Tax effects of temporary differences representing the net DTA (DTL) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
DTA, Federal net operating losses (NOLs)	$ 93,293	$ 67,610
DTA, Other loss carryforwards	610	552
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Asset Retirement Obligations	1,074	960
DTA, Unrealized share-based compensation	959	1,210
Deferred Tax Assets, Tax Deferred Expense, Other	929	1,999
DTA, Other	1,029	874
DTA, Valuation Allowance	(82,618)	0
Total deferred tax assets	15,276	73,205
Deferred tax liabilities:
DTL, Oil and gas exploration and development costs	(13,008)	(48,329)
Deferred Tax Liabilities, Derivatives	(1,653)	(1,820)
Deferred Tax Liabilities, Leasing Arrangements	(917)	(1,968)
DTL, Other	(1)	(1)
Total deferred tax liabilites	15,579	52,118
Net deferred tax liabilities	(303)	21,087
State deferred tax liabilities, net	(303)	(1,582)
Federal deferred tax assets, net	$ 0	$ 22,669