Information Relating to the Consolidated Statement of Cash Flows (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Net (increase) decrease in operating working capital
Decrease (increase) in accounts and notes receivable	$ 757	$ (1,215)
Increase in inventories	(2,068)	(919)
Increase in prepaid expenses and other current assets	(841)	(904)
Increase in accounts payable and accrued liabilities	25	2,493
(Decrease) increase in income and other taxes payable	(821)	2,049
Net (increase) decrease in operating working capital	(2,948)	1,504
Cash Payment for Interest on Debt and For Income Taxes
Interest on debt (net of capitalized interest)	32	46
Income taxes	14,345	12,982
Net sales (purchases) of time deposits
Time deposits purchased	(17)	(6,439)
Time deposits matured	3,967	3,435
Net sales (purchases) of time deposits	3,950	(3,004)
Net sales (purchases) of marketable securities
Marketable securities purchased	(35)	(113)
Marketable securities sold	31	38
Net purchases of marketable securities	(4)	(75)
Capital expenditures
Additions to properties, plant and equipment	19,310	18,458
Additions to investments	782	639
Current year dry hole expenditures	440	217
Payments for other liabilities and assets, net	(80)	(121)
Capital expenditures	20,452	19,193
Expensed exploration expenditures	853	569
Assets acquired through capital lease obligations	0	5
Capital and exploratory expenditures, excluding equity affiliates	21,305	19,767
Company's share of expenditures by equity affiliates	1,368	1,035
Capital and exploratory expenditures, including equity affiliates	$ 22,673	$ 20,802