v3.22.2.2
Fair Value of Financial Instruments - Carrying Value and Estimated Fair Value of Company's Financial Instruments (Details) - USD ($)
$ in Thousands
Sep. 30, 2022
Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Participations sold $ (22,696) $ (27,064)
Commercial Mortgage Portfolio Segment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Participations sold (22,696) (27,064)
Carrying Value    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Cash and cash equivalents 319,264 343,106
Carrying Value | Level III    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Secured debt arrangements, net (5,350,586) (4,150,268)
Participations sold (22,696) (27,064)
Carrying Value | Level III | Secured Debt    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Senior secured term loans, net (764,899) (768,325)
Carrying Value | Level III | Senior Notes    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Senior secured term loans, net (494,644) (494,051)
Carrying Value | Level III | 2022 Notes    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Notes 0 (343,117)
Carrying Value | Level III | 2023 Notes    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Notes (229,175) (226,862)
Carrying Value | Level III | Commercial Mortgage Portfolio Segment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Loans 8,013,469 7,012,312
Carrying Value | Level III | Subordinate Mortgage Portfolio Segment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Loans 717,837 844,948
Estimate of Fair Value Measurement    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Cash and cash equivalents 319,264 343,106
Estimate of Fair Value Measurement | Level III    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Secured debt arrangements, net (5,350,586) (4,150,268)
Participations sold (22,696) (27,064)
Estimate of Fair Value Measurement | Level III | Secured Debt    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Senior secured term loans, net (749,917) (782,995)
Estimate of Fair Value Measurement | Level III | Senior Notes    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Senior secured term loans, net (375,845) (489,175)
Estimate of Fair Value Measurement | Level III | 2022 Notes    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Notes 0 (347,552)
Estimate of Fair Value Measurement | Level III | 2023 Notes    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Notes (230,000) (231,150)
Estimate of Fair Value Measurement | Level III | Commercial Mortgage Portfolio Segment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Loans 7,991,134 6,945,038
Estimate of Fair Value Measurement | Level III | Subordinate Mortgage Portfolio Segment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Loans $ 718,524 $ 725,906