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Commitments And Contingencies (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Off-balance Sheet Commitments:
Obligation with Joint and Several Liability Arrangement, Description	As provided in the Bank Act or in FHFA regulations, consolidated obligations are backed only by the financial resources of the FHLBanks. FHLBank Topeka is jointly and severally liable with the other FHLBanks for the payment of principal and interest on all of the consolidated obligations issued by the FHLBanks.
Obligation with joint and several liability arrangement, off balance sheet amount	$ 1,157,680,910		$ 1,122,389,398
Carrying value included in other liabilities	$ 60,729		$ 70,984
Number of in-district state housing authorities with standby bond purchase agreements	2		2
Stand by Bond Purchase Agreements, Aquired And Sold At Par, During the Period	$ 0	$ 0
Mortgage Delivery Commitments Derivative Asset (Liability)	$ 566		$ 43
Standby Letters of Credit Outstanding [Member]
Off-balance Sheet Commitments:
Commitment Expiration Year (no later than)	2029
Carrying value included in other liabilities	$ 2,577		$ 2,571
Forward Settling Advance Commitments [Member]
Off-balance Sheet Commitments:
Term (up to)	24 months
Commitments for standby bond purchases [Member]
Off-balance Sheet Commitments:
Commitment Expiration Year (no later than)	2029
Mortgage Receivable [Member] \| Commitments to fund or purchase mortgage loans [Member]
Off-balance Sheet Commitments:
Term (up to)	60 days