Information Relating to the Consolidated Statement of Cash Flows (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net decrease (increase) in operating working capital was composed of the followings:
Increase in accounts and notes receivable	$ (2,156)	$ (2,767)	$ (1,476)
(Increase) decrease in inventories	(404)	15	1,213
Increase in prepaid expenses and other current assets	(853)	(542)	(264)
Increase (decrease) in accounts payable and accrued liabilities	3,839	3,049	(1,121)
Increase (decrease) in income and other taxes payable	1,892	321	(653)
Net decrease (increase) in operating working capital	2,318	76	(2,301)
Net cash provided by operating activities includes the following cash payment for interest and income taxes:
Interest paid on debt (net of capitalized interest)		34
Income taxes	17,374	11,749	7,537
Net sales of marketable securities consisted of the following gross amounts:
Marketable securities purchased	(112)	(90)	(30)
Marketable securities sold	38	41	157
Net (purchases) sales of marketable securities	(74)	(49)	127
Net purchases of time deposits consisted of the following gross amounts:
Time deposits purchased	(6,439)	(5,060)
Time deposits matured	5,335	2,205
Net purchases of time deposits	(1,104)	(2,855)
Capital expenditures
Additions to properties, plant and equipment	25,440	18,474	16,107
Additions to investments	900	861	942
Current year dry hole expenditures	332	414	468
Payments for other liabilities and assets, net	(172)	(137)	2,326
Capital expenditures	26,500	19,612	19,843
Expensed exploration expenditures	839	651	790
Assets acquired through capital lease obligations and other financing obligations	32	104	19
Capital and exploratory expenditures, excluding equity affiliates	27,371	20,367	20,652
Company's share of expenditures by equity affiliates	1,695	1,388	1,585
Capital and exploratory expenditures, including equity affiliates	$ 29,066	$ 21,755	$ 22,237