Annual report pursuant to Section 13 and 15(d)

Indebtedness - Additional Information (Details)

v3.19.3.a.u2
Indebtedness - Additional Information (Details)
12 Months Ended
Dec. 31, 2019
USD ($)
revolving_facilitiy
Dec. 31, 2018
USD ($)
Debt Instrument [Line Items]    
Loan outstanding balance $ 2,254,940,000 $ 1,748,922,000
Recourse Debt    
Debt Instrument [Line Items]    
Loan outstanding balance 239,485,000 247,000,000
Non Recourse Debt    
Debt Instrument [Line Items]    
Loan outstanding balance 2,015,455,000 1,501,922,000
Senior secured revolving letter of credit facility    
Debt Instrument [Line Items]    
Loan outstanding balance $ 351,900,000  
LIBOR | Line of Credit | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 2.50%  
Facility available period 3 years  
Debt instrument, variable rate periodic increase 2.75%  
Revolving line of credit facility available period, period increase 2 years  
Aggregation facility | Line of Credit | Non Recourse Debt    
Debt Instrument [Line Items]    
Loan outstanding balance $ 236,200,000  
Aggregation facility | LIBOR | Senior secured revolving letter of credit facility | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 3.00%  
Aggregation facility | LIBOR | Term Loan | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 9.00%  
Bank line of credit    
Debt Instrument [Line Items]    
Minimum unencumbered liquid assets to be maintained $ 25,000,000.0  
Debt covenant, liability maintenance 35,000,000.0  
Bank line of credit | Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 250,000,000.0  
Interest coverage ratio 350.00%  
Loan outstanding balance $ 239,485,000 $ 247,000,000
Bank line of credit | LIBOR | Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 3.25%  
Bank line of credit | Base Rate | Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 2.25%  
Bank line of credit | Federal Funds Rate | Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 0.50%  
Bank line of credit | Prime Rate | Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 1.00%  
Bank line of credit | Minimum | Recourse Debt    
Debt Instrument [Line Items]    
Interest Rate 5.09% 5.45%
Bank line of credit | Maximum | Recourse Debt    
Debt Instrument [Line Items]    
Interest Rate 5.38% 5.77%
Term Loan Due in October 2024 | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 375,800,000  
Term Loan Due in October 2024 | Term Loan | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity 363,300,000  
Term Loan Due in October 2024 | Letter of Credit | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 12,500,000  
Term Loan | LIBOR | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 5.00%  
Debt instrument, variable rate periodic increase 6.50%  
Term Loan | Minimum | Non Recourse Debt    
Debt Instrument [Line Items]    
Prepayment penalty percent 0.00%  
Term Loan | Maximum | Non Recourse Debt    
Debt Instrument [Line Items]    
Prepayment penalty percent 1.00%  
Term Loan B | Minimum | Non Recourse Debt    
Debt Instrument [Line Items]    
Prepayment penalty percent 0.00%  
Term Loan B | Maximum | Non Recourse Debt    
Debt Instrument [Line Items]    
Prepayment penalty percent 5.00%  
Term Loan B | Aggregation Facility, October 2024 | Non Recourse Debt    
Debt Instrument [Line Items]    
Interest Rate 9.25%  
Term Loan Due in December 2020 | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 595,000,000.0  
Term Loan A | LIBOR | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 2.125%  
Term Loan A | Base Rate | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 1.125%  
Term Loan Due in April 2024 | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 202,000,000.0  
Loan outstanding balance $ 180,700,000  
Facility available period 4 years  
Term Loan Due in April 2024 | Term Loan | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 195,000,000.0  
Term Loan Due in April 2024 | Letter of Credit | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 7,000,000.0  
Term Loan Due in April 2024 | LIBOR | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 2.25%  
Term Loan Due in April 2024 | Base Rate | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 1.25%  
Term Loan Due in April 2024 | Federal Funds Rate | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 0.50%  
Term Loan Due in April 2024 | Aggregation Facility, October 2024 | LIBOR | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate, federal funds rate 1.00%  
Bank term loan due April 2022 | Non Recourse Debt    
Debt Instrument [Line Items]    
Loan outstanding balance $ 16,800,000  
Bank term loan due April 2022 | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Interest Rate 4.50%  
Bank term loan due September 2022, tranche two | Non Recourse Debt    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 2.25%  
Loan outstanding balance $ 13,800,000  
Bank term loan due January 2030 | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 124,000,000.0  
Interest Rate 10.50%  
Bank term loan due July 2030 | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 63,300,000  
Interest Rate 6.75%  
Bank term loan due July 2030 | Minimum | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Interest Rate 2.00%  
Bank term loan due July 2030 | Maximum | Non Recourse Debt | 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 $ 9,500,000  
Interest Rate 5.61%  
Bank term loan due November 2025 | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Loan outstanding balance $ 129,600,000  
Bank term loan due November 2025 | LIBOR | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 6.75%  
Bank term loan due November 2025 | LIBOR Floor Rate | Non Recourse Debt | Subsidiary    
Debt Instrument [Line Items]    
Debt instrument, basis spread on variable rate 2.00%  
Bank loan due March 2024 | Senior secured revolving letter of credit facility | Non Recourse Debt    
Debt Instrument [Line Items]    
Line of credit, maximum borrowing capacity $ 134,000,000.0  
Loan outstanding balance $ 13,600,000  
Number of revolving facilities | revolving_facilitiy 2  
Securitization loans | Subsidiary one    
Debt Instrument [Line Items]    
Secured borrowing, carrying amount $ 157,600,000 $ 164,700,000
Debt instrument discount rate 0.08%  
Securitization loans | Subsidiary two    
Debt Instrument [Line Items]    
Debt instrument discount rate 1.47%  
Securitization loans | Non Recourse Debt | Subsidiary one    
Debt Instrument [Line Items]    
Loan outstanding balance $ 84,400,000  
Securitization loans | Non Recourse Debt | Subsidiary two    
Debt Instrument [Line Items]    
Loan outstanding balance 300,000,000.0  
Securitization debt | Non Recourse Debt | Subsidiary three    
Debt Instrument [Line Items]    
Loan outstanding balance $ 187,200,000  
Debt instrument discount rate 0.01%  
Securitization debt | Non Recourse Debt | Subsidiary four    
Debt Instrument [Line Items]    
Loan outstanding balance $ 304,300,000  
Debt instrument discount rate 0.05%