Tax effects of temporary differences representing the net DTA (DTL) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
DTA, Federal net operating losses (NOLs)	$ 67,610	$ 71,736
DTA, Other loss carryforwards	552	583
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Asset Retirement Obligations	960	920
DTA, Unrealized share-based compensation	1,210	906
Deferred Tax Assets, Tax Deferred Expense, Other	1,999	0
DTA, Other	874	956
DTA, Valuation Allowance	0	(42,335)
Total deferred tax assets	73,205	32,766
Deferred tax liabilities:
DTL, Oil and gas exploration and development costs	(48,329)	(30,935)
Deferred Tax Liabilities, Derivatives	(1,820)	(2,817)
Deferred Tax Liabilities, Leasing Arrangements	(1,968)	0
DTL, Other	(1)	(28)
Total deferred tax liabilites	52,118	33,780
Net deferred tax liabilities	21,087	(1,014)
State deferred tax liabilities, net	(1,582)	(1,014)
Federal deferred tax assets, net	$ 22,669	$ 0