Property, Plant And Equipment And Asset Retirement Obligations (Property, Plant And Equipment) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Cost	$ 393,995	$ 373,938
Property, Plant and Equipment, Net	214,664	199,548	139,116
Upstream [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Cost	283,710	264,136
Property, Plant and Equipment, Net	163,975	148,152
Downstream [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Cost	67,900	68,652
Property, Plant and Equipment, Net	28,801	30,095
Chemical [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Cost	30,405	29,524
Property, Plant and Equipment, Net	14,469	14,255
Other [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Cost	11,980	11,626
Property, Plant and Equipment, Net	$ 7,419	$ 7,046

Gross amount, at the balance sheet date, of long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

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Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

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