Supplemental Oil and Natural Gas Disclosures - Standardized Measure of Discounted Future Net Cash Flows (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves [Line Items]
Future cash inflows	$ 1,619,147	$ 2,038,508	$ 1,643,582
Future production costs	(177,550)	(222,342)	(211,064)
Future development costs	(54,132)	(58,403)	(70,111)
Future income tax expense	(5,244)	(6,333)	(2,655)
Future net cash flows (undiscounted)	1,382,221	1,751,430	1,359,752
Annual discount 10% for estimated timing	(534,327)	(663,814)	(497,103)
Standardized measure of discounted future net cash flows	$ 847,894	$ 1,087,616	862,649	$ 603,015
Noncontrolling Interest
Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves [Line Items]
Standardized measure of discounted future net cash flows			$ 500