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Partners' Equity Narrative (Details) - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2013
Jun. 30, 2016
May 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Special L.P. interests $ 5,290,000 $ 5,290,000        
Total intrinsic value of options exercised 700,000 2,800,000 $ 3,000,000      
Cash received from unit option exercises 65,000 $ 0 $ 0      
2016 Omnibus incentive Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unit options and other forms of equity authorized under equity incentive plan (in shares)         2,800,000.0  
2008 Omnibus Incentive Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unit options and other forms of equity authorized under equity incentive plan (in shares)           2,500,000.0
Compensation Plans Settable in Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Distribution equivalent liability 1,000,000          
Compensation Plans Settable in Equity [Member] | Other Accrued Liabilities [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Distribution equivalent liability 600,000          
Compensation Plans Settable in Equity [Member] | Other Liabilities [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Distribution equivalent liability $ 400,000          
Phantom Share Units (PSUs) [Member] | Compensation Plans Settable in Cash or Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 0          
Award vesting period 4 years          
Performance Units [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 112,000          
Performance Units [Member] | Compensation Plans Settable in Cash or Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 0          
Award vesting period 3 years          
Performance Units [Member] | Compensation Plans Settable in Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unamortized compensation related to unvested phantom unit awards $ 12,100,000          
Period to achieve performance targets 3 years          
Award requisite service period 3 years          
Unamortized compensation related to unvested phantom unit awards, period for recognition 2 years 2 months          
Performance Units [Member] | Compensation Plans Settable in Equity [Member] | Other Liabilities [Member] | Share-based Compensation Award, Tranche One [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Deferred compensation share-based arrangements, liability $ 700,000          
Distribution Equivalent Units [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 2,000          
Deferred Units [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 9,000          
Deferred Units [Member] | Compensation Plans Settable in Cash or Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting period 1 year          
Aggregate market value of contingently issuable units $ 2,900,000          
Unamortized compensation related to unvested phantom unit awards $ 0          
Forfeitable Distribution-Equivalent Units [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 20,000          
Retention Grant Units [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Options, nonvested (in shares) 62,117          
Restricted Stock Units (RSUs) [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Non-option equity instruments awarded (in shares) 98,000          
Award vesting period 3 years          
Restricted Stock Units (RSUs) [Member] | Share-based Compensation Award, Tranche One [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting period 2 years          
Vested (in shares) 32,154          
Restricted Stock Units (RSUs) [Member] | Share-based Compensation Award, Tranche Two [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting period 3 years          
Vested (in shares) 29,253          
Restricted Stock Units (RSUs) [Member] | Compensation Plans Settable in Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unamortized compensation related to unvested phantom unit awards $ 10,000,000          
Unamortized compensation related to unvested phantom unit awards, period for recognition 2 years 3 months          
2013 and 2012 Option Awards [Member] | Compensation Plans Settable in Equity [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting period 3 years          
Expected term, maximum       10 years    
Fixed Price Options [Member] | 2008 Omnibus Incentive Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unit options outstanding (in shares) 373,612