Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 630	$ 511
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation, depletion, and amortization	385	320
Loss contingency for Macondo well incident	300	0
Other changes:
Inventories	(346)	(159)
Receivables	(233)	(278)
Accounts payable	104	220
Other	(106)	(49)
Total cash flows from operating activities	734	565
Cash flows from investing activities:
Capital expenditures	(782)	(704)
Sales of marketable securities	150	300
Purchases of marketable securities	(100)	(501)
Other investing activities	5	(12)
Total cash flows from investing activities	(727)	(917)
Cash flows from financing activities:
Dividends to shareholders	(83)	(82)
Proceeds from exercises of stock options	46	66
Other financing activities	(12)	7
Total cash flows from financing activities	(49)	(9)
Effect of exchange rate changes on cash	(1)	(7)
Decrease in cash and equivalents	(43)	(368)
Cash and equivalents at beginning of period	2,698	1,398
Cash and equivalents at end of period	2,655	1,030
Cash payments during the period for:
Interest	122	134
Income taxes	$ 165	$ 96