Income Taxes	3 Months Ended
May. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Blocker, a wholly owned subsidiary of NGA, has elected to be taxed as a corporation. Accordingly, equity in the flow-through earnings of Mesquite (and Eldorado through September 18, 2014), realized gains on available-for-sale securities, interest income from the Credit Agreement, and interest expense on intercompany borrowings received from Holdco to fund a portion of the Credit Agreement are taxed to Blocker. NGA recognizes interest income on intercompany loans to Blocker and incurs certain costs, primarily associated with being a public company, including professional and other fees, which, for tax purposes, flow through to its members. The Company's deferred tax assets consist primarily of impairment charges related to its investments in ERI and Mesquite and, because realization is not considered more likely than not, the Company has recorded a valuation allowance of 100%. For these reasons, the Company’s effective tax rates for the periods presented are different than the statutory federal rate of 35%. In assessing the realizability of the deferred tax assets, management considers whether future taxable income will be sufficient during the periods in which those temporary differences reverse. Management considers the scheduled reversal of deferred tax liabilities, projected taxable income, and tax planning strategies in making this assessment. The Company has recorded a valuation allowance of 100% of its net deferred tax assets as of May 31, 2015 and February 28, 2015, though subsequent to February 28, 2015, the estimated fair value of the Company's available-for-sale securities has appreciated substantially. If the ERI shares were unrestricted and had been sold as of May 31, 2015, most of the related deferred tax asset could have been realized. However, the Company is restricted from disposing of the investment, has no immediate plans to sell its investment, and the trading value of ERI's shares is subject to potentially significant daily changes in value. Accordingly, management believes there is insufficient information to reduce the valuation allowance at this time.

Income Taxes

3 Months Ended

May. 31, 2015

Blocker, a wholly owned subsidiary of NGA, has elected to be taxed as a corporation. Accordingly, equity in the flow-through earnings of Mesquite (and Eldorado through September 18, 2014), realized gains on available-for-sale securities, interest income from the Credit Agreement, and interest expense on intercompany borrowings received from Holdco to fund a portion of the Credit Agreement are taxed to Blocker. NGA recognizes interest income on intercompany loans to Blocker and incurs certain costs, primarily associated with being a public company, including professional and other fees, which, for tax purposes, flow through to its members. The Company's deferred tax assets consist primarily of impairment charges related to its investments in ERI and Mesquite and, because realization is not considered more likely than not, the Company has recorded a valuation allowance of 100%. For these reasons, the Company’s effective tax rates for the periods presented are different than the statutory federal rate of 35%.

In assessing the realizability of the deferred tax assets, management considers whether future taxable income will be sufficient during the periods in which those temporary differences reverse. Management considers the scheduled reversal of deferred tax liabilities, projected taxable income, and tax planning strategies in making this assessment. The Company has recorded a valuation allowance of 100% of its net deferred tax assets as of May 31, 2015 and February 28, 2015, though subsequent to February 28, 2015, the estimated fair value of the Company's available-for-sale securities has appreciated substantially. If the ERI shares were unrestricted and had been sold as of May 31, 2015, most of the related deferred tax asset could have been realized. However, the Company is restricted from disposing of the investment, has no immediate plans to sell its investment, and the trading value of ERI's shares is subject to potentially significant daily changes in value. Accordingly, management believes there is insufficient information to reduce the valuation allowance at this time.