Property, Net Of Accumulated Depreciation (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Property, Net Of Accumulated Depreciation [Abstract]
Interest costs capitalized as part of property, net	$ 22,000,000	$ 10,000,000	$ 43,000,000	$ 17,000,000
Precious metals	2,500,000,000		2,500,000,000		2,500,000,000
Depletion expense	$ 5,000,000	$ 6,000,000	$ 10,000,000	$ 10,000,000