Employee Benefit Plans (Schedule Of Stock Related Compensation Expense Relating To The Stock Options, RSUs, LTIP And Cash Equivalent Awards) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule Of Stock Related Compensation Expense Relating To the Stock Options, RSUs, LTIP And Cash Equivalent Awards [Line Items]
Compensation expense	$ 42,589	$ 49,375	$ 40,399
General And Administrative Expense [Member] | Stock Options [Member]
Schedule Of Stock Related Compensation Expense Relating To the Stock Options, RSUs, LTIP And Cash Equivalent Awards [Line Items]
Compensation expense	4,098	2,953	2,556
General And Administrative Expense [Member] | RSUs [Member]
Schedule Of Stock Related Compensation Expense Relating To the Stock Options, RSUs, LTIP And Cash Equivalent Awards [Line Items]
Compensation expense	13,140	13,473	9,003
General And Administrative Expense [Member] | LTIP Award [Member]
Schedule Of Stock Related Compensation Expense Relating To the Stock Options, RSUs, LTIP And Cash Equivalent Awards [Line Items]
Compensation expense	5,056	17,817	25,580
General And Administrative Expense [Member] | Cash-Equivalent Stock Awards [Member]
Schedule Of Stock Related Compensation Expense Relating To the Stock Options, RSUs, LTIP And Cash Equivalent Awards [Line Items]
Compensation expense	$ 20,295	$ 15,132	$ 3,260