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Equity-Based Compensation Plans And Employee Benefit Plans (Assumptions Used To Determine Fair Value Of Rights) (Details)
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Equity-Based Compensation Plans And Employee Benefit Plans [Abstract]      
Expected life of rights (in years), Minimum 0.00 0.00 0.25
Expected life of rights (in years), Maximum 3.41 4.41 5.50
Risk-free interest rate, Minimum 0.00% 0.12% 0.05%
Risk-free interest rate, Maximum 0.58% 1.73% 2.52%
Expected unit price volatility 40.60% 41.90% 43.80%
Expected future distribution yield 6.00% 6.00% 8.50%