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Equity-Based Compensation (Assumptions) (Details) - Performance Shares - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2017
Equity-Based Compensation [Line Items]    
Risk-free interest rate 2.51% 1.52%
Look-back period 2 years 10 months 2 days 2 years 9 months 29 days
Expected volatility 25.01% 49.34%
Grant date fair value of performance units granted $ 0.76 $ 0.90