Secured Debt, Net - Schedule of All in Cost of Secured Credit Facilities (Details) - Secured credit facilities - Line of Credit - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 66,924	$ 3,350,146
Total Borrowings	$ 12,809,913	$ 13,549,748
Wtd. Avg. All-in Cost (percentage)	1.89%	1.85%
Collateral	$ 18,613,231	$ 19,694,790
Wtd. Avg. All-in Yield (percentage)	3.69%	3.70%
Net Interest Margin (percentage)	1.80%	1.85%
+ 1.50% or less
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 0	$ 1,329,508
Total Borrowings	$ 5,625,471	$ 7,433,204
Wtd. Avg. All-in Cost (percentage)	1.53%	1.53%
Collateral	$ 8,308,855	$ 10,465,647
Wtd. Avg. All-in Yield (percentage)	3.27%	3.24%
Net Interest Margin (percentage)	1.74%	1.71%
+ 1.51% to + 1.75%
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 0	$ 368,265
Total Borrowings	$ 2,794,848	$ 2,246,223
Wtd. Avg. All-in Cost (percentage)	1.82%	1.88%
Collateral	$ 3,902,545	$ 3,538,815
Wtd. Avg. All-in Yield (percentage)	3.57%	3.73%
Net Interest Margin (percentage)	1.75%	1.85%
+ 1.76% to + 2.00%
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 0	$ 405,723
Total Borrowings	$ 1,912,045	$ 1,514,541
Wtd. Avg. All-in Cost (percentage)	2.13%	2.16%
Collateral	$ 2,974,091	$ 2,483,240
Wtd. Avg. All-in Yield (percentage)	4.01%	4.14%
Net Interest Margin (percentage)	1.88%	1.98%
+ 2.01% or more
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 66,924	$ 1,246,650
Total Borrowings	$ 2,477,549	$ 2,355,780
Wtd. Avg. All-in Cost (percentage)	2.61%	2.63%
Collateral	$ 3,427,740	$ 3,207,088
Wtd. Avg. All-in Yield (percentage)	4.62%	4.78%
Net Interest Margin (percentage)	2.01%	2.15%