Fair Value - Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financial assets not carried at fair value:
Loans	$ 18,452,424	$ 18,401,439
HTM debt securities	642,979	676,652
Carrying Value
Financial assets not carried at fair value:
Loans	18,452,424	18,401,439
HTM debt securities	632,739	673,470
Financial liabilities not carried at fair value:
Secured financing agreements, CLOs and SASB	18,519,771	18,177,756
Unsecured senior notes	2,331,445	2,329,211
Fair Value
Financial assets not carried at fair value:
Loans	18,241,160	18,215,072
HTM debt securities	597,360	637,275
Financial liabilities not carried at fair value:
Secured financing agreements, CLOs and SASB	18,264,505	18,017,651
Unsecured senior notes	$ 2,164,549	$ 2,199,135