(3) Income Taxes (in thousands) (Detail) - Deferred tax assets and liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Long-term deferred tax assets:
AMT credit carryforwards		$ 1,137
Stock-based compensation	582	596
Investment in Savoy	1,582	960
Oil and gas properties	1,778	1,540
Net long-term deferred tax assets	3,942	4,233
Long-term deferred tax liabilities:
Coal properties	(39,826)	(35,333)
Net deferred tax liability	$ 35,884	$ 31,100

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from equity method investments.

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Amount after allocation of valuation allowances of noncurrent deferred tax asset attributable to deductible temporary differences and carryforwards. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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- Definition

Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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