Recently Issued Accounting Standards and Interpretations Recently Issued Accounting Standards and Interpretations (Policies)	6 Months Ended
	Jun. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Finance, Loan and Lease Receivables, Held-for-investment, Allowance and Nonperforming Loans, Nonperforming Loans Policy [Policy Text Block]	Mortgage Loans Held for Portfolio - FHA The FHLB invests in fixed-rate mortgage loans secured by one-to-four family residential properties insured by the FHA. The FHLB expects to recover any losses from such loans from the FHA. Any losses from these loans that are not recovered from the FHA would be due to a claim rejection by the FHA and, as such, would be recoverable from the selling participating financial institutions. Therefore, the FHLB only has credit risk for these loans if the seller or servicer fails to pay for losses not covered by the FHA insurance. As a result, the FHLB did not establish an allowance for credit losses on its FHA insured mortgage loans. Furthermore, due to the insurance, none of these mortgage loans have been placed on non-accrual status. Mortgage Loans Held for Portfolio - Conventional Mortgage Purchase Program (MPP) The FHLB determines the allowance for conventional loans through analyses that include consideration of various data observations such as past performance, current performance, loan portfolio characteristics, collateral-related characteristics, industry data, and prevailing economic conditions. The measurement of the allowance for credit losses consists of: (1) collectively evaluating homogeneous pools of residential mortgage loans; (2) reviewing specifically identified loans for impairment; and (3) considering other relevant qualitative factors. Collectively Evaluated Mortgage Loans. The credit risk analysis of conventional loans evaluated collectively for impairment considers historical delinquency migration, applies estimated loss severities, and incorporates the associated credit enhancements in order to determine the FHLB's best estimate of probable incurred losses at the reporting date. The FHLB performs the credit risk analysis of all conventional mortgage loans at the individual Master Commitment Contract level to properly determine the credit enhancements available to recover losses on loans under each individual Master Commitment Contract. The Master Commitment Contract is an agreement with a member in which the member agrees to make a best efforts attempt to sell a specific dollar amount of loans to the FHLB generally over a one-year period. Migration analysis is a methodology for determining, through the FHLB's experience over a historical period, the rate of default on loans. The FHLB applies migration analysis to loans based on payment status categories such as current, 30, 60, and 90 days past due. The FHLB then estimates, based on historical experience, how many loans in these categories may migrate to a loss realization event and applies a current loss severity to estimate losses. The estimated losses are then reduced by the probable cash flows resulting from available credit enhancements. Any credit enhancement cash flows that are projected and assessed as not probable of receipt do not reduce estimated losses. Individually Evaluated Mortgage Loans. Conventional mortgage loans that are considered troubled debt restructurings are specifically identified for purposes of calculating the allowance for credit losses. The FHLB measures impairment of these specifically identified loans by either estimating the present value of expected cash flows, estimating the loan's observable market price, or estimating the fair value of the collateral if the loan is collateral dependent. The FHLB removes specifically identified loans evaluated for impairment from the collectively evaluated mortgage loan population. Qualitative Factors. The FHLB also assesses other qualitative factors in its estimation of loan losses for the collectively evaluated population. This amount represents a subjective management judgment, based on facts and circumstances that exist as of the reporting date, that is intended to cover other incurred losses that may not otherwise be captured in the methodology described above.
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	A loan considered a troubled debt restructuring is individually evaluated for impairment when determining its related allowance for credit losses. Credit loss is measured by estimating expected cash shortfalls incurred as of the reporting date.
Segment Reporting, Policy [Policy Text Block]	The FHLB has identified two primary operating segments based on its method of internal reporting: Traditional Member Finance and the MPP. These segments reflect the FHLB's two primary Mission Asset Activities and the manner in which they are managed from the perspective of development, resource allocation, product delivery, pricing, credit risk and operational administration. The segments identify the principal ways the FHLB provides services to member stockholders.
Fair Value of Financial Instruments, Policy [Policy Text Block]	The fair value amounts recorded on the Statements of Condition and presented in the related note disclosures have been determined by the FHLB using available market information and the FHLB's best judgment of appropriate valuation methods. The fair values reflect the FHLB's judgment of how a market participant would estimate the fair values.
Fair Value Transfer, Policy [Policy Text Block]	The FHLB reviews the fair value hierarchy classifications on a quarterly basis. Changes in the observability of the valuation inputs may result in a reclassification of certain financial assets or liabilities. Such reclassifications are reported as transfers in/out at fair value as of the beginning of the quarter in which the changes occur.