Acquisitions, Dispositions, and Other Transactions - Summary of Assets Held for Sale (Details) - Anadarko's Africa Assets - Discontinued Operations, Disposed of by Sale $ in Millions	Sep. 30, 2019 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 16
Inventories	207
Other current assets	110
Property, plant and equipment, net	5,863
Operating lease assets	29
Long-term receivables and other assets, net	220
Assets held for sale	6,445
Current maturities of debt - finance leases	13
Current operating lease liabilities	11
Accounts payable	217
Accrued liabilities	152
Long-term debt, net - finance leases	187
Deferred income taxes	1,281
Asset retirement obligations	142
Other	200
Liabilities of assets held for sale	2,203
Net assets held for sale	$ 4,242