Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company typically provides for income taxes at a statutory rate adjusted for permanent differences expected to be realized, primarily statutory depletion, non-deductible stock compensation expenses and state income taxes. As a result of ceiling test write-downs recognized, the Company has incurred a cumulative three year loss. Because of the impact the cumulative loss has on the determination of the recoverability of deferred tax assets through future earnings, the Company assessed the realizability of its deferred tax assets based on the future reversals of existing deferred tax liabilities. Accordingly, the Company established a valuation allowance for a portion of the deferred tax asset. The valuation allowance was $116.3 million and $115.9 million as of March 31, 2018 and December 31, 2017, respectively. The Tax Cuts and Jobs Act (the "Act") was enacted on December 22, 2017. The Act, among other things, reduces the U.S. federal corporate tax rate from 35% to 21%, eliminates the corporate alternative minimum tax and changes how existing alternative minimum tax credits are realized, creates a new limitation on deductible interest expense and changes the rules related to uses and limitations of net operating loss carryforwards generated in tax years beginning after December 31, 2017. As of March 31, 2018, the Company has not completed its accounting for the tax effects of enactment of the Act. However, the Company made a reasonable estimate of the effects on its existing deferred tax balances and recognized a provisional amount of $64.9 million as of December 31, 2017 to remeasure deferred tax assets and liabilities based on the rate at which they are expected to reverse in the future, which is generally 21%. This amount was included as a component of income tax expense (benefit) from continuing operations and was fully offset by the related adjustment to the Company's valuation allowance. The Company is still analyzing certain aspects of the Act and refining its calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts.

Income Taxes

The Company typically provides for income taxes at a statutory rate adjusted for permanent differences expected to be realized, primarily statutory depletion, non-deductible stock compensation expenses and state income taxes. As a result of ceiling test write-downs recognized, the Company has incurred a cumulative three year loss. Because of the impact the cumulative loss has on the determination of the recoverability of deferred tax assets through future earnings, the Company assessed the realizability of its deferred tax assets based on the future reversals of existing deferred tax liabilities. Accordingly, the Company established a valuation allowance for a portion of the deferred tax asset. The valuation allowance was $116.3 million and $115.9 million as of March 31, 2018 and December 31, 2017, respectively.

The Tax Cuts and Jobs Act (the "Act") was enacted on December 22, 2017. The Act, among other things, reduces the U.S. federal corporate tax rate from 35% to 21%, eliminates the corporate alternative minimum tax and changes how existing alternative minimum tax credits are realized, creates a new limitation on deductible interest expense and changes the rules related to uses and limitations of net operating loss carryforwards generated in tax years beginning after December 31, 2017. As of March 31, 2018, the Company has not completed its accounting for the tax effects of enactment of the Act. However, the Company made a reasonable estimate of the effects on its existing deferred tax balances and recognized a provisional amount of $64.9 million as of December 31, 2017 to remeasure deferred tax assets and liabilities based on the rate at which they are expected to reverse in the future, which is generally 21%. This amount was included as a component of income tax expense (benefit) from continuing operations and was fully offset by the related adjustment to the Company's valuation allowance. The Company is still analyzing certain aspects of the Act and refining its calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts.