Properties, Plants, And Equipment, Net (Schedule Of Properties, Plants, And Equipment, Net) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Properties, Plants, And Equipment, Net [Abstract]
Land and land rights, including mines	$ 667	$ 631
Structures	12,111	11,657
Machinery and equipment	23,333	23,189
Properties, plants, and equipment, gross	36,111	35,477
Less: accumulated depreciation, depletion, and amortization	18,404	17,487
Properties, plants, and equipment excluding construction work-in-progress	17,707	17,990
Construction work-in-progress	1,709	2,193
Properties, plants, and equipment, net	$ 19,416	$ 20,183