ShareBased Compensation Plans Compensation Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Expense	$ 11,649	$ 13,969	$ 25,637
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Expense	7,141	9,979	19,476
PBRSU [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Expense	1,779	2,098	0
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Expense	2,430	1,469	5,212
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Expense	$ 299	$ 423	$ 949