Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurement - Schedule of Carrying Values and Fair Values of Debt Instruments (Details)

v3.20.2
Fair Value Measurement - Schedule of Carrying Values and Fair Values of Debt Instruments (Details) - USD ($)
$ in Thousands
Jun. 30, 2020
Dec. 31, 2019
Carrying Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value $ 2,423,541 $ 2,254,940
Carrying Value | Bank line of credit    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 236,435 239,485
Carrying Value | Senior debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 774,451 625,519
Carrying Value | Subordinated debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 551,042 513,938
Carrying Value | Securitization debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 861,613 875,998
Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 2,542,513 2,321,409
Fair Value | Bank line of credit    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 236,435 239,485
Fair Value | Senior debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 775,765 626,023
Fair Value | Subordinated debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value 585,204 524,581
Fair Value | Securitization debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt instrument, fair value $ 945,109 $ 931,320