Property, Net Of Accumulated Depreciation (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Property, Net Of Accumulated Depreciation [Abstract]
Interest costs capitalized as part of property, net	$ 19,000,000	$ 11,000,000	$ 62,000,000	$ 28,000,000
Precious metals	2,500,000,000		2,500,000,000		2,500,000,000
Depletion expense	$ 4,000,000	$ 6,000,000	$ 14,000,000	$ 16,000,000