Quarterly report pursuant to Section 13 or 15(d)

Bank Loans (Narrative) (Details)

v3.21.2
Bank Loans (Narrative) (Details)
 1 Months Ended 2 Months Ended 9 Months Ended
Sep. 30, 2021
USD ($)
Sep. 30, 2021
USD ($)
item
Sep. 30, 2021
USD ($)
Jul. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Line of Credit Facility [Line Items]          
Credit facility, outstanding $ 0 $ 0 $ 0   $ 0
Payment of deferred financing costs     2,248,000    
Wells Fargo Credit Facility [Member]          
Line of Credit Facility [Line Items]          
Line of credit, borrowing limit $ 400,000,000.0 $ 400,000,000.0 $ 400,000,000.0 $ 250,000,000.0  
Line of credit, expiration date     Aug. 24, 2025    
Number of six-month extension options | item   2      
Number of twelve-month extension options | item   1      
Spread over LIBOR     0.70%    
Line of credit, facility fee percent     0.10%    
Sustainability-linked pricing component, pricing improvement percentage 0.01%        
Option to increase commitments, additional amount $ 300,000,000.0 $ 300,000,000.0 $ 300,000,000.0    
Payment of deferred financing costs   2,200,000      
Unamortized loan origination costs $ 2,200,000 $ 2,200,000 $ 2,200,000   $ 200,000
Line of credit, frequency of interest payment     monthly    
Wells Fargo Credit Facility [Member] | Minimum [Member]          
Line of Credit Facility [Line Items]          
Spread over LIBOR     0.70%    
Line of credit, facility fee percent     0.10%    
Wells Fargo Credit Facility [Member] | Maximum [Member]          
Line of Credit Facility [Line Items]          
Spread over LIBOR     1.35%    
Line of credit, facility fee percent     0.25%