Information Relating to the Consolidated Statement of Cash Flows - Summary of Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net decrease (increase) in operating working capital was composed of the following:
Decrease (increase) in accounts and notes receivable	$ 1,852	$ 437	$ (915)
Decrease (increase) in inventories	7	(424)	(267)
Decrease (increase) in prepaid expenses and other current assets	(323)	(149)	173
Increase (decrease) in accounts payable and accrued liabilities	(109)	(494)	998
Increase (decrease) in income and other taxes payable	67	(88)	531
Net decrease (increase) in operating working capital	1,494	(718)	520
Net cash provided by operating activities includes the following cash payments:
Interest on debt (net of capitalized interest)	810	736	265
Income taxes	4,817	4,748	3,132
Proceeds and deposits related to asset sales and returns of investment consisted of the following gross amounts:
Proceeds and deposits related to asset sales	2,809	2,000	4,930
Returns of investment from equity affiliates	142	392	166
Proceeds and deposits related to asset sales and returns of investment	2,951	2,392	5,096
Net maturities (investments) of time deposits consisted of the following gross amounts:
Investments in time deposits	0	(950)	0
Maturities of time deposits	950	0	0
Net maturities of (investments in) time deposits	950	(950)	0
Net sales (purchases) of marketable securities consisted of the following gross amounts:
Marketable securities purchased	(1)	(51)	(3)
Marketable securities sold	3	0	7
Net sales (purchases) of marketable securities	2	(51)	4
Net repayment (borrowing) of loans by equity affiliates:
Borrowing of loans by equity affiliates	(1,350)	0	(142)
Repayment of loans by equity affiliates	105	111	126
Net repayment (borrowing) of loans by equity affiliates	(1,245)	111	(16)
Net borrowings (repayments) of short-term obligations consisted of the following gross and net amounts:
Proceeds from issuances of short-term obligations	2,586	2,486	5,051
Repayments of short-term obligations	(1,430)	(4,136)	(8,820)
Net borrowings (repayments) of short-term obligations with three months or less maturity	(3,977)	3,671	(1,373)
Net borrowings (repayments) of short-term obligations	(2,821)	2,021	(5,142)
Capital expenditures
Additions to properties, plant and equipment	13,839	13,384	13,222
Additions to investments	140	65	25
Current-year dry hole expenditures	124	344	157
Payments for other liabilities and assets, net	13	(1)	0
Capital expenditures	14,116	13,792	13,404
Expensed exploration expenditures	598	523	666
Assets acquired through finance leases and other obligations	181	75	8
Payments for other assets and liabilities, net	(13)	0	0
Capital and exploratory expenditures, excluding equity affiliates	14,882	14,390	14,078
Company’s share of expenditures by equity affiliates	6,112	5,716	4,743
Capital and exploratory expenditures, including equity affiliates	20,994	20,106	18,821
Net sales (purchases) of treasury shares consists of the following gross and net amounts:
Shares issued for share-based compensation plans	1,104	1,147	1,118
Shares purchased under share repurchase and deferred compensation plans	(4,039)	(1,751)	(1)
Net sales (purchases) of treasury shares	(2,935)	(604)	1,117
Non-cash additions to properties, plant and equipment	$ (239)	$ 25	$ 1,183