Additional Financial Statement Information - Additional Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Net
Commodity Sales	$ 446	$ 383
Joint Interest Billings	164	137
Other	128	111
Allowance	(8)	(15)
Total	730	616
Other Current Assets
Commodity Derivative Assets	14	180
Inventories, Materials and Supplies	59	55
Assets Held for Sale	14	133
Prepaid Expenses and Other Current Assets	61	50
Total	148	418
Other Noncurrent Assets
Total Equity Method Investments	1,066	286
Operating Lease Right-of-Use Assets	227
Customer-Related Intangible Assets, Net	278	310
Goodwill	110	110
Mutual Fund Investments	27	38
Other Noncurrent Assets	126	97
Total	1,834	841
Other Current Liabilities
Production and Ad Valorem Taxes	118	103
Asset Retirement Obligations	84	118
Interest Payable	74	66
Operating Lease Liabilities	88
Compensation and Benefits Payable	126	83
Other Current Liabilities	229	149
Total	719	519
Other Noncurrent Liabilities
Deferred Compensation Liabilities	133	147
Asset Retirement Obligations	730	762
Operating Lease Liabilities	164
Firm Transportation Exit Cost Accrual	129	67
Other Noncurrent Liabilities	222	189
Total	$ 1,378	$ 1,165