Information Relating to the Consolidated Statement of Cash Flows - Summary of Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net decrease (increase) in operating working capital was composed of the following:
Decrease (increase) in accounts and notes receivable	$ 2,986	$ 473
Decrease (increase) in inventories	(733)	(1,098)
Decrease (increase) in prepaid expenses and other current assets	120	(667)
Increase (decrease) in accounts payable and accrued liabilities	(3,268)	(160)
Increase (decrease) in income and other taxes payable	(201)	242
Net decrease (increase) in operating working capital	(1,096)	(1,210)
Net cash provided by operating activities includes the following cash payments:
Interest on debt (net of capitalized interest)	106	186
Income taxes	981	757
Proceeds and deposits related to asset sales and returns of investment consisted of the following gross amounts:
Proceeds and deposits related to asset sales	363	276
Returns of investment from equity affiliates	11	18
Proceeds and deposits related to asset sales and returns of investment	374	294
Net maturities (investments) of time deposits consisted of the following gross amounts:
Investments in time deposits	0	0
Time deposits matured	0	950
Net sales (purchases) of time deposits	0	950
Net sales (purchases) of marketable securities consisted of the following gross amounts:
Marketable securities purchased	0	(1)
Marketable securities sold	0	3
Net sales (purchases) of marketable securities	0	2
Net repayment (borrowing) of loans by equity affiliates:
Borrowing of loans by equity affiliates	(425)	(350)
Repayment of loans by equity affiliates	26	29
Net repayment (borrowing) of loans by equity affiliates	(399)	(321)
Net borrowings (repayments) of short-term obligations consisted of the following gross and net amounts:
Proceeds from issuances of short-term obligations	4,952	359
Repayments of short-term obligations	(1,010)	(134)
Net borrowings (repayments) of short-term obligations with three months or less maturity	4,225	711
Net borrowings (repayments) of short-term obligations	8,167	936
Net sales (purchases) of treasury shares consists of the following gross and net amounts:
Shares issued for share-based compensation plans	178	523
Shares purchased under share repurchase and deferred compensation plans	(1,751)	(538)
Net sales (purchases) of treasury shares	(1,573)	(15)
Capital expenditures
Additions to properties, plant and equipment	3,071	2,865
Additions to investments	13	14
Current-year dry hole expenditures	49	74
Payments for other assets and liabilities, net	0	0
Capital expenditures	3,133	2,953
Expensed exploration expenditures	108	103
Assets acquired through finance lease obligations and other financing obligations	0	146
Payments for other assets and liabilities, net	0	0
Capital and exploratory expenditures, excluding equity affiliates	3,241	3,202
Company's share of expenditures by equity affiliates	1,183	1,532
Capital and exploratory expenditures, including equity affiliates	$ 4,424	$ 4,734