Borrowings - Additional Information (Detail) $ in Millions	1 Months Ended	12 Months Ended
Dec. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Debt Instrument [Line Items]
Credit facility drawn	$ 3,000	$ 3,000
FHLBs Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	17,700	17,700
Federal Reserve Bank of New York
Debt Instrument [Line Items]
Available line of credit	24,500	24,500
Junior Subordinated Debt
Debt Instrument [Line Items]
Repayment of subordinated debt	$ 130
Loss on extinguishment of debt		$ 20
Short-term Borrowings
Debt Instrument [Line Items]
Stated maturity		1 year

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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