Derivatives and Hedging Activities (Fair Value Hedges) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recorded in Net Interest Income	$ 237	$ 236	$ 473	$ 483
Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	(163)	110	(518)	676
Gain (Loss) on Hedged Item	191	(144)	576	(740)
Amount Recorded in Net Interest Income	28	(34)	58	(64)
Fair value hedges \| Available-for-sale debt securities
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	(171)	176	(544)	793
Gain (Loss) on Hedged Item	268	(35)	738	(510)
Amount Recorded in Net Interest Income	97	141	194	283
Fair value hedges \| Advances
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	(35)	132	(195)	654
Gain (Loss) on Hedged Item	131	59	389	(266)
Amount Recorded in Net Interest Income	96	191	194	388
Fair value hedges \| Consolidated obligation bonds
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	43	(198)	221	(771)
Gain (Loss) on Hedged Item	(209)	(169)	(552)	35
Amount Recorded in Net Interest Income	(166)	(367)	(331)	(736)
Fair value hedges \| Other
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	0	0	0	0
Gain (Loss) on Hedged Item	1	1	1	1
Amount Recorded in Net Interest Income	$ 1	$ 1	$ 1	$ 1

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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