Quarterly report pursuant to Section 13 or 15(d)

Credit Facility - Additional Information (Details)

v3.8.0.1
Credit Facility - Additional Information (Details) - Senior Secured Revolving Credit Facility [Member]
 3 Months Ended
Mar. 31, 2018
USD ($)
Line of Credit Facility [Line Items]  
Maximum advances on credit facilities $ 1,500,000,000
Credit facility outstanding 500,000,000
Unamortized issuance costs $ 4,000,000
Availability fee percentage 0.50%
Default underlying financings (percent) 50.00%
LIBOR [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 1.00%
Federal Funds Rate [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 0.50%
Base Rate [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 0.00%
G&I Facility [Member]  
Line of Credit Facility [Line Items]  
Fixed interest rate 1.50%
G&I Facility [Member] | U.S. Federal Government [Member]  
Line of Credit Facility [Line Items]  
Applicable valuation percentages 85.00%
G&I Facility [Member] | Institutional [Member]  
Line of Credit Facility [Line Items]  
Applicable valuation percentages 80.00%
G&I Facility [Member] | LIBOR [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 1.50%
G&I Facility [Member] | LIBOR [Member] | Credit Default Option [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 2.50%
PF Facility [Member]  
Line of Credit Facility [Line Items]  
Fixed interest rate 2.50%
Applicable valuation percentages 67.00%
PF Facility [Member] | LIBOR [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 2.50%
PF Facility [Member] | LIBOR [Member] | Credit Default Option [Member]  
Line of Credit Facility [Line Items]  
Basis spread on variable rate 5.00%