Share-Based Awards (Summary Of Stock Appreciation Right Transactions) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, beginning of period	6,978,000
Weighted-Average Price, Options outstanding, beginning of period	$ 36
Options granted	431,000
Weighted-Average Price, Options granted	$ 41
Options exercised	(374,000)
Weighted-Average Price, Options exercised	$ 21
Options forfeited	(724,000)
Weighted-Average Price, Options forfeited	$ 44
Options outstanding, end of period	6,311,000	6,978,000
Weighted-Average Price, Options outstanding, end of period	$ 37	$ 36
Exercisable, end of period	4,211,000
Weighted-Average Price, Exercisable, end of period	$ 43
Weighted-average Aggregate weighted-average fair value of options	$ 15	$ 8	$ 5
Stock Appreciation Rights (SAR's) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, beginning of period	309,000
Weighted-Average Price, Options outstanding, beginning of period	$ 21
Options granted	16,000
Weighted-Average Price, Options granted	$ 41
Options exercised	(40,000)
Weighted-Average Price, Options exercised	$ 20
Options forfeited	(12,000)
Weighted-Average Price, Options forfeited	$ 61
Options outstanding, end of period	273,000	309,000
Weighted-Average Price, Options outstanding, end of period	$ 21	$ 21
Exercisable, end of period	116,000
Weighted-Average Price, Exercisable, end of period	$ 23
Weighted-average Aggregate weighted-average fair value of options	$ 15	$ 8	$ 5