Investment Debt Securities (Trading Debt Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Trading debt securities	$ 4,216	$ 3,240
U.S. Government & other government related
Debt and Equity Securities, FV-NI [Line Items]
Trading debt securities	4,214	3,238
GSE MBS
Debt and Equity Securities, FV-NI [Line Items]
Trading debt securities	$ 2	$ 2

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant