Fair Value (Fair Value Option) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Fair Value, Option, Quantitative Disclosures [Line Items]
Balance, beginning of the period	$ 5,441
Net gain/(loss) on advances and consolidated obligation bonds held under fair value option	(26)	$ 29
Balance, end of the period	5,151
Advances
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain/(loss) on advances and consolidated obligation bonds held under fair value option	(25)	33
Consolidated obligation bonds
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain/(loss) on advances and consolidated obligation bonds held under fair value option	$ (1)	$ (4)

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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