Discontinued Operations and Assets Held for Sale - Results of Operations Associated with Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Revenues 1	$ 1,364,943	$ 854,251		$ 781,995
Lease operating expense	127,138	202,062		168,903
Depreciation, depletion and amortization	33,697	196,287		205,841
Other costs and expenses (benefits)	81,538	70,088		53,409
Total income from discontinued operations before taxes	1,122,570	385,814		353,842
Income tax expense	(58,083)	(135,466)		(112,616)
Income from discontinued operations	$ 1,064,487	$ 250,348	[1],[2]	$ 241,226	[1],[2]

[1] ¹ Reclassified to conform with current presentation (see Notes C and E). 2017 revenue is presented net of $58.9 million of transportation, gathering and processing costs as historically shown prior to the adoption of ASC 606 on January 1, 2018. See Notes to Consolidated Financial Statements, page 58.

[2] Reclassified to conform with current presentation (see Note E)