XML 103 R90.htm IDEA: XBRL DOCUMENT v3.22.0.1
Debt - Unsecured Revolving Lines of Credit - Additional Information (Details) - USD ($)
Dec. 31, 2021
Dec. 31, 2020
Feb. 28, 2018
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 900,000,000.0    
Letters of credit, outstanding amount 19,700,000 $ 35,600,000  
Unsecured Debt      
Debt Instrument [Line Items]      
Maximum borrowing capacity 700,000,000.0    
Revolving Credit Facility      
Debt Instrument [Line Items]      
Maximum borrowing capacity 300,000,000.0    
Revolving Credit Facility | Unsecured Debt      
Debt Instrument [Line Items]      
Maximum borrowing capacity 50,000,000.0   $ 250,000,000.0
Core Portfolio | Revolving Credit Facility | Unsecured Debt      
Debt Instrument [Line Items]      
Debt available balance 183,100,000 101,100,000  
Maximum borrowing capacity 300,000,000.0    
Credit facility amount outstanding 112,900,000 138,400,000  
Letters of credit, outstanding amount 4,000,000.0 10,500,000  
Unsecured revolving line of credit $ 66,400,000 $ 138,400