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Long-Term Incentive Plan - Narrative (Details) - shares
12 Months Ended
Oct. 09, 2015
Dec. 31, 2017
Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]      
Period of anniversary   5 years  
Long-term Incentive Plan      
Defined Benefit Plan Disclosure [Line Items]      
Award vesting rights, percentage 10.00%    
Award vesting period 3 years    
Total pool units available for grant under long-term incentive plan 1,000,000    
Pool units outstanding under long-term incentive plan     925,000
Percentage of cumulative internal rate of return (at least) 15.00%    
Period of payment to participants 60 days