Information Relating to the Consolidated Statement of Cash Flows (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net decrease (increase) in operating working capital was composed of the following:
Decrease (increase) in accounts and notes receivable	$ 1,153		$ (2,156)		$ (2,767)
(Increase) decrease in inventories	(233)		(404)		15
Increase in prepaid expenses and other current assets	(471)		(853)		(542)
Increase in accounts payable and accrued liabilities	544		3,839		3,049
(Decrease) increase in income and other taxes payable	(630)		1,892		321
Net decrease in operating working capital	363		2,318		76
Net cash provided by operating activities includes the following cash payments for interest and income taxes:
Interest paid on debt (net of capitalized interest)	0		0		34
Income taxes	17,334		17,374		11,749
Net sales of marketable securities consisted of the following gross amounts:
Marketable securities purchased	(35)		(112)		(90)
Marketable securities sold	32		38		41
Net purchases of marketable securities	(3)		(74)		(49)
Net sales (purchases) of time deposits consisted of the following gross amounts:
Time deposits purchased	(717)		(6,439)		(5,060)
Time deposits matured	3,967		5,335		2,205
Net sales (purchases) of time deposits	3,250		(1,104)		(2,855)
Capital expenditures
Additions to properties, plant and equipment	29,526	[1]	25,440	[1]	18,474	[1]
Additions to investments	1,042		900		861
Current-year dry hole expenditures	475		332		414
Payments for other liabilities and assets, net	(105)		(172)		(137)
Capital expenditures	30,938		26,500		19,612
Expensed exploration expenditures	1,173		839		651
Assets acquired through capital lease obligations and other financing obligations	1		32		104
Capital and exploratory expenditures, excluding equity affiliates	32,112		27,371		20,367
Company's share of expenditures by equity affiliates	2,117		1,695		1,388
Capital and exploratory expenditures, including equity affiliates	$ 34,229		$ 29,066		$ 21,755

[1] Excludes noncash additions of $4,569 in 2012, $945 in 2011 and $2,753 in 2010.