v3.26.1
Derivative Instruments - Summary of Notional Balances and Fair Values of Derivatives (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Assets    
Gross derivative assets $ 544 $ 569
Collateral posted/held 18 24
Counterparty netting adjustment (476) (419)
Net derivative assets 86 174
Liabilities    
Gross derivative liabilities 604 661
Collateral posted/held 3 (2)
Counterparty netting adjustment (476) (419)
Net derivative liabilities 131 240
Interest rate swaps    
Derivatives, Fair Value [Line Items]    
Notional balances 76,720 74,630
Assets    
Gross derivative assets 330 228
Liabilities    
Gross derivative liabilities 370 442
Cross currency swaps    
Derivatives, Fair Value [Line Items]    
Notional balances 8,705 10,807
Assets    
Gross derivative assets 214 341
Liabilities    
Gross derivative liabilities $ 234 $ 219