Guarantor Financial Statements - Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 326		$ 215	$ 114		$ 112
Accounts receivable, net	517		392
Accounts Receivable, Related Parties, Current	0		0
Intercompany receivable	0		0
Inventories	44		37
Derivative instruments	29		231
Other current assets	56		50
Total current assets	972		925
Property and equipment:
Oil and natural gas properties, at cost, based on the full cost method of accounting	24,076		22,299
Midstream assets	828		700
Other property, equipment and land	150		147
Accumulated depletion, depreciation, amortization and impairment	(3,451)		(2,774)
Net property and equipment	21,603		20,372
Funds held in escrow	13		0
Equity method investments	187		1
Derivative instruments	23		0
Investment in subsidiaries	0		0
Deferred tax asset	150		97
Investment in real estate, net	112		116
Other assets	111		85
Total assets	23,171		21,596	8,954
Current liabilities:
Accounts payable-trade	204		128
Intercompany payable	0		0
Accrued capital expenditures	573		495
Other accrued liabilities	239		253
Revenues and royalties payable	139		143
Derivative instruments	25		0
Total current liabilities	1,180		1,019
Long-term debt	4,472		4,464
Derivative instruments	8		15
Asset retirement obligations	142		136	22
Deferred income taxes	1,909		1,785
Other long-term liabilities	10		10
Total liabilities	7,721		7,429
Commitments and contingencies
Stockholders’ equity	14,004		13,700
Non-controlling interest	1,446		467
Total equity	15,450	$ 14,514	14,167	6,012	$ 5,735	5,582
Total liabilities and equity	23,171		21,596
Eliminations [Member]
Current assets:
Cash and cash equivalents	0		0	0		0
Accounts receivable, net	0		0
Accounts Receivable, Related Parties, Current	(9)		(9)
Intercompany receivable	(5,581)		(4,664)
Inventories	0		0
Derivative instruments	0		0
Other current assets	0		0
Total current assets	(5,590)		(4,673)
Property and equipment:
Oil and natural gas properties, at cost, based on the full cost method of accounting	(154)		(4)
Midstream assets	0		0
Other property, equipment and land	0		0
Accumulated depletion, depreciation, amortization and impairment	(3)		(12)
Net property and equipment	(157)		(16)
Funds held in escrow	0
Equity method investments	0		0
Derivative instruments	0
Investment in subsidiaries	(12,008)		(11,688)
Deferred tax asset	0		0
Investment in real estate, net	0		0
Other assets	0		0
Total assets	(17,755)		(16,377)
Current liabilities:
Accounts payable-trade	(17)		0
Intercompany payable	(5,015)		(4,673)
Accrued capital expenditures	0		0
Other accrued liabilities	0		0
Revenues and royalties payable	0		0
Derivative instruments	0
Total current liabilities	(5,032)		(4,673)
Long-term debt	0		0
Derivative instruments	0		0
Asset retirement obligations	0		0
Deferred income taxes	0		0
Other long-term liabilities	0		0
Total liabilities	(5,032)		(4,673)
Commitments and contingencies
Stockholders’ equity	(13,026)		(11,476)
Non-controlling interest	303		(228)
Total equity	(12,723)		(11,704)
Total liabilities and equity	(17,755)		(16,377)
Parent Company [Member] | Reportable Legal Entities [Member]
Current assets:
Cash and cash equivalents	295		84	66		54
Accounts receivable, net	0		0
Accounts Receivable, Related Parties, Current	0		0
Intercompany receivable	4,383		4,469
Inventories	0		0
Derivative instruments	0		0
Other current assets	1		3
Total current assets	4,679		4,556
Property and equipment:
Oil and natural gas properties, at cost, based on the full cost method of accounting	0		0
Midstream assets	0		0
Other property, equipment and land	0		0
Accumulated depletion, depreciation, amortization and impairment	0		0
Net property and equipment	0		0
Funds held in escrow	0
Equity method investments	0		0
Derivative instruments	0
Investment in subsidiaries	12,008		11,576
Deferred tax asset	0		0
Investment in real estate, net	0		0
Other assets	0		0
Total assets	16,687		16,132
Current liabilities:
Accounts payable-trade	0		0
Intercompany payable	134		0
Accrued capital expenditures	0		0
Other accrued liabilities	14		14
Revenues and royalties payable	0		0
Derivative instruments	0
Total current liabilities	148		14
Long-term debt	2,036		2,036
Derivative instruments	0		0
Asset retirement obligations	0		0
Deferred income taxes	499		382
Other long-term liabilities	0		0
Total liabilities	2,683		2,432
Commitments and contingencies
Stockholders’ equity	14,004		13,700
Non-controlling interest	0		0
Total equity	14,004		13,700
Total liabilities and equity	16,687		16,132
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Current assets:
Cash and cash equivalents	15		100	12		34
Accounts receivable, net	468		351
Accounts Receivable, Related Parties, Current	0		0
Intercompany receivable	1,198		195
Inventories	31		28
Derivative instruments	29		231
Other current assets	50		43
Total current assets	1,791		948
Property and equipment:
Oil and natural gas properties, at cost, based on the full cost method of accounting	22,388		20,586
Midstream assets	6		284
Other property, equipment and land	56		71
Accumulated depletion, depreciation, amortization and impairment	(3,123)		(2,486)
Net property and equipment	19,327		18,455
Funds held in escrow	0
Equity method investments	0		1
Derivative instruments	23
Investment in subsidiaries	0		112
Deferred tax asset	0		0
Investment in real estate, net	2		12
Other assets	88		68
Total assets	21,231		19,596
Current liabilities:
Accounts payable-trade	204		128
Intercompany payable	4,881		4,673
Accrued capital expenditures	505		495
Other accrued liabilities	192		170
Revenues and royalties payable	139		143
Derivative instruments	25
Total current liabilities	5,946		5,609
Long-term debt	2,222		2,017
Derivative instruments	8		15
Asset retirement obligations	137		136
Deferred income taxes	1,408		1,403
Other long-term liabilities	10		10
Total liabilities	9,731		9,190
Commitments and contingencies
Stockholders’ equity	11,500		10,406
Non-controlling interest	0		0
Total equity	11,500		10,406
Total liabilities and equity	21,231		19,596
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Current assets:
Cash and cash equivalents	16		31	$ 36		$ 24
Accounts receivable, net	49		41
Accounts Receivable, Related Parties, Current	9		9
Intercompany receivable	0		0
Inventories	13		9
Derivative instruments	0		0
Other current assets	5		4
Total current assets	92		94
Property and equipment:
Oil and natural gas properties, at cost, based on the full cost method of accounting	1,842		1,717
Midstream assets	822		416
Other property, equipment and land	94		76
Accumulated depletion, depreciation, amortization and impairment	(325)		(276)
Net property and equipment	2,433		1,933
Funds held in escrow	13
Equity method investments	187		0
Derivative instruments	0
Investment in subsidiaries	0
Deferred tax asset	150		97
Investment in real estate, net	110		104
Other assets	23		17
Total assets	3,008		2,245
Current liabilities:
Accounts payable-trade	17		0
Intercompany payable	0		0
Accrued capital expenditures	68		0
Other accrued liabilities	33		69
Revenues and royalties payable	0		0
Derivative instruments	0
Total current liabilities	118		69
Long-term debt	214		411
Derivative instruments	0		0
Asset retirement obligations	5		0
Deferred income taxes	2		0
Other long-term liabilities	0		0
Total liabilities	339		480
Commitments and contingencies
Stockholders’ equity	1,526		1,070
Non-controlling interest	1,143		695
Total equity	2,669		1,765
Total liabilities and equity	$ 3,008		$ 2,245