v3.26.1
Derivatives - Narrative (Details) - USD ($)
Jun. 30, 2026
Dec. 31, 2025
Derivative [Line Items]    
Margin deposit assets $ 558,000,000 $ 392,000,000
Variation margin receivable, derivative   17,000,000
Variation margin payable, derivative 52,000,000  
Interest rate swaps    
Derivative [Line Items]    
Derivative assets 0  
Net asset position 173,000,000  
Total derivatives liabilities   (46,000,000)
U.S. Treasury futures    
Derivative [Line Items]    
Derivative assets 0  
Net asset position $ 38,000,000 $ 22,000,000