Incentive Plans (Details 2) (Stock Options/SOSARs [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y
Stock Options/SOSARs [Member]
Stock Options/SOSARs
Number of Shares, Outstanding at January 1, 2011	6,479,296
Number of Shares, Granted	656,360
Number of Shares, Exercised	(85,394)
Number of Shares, Forfeited or expired	(408,415)
Number of Shares, Outstanding at December 31, 2011	6,641,847
Number of Shares, Vested and expected to vest	6,768,683
Number of Shares, Exercisable at December 31, 2011	5,414,035
Weighted-average Exercise Price, Outstanding at January 1, 2011	$ 55.97
Weighted-average Exercise Price, Granted	$ 35.38
Weighted-average Exercise Price, Exercised	$ 42.11
Weighted-average Exercise Price, Forfeited or expired	$ 46.58
Weighted-average Exercise Price, Outstanding at December 31, 2011	$ 54.69
Weighted-average Exercise Price, Vested and expected to vest	$ 54.19
Weighted-average Exercise Price, Exercisable at December 31, 2011	$ 57.61
Weighted-average Remaining Contractual Life (Years), Outstanding at December 31, 2011	4.71
Weighted-average Remaining Contractual Life (Years), Vested and expected to vest	4.80
Weighted-average Remaining Contractual Life (Years), Exercisable at December 31, 2011	3.87
Aggregate Intrinsic Value, Outstanding at December 31, 2011	$ 7,202
Aggregate Intrinsic Value, Vested and expected to vest	8,575
Aggregate Intrinsic Value, Exercisable at December 31, 2011	$ 4,874