Derivatives and Hedging Activities Cumulative Basis Adjustments for Fair Value Hedges (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Consolidated Obligation Bonds [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Fair Value Hedge	$ 26,303	$ 20,546
Hedged Liability, Active Fair Value Hedge, Cumulative Increase (Decrease)	(21)	56
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	(21)	56
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	0	0
Available-for-sale Securities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Fair Value Hedge	19,732	19,983
Hedged Asset, Active Fair Value Hedge, Cumulative Increase (Decrease)	(406)	(315)
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	(41)	(42)
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(447)	(357)
Advances [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Fair Value Hedge	63,269	58,516
Hedged Asset, Active Fair Value Hedge, Cumulative Increase (Decrease)	(159)	82
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	(6)	(10)
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(165)	72
Consolidated Obligation Discount Notes [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Fair Value Hedge	70,916	61,439
Hedged Liability, Active Fair Value Hedge, Cumulative Increase (Decrease)	(8)	17
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	(8)	17
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	$ 0	$ 0