Equity- Based Compensation (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified
 6 Months Ended
Jun. 30, 2012
Dec. 31, 2011
Partnership Restricted Equity Units (Class A-2) [Member]
    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Beginning Balance, Number of Shares   93.0
Beginning Balance, Weighted Average Grant Date Fair Value   $ 2.27
Granted at fair market value, Number of Shares 11.2  
Granted at fair market value, Weighted Average Grant Date Fair Value $ 0.11  
Forfeited, Number of Shares (0.1)  
Forfeited, Weighted Average Grant Date Fair Value $ 0.11  
Net shares settlement, Number of Shares (0.6)  
Net share settlement, Weighted Average Grant Date Fair Value $ 0.11  
Ending Balance, Number of Shares 103.5 93.0
Ending Balance, Weighted Average Grant Date Fair Value $ 2.05 $ 2.27
Worldwide [Member]
    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Beginning Balance, Number of Shares   1.9
Beginning Balance, Weighted Average Grant Date Fair Value   $ 1.85
Vesting of restricted share units, Number of Shares 0.2  
Vesting of restricted share units, Weighted Average Grant Date Fair Value $ 1.85  
Net shares settlement, Number of Shares (0.5)  
Net share settlement, Weighted Average Grant Date Fair Value $ 1.85  
Ending Balance, Number of Shares 1.6 1.9
Ending Balance, Weighted Average Grant Date Fair Value $ 1.85 $ 1.85
Restricted Share Units [Member]
    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Beginning Balance, Number of Shares   0.8
Beginning Balance, Weighted Average Grant Date Fair Value   $ 1.85
Vesting of restricted share units, Number of Shares (0.2)  
Vesting of restricted share units, Weighted Average Grant Date Fair Value $ 1.85  
Ending Balance, Number of Shares 0.6 0.8
Ending Balance, Weighted Average Grant Date Fair Value $ 1.85 $ 1.85