Non-Mineral Leases - Balance Sheet Liabilities (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018
Short-term debt		$ 121	$ 112
Other accruals		1,030	1,259
Long-term debt		14,799	14,856
Other liabilities and deferred credits		1,794	1,192
Operating Lease, Liability		805
Finance Lease, Liability Total		742
Previously Reported [Member]
Short-term debt			79
Long-term debt			698
Finance Lease, Liability Total			$ 777
Accounting Standards Update 2016-02 (Topic 842) [Member]
Short-term debt	[1]	86
Other accruals		249
Long-term debt	[1]	656
Other liabilities and deferred credits		556
Operating Lease, Liability		805
Finance Lease, Liability Total		$ 742

[1] *Short-term debt and long-term debt include proportionately consolidated finance lease liabilities of $55 million and $595 million, respectively. **As a result of the sale of two ConocoPhillips U.K. subsidiaries, lease liabilities decreased approximately $0.2 billion in the third quarter of 2019. See Note 5–Asset Dispositions for additional information.