Stock-Based Compensation (Summary Of PSP Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value, Outstanding	$ 12.62
Granted Shares, Outstanding	192,245
Awarded Shares, Outstanding	38,449
Shares Not Yet Awarded, Outstanding	153,796
Weighted-Average Grant Date Fair Value, Granted	$ 23.94	$ 12.62
Granted Shares, Granted	2,375,892	192,245
Shares Not Yet Awarded, Granted	2,375,892	192,245
Weighted-Average Grant Date Fair Value, Awarded	$ 11.41	$ 12.62
Awarded Shares, Awarded	(1,041)	38,449
Shares Not Yet Awarded, Awarded	1,041	(38,449)
Weighted-Average Grant Date Fair Value, Forfeited	$ 23.94
Granted Shares, Forfeited	(90,080)
Shares Not Yet Awarded, Forfeited	(90,080)
Weighted-Average Grant Date Fair Value, Outstanding	$ 23.06	$ 12.62
Granted Shares, Outstanding	2,478,057	192,245
Awarded Shares, Outstanding	37,408	38,449
Shares Not Yet Awarded, Outstanding	2,440,649	153,796
Performance Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value, Outstanding	$ 7.32	$ 7.39	$ 7.21
Granted Shares, Outstanding	5,791,854	7,758,547	7,822,076
Awarded Shares, Outstanding	3,391,519	4,423,436	4,629,221
Shares Not Yet Awarded, Outstanding	2,400,335	3,335,111	3,192,855
Weighted-Average Grant Date Fair Value, Granted	$ 0.00	$ 9.67	$ 11.80
Granted Shares, Granted		384,420	389,580
Shares Not Yet Awarded, Granted		384,420	389,580
Weighted-Average Grant Date Fair Value, Awarded	$ 9.56	$ 9.49
Awarded Shares, Awarded	447,154	474,113
Shares Not Yet Awarded, Awarded	(447,154)	(474,113)
Weighted-Average Grant Date Fair Value, Vested	$ 6.01	$ 2.02	$ 6.05
Granted Shares, Vested	(106,490)	(1,388,789)	(73,860)
Awarded Shares, Vested	(106,490)	(1,388,789)	(73,860)
Weighted-Average Grant Date Fair Value, Forfeited	$ 9.48	$ 7.91	$ 10.42
Granted Shares, Forfeited	(753,552)	(962,324)	(379,249)
Awarded Shares, Forfeited	(386,914)	(117,241)	(131,925)
Shares Not Yet Awarded, Forfeited	(366,638)	(845,083)	(247,324)
Weighted-Average Grant Date Fair Value, Outstanding	$ 8.08	$ 7.32	$ 7.39
Granted Shares, Outstanding	4,931,812	5,791,854	7,758,547
Awarded Shares, Outstanding	3,345,269	3,391,519	4,423,436
Shares Not Yet Awarded, Outstanding	1,586,543	2,400,335	3,335,111