v3.25.4
Derivatives - Additional Information (Detail) - USD ($)
6 Months Ended
Dec. 31, 2025
Jun. 30, 2025
Derivative [Line Items]    
Minimum required liquidity under certain counterparty agreements $ 1,000,000,000  
Minimum liquidity for the period as defined by certain counterparty agreements 1,000,000,000  
Gross amounts of derivative assets, elected to offset 295,000,000 $ 452,000,000
Gross amounts of derivative liabilities, elected to offset $ 902,000,000 $ 1,800,000,000
Senior Unsecured Obligations    
Derivative [Line Items]    
Debt instrument credit rating AAA