Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets
Net operating loss carryforwards	$ 122,952	$ 119,900
Unrealized loss on derivatives	8,997	960
Percentage depletion carryover	1,462	1,467
Compensation	10,405	13,690
Lease liabilities	9,380	17,107
Other	8,334	8,139
Deferred Tax Assets, Gross	161,530	161,263
Valuation allowance on deferred tax assets	(110,681)	(6,736)
Total deferred tax assets, net of valuation allowance	50,849	154,527
Deferred tax liabilities
Property and equipment	(11,879)	(151,504)
Less than wholly-owned subsidiaries	(26,564)	(20,604)
Lease right of use assets	(9,380)	(17,107)
Other	(2,684)	(2,641)
Total deferred tax liabilities	(50,507)	(191,856)
Net deferred tax assets (liabilities)	$ 342	$ (37,329)