Derivative Financial Instruments - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Exchange traded derivatives as a percentage of total derivative assets (less than)	1.00%
Exchange traded derivatives as a percentage of total derivative liabilities (less than)	1.00%
Losses related to discontinued cash flow hedge relationships	$ 16	$ 10
Cash flow hedge loss to be amortized within twelve months	55
Aggregate fair value of all derivative instruments with credit-risk related contingent features	117		$ 58
Collateral already posted aggregate fair value	$ 62		$ 25
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Income (Expense), Operating