Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Summary Of Significant Accounting Policies [Line Items]
Impairment and abandonment expense	$ 9,642	$ 719	$ 49,553
Operating right-of-use asset	8,145			$ 8,600
Capitalized Costs, Oil and Gas Producing Activities, Net	2,043,447	$ 2,020,873
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		407,949
Environmental Remediation Expense	$ 300	$ 1,900
Contract Payment Term	1 month
Current operating lease liability	$ 1,287	$ 0		300
Noncurrent operating lease liability	$ 13,195			13,700
Lease Incentives And Deferred Rent Reduction Of ROU Asset Beginning Balance				$ 5,400
Uinta Basin
Summary Of Significant Accounting Policies [Line Items]
Non-cash impairment of oil and gas properties			37,900
Piceance
Summary Of Significant Accounting Policies [Line Items]
Non-cash impairment of oil and gas properties			9,100
DJ Basin, Non-Core
Summary Of Significant Accounting Policies [Line Items]
Non-cash impairment of oil and gas properties			$ 2,100
Minimum
Summary Of Significant Accounting Policies [Line Items]
Revenue, Contract Term	1 month
Maximum
Summary Of Significant Accounting Policies [Line Items]
Revenue, Contract Term	18 years