Quarterly report pursuant to Section 13 or 15(d)

Indebtedness - Narrative (Details)

v3.20.2
Indebtedness - Narrative (Details) - USD ($)
6 Months Ended
Jun. 30, 2020
Dec. 31, 2019
Debt Instrument [Line Items]    
Loan outstanding balance $ 2,423,541,000 $ 2,254,940,000
Recourse debt    
Debt Instrument [Line Items]    
Loan outstanding balance 236,435,000 239,485,000
Non-recourse debt    
Debt Instrument [Line Items]    
Loan outstanding balance $ 2,187,106,000 2,015,455,000
Non-recourse debt | LIBOR | Term loan | Aggregation facility    
Debt Instrument [Line Items]    
Basis spread on variable rate 9.00%  
Non-recourse debt | LIBOR | Line of credit | Aggregation facility, March 2023    
Debt Instrument [Line Items]    
Facility available period 3 years  
Facility available, period increase 2 years  
Bank line of credit | Recourse debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 250,000,000.0  
Minimum unencumbered liquid assets to be maintained 25,000,000.0  
Minimum required quarter-end unencumbered cash balance $ 35,000,000.0  
Interest coverage ratio 300.00%  
Loan outstanding balance $ 236,435,000 $ 239,485,000
Bank line of credit | Recourse debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 3.49% 5.09%
Bank line of credit | Recourse debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 4.87% 5.38%
Bank line of credit | Recourse debt | LIBOR    
Debt Instrument [Line Items]    
Basis spread on variable rate 3.25%  
Bank line of credit | Recourse debt | Base Rate    
Debt Instrument [Line Items]    
Basis spread on variable rate 2.25%  
Bank line of credit | Recourse debt | Federal Funds Rate    
Debt Instrument [Line Items]    
Basis spread on variable rate 0.50%  
Bank line of credit | Recourse debt | LIBOR Floor Rate    
Debt Instrument [Line Items]    
Basis spread on variable rate 1.00%  
Term Loan Due in October 2024 | Non-recourse debt | Senior secured revolving letter of credit facility | Aggregation facility, October 2024    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 375,800,000  
Loan outstanding balance 352,400,000  
Term Loan Due in October 2024 | Non-recourse debt | Term loan | Aggregation facility, October 2024    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity 363,300,000  
Term Loan Due in October 2024 | Non-recourse debt | Revolving debt | Aggregation facility, October 2024    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 12,500,000  
Term Loan A | Non-recourse debt | LIBOR | Aggregation facility, October 2024    
Debt Instrument [Line Items]    
Basis spread on variable rate 2.125%  
Term Loan A | Non-recourse debt | Base Rate | Aggregation facility, October 2024    
Debt Instrument [Line Items]    
Basis spread on variable rate 1.125%  
Term Loan B | Non-recourse debt | Aggregation facility, October 2024    
Debt Instrument [Line Items]    
Interest rate 9.25%  
Term Loan due in April 2024 | Non-recourse debt | Senior secured revolving letter of credit facility | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 202,000,000.0  
Loan outstanding balance 178,400,000  
Term Loan due in April 2024 | Non-recourse debt | Revolving debt | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity 7,000,000.0  
Term Loan due in April 2024 | Non-recourse debt | Delayed draw term loan | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 195,000,000.0  
Term Loan due in April 2024 | Non-recourse debt | LIBOR | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Basis spread on variable rate 2.25%  
Facility available period 4 years  
Term Loan due in April 2024 | Non-recourse debt | Base Rate | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Basis spread on variable rate 1.25%  
Term Loan due in April 2024 | Non-recourse debt | Federal Funds Rate | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Basis spread on variable rate 0.50%  
Term Loan due in April 2024 | Non-recourse debt | LIBOR Floor Rate | Aggregation facility, April 2024    
Debt Instrument [Line Items]    
Basis spread on variable rate 1.00%  
Term Loan due in March 2023 | Non-recourse debt | Line of credit | Aggregation facility, March 2023    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 595,000,000.0  
Loan outstanding balance $ 346,300,000  
Term Loan due in March 2023 | Non-recourse debt | LIBOR | Line of credit | Aggregation facility, March 2023    
Debt Instrument [Line Items]    
Basis spread on variable rate 2.50%  
Basis spread on variable rate, year four 2.75%  
Subordinated debt | Non-recourse debt    
Debt Instrument [Line Items]    
Loan outstanding balance $ 551,042,000 $ 513,938,000
Subordinated debt | Non-recourse debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 6.00% 6.93%
Subordinated debt | Non-recourse debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 10.50% 10.80%
Subordinated debt | Non-recourse debt | Aggregation facility, March 2023 | Minimum    
Debt Instrument [Line Items]    
Prepayment penalty percent 0.00%  
Subordinated debt | Non-recourse debt | Aggregation facility, March 2023 | Maximum    
Debt Instrument [Line Items]    
Prepayment penalty percent 100.00%  
Subordinated debt | Non-recourse debt | LIBOR | Aggregation facility, March 2023    
Debt Instrument [Line Items]    
Facility available period 3 years  
Subordinated debt | Non-recourse debt | LIBOR | Line of credit | Aggregation facility, March 2023    
Debt Instrument [Line Items]    
Basis spread on variable rate 5.00%  
Basis spread on variable rate, year four 6.50%  
Bank Term Loan due April 2022 | Non-recourse debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 15,100,000  
Interest rate 4.50%  
Bank Term Loan due September 2022 | Non-recourse debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 12,300,000  
Bank Term Loan due September 2022 | Non-recourse debt | LIBOR | Subsidiary    
Debt Instrument [Line Items]    
Interest rate 2.25%  
Bank Term Loan due January 2030 | Non-recourse debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 128,500,000  
Interest rate 10.50%  
Bank Term Loan due July 2030 | Non-recourse debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 64,100,000  
Interest rate 6.75%  
Bank Term Loan due July 2030 | Non-recourse debt | Minimum | Subsidiary    
Debt Instrument [Line Items]    
Interest rate 2.00%  
Bank Term Loan due July 2030 | Non-recourse debt | Maximum | Subsidiary    
Debt Instrument [Line Items]    
Interest rate 3.25%  
Bank Term Loan due July 2027 | Non-recourse debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 9,200,000  
Interest rate 5.61%  
Bank Term Loan due November 2025 | Non-recourse debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 130,500,000  
Bank Term Loan due November 2025 | Non-recourse debt | LIBOR | Subsidiary    
Debt Instrument [Line Items]    
Basis spread on variable rate 6.75%  
Bank Term Loan due November 2025 | Non-recourse debt | LIBOR Floor Rate | Subsidiary    
Debt Instrument [Line Items]    
Basis spread on variable rate 2.00%  
Bank Loan due March 2024 | Non-recourse debt | Senior secured revolving letter of credit facility    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 134,000,000.0  
Loan outstanding balance $ 88,800,000  
Bank Loan due March 2024 | Non-recourse debt | LIBOR | Senior secured revolving letter of credit facility    
Debt Instrument [Line Items]    
Basis spread on variable rate 3.00%  
Securitization debt | Non-recourse debt | Subsidiary one    
Debt Instrument [Line Items]    
Loan outstanding balance $ 81,600,000  
Secured borrowings assets carrying amount $ 153,700,000 $ 157,600,000
Debt instrument discount rate 0.08%  
Securitization debt | Non-recourse debt | Subsidiary two    
Debt Instrument [Line Items]    
Loan outstanding balance $ 297,900,000  
Debt instrument discount rate 1.47%  
Securitization debt | Non-recourse debt | Subsidiary three    
Debt Instrument [Line Items]    
Loan outstanding balance $ 181,200,000  
Debt instrument discount rate 0.01%  
Securitization debt | Non-recourse debt | Subsidiary four    
Debt Instrument [Line Items]    
Loan outstanding balance $ 300,900,000  
Debt instrument discount rate 0.05%