Annual report pursuant to Section 13 and 15(d)

Stock Based Compensation - Short-Term Incentive Plan and Long-Term Incentive Plan Narrative (Details)

v3.19.3.a.u2
Stock Based Compensation - Short-Term Incentive Plan and Long-Term Incentive Plan Narrative (Details)
12 Months Ended
Dec. 31, 2019
employment_year
shares
Dec. 31, 2018
shares
Dec. 31, 2017
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighting for performance measurement on FTSE NAREIT Diversified Index 50.00%    
Restricted Share Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Recognition period for compensation costs not yet recognized 22 months    
One-time equity award granted (shares) | shares 213,782 304,087 330,639
Retirement age with 20 years employment | employment_year 55    
Years of employment for retirement age metric 20 years    
Retirement age | employment_year 65    
Restricted Share Awards | Chief Executive Officer      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
One-time equity award granted (shares) | shares     100,000
Percentage of equity award that vests on fifth anniversary of grant date     100.00%
STIP      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance period 1 year    
Percentage of potential award based upon service requirement 50.00%    
Percentage of STIP award with grant date of Compensation Committee approval date 50.00%    
STIP | Performance-Based Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 3 years    
LTIP      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Percentage payable In unrestricted shares 75.00%    
Percentage payable in restricted shares 25.00%    
Performance period 3 years   3 years
Award vesting period 3 years    
Performance evaluated on absolute total shareholder return 50.00%   50.00%
Performance evaluated on relative total shareholder return 50.00%   50.00%
Weighting for performance measurement based on select peer companies 0.50    
Weighting for performance measurement on FTSE NAREIT Diversified Index 50.00%    
LTIP | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance evaluated on absolute total shareholder return 39.00% 35.00% 13.00%
Performance evaluated on relative total shareholder return 35.00% 31.00% 37.00%
Grant date fair value as a percentage of base salary 80.00%    
LTIP | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance evaluated on absolute total shareholder return 74.00% 68.00% 31.00%
Performance evaluated on relative total shareholder return 68.00% 60.00% 67.00%
Grant date fair value as a percentage of base salary 150.00%    
Cash | STIP      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Percentage payable In unrestricted shares 100.00%    
Cash | STIP | Performance-Based Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Percentage payable In unrestricted shares 50.00%    
Restricted Share Units | STIP | Performance-Based Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Percentage payable in restricted shares 50.00%    
Restricted Share Units | LTIP      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance period 1 year 3 years  
Restricted Share Units | LTIP | Performance-Based Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Recognition period for compensation costs not yet recognized 4 years    
Unrestricted Share Awards | LTIP      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Recognition period for compensation costs not yet recognized 3 years