Secured Borrowings - Secured Financing Agreements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Secured Borrowings
Available-for-sale securities	$ 91,941	$ 93,806
Secured financing agreements, net	12,438,438	11,151,557
Revolving Credit Facility
Secured Borrowings
Equity interests in certain subsidiaries used to secure facilities	5,800,000
Borrowing Base Facility
Secured Borrowings
Maximum Facility Size	410,000
Maximum facility size subject to certain conditions	750,000
Commercial Financing Facilities
Secured Borrowings
Maximum Facility Size	639,900
Secured Borrowings
Secured Borrowings
Maximum Facility Size	22,038,517
Long-term debt, gross	12,529,958	11,236,129
Unamortized net discount	(20,134)	(19,338)
Unamortized deferred financing costs	(71,386)	(65,234)
Secured financing agreements, net	12,438,438	11,151,557
Secured Borrowings | Borrowing Base Facility
Secured Borrowings
Maximum Facility Size	750,000
Long-term debt, gross	1,000	2,000
Secured Borrowings | Commercial Financing Facilities
Secured Borrowings
Maximum Facility Size	739,907
Long-term debt, gross	359,476	330,081
Secured Borrowings | Infrastructure Financing Facilities
Secured Borrowings
Maximum Facility Size	1,425,000
Long-term debt, gross	593,902	499,242
Secured Borrowings | Property Mortgages - Variable rate
Secured Borrowings
Maximum Facility Size	597,941
Long-term debt, gross	$ 595,555	595,645
Secured Borrowings | Property Mortgages - Fixed rate
Secured Borrowings
Coupon Rate	4.51%
Maximum Facility Size	$ 20,154
Long-term debt, gross	20,154	20,209
Secured Borrowings | Term Loans and Revolver
Secured Borrowings
Maximum Facility Size	1,783,803
Long-term debt, gross	1,583,803	1,452,567
Secured Borrowings | Total Other Secured Financing
Secured Borrowings
Maximum Facility Size	5,316,805
Long-term debt, gross	3,153,890	2,899,744
Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	16,283,706
Secured Borrowings | Asset Pledged as Collateral | Borrowing Base Facility
Secured Borrowings
Available-for-sale securities	16,800
Secured Borrowings | Asset Pledged as Collateral | Commercial Financing Facilities
Secured Borrowings
Available-for-sale securities	519,077
Secured Borrowings | Asset Pledged as Collateral | Infrastructure Financing Facilities
Secured Borrowings
Available-for-sale securities	812,409
Secured Borrowings | Asset Pledged as Collateral | Property Mortgages - Variable rate
Secured Borrowings
Available-for-sale securities	652,387
Secured Borrowings | Asset Pledged as Collateral | Property Mortgages - Fixed rate
Secured Borrowings
Available-for-sale securities	23,465
Secured Borrowings | Asset Pledged as Collateral | Total Other Secured Financing
Secured Borrowings
Available-for-sale securities	$ 2,024,138
Secured Borrowings | Index | Commercial Financing Facilities
Secured Borrowings
Pricing margin (as a percent)	1.99%
Secured Borrowings | SOFR | Borrowing Base Facility
Secured Borrowings
Pricing margin (as a percent)	2.10%
Secured Borrowings | SOFR | Infrastructure Financing Facilities
Secured Borrowings
Pricing margin (as a percent)	2.02%
Secured Borrowings | SOFR | Property Mortgages - Variable rate
Secured Borrowings
Pricing margin (as a percent)	2.56%
Secured Borrowings | SOFR | Term Loans and Revolver
Secured Borrowings
Pricing margin (as a percent)	2.25%
Line of Credit | Commercial Financing Facilities
Secured Borrowings
Line of credit capacity if conditions are met	$ 739,900
Commercial Loans
Secured Borrowings
Maximum Facility Size	10,900,000
Secured financing agreements, net	2,600,000
Line of credit capacity if conditions are met	11,300,000
Commercial Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	11,265,459
Long-term debt, gross	6,135,951	5,137,103
Commercial Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	$ 9,978,479
Commercial Loans | Secured Borrowings | Index
Secured Borrowings
Pricing margin (as a percent)	2.09%
Residential Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	$ 3,450,000
Long-term debt, gross	2,124,368	2,126,692
Residential Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	$ 2,371,209
Residential Loans | Secured Borrowings | SOFR
Secured Borrowings
Pricing margin (as a percent)	1.73%
Infrastructure Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	$ 650,000
Long-term debt, gross	371,480	264,432
Infrastructure Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	$ 486,388
Infrastructure Loans | Secured Borrowings | Index
Secured Borrowings
Pricing margin (as a percent)	2.18%
Conduit Loans | Secured Borrowings
Secured Borrowings
Maximum Facility Size	$ 375,000
Long-term debt, gross	44,979	87,061
Conduit Loans | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	$ 57,664
Conduit Loans | Secured Borrowings | SOFR
Secured Borrowings
Pricing margin (as a percent)	2.18%
CMBS/RMBS
Secured Borrowings
Coupon Rate	3.94%
Secured financing agreements, net	$ 322,400
Amount outstanding on a repurchase facility not subject to margin calls	322,400
Amount outstanding on repurchase facility	$ 28,100
Pro rata share owned by a non-controlling partner in a consolidated joint venture	49.00%
CMBS/RMBS | Certain Facilities
Secured Borrowings
Secured financing agreements, net	$ 322,200
Rolling maturity period	12 months
CMBS/RMBS | SOFR | Weighted-average
Secured Borrowings
Coupon Rate	2.02%
CMBS/RMBS | Secured Borrowings
Secured Borrowings
Maximum Facility Size	$ 981,253
Long-term debt, gross	699,290	721,097
CMBS/RMBS | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	1,365,828
Total Repurchase Agreements | Secured Borrowings
Secured Borrowings
Maximum Facility Size	16,721,712
Long-term debt, gross	9,376,068	$ 8,336,385
Total Repurchase Agreements | Secured Borrowings | Asset Pledged as Collateral
Secured Borrowings
Available-for-sale securities	$ 14,259,568