Quarterly report pursuant to Section 13 or 15(d)

Bank Loans (Narrative) (Details)

v3.19.3
Bank Loans (Narrative) (Details) - USD ($)
9 Months Ended
Sep. 30, 2019
Dec. 31, 2018
Line of Credit Facility [Line Items]    
Credit facility, outstanding $ 50,000,000 $ 0
Wells Fargo Credit Facility [Member]    
Line of Credit Facility [Line Items]    
Line of credit, expiration date Jan. 10, 2022  
Line of credit, borrowing limit $ 250,000,000.0  
Line of credit, frequency of interest payment monthly  
Spread over LIBOR 0.825%  
Line of credit, facility fee percent 0.125%  
Credit Facility, interest rate 2.88%  
Unamortized loan origination costs $ 518,000 $ 691,000
Wells Fargo Credit Facility [Member] | Maximum [Member]    
Line of Credit Facility [Line Items]    
Spread over LIBOR 1.55%  
Line of credit, facility fee percent 0.30%  
Wells Fargo Credit Facility [Member] | Minimum [Member]    
Line of Credit Facility [Line Items]    
Spread over LIBOR 0.80%  
Line of credit, facility fee percent 0.10%