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Employee Benefit Plans - Additional Information (Details) - 401(k) Plan - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Defined Contribution Plan Disclosure [Line Items]      
Maximum tax-deferred contributions 100.00%    
Vesting period 3 years    
Partnership's defined contributions $ 0.6 $ 0.5 $ 0.6
Maximum      
Defined Contribution Plan Disclosure [Line Items]      
Matching employee contributions 5.00%    
After One Year      
Defined Contribution Plan Disclosure [Line Items]      
Graded vesting percentage 33.00%    
After Two Years      
Defined Contribution Plan Disclosure [Line Items]      
Graded vesting percentage 66.00%    
After Three Years      
Defined Contribution Plan Disclosure [Line Items]      
Graded vesting percentage 100.00%    
Service period 3 years