v3.26.1
Secured Borrowings - Secured Financing Agreements (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Secured Borrowings    
Available-for-sale securities $ 86,717 $ 88,283
Secured financing agreements, net 13,769,576 12,678,948
Revolving Credit Facility    
Secured Borrowings    
Equity interests in certain subsidiaries used to secure facilities 7,800,000  
Borrowing Base Facility    
Secured Borrowings    
Maximum Facility Size 615,000  
Line of credit capacity if conditions are met 1,300,000  
Maximum facility size subject to certain conditions 1,300,000  
Commercial Financing Facilities    
Secured Borrowings    
Maximum Facility Size 997,500  
Secured Borrowings    
Secured Borrowings    
Maximum Facility Size 24,302,361  
Long-term debt, gross 13,863,136 12,780,793
Unamortized net discount (17,507) (19,084)
Unamortized deferred financing costs (76,053) (82,761)
Secured financing agreements, net 13,769,576 12,678,948
Secured Borrowings | Borrowing Base Facility    
Secured Borrowings    
Maximum Facility Size 1,250,000  
Long-term debt, gross 4,000 2,000
Secured Borrowings | Commercial Financing Facilities    
Secured Borrowings    
Maximum Facility Size 1,097,495  
Long-term debt, gross 478,425 480,611
Secured Borrowings | Infrastructure Financing Facilities    
Secured Borrowings    
Maximum Facility Size 1,175,000  
Long-term debt, gross 497,016 515,004
Secured Borrowings | Property Financing    
Secured Borrowings    
Maximum Facility Size 1,070,691  
Long-term debt, gross 558,961 622,906
Secured Borrowings | Property Financing | Fundamental Income Properties, LLC    
Secured Borrowings    
Long-term debt, gross 90,800  
Secured Borrowings | Term Loans and Revolver    
Secured Borrowings    
Maximum Facility Size 2,464,480  
Long-term debt, gross 2,264,481 2,270,180
Secured Borrowings | Total Other Secured Financing    
Secured Borrowings    
Maximum Facility Size 7,057,666  
Long-term debt, gross 3,802,883 3,890,701
Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities 16,767,838  
Secured Borrowings | Asset Pledged as Collateral | Borrowing Base Facility    
Secured Borrowings    
Available-for-sale securities 237,542  
Secured Borrowings | Asset Pledged as Collateral | Commercial Financing Facilities    
Secured Borrowings    
Available-for-sale securities 704,673  
Secured Borrowings | Asset Pledged as Collateral | Infrastructure Financing Facilities    
Secured Borrowings    
Available-for-sale securities 618,434  
Secured Borrowings | Asset Pledged as Collateral | Property Financing    
Secured Borrowings    
Available-for-sale securities 741,081  
Secured Borrowings | Asset Pledged as Collateral | Total Other Secured Financing    
Secured Borrowings    
Available-for-sale securities $ 2,301,730  
Secured Borrowings | Index | Commercial Financing Facilities    
Secured Borrowings    
Pricing margin (as a percent) 1.98%  
Secured Borrowings | SOFR | Borrowing Base Facility    
Secured Borrowings    
Pricing margin (as a percent) 2.00%  
Secured Borrowings | SOFR | Infrastructure Financing Facilities    
Secured Borrowings    
Pricing margin (as a percent) 1.96%  
Secured Borrowings | SOFR | Property Financing    
Secured Borrowings    
Pricing margin (as a percent) 2.29%  
Secured Borrowings | SOFR | Term Loans and Revolver    
Secured Borrowings    
Pricing margin (as a percent) 2.00%  
Line of Credit | Commercial Financing Facilities    
Secured Borrowings    
Line of credit capacity if conditions are met $ 1,100,000  
Commercial Loans    
Secured Borrowings    
Maximum Facility Size 11,900,000  
Long-term debt, gross 2,800,000  
Line of credit capacity if conditions are met 12,300,000  
Commercial Loans | Secured Borrowings    
Secured Borrowings    
Maximum Facility Size 12,330,841  
Long-term debt, gross 7,242,074 6,048,734
Commercial Loans | Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities $ 10,795,866  
Commercial Loans | Secured Borrowings | Index    
Secured Borrowings    
Pricing margin (as a percent) 1.80%  
Residential Loans | Secured Borrowings    
Secured Borrowings    
Maximum Facility Size $ 2,950,000  
Long-term debt, gross 1,945,826 1,929,400
Residential Loans | Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities $ 2,216,293  
Residential Loans | Secured Borrowings | SOFR    
Secured Borrowings    
Pricing margin (as a percent) 1.65%  
Infrastructure Loans | Secured Borrowings    
Secured Borrowings    
Maximum Facility Size $ 650,000  
Long-term debt, gross 93,858 211,651
Infrastructure Loans | Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities $ 157,188  
Infrastructure Loans | Secured Borrowings | Index    
Secured Borrowings    
Pricing margin (as a percent) 2.00%  
Conduit Loans | Secured Borrowings    
Secured Borrowings    
Maximum Facility Size $ 375,000  
Long-term debt, gross 41,325 0
Conduit Loans | Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities $ 54,456  
Conduit Loans | Secured Borrowings | SOFR    
Secured Borrowings    
Pricing margin (as a percent) 2.00%  
CMBS/RMBS    
Secured Borrowings    
Long-term debt, gross $ 338,100  
Coupon Rate 4.02%  
Amount outstanding on a repurchase facility not subject to margin calls $ 317,000  
Amount outstanding on repurchase facility $ 25,200  
Pro rata share owned by a non-controlling partner in a consolidated joint venture 49.00%  
CMBS/RMBS | Certain Facilities    
Secured Borrowings    
Long-term debt, gross $ 286,000  
CMBS/RMBS | Certain Facilities | Minimum    
Secured Borrowings    
Rolling maturity period 6 months  
CMBS/RMBS | Certain Facilities | Maximum    
Secured Borrowings    
Rolling maturity period 12 months  
CMBS/RMBS | SOFR | Weighted-average    
Secured Borrowings    
Coupon Rate 1.64%  
CMBS/RMBS | Secured Borrowings    
Secured Borrowings    
Maximum Facility Size $ 938,854  
Long-term debt, gross 737,170 700,307
CMBS/RMBS | Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities 1,242,305  
Total Repurchase Agreements | Secured Borrowings    
Secured Borrowings    
Maximum Facility Size 17,244,695  
Long-term debt, gross 10,060,253 $ 8,890,092
Total Repurchase Agreements | Secured Borrowings | Asset Pledged as Collateral    
Secured Borrowings    
Available-for-sale securities $ 14,466,108