Other Noncurrent Assets (Schedule Of Other Noncurrent Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Other Noncurrent Assets [Abstract]
Intangibles, net (E)	$ 494	$ 524
Value-added tax receivable	510	495
Cash surrender value of life insurance	455	464
Prepaid gas transmission contract	346	332
Deferred mining costs, net	221	173
Unamortized debt expense	98	95
Fair value of derivative contracts (X)	44	92
Prepaid pension benefit (W)	109	84
Other	291	286
Other assets, noncurrent, total	$ 2,568	$ 2,545