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Share-Based Payments and Employee Benefits - LTIP and Time-Based LTIP Units (Details)
5 Months Ended 12 Months Ended
Aug. 01, 2017
installment
$ / shares
shares
Jul. 18, 2017
USD ($)
person
shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2017
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Compensation expense recognition period (in years)       3 years 3 months 18 days
LTIP and Time-Based LTIP Units        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Equity grants (in shares)       409,611
Weighted average grant-date fair value (in dollars per share) | $ / shares     $ 33.68 $ 0.00
Shares        
Beginning balance (in shares)       0
Granted (in shares)       409,611
Vested in period (in shares)       (77,129)
Forfeited (in shares)       (275)
Ending balance (in shares)     332,207 332,207
Weighted Average Grant-Date Fair Value        
Beginning balance (in dollars per share) | $ / shares       $ 0.00
Granted (in dollars per share) | $ / shares       33.41
Vested (in dollars per share) | $ / shares       32.26
Forfeited (in dollars per share) | $ / shares       33.71
Ending balance (in dollars per share) | $ / shares     $ 33.68 $ 33.68
LTIP and Time-Based LTIP Units | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Expected volatility rate       17.00%
Risk-free interest rate       1.30%
Expected life (in years)       2 years
LTIP and Time-Based LTIP Units | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Expected volatility rate       19.00%
Risk-free interest rate       1.50%
Expected life (in years)       3 years
LTIP Units        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Equity grants (in shares)   47,166    
Fair value of awards on grant date | $     $ 3,500,000  
Shares        
Granted (in shares)   47,166    
LTIP Units | Vesting Period One        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Percentage of vesting rights for each tranche   50.00%    
LTIP Units | Vesting Period Two        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Percentage of vesting rights for each tranche   50.00%    
Time-Based LTIP Units        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Equity grants (in shares) 302,518      
Vesting period       4 years
Number of installments | installment 4      
Weighted average grant-date fair value (in dollars per share) | $ / shares $ 33.71      
Compensation expense recognition period (in years)       4 years
Shares        
Granted (in shares) 302,518      
Weighted Average Grant-Date Fair Value        
Ending balance (in dollars per share) | $ / shares $ 33.71      
Trustee | LTIP Units        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Number of non-employee trustees | person   7    
Fair value of awards on grant date | $   $ 250,000    
Trustee | LTIP Units | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Vesting period   31 months    
Trustee | LTIP Units | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Vesting period   60 months    
Key Employee | LTIP Units        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]        
Equity grants (in shares)   59,927    
Shares        
Granted (in shares)   59,927