Loans - Variable Rate Loans Held for Investment (Details) $ in Thousands	Jun. 30, 2021 USD ($)
Variable rate loans held-for-investment
Carrying Value	$ 12,242,355
Weighted-average Spread Above Index	4.20%
Commercial loans
Variable rate loans held-for-investment
Carrying Value	$ 10,538,637
Weighted-average Spread Above Index	4.20%
Infrastructure loans
Variable rate loans held-for-investment
Carrying Value	$ 1,703,718
Weighted-average Spread Above Index	3.80%