Assets Held for Sale and Discontinued Operations - Results of Operations Associated with Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	$ 4,090	$ 1,364,943	$ 854,251
Lease operating expense	0	127,138	202,062
Depreciation, depletion and amortization	0	33,697	196,287
Other costs and expenses (benefits)	11,241	81,538	70,088
Total income from discontinued operations before taxes	(7,151)	1,122,570	385,814
Income tax expense	0	58,083	135,466
Income from discontinued operations	$ (7,151)	1,064,487	$ 250,348	[1]
Malaysia
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposition of business		$ 985,400

[1] Reclassified to conform with current presentation