v3.26.1
DERIVATIVE INSTRUMENTS - Schedule of Derivative Contracts (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Interest rate futures | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount $ 6,589,337 $ 7,575,688
Interest rate futures | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 2,575,495 4,179,575
Interest rate swaps | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 13,030 0
Interest rate swaps | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 36,200 29,600
Foreign currency forward contracts, underwriting and non-investment operations | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 967,747 1,102,740
Foreign currency forward contracts, underwriting and non-investment operations | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 292,202 412,005
Foreign currency forward contracts, investment operations | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 152,815 159,267
Foreign currency forward contracts, investment operations | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 207,197 186,854
Foreign currency forward contracts, investment operations | Derivative instruments designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 0 0
Foreign currency forward contracts, investment operations | Derivative instruments designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 65,289 64,142
Credit default swaps | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 46,845 39,500
Credit default swaps | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 1,453,875 847,864
Equity futures | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 1,643,364 1,729,226
Equity futures | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount 0 0
Commodity futures | Derivative instruments not designated as hedges | Long    
Derivative [Line Items]    
Derivative, notional amount 553,678 1,189,027
Commodity futures | Derivative instruments not designated as hedges | Short    
Derivative [Line Items]    
Derivative, notional amount $ 0 $ 0