Secured Borrowings - Secured Financing Agreements (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022
Secured Borrowings
Pledged Asset Carrying Value	$ 102,076	$ 102,076	$ 113,386
Secured financing agreements, net	13,557,881	13,557,881	14,501,532
Revolving Credit Facility
Secured Borrowings
Maximum borrowing capacity	150,000	150,000
Equity interests in certain subsidiaries used to secure facilities		5,700,000
Borrowing Base Facility
Secured Borrowings
Maximum Facility Size	450,000	450,000
Maximum facility size subject to certain conditions	750,000	750,000
Commercial Financing Facilities
Secured Borrowings
Maximum Facility Size	453,300	$ 453,300
Property Mortgages - Fixed rate
Secured Borrowings
Maturity period		3 years 9 months 18 days
Term Loan Facility
Secured Borrowings
Maximum borrowing capacity	774,800	$ 774,800
Term Loan Facility Maturing November 2027
Secured Borrowings
Maximum borrowing capacity	$ 595,500	$ 595,500
Floor interest rate (as a percent)		0.50%
SOFR
Secured Borrowings
Pricing margin (as a percent)	2.53%
SOFR | Revolving Credit Facility
Secured Borrowings
Coupon Rate	2.60%	2.60%
SOFR | Term Loan Facility
Secured Borrowings
Floor interest rate (as a percent)		0.75%
SOFR | Term Loan Facility Maturing November 2027
Secured Borrowings
Pricing margin (as a percent)		3.25%
SOFR + 2.60% | Term Loan Facility
Secured Borrowings
Pricing margin (as a percent)		2.60%
Maximum borrowing capacity	$ 384,000	$ 384,000
SOFR + 3.35% | Term Loan Facility
Secured Borrowings
Pricing margin (as a percent)		3.35%
Maximum borrowing capacity	390,800	$ 390,800
Secured Borrowings
Secured Borrowings
Maximum Facility Size	22,787,928	22,787,928
Long term debt, gross	13,643,930	13,643,930	14,610,127
Unamortized net discount	(26,039)	(26,039)	(30,320)
Unamortized deferred financing costs	(60,010)	(60,010)	(78,275)
Secured financing agreements, net	13,557,881	13,557,881	14,501,532
Secured Borrowings | Borrowing Base Facility
Secured Borrowings
Maximum Facility Size	750,000	750,000
Long term debt, gross	3,920	3,920	0
Secured Borrowings | Commercial Financing Facilities
Secured Borrowings
Maximum Facility Size	553,319	553,319
Long term debt, gross	355,962	355,962	311,825
Secured Borrowings | Residential Financing Facility
Secured Borrowings
Maximum Facility Size	0	0
Long term debt, gross	0	0	244,418
Secured Borrowings | Infrastructure Financing Facilities
Secured Borrowings
Maximum Facility Size	1,550,000	1,550,000
Long term debt, gross	$ 608,847	$ 608,847	765,265
Secured Borrowings | Property Mortgages - Fixed rate
Secured Borrowings
Coupon Rate	4.40%	4.40%
Maximum Facility Size	$ 224,898	$ 224,898
Long term debt, gross	224,898	224,898	261,100
Secured Borrowings | Property Mortgages - Variable rate
Secured Borrowings
Maximum Facility Size	849,328	849,328
Long term debt, gross	846,946	846,946	847,633
Secured Borrowings | Term Loans and Revolver
Secured Borrowings
Maximum Facility Size	1,520,275	1,520,275
Long term debt, gross	1,370,275	1,370,275	1,380,766
Secured Borrowings | Total Other Secured Financing
Secured Borrowings
Maximum Facility Size	5,447,820	5,447,820
Long term debt, gross	$ 3,410,848	$ 3,410,848	3,811,007
Secured Borrowings | First Mortgage and Mezzanine
Secured Borrowings
Coupon Rate	3.34%	3.34%
Long term debt, gross	$ 600,000	$ 600,000
Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	17,352,777	17,352,777
Secured Borrowings | Asset Pledged as Collateral | Borrowing Base Facility
Secured Borrowings
Pledged Asset Carrying Value	47,724	47,724
Secured Borrowings | Asset Pledged as Collateral | Commercial Financing Facilities
Secured Borrowings
Pledged Asset Carrying Value	502,694	502,694
Secured Borrowings | Asset Pledged as Collateral | Residential Financing Facility
Secured Borrowings
Pledged Asset Carrying Value	0	0
Secured Borrowings | Asset Pledged as Collateral | Infrastructure Financing Facilities
Secured Borrowings
Pledged Asset Carrying Value	857,350	857,350
Secured Borrowings | Asset Pledged as Collateral | Property Mortgages - Fixed rate
Secured Borrowings
Pledged Asset Carrying Value	326,161	326,161
Secured Borrowings | Asset Pledged as Collateral | Property Mortgages - Variable rate
Secured Borrowings
Pledged Asset Carrying Value	965,870	965,870
Secured Borrowings | Asset Pledged as Collateral | Total Other Secured Financing
Secured Borrowings
Pledged Asset Carrying Value	2,699,799	$ 2,699,799
Secured Borrowings | Index | Commercial Financing Facilities
Secured Borrowings
Pricing margin (as a percent)		2.16%
Secured Borrowings | Index | Infrastructure Financing Facilities
Secured Borrowings
Pricing margin (as a percent)		2.14%
Secured Borrowings | SOFR | Borrowing Base Facility
Secured Borrowings
Pricing margin (as a percent)		2.11%
Secured Borrowings | SOFR | First Mortgage and Mezzanine | Weighted Average
Secured Borrowings
Pricing margin (as a percent)		2.07%
Line of Credit | Commercial Financing Facilities
Secured Borrowings
Line of credit capacity if conditions are met	553,300	$ 553,300
Commercial Loans
Secured Borrowings
Maximum Facility Size	11,900,000	11,900,000
Secured financing agreements, net	2,700,000	2,700,000
Line of credit capacity if conditions are met	12,000,000	$ 12,000,000
Commercial Loans | SOFR | Weighted Average
Secured Borrowings
Pricing margin (as a percent)		3.36%
Commercial Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	12,039,568	$ 12,039,568
Long term debt, gross	6,768,758	6,768,758	7,746,867
Commercial Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	10,197,141	$ 10,197,141
Commercial Loans | Secured Borrowings | Index
Secured Borrowings
Pricing margin (as a percent)		2.02%
Residential Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	3,200,000	$ 3,200,000
Long term debt, gross	2,321,057	2,321,057	1,912,774
Residential Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	2,509,325	$ 2,509,325
Residential Loans | Secured Borrowings | SOFR
Secured Borrowings
Pricing margin (as a percent)		1.97%
Infrastructure Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	650,000	$ 650,000
Long term debt, gross	333,119	333,119	290,431
Infrastructure Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	397,130	$ 397,130
Infrastructure Loans | Secured Borrowings | SOFR
Secured Borrowings
Pricing margin (as a percent)		2.07%
Conduit Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	388,937	$ 388,937
Long term debt, gross	53,059	53,059	8,423
Conduit Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	$ 68,058	$ 68,058
Conduit Loans | Secured Borrowings | SOFR
Secured Borrowings
Pricing margin (as a percent)		2.07%
CMBS/RMBS
Secured Borrowings
Coupon Rate	3.27%	3.27%
Secured financing agreements, net	$ 259,500	$ 259,500
Amount outstanding on a repurchase facility not subject to margin calls	259,500	259,500
Amount outstanding on repurchase facility	$ 40,600	$ 40,600
Pro rata share owned by a non-controlling partner in a consolidated joint venture	49.00%	49.00%
CMBS/RMBS | Certain Facilities
Secured Borrowings
Secured financing agreements, net	$ 348,000	$ 348,000
Rolling maturity period		11 months
Maturity period		12 months
CMBS/RMBS | SOFR | Weighted Average
Secured Borrowings
Coupon Rate	2.21%	2.21%
CMBS/RMBS | Secured Borrowings
Secured Borrowings
Maximum Facility Size	$ 1,061,603	$ 1,061,603
Long term debt, gross	757,089	757,089	840,625
CMBS/RMBS | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	1,481,324	1,481,324
Total Repurchase Agreements | Secured Borrowings
Secured Borrowings
Maximum Facility Size	17,340,108	17,340,108
Long term debt, gross	10,233,082	10,233,082	$ 10,799,120
Total Repurchase Agreements | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Pledged Asset Carrying Value	$ 14,652,978	$ 14,652,978