Secured Debt, Net - Schedule of All in Cost of Secured Credit Facilities (Details) - Secured credit facilities - Line of Credit - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 1,651,729	$ 7,763,563
Total Borrowings	$ 13,117,249	$ 12,299,580
Wtd. Avg. All-in Cost (percentage)	1.71%	1.72%
Collateral	$ 18,710,706	$ 17,042,381
Wtd. Avg. All-in Yield (percentage)	3.50%	3.49%
Net Interest Margin (percentage)	1.79%	1.77%
+ 1.50% or less
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 1,267,118	$ 5,306,925
Total Borrowings	$ 8,320,043	$ 7,746,026
Wtd. Avg. All-in Cost (percentage)	1.51%	1.52%
Collateral	$ 11,497,642	$ 10,193,801
Wtd. Avg. All-in Yield (percentage)	3.18%	3.18%
Net Interest Margin (percentage)	1.67%	1.66%
+ 1.51% to + 1.75%
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 283,924	$ 1,477,177
Total Borrowings	$ 2,825,032	$ 2,710,587
Wtd. Avg. All-in Cost (percentage)	1.87%	1.88%
Collateral	$ 4,124,634	$ 3,977,492
Wtd. Avg. All-in Yield (percentage)	3.60%	3.55%
Net Interest Margin (percentage)	1.73%	1.67%
+ 1.76% to + 2.00%
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 74,596	$ 668,470
Total Borrowings	$ 1,060,611	$ 998,781
Wtd. Avg. All-in Cost (percentage)	2.17%	2.13%
Collateral	$ 1,623,549	$ 1,458,074
Wtd. Avg. All-in Yield (percentage)	4.35%	4.28%
Net Interest Margin (percentage)	2.18%	2.15%
+ 2.01% or more
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 26,091	$ 310,991
Total Borrowings	$ 911,563	$ 844,186
Wtd. Avg. All-in Cost (percentage)	2.52%	2.49%
Collateral	$ 1,464,881	$ 1,413,014
Wtd. Avg. All-in Yield (percentage)	4.79%	4.75%
Net Interest Margin (percentage)	2.27%	2.26%