Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 2,080	$ 2,089	$ 324
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	1,574	1,534	1,473
Asset impairment losses	1,014	0	2
Loss on shutdown and sales of refinery assets, net	0	12	888
Gain on sale of investment in Cameron Highway Oil Pipeline Company	0	0	(55)
Stock-based compensation expense	58	58	54
Deferred income tax expense	963	461	347
Changes in current assets and current liabilities	(302)	81	68
Changes in deferred charges and credits and other operating activities, net	(117)	(197)	(56)
Net cash provided by operating activities	5,270	4,038	3,045
Cash flows from investing activities:
Capital expenditures	(2,931)	(2,355)	(1,730)
Deferred turnaround and catalyst costs	(479)	(629)	(535)
Acquisition of Pembroke Refinery, net of cash acquired	0	(1,691)	0
Acquisition of Meraux Refinery	0	(547)	0
Acquisitions of ethanol plants	0	0	(260)
Minor acquisitions	(80)	(37)	0
Proceeds from the sale of investment in Cameron Highway Oil Pipeline Company	0	0	330
Other investing activities, net	(21)	(39)	23
Net cash used in investing activities	(3,351)	(5,298)	(1,405)
Non-bank debt:
Borrowings	300	0	1,544
Repayments	(862)	(774)	(517)
Bank credit agreements:
Borrowings	1,100	0	0
Repayments	(1,100)	(4)	0
Accounts receivable sales program:
Proceeds from the sale of receivables	1,500	150	1,225
Repayments	(1,650)	0	(1,325)
Proceeds from the exercise of stock options	59	49	20
Purchase of common stock for treasury	(281)	(349)	(13)
Common stock dividends	(360)	(169)	(114)
Contributions from noncontrolling interest	44	22	0
Other financing activities, net	17	9	(4)
Net cash provided by (used in) financing activities	(1,233)	(1,066)	816
Effect of foreign exchange rate changes on cash	13	16	53
Net increase (decrease) in cash and temporary cash investments	699	(2,310)	2,509
Cash and temporary cash investments at beginning of year	1,024	3,334	825
Cash and temporary cash investments at end of year	$ 1,723	$ 1,024	$ 3,334