Stock-Based Compensation 5 (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of SARs	1,663,340	1,783,956	1,493,131	1,200,552
Weighted-average remaining contractual life	7.36
Weighted-average exercise price - Outstanding	$ 20.63	$ 20.50	$ 19.18	$ 18.02
Exercisable	1,278,950	900,965	494,775
Weighted-average exercise price - Exercisable	$ 19.71	$ 20.53	$ 22.06
Price Range 12.55 - 17.50 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of SARs	568,685
Weighted-average remaining contractual life	6.96
Weighted-average exercise price - Outstanding	$ 12.55
Exercisable	568,685
Weighted-average exercise price - Exercisable	$ 12.55
Price Range 17.51 - 25.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of SARs	745,401
Weighted-average remaining contractual life	8.44
Weighted-average exercise price - Outstanding	$ 23.17
Exercisable	365,287
Weighted-average exercise price - Exercisable	$ 22.68
Price Range 25.01 - 28.48 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of SARs	349,254
Weighted-average remaining contractual life	5.71
Weighted-average exercise price - Outstanding	$ 28.35
Exercisable	344,978
Weighted-average exercise price - Exercisable	$ 28.36