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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, 2012
Dec. 31, 2011
Dec. 31, 2010
Risk-free interest rate, Minimum 0.00% 0.00% 0.12%
Risk-free interest rate, Maximum 0.07% 0.58% 1.73%
Expected unit price volatility 39.30% 40.60% 41.90%
Expected future distribution yield 5.00% 6.00% 6.00%
Minimum [Member]
     
Expected life of rights (in years), Minimum   0 years 0 years
Maximum [Member]
     
Expected life of rights (in years), Minimum 1 year 3 years 4 months 28 days 4 years 4 months 28 days