Derivatives and Hedging Activities Net Gains (Losses) on Fair Value Hedging Relationships (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Available-for-sale securities	$ 322	$ 339
Consolidated obligations - Bonds	(914)	(1,057)
Consolidated obligations - Discount notes	(888)	(696)
Interest Rate Contract [Member] | Interest Expense [Member] | Consolidated Obligation Bonds [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivatives	(67)	49
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	77	(54)
Gain (Loss) on Fair Value Hedges Recognized in Net Interest Income	10	(5)
Interest Rate Contract [Member] | Interest Expense [Member] | Consolidated Obligation Discount Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivatives	(15)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	25
Gain (Loss) on Fair Value Hedges Recognized in Net Interest Income	10
Interest Rate Contract [Member] | Interest Income [Member] | Advances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivatives	277	(341)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(238)	461
Gain (Loss) on Fair Value Hedges Recognized in Net Interest Income	39	120
Interest Rate Contract [Member] | Interest Income [Member] | Available-for-sale Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivatives	119	(334)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(90)	384
Gain (Loss) on Fair Value Hedges Recognized in Net Interest Income	$ 29	$ 50