securities held for future distribution in respect of Allowed General Unsecured Claims and the GUC Trust Units, and include amounts set aside from distribution to fund estimated and projected Wind-Down and Reporting Costs (including projected Dividend Taxes) and potential Taxes on Distribution as described in Note 2. The securities held consist of shares of New GM Common Stock and New GM Warrants as further described in Notes 1 and 6. The GUC Trust has valued its holdings in the securities at their fair value based on quoted market prices as of the last trading day of the fiscal year. Dividends on holdings of New GM Common Stock are recorded as received (or accrued as of the record date for any declared but unpaid dividends). Such dividends and any future declared dividends on New GM Common Stock are required to be applied to the same purpose as the New GM Common Stock to which such dividends relate. If shares of New GM Common Stock are distributed to holders of subsequently Resolved Allowed Claims and GUC Trust Units, then the dividends relating to those shares will also be distributed to such holders. If, however, shares of New GM Common Stock are sold by the GUC Trust in accordance with the GUC Trust Agreement to fund the costs and liabilities of the GUC Trust, then, in that case the dividends relating to those shares will be applied to such costs and liabilities of the GUC Trust and (just like the cash proceeds from the sale of the shares of New GM Common Stock) will be maintained in Other Administrative Cash. Because such dividends are applied to the same purpose as the New GM Common Stock, references to New GM Common Stock and New GM Securities that have been set aside from distribution, reserved or sold should be understood to include the dividends (if any) relating to such New GM Common Stock, unless expressly indicated otherwise. The amount of cash and cash equivalents held by the GUC Trust that relates to dividends received by the GUC Trust on New GM Common Stock held by the GUC Trust is referred to as Dividend Cash.
Other Assets and Deposits	*Other Assets and Deposits* Other assets and deposits consist principally of prepaid insurance, prepaid expenses and retainers for professionals.
Accounts Payable and Other Liabilities	*Accounts Payable and Other Liabilities* Accounts payable and other liabilities represent amounts due to professionals, service providers, and vendors for services rendered or goods received through the end of the period.
Income Taxes	*Income Taxes* The GUC Trust is considered to be a “Disputed Ownership Fund” pursuant to Treasury Regulation Section 1.468B-9. Because all of the assets that have been transferred to the GUC Trust are passive investments, the GUC Trust is taxed as a Qualified Settlement Fund (or QSF) pursuant to Treasury Regulation Section 1.468B-9(c)(1)(ii). The QSF tax status of the GUC Trust has been approved by the Internal Revenue Service in a private letter ruling issued on March 2, 2011. In general, a QSF is considered to be a C Corporation but pays Federal income tax using trust income tax rates on its modified gross income. Modified gross income includes gross income pursuant to Internal Revenue Code Section 61 less administrative expenses, certain losses from the sale, exchange or worthlessness of property, and net operating losses. In general, a Disputed Ownership Fund taxed as a QSF does not recognize gross income on assets transferred to it; therefore, the GUC Trust has not recognized gross income on the transfer of assets from MLC. The GUC Trust is currently expected to generate gross income in the form of interest income and dividends on New GM Common Stock and recognize gains and/or losses upon its disposition of shares of New GM Common Stock and New GM Warrants which it now holds, which will be reduced by administrative expenses and any accumulated net operating and capital losses, to compute modified gross income. During the year ended March 31, 2014, the GUC Trust made a determination to file its U.S. federal income tax returns taking the tax position that beneficial ownership for a substantial majority of New GM Securities was transferred from MLC to the GUC Trust on March 31, 2011, and that the tax basis of such New GM Securities should be determined with reference to the value of such securities on such date instead of December 15, 2011, when record ownership of the remaining New GM Securities still held by MLC was transferred from MLC to the GUC Trust. Accordingly, the GUC Trust filed its U.S. federal income tax returns for the year ended March 31, 2013 with the Internal Revenue Service using the new tax position. Such new tax position, however, as of the date hereof, has not been sustained on examination by the Internal Revenue Service. As the GUC Trust is taxable for Federal income tax purposes, a current income tax liability or asset, if any, is recognized for estimated taxes payable or receivable for the year. Deferred tax liabilities and assets are recognized for the estimated future tax effects of temporary differences between financial reporting and tax accounting. Deferred tax assets are reviewed for recoverability and valuation allowances are provided as necessary. The GUC Trust is not subject to state income taxes under current law. Accordingly, no current or deferred state income tax liabilities and assets are recorded. The GUC Trust recognizes the tax benefit from an uncertain tax position only if it is more likely than not the tax position will be sustained on examination by the taxing authority, based on the technical merits of the position. The GUC Trust’s Federal income tax returns for the years ended March 31, 2012 and 2013 are no longer subject to examination as a result of the application of Section 505(b) of the Bankruptcy Code. However, net operating and capital loss carryovers generated in the years ended March 31, 2012 and 2013, could be subject to examination by the Internal Revenue Service in subsequent years when the losses are utilized. As of March 31, 2014, there are no known items which would result in a significant accrual for uncertain tax positions.
Reserves for Residual Wind-Down Claims and Residual Wind-Down Costs	*Reserves for Residual Wind-Down Claims and Residual Wind-Down Costs* Upon the dissolution of MLC, which occurred on December 15, 2011, the GUC Trust became responsible for resolving and satisfying (to the extent allowed) all remaining Residual Wind-Down Claims. On the date of dissolution of the Debtors, the Debtors transferred to the GUC Trust cash in an amount necessary to satisfy the ultimate allowed amount of such Residual Wind-Down Claims and Residual Wind-Down Costs, as estimated by the Debtors. Should the Residual Wind-Down Claims and the Residual Wind-Down Costs be less than the cash amount transferred by the Debtors, any excess funds will be returned to the DIP Lenders.
Reserves for Expected Costs of Liquidation	*Reserves for Expected Costs of Liquidation* Under the liquidation basis of accounting, the GUC Trust is required to estimate and accrue the costs associated with implementing the Plan and distributing the GUC Trust’s distributable assets. These costs, described as Wind-Down Costs and Reporting Costs in Note 2, consist principally of professional fees, costs of governance, and other administrative expenses. These amounts may vary significantly due to, among other things, the time and effort required to complete all distributions under the Plan. The GUC Trust has recorded reserves for expected costs of liquidation that represent estimated costs to be incurred over the remaining liquidation period of the GUC Trust for which there is a reasonable basis for estimation. The amount of liquidation costs that will ultimately be incurred depends both on the period of time and on the extent of activities required for the GUC Trust to complete its functions and responsibilities under the Plan and the GUC Trust Agreement. Significant uncertainty remains both as to that time period and as to the extent of those activities. As of March 31, 2014, such remaining liquidation period has been estimated on a probability-weighted basis, which the GUC Trust believes is the most appropriate measurement basis in the circumstances. It is reasonably possible that the GUC Trust’s estimates regarding the costs and remaining liquidation period could change in the near term. As the GUC Trust incurs such costs, the reserves are released to offset the costs incurred and a liability to the service provider is recognized as an accounts payable or accrued expense until paid. The process of recording reserves as a matter of financial reporting is separate and distinct from the process by which New GM Securities (including related Dividend Cash) are set aside from distribution for the purposes of funding estimated and projected Wind-Down and Reporting Costs and potential Taxes on Distribution as described in Note 2.
Use of Estimates	*Use of Estimates* The preparation of financial statements on a liquidation basis in conformity with U.S. GAAP requires the use of estimates and assumptions that affect reported amounts of assets and liabilities. These estimates are subject to known and unknown risks, uncertainties and other factors that could materially impact the amounts reported and disclosed in the financial statements and related footnotes. Significant estimates include the anticipated amounts and timing of future cash flows for expected liquidation costs, Residual Wind-Down Claims, fair value of marketable securities and the fair value of New GM Warrants held by MLC for the benefit of the GUC Trust on April 1, 2011. Actual results could differ from those estimates.
New Accounting Standard	*New Accounting Standard* In April 2013, the FASB issued Accounting Standards Update No. 2013-07, Liquidation Basis of Accounting, which amended the FASB Accounting Standards Codification and provides guidance as to when an entity should apply the liquidation basis of accounting. In addition, this guidance establishes principles for the recognition and measurement of assets and liabilities and requirements for financial statements prepared using the liquidation basis of accounting. The provisions of this Accounting Standards Update are effective beginning April 1, 2014 for the GUC Trust. Such provisions require that income or cash expected to be received over the liquidation period be estimated and accrued to the extent that a reasonable basis for estimation exists. With respect to dividends on New GM Common Stock held by the GUC Trust, such dividends have been recorded as received (or accrued as of the record date for any declared but unpaid dividends) in the accompanying financial statements. The GUC Trust has not yet determined the impact the adoption of these provisions will have on its financial statements.