Taxes (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Deferred tax liabilities
Properties, plant and equipment	$ 23,597	$ 19,855
Investments and other	2,271	2,401
Total deferred tax liabilities	25,868	22,256
Deferred tax assets
Foreign tax credits	(8,476)	(6,669)
Abandonment/environmental reserves	(5,387)	(5,004)
Employee benefits	(4,773)	(3,627)
Deferred credits	(1,548)	(2,176)
Tax loss carryforwards	(828)	(882)
Other accrued liabilities	(531)	(486)
Inventory	(360)	(483)
Miscellaneous	(1,595)	(1,676)
Total deferred tax assets	(23,498)	(21,003)
Deferred tax assets valuation allowance	11,096	9,185
Total deferred taxes, net	13,466	10,438
Classification of deferred taxes
Prepaid expenses and other current assets	(1,149)	(1,624)
Deferred charges and other assets	(1,224)	(851)
Federal and other taxes on income	(295)	(216)
Noncurrent deferred income taxes	15,544	12,697
Total deferred taxes, net	$ 13,466	$ 10,438