Basis of Presentation - Balance Sheet Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Accounts Receivable, Net
Commodity Sales		$ 270	$ 446
Joint Interest Billings		115	164
Other		88	128
Current Expected Credit Losses		(8)	(8)
Total		465	730
Other Current Assets
Commodity Derivative Assets		61	14
Inventory - Materials and Supplies		68	59
Assets held for sale		2	14
Prepaid Expenses and Other Current Assets		83	61
Total		214	148
Other Noncurrent Assets
Equity Method Investments		1,246	1,066
Operating lease right of use assets		225	227
Customer-related intangible assets, net		262	278
Goodwill		0	110
Other Assets, Noncurrent		177	153
Total		1,910	1,834
Other Current Liabilities
Production and Ad Valorem Taxes		109	118
Commodity Derivative Liabilities		151	36
Asset Retirement Obligations		89	84
Interest Payable		59	74
Operating Lease Liabilities		79	88
Compensation and Benefits Payable		53	126
Other Liabilities, Current		166	193
Total		706	719
Other Noncurrent Liabilities
Deferred Compensation Liabilities		121	133
Asset Retirement Obligations		732	730
Operating Lease Liabilities		169	164
Firm transportation exit cost accrual		113	129
Other Liabilities, Noncurrent		153	222
Total		1,288	1,378
Lease renewal term	5 years
Lease renewal	$ 28
Accumulated amortization		$ 78	$ 62
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]		us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent