Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesFor the six months ended June 30, 2021 and 2020, the Company calculated the provision for income taxes for interim periods by applying an estimate of the annual effective tax rate for the full fiscal year to "ordinary" income or loss (pre-tax income or loss excluding unusual or infrequently occurring items) for the period. There were no material changes to the Company's methodology for determining unrecognized tax benefits during the six months ended June 30, 2021.The Company recorded income tax benefit at an effective tax rate of 27.0% and 14.0% for the six months ended June 30, 2021 and 2020, respectively. The Company's effective tax rate for the six months ended June 30, 2021 was higher compared to the U.S. federal statutory rate due primarily to state taxes, including valuation allowances limiting certain state tax benefits and West Virginia tax legislation enacted on April 13, 2021 that changed the way taxable income is apportioned to West Virginia for tax years beginning on or after January 1, 2022. The Company's effective tax rate for the six months ended June 30, 2020 was lower compared to the U.S. federal statutory rate due primarily to valuation allowances provided against federal and state deferred tax assets for the additional unrealized losses on the Company's investment in Equitrans Midstream incurred in the first half of 2020 that, if such investment is sold, would become capital losses. The Company believes that it is more likely than not that such additional unrealized losses will not be realized for tax purposes.