Derivatives and Hedging Activities (Derivatives in Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 46	$ (35)
Interest Income, Federal Home Loan Bank Advances, Including Prepayment Fees	1,293	1,187
Consolidated obligations - Discount notes	(888)	(696)
Available-for-sale securities	322	339
Consolidated Obligation Bonds [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge	26,303		$ 20,546
Hedged Liability, Active Fair Value Hedge, Cumulative Increase (Decrease)	(21)		56
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	0		0
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	(21)		56
Consolidated Obligation Discount Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge	70,916		61,439
Hedged Liability, Active Fair Value Hedge, Cumulative Increase (Decrease)	(8)		17
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	0		0
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	(8)		$ 17
Gain (Loss) on Derivative Instruments [Member] | Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	43	(53)
Gain (Loss) on Derivative Instruments [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	3	(2)
Gain (Loss) on Derivative Instruments [Member] | Net Interest Settlements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	3	18
Interest Expense [Member] | Interest Rate Contract [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
Mortgage Receivable [Member] | Gain (Loss) on Derivative Instruments [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (3)	$ 2