Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011
Undistributed earnings with no provision for deferred or foreign income taxes	$ 1,700,000,000
Minimum [Member]
Estimated amount of unrecognized deferred tax liability related to undistributed earnings	250,000,000
Maximum [Member]
Estimated amount of unrecognized deferred tax liability related to undistributed earnings	$ 325,000,000