Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation and Other Compensation Matters (Narrative) (Details)

v3.22.0.1
Share-Based Compensation and Other Compensation Matters (Narrative) (Details)
$ / shares in Units, $ in Thousands
12 Months Ended
Feb. 01, 2022
shares
Feb. 03, 2021
shares
Jan. 13, 2020
shares
Jan. 01, 2019
$ / shares
Dec. 31, 2021
USD ($)
form
Percentile_Rank
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Dec. 31, 2019
USD ($)
$ / shares
shares
May 31, 2017
shares
Executives and Non-Employee Trustees                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Estimated pre-vesting forfeitures         0.00% 0.00% 0.00%  
Minimum | All Other Employees                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Estimated pre-vesting forfeitures         0.00% 0.00% 0.00%  
Maximum | All Other Employees                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Estimated pre-vesting forfeitures         8.00% 8.00% 8.00%  
Restricted shares                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Unrecognized compensation cost | $         $ 5,200      
Expected weighted average period during which unrecognized compensation cost will be recognized         2 years      
Aggregate intrinsic value of shares issued | $         $ 4,300 $ 4,400 $ 4,900  
Grant date fair value (in dollars per share or unit) | $ / shares         $ 26.17 $ 25.22 $ 26.56  
Number of common shares issued (in shares)         164,575 173,191 185,001  
Grant date fair value (in dollars per share or unit) of awards issued | $ / shares         $ 25.95 $ 28.14 $ 28.01  
Restricted shares | Non-Employee Trustees                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting period         1 year      
Performance-based PIUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Unrecognized compensation cost | $         $ 3,000      
Expected weighted average period during which unrecognized compensation cost will be recognized         2 years      
Percentile ranks to fall between for PIUs | Percentile_Rank         2      
Percent of award distribution rights         10.00%      
Performance period of the award         3 years      
Performance-based PIUs | Former Executive Vice President and Chief Operating Officer                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Shares excluded from outstanding amount (shares)         73,184      
Time-based PIUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Unrecognized compensation cost | $         $ 2,700      
Expected weighted average period during which unrecognized compensation cost will be recognized         2 years      
Aggregate intrinsic value of shares issued | $         $ 1,200 $ 640    
Grant date fair value (in dollars per share or unit) | $ / shares         $ 26.16 $ 25.47 $ 26.01  
Number of common shares issued (in shares)         45,244 25,182    
Grant date fair value (in dollars per share or unit) of awards issued | $ / shares         $ 25.28 $ 26.30    
Time-based PIUs | Non-Employee Trustees                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting period         1 year      
Deferred Share Awards                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Unrecognized compensation cost | $         $ 34      
Aggregate intrinsic value of shares issued | $             $ 86  
Grant date fair value (in dollars per share or unit) | $ / shares         $ 27.12 $ 23.68 $ 27.60  
Number of common shares issued (in shares)         0 0 3,097  
Grant date fair value (in dollars per share or unit) of awards issued | $ / shares             $ 26.77  
Deferred Share Awards | Non-Employee Trustees                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting period         1 year      
Profit Interest Units                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of forms of profit interest units | form         2      
Performance share units                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Performance period of the award         3 years      
The number of percentile ranks to fall between to earn interpolated PSUs between such percentile ranks, conditioned on the percentile rank exceeding 25% | Percentile_Rank         2      
2017 Omnibus Equity and Incentive Plan | Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of common shares of beneficial interest authorized to be issued               3,400,000
2017 PSU Grants | Performance share units | Executives                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Shares issued for awards vested in period (in shares)     23,181          
2018 PSU Grants | Performance share units | Executives                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Shares issued for awards vested in period (in shares)   93,824            
2019 PB PIU | Performance-based PIUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Baseline Common Share Value (in dollars per share) | $ / shares       $ 21.03        
Expected volatility of common shares (as a percent)       21.00%        
Risk-free interest rate (as a percent)       2.51%        
2019 PB PIU | Performance-based PIUs | Executives | Subsequent Event                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Shares issued for awards vested in period (in shares) 156,104