| Summary of Significant Accounting Policies | Summary of Significant Accounting Policies Use of Estimates. The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America (GAAP) requires the Bank’s management to make subjective assumptions and estimates, which are based upon the information then available to the Bank and are inherently uncertain and subject to change. These assumptions and estimates may affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of income and expenses. Actual results could differ significantly from these estimates. Estimated Fair Values. The estimated fair value amounts, recorded on the Statements of Condition and in the note disclosures for the periods presented, have been determined by the Bank using available market and other pertinent information and reflect the Bank’s best judgment of appropriate valuation methods. Although the Bank uses its best judgment in estimating the fair value of these financial instruments, there are inherent limitations in any valuation technique. Therefore, these fair values may not be indicative of the amounts that would have been realized in market transactions at the reporting dates. Financial Instruments Meeting Netting Requirements. The Bank has certain financial instruments, including derivative instruments and securities purchased under agreements to resell, that are subject to offset under master netting agreements or by operation of law. The Bank has elected to offset its derivative asset and liability positions, as well as cash collateral received or pledged, when it has the legal right of offset under these master agreements. The Bank does not have any offsetting liabilities related to its securities purchased under agreements to resell for the periods presented. The net exposure for these financial instruments can change on a daily basis; therefore, there may be a delay between the time this exposure change is identified and additional collateral is requested, and the time when this collateral is received or pledged. There may be a delay for excess collateral to be returned. For derivative instruments, any excess cash collateral received or pledged is recognized as a derivative liability or derivative asset based on the terms of the individual master agreement between the Bank and its derivative counterparty. Additional information regarding these agreements is provided in Note 17—Derivatives and Hedging Activities. Based on the fair value of the related securities held as collateral, the securities purchased under agreements to resell were fully collateralized for the periods presented. Interest-bearing Deposits, Securities Purchased under Agreements to Resell, and Federal Funds Sold . Interest-bearing deposits, securities purchased under agreements to resell, and federal funds sold provide short-term liquidity and are carried at cost. The Bank treats securities purchased under agreements to resell as short-term collateralized loans, which are classified as assets on the Statements of Condition. Securities purchased under agreements to resell are held in safekeeping in the name of the Bank by third-party custodians approved by the Bank. Should the fair value of the underlying securities decrease below the fair value required as collateral, the counterparty has the option to (1) place an equivalent amount of additional securities in safekeeping in the name of the Bank, or (2) remit an equivalent amount of cash; otherwise, the dollar value of the resale agreement will be decreased accordingly. Federal funds sold consist of short-term, unsecured loans transacted with counterparties that are considered by the Bank to be of investment quality. Interest on interest-bearing deposits, securities purchased under agreements to resell, and federal funds sold is accrued as earned and recorded in interest income on the Statements of Income. Investment Securities. Investment securities that the Bank has both the ability and intent to hold to maturity are classified as held-to-maturity and are carried at amortized cost, adjusted for periodic principal repayments, amortization of premiums, and accretion of discounts. Amortization of premiums and accretion of discounts are computed using the contractual level-yield method (contractual interest method), adjusted for actual prepayments. The contractual interest method recognizes the income effects of premiums and discounts over the contractual life of the securities based on the actual behavior of the underlying assets, including adjustments for actual prepayment activities, and reflects the contractual terms of the securities without regard to changes in estimated prepayments based on assumptions about future borrower behavior. The Bank classifies certain investment securities acquired for purposes of liquidity and asset-liability management as trading investments and carries these securities at their estimated fair value. The Bank does not participate in speculative trading practices in these investments and generally holds them until maturity, except to the extent management deems necessary to manage the Bank’s liquidity position. The Bank records changes in the fair value of these investments in noninterest income (loss) as “Net losses on trading securities” on the Statements of Income, along with gains and losses on sales of investment securities using the specific identification method. Amortization of premiums and accretion of discounts are computed using the contractual level-yield method. The Bank classifies certain securities that are not held-to-maturity or trading as available-for-sale and carries these securities at their estimated fair value. The Bank records changes in the fair value of these investments in other comprehensive income. The Bank intends to hold its available-for-sale securities for an indefinite period of time but may sell them prior to maturity in response to changes in interest rates, prepayment risk, or other factors. Other-than-temporary Impairment of Investment Securities. The Bank evaluates its individual available-for-sale and held-to-maturity securities in unrealized loss positions for other-than-temporary impairment on a quarterly basis. A security is considered impaired when its fair value is less than its amortized cost. The Bank considers an other-than-temporary impairment to have occurred under any of the following circumstances: • the Bank has an intent to sell the impaired debt security; • if, based on available evidence, the Bank believes it is more likely than not that it will be required to sell the impaired debt security before the recovery of its amortized cost basis; or • the Bank does not expect to recover the entire amortized cost basis of the impaired debt security. If either of the first two conditions above is met, the Bank recognizes an other-than-temporary impairment loss in earnings equal to the entire difference between the security’s amortized cost basis and its fair value as of the Statements of Condition date. For securities in an unrealized loss position that meet neither of the first two conditions, the Bank performs a cash flow analysis to determine if it will recover the entire amortized cost basis of each of these securities. The present value of the cash flows expected to be collected is compared to the amortized cost basis of the debt security to determine whether a credit loss exists. If there is a credit loss (the difference between the present value of the cash flows expected to be collected and the amortized cost basis of the debt security), the carrying value of the debt security is adjusted to its fair value. However, rather than recognizing the entire difference between the amortized cost basis and fair value in earnings, only the amount of the impairment representing the credit loss (i.e., the credit component) is recognized in earnings, while the amount related to all other factors (i.e., the non-credit component) is recognized in other comprehensive income. The credit loss on a debt security is limited to the amount of that security’s unrealized losses. The total other-than-temporary impairment is presented on the Statements of Income with an offset for the amount of the non-credit component of other-than-temporary impairment that is recognized in other comprehensive income. The remaining amount on the Statements of Income represents the credit loss for the period. For subsequent accounting of an other-than-temporarily impaired security, the Bank records an additional other-than-temporary impairment if the present value of cash flows expected to be collected is less than the amortized cost of the security. The total amount of this additional other-than-temporary impairment (both credit and non-credit component, if any) is determined as the difference between the security’s amortized cost, less the amount of other-than-temporary impairment recognized in other comprehensive income prior to the determination of this additional other-than-temporary impairment, and its fair value. Any additional credit loss is limited to that security’s unrealized losses or the difference between the security’s amortized cost and its fair value as of the Statements of Condition date. This additional credit loss, up to the amount in accumulated other comprehensive income related to the security, is reclassified out of accumulated other comprehensive income and recognized in earnings. Any credit loss in excess of the related other comprehensive income is recorded as additional total other-than-temporary impairment loss and recognized in earnings. For debt securities classified as available-for-sale, the Bank does not accrete the other-than-temporary impairment recognized in accumulated other comprehensive income to the carrying value. Rather, subsequent related increases and decreases (if not an other-than-temporary impairment) in the fair value of available-for-sale securities are netted against the non-credit component of other-than-temporary impairment recognized previously in accumulated other comprehensive income. Upon subsequent evaluation of a debt security where there is no additional other-than-temporary impairment, the Bank adjusts the accretable yield on a prospective basis if there is a significant increase in the security’s expected cash flows. As of the impairment measurement date, a new accretable yield is calculated for the impaired investment security. This adjusted yield is then used to calculate the interest income recognized over the remaining life of the security so as to match the amount and timing of future cash flows expected to be collected. Subsequent significant increases in estimated cash flows change the accretable yield on a prospective basis. Advances. The Bank reports advances (secured loans to members, former members, or housing associates), net of discounts on advances related to the Affordable Housing Program (AHP) and the Economic Development and Growth Enhancement Program (EDGE), unearned commitment fees, and hedging basis adjustments. The Bank accretes the discounts on advances and amortizes the recognized unearned commitment fees and hedging adjustments to interest income using the contractual interest method. The Bank records interest on advances to interest income as earned. Prepayment Fees . The Bank charges a borrower a prepayment fee when the borrower prepays certain advances before the original maturity date. The Bank records prepayment fees, net of basis adjustments related to hedging activities included in the carrying value of the advance as “Prepayment fees on advances, net” in the interest income section of the Statements of Income. In cases in which there is a prepayment of an existing advance and a contemporaneous funding of a new advance, the Bank evaluates whether the new advance meets the accounting criteria to qualify as a modification of an existing advance or whether it constitutes a new advance. If the new advance qualifies as a modification of the existing advance, the hedging basis adjustments and the net prepayment fee on the prepaid advance are recorded in the carrying value of the modified advance and amortized over the life of the modified advance using the contractual interest method. This amortization is recorded in advance interest income. If the Bank determines that the transaction does not qualify as a modification of an existing advance, it is treated as an advance termination with subsequent funding of a new advance, and the Bank records the net fees as “Prepayment fees, net” in the interest income section of the Statements of Income. Mortgage Loans Held for Portfolio. The Bank classifies mortgage loans that it has the intent and ability to hold for the foreseeable future, or until maturity or payoff, as held for portfolio. Accordingly, these mortgage loans are reported net of unamortized premiums, unaccreted discounts, mark-to-market basis adjustments on loans initially classified as mortgage loan commitments, and any allowance for credit losses. The Bank defers and amortizes premiums and accretes discounts (1) paid to and received by the participating financial institutions (PFIs), and (2) mark-to-market basis adjustments on loans initially classified as mortgage loan commitments, as interest income using the contractual interest method. A mortgage loan is considered past due when the principal or interest payment is not received in accordance with the contractual terms of the loan. The Bank places a conventional mortgage loan on nonaccrual status when the collection of the contractual principal or interest from the borrower is 90 days or more past due. When a mortgage loan is placed on nonaccrual status, accrued but uncollected interest is reversed against interest income. The Bank records cash payments received on nonaccrual loans as interest income and as a reduction of principal as specified in the contractual agreement. A loan on nonaccrual status may be restored to accrual status when the contractual principal and interest are less than 90 days past due. A government-guaranteed or -insured loan is not placed on nonaccrual status when the collection of the contractual principal or interest is 90 days or more past due because of (1) the U.S. government guarantee or insurance on the loan, and (2) the contractual obligation of the loan servicer to repurchase the loan when certain criteria are met. A mortgage loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect all amounts due according to the contractual terms of the mortgage loan agreement. Interest income is recognized in the same manner as nonaccrual loans. Finance Agency regulations require that mortgage loans held in the Bank’s portfolios be credit enhanced so that the Bank’s risk of loss is limited to the losses of an investor in at least an investment-grade category, such as “BBB.” For conventional mortgage loans, PFIs retain a portion of the credit risk on the loans they sell to the Bank by providing credit enhancement either through a direct liability to pay credit losses up to a specified amount or through a contractual obligation to provide supplemental mortgage insurance. PFIs are paid a credit enhancement fee (CE Fee) for assuming credit risk, and in some instances, all or a portion of the CE Fee may be performance based. CE Fees are paid monthly based on the remaining unpaid principal balance of the loans in a master commitment. CE Fees are recorded as an offset to mortgage loan interest income. To the extent that the Bank experiences losses in a master commitment, it may be able to recapture CE Fees paid to the PFI to offset these losses. Allowance for Credit Losses. The allowance for credit losses is a valuation allowance separately established for each identified portfolio segment of financing receivables, if necessary, to provide for probable incurred losses in the Bank’s portfolio as of the Statements of Condition date. A portfolio segment is defined as the level at which an entity develops and documents a systematic methodology for determining its allowance for credit losses. The Bank has developed and documented a systematic methodology for determining an allowance for credit losses for the following portfolio segments of financing receivables: advances and standby letters of credit, government-guaranteed or -insured residential mortgage loans held for portfolio, conventional residential mortgage loans held for portfolio, term federal funds sold, and term securities purchased under agreements to resell. A portfolio segment may be further disaggregated into classes of financing receivables to the extent that it is needed to understand the exposure to credit risk arising from these financing receivables; however, the Bank determined that no further disaggregation of the portfolio segments identified above is needed. The Bank manages its credit exposure to advances and standby letters of credit through an integrated approach that includes (1) establishing a credit limit for each borrower; (2) an ongoing review of each borrower’s financial condition; and (3) collateral and lending policies to limit risk of loss, while balancing each borrower’s needs for a reliable source of funding. In addition, the Bank lends to financial institutions within its district and housing associates in accordance with federal statutes and Finance Agency regulations. Specifically, the Bank complies with the FHLBank Act, which requires the Bank to obtain sufficient collateral to fully secure advances. The estimated value of the collateral required to secure each borrower’s advances is calculated by applying discounts to the fair value or unpaid principal balance of the collateral, as applicable. The Bank accepts certain investment securities, residential mortgage loans, deposits, and other real estate related assets as collateral. The Bank’s capital stock owned by its member borrower is also pledged as additional collateral. Collateral arrangements may vary depending upon borrower credit quality, financial condition and performance, borrowing capacity, and the Bank’s overall credit exposure to the borrower. The Bank can call for additional or substitute collateral to protect its security interest. The Bank believes that these policies effectively manage credit risk from advances and standby letters of credit. Based upon the financial condition of the borrower, the Bank either allows a borrower to retain physical possession of the collateral pledged to it or requires the borrower to specifically assign the collateral to or place the collateral in physical possession of the Bank or its safekeeping agent. The Bank requires its borrowers to execute an advances and security agreement that establishes the Bank’s security interest in all collateral pledged by the borrower to the Bank. The Bank perfects its security interest in all pledged collateral. The FHLBank Act affords any security interest granted to the Bank by a borrower priority over the claims or rights of any other party (including any receiver, conservator, trustee, or similar party having rights of a lien creditor), except for claims or rights of a third party that (1) would be entitled to priority under otherwise applicable law, and (2) is an actual bona fide purchaser for value or is an actual secured party whose security interest is perfected in accordance with state law. Using a risk-based approach and taking into consideration each borrower’s financial strength, the Bank considers the types and amounts of pledged collateral to be the primary indicator of credit quality on its advances. The Bank had rights to collateral on a borrower-by-borrower basis with an estimated value equal to or greater than its outstanding extensions of credit as of December 31, 2018 and 2017 . The Bank continues to evaluate and make changes to its collateral policies, as necessary, based on current market conditions. No advance was past due, on nonaccrual status, or considered impaired as of December 31, 2018 and 2017 . In addition, there were no troubled debt restructurings related to advances as of December 31, 2018 and 2017 . Based upon the collateral held as security, the Bank’s collateral policies, credit analysis, and the repayment history on advances, the Bank did not anticipate any credit losses on advances or standby letters of credit as of December 31, 2018 and 2017 . Accordingly, the Bank has not recorded any allowance for credit losses on advances, nor has the Bank recorded any liability to reflect an allowance for credit losses for off-balance sheet credit exposure as of December 31, 2018 and 2017 . The Bank invested in government-guaranteed or -insured fixed-rate mortgage loans secured by one-to-four family residential properties. Government-guaranteed or -insured mortgage loans are mortgage loans guaranteed or insured by the Department of Veterans Affairs or the Federal Housing Administration. The servicer provides and maintains insurance or a guarantee from the applicable government agency. The servicer is responsible for compliance with all government agency requirements and for obtaining the benefit of the applicable insurance or guarantee with respect to defaulted government-guaranteed or -insured mortgage loans. Any losses incurred on these loans that are not recovered from the issuer or the guarantor are absorbed by the servicers. Therefore, the Bank only has credit risk for these loans if the servicer fails to pay for losses not covered by insurance or guarantees. Based on the Bank’s assessment of its servicers, the Bank did not establish an allowance for credit losses for its government-guaranteed or -insured mortgage loan portfolio as of December 31, 2018 and 2017 . Modified loans that are considered a troubled debt restructuring are evaluated individually for impairment. All other conventional residential mortgage loans are evaluated collectively for impairment. The allowance for conventional residential mortgage loans is determined by an analysis (performed at least quarterly) that includes segregating the portfolio into various aging groups. For loans that are 60 days or less past due, the Bank calculates a loss severity, default rate, and the expected loss based on individual loan characteristics. For loans that are more than 60 days past due, the allowance is determined using an automated valuation model. Modified loans that are considered a troubled debt restructuring are individually evaluated for impairment when determining the related allowance for credit losses. Credit loss is measured by factoring in expected cash shortfalls (i.e., loss severity rate) incurred as of the reporting date, as well as the economic loss attributable to delaying the original contractual principal and interest due dates. A charge-off is recorded if the recorded investment in the loan will not be recovered. The Bank evaluates whether to record a charge-off on a conventional residential mortgage loan upon the occurrence of a confirming event. Once a loan is 180 days delinquent, the Bank classifies as a loss and charges off the portion of outstanding conventional residential mortgage loan balances in excess of the fair value of the underlying property, less costs to sell and adjusted for any available credit enhancements. Term federal funds sold are generally short-term, their recorded balance approximates fair value, and they are transacted with counterparties that the Bank considers to be of investment quality. The Bank’s investment in federal funds sold are evaluated for purposes of an allowance for credit losses only if the investment is not paid when due. All investments in federal funds sold are unsecured and were repaid or expected to be repaid according to the contracted terms as of December 31, 2018 and 2017 . Securities purchased under agreements to resell are considered collateralized financing arrangements and effectively represent short-term loans transacted with counterparties that the Bank considers to be of investment quality. The terms of these loans are structured such that if the fair value of the underlying securities decreases below the fair value required as collateral, the counterparty must place an equivalent amount of additional securities as collateral or remit an equivalent amount of cash. If an agreement to resell is deemed to be impaired, the difference between the fair value of the collateral and the amortized cost of the agreement is recognized in earnings. Based upon the collateral held as security, the Bank determined that no allowance for credit losses was needed for the securities purchased under agreements to resell as of December 31, 2018 and 2017 . Real estate owned (REO) includes assets that have been received in satisfaction of debt through foreclosures. REO is initially recorded at fair value, less estimated selling costs and is subsequently carried at the lower of that amount or current fair value, less estimated selling costs. The Bank recognizes a charge-off to the allowance for credit losses if the fair value of the REO, less estimated selling costs is less than the recorded investment in the loan at the date of transfer from loans to REO. Any subsequent realized gains, realized or unrealized losses, and carrying costs are included in noninterest income (loss) on the Statements of Income. REO is recorded in “Other assets” on the Statements of Condition and was $1 and $2 as of December 31, 2018 and 2017 , respectively. Derivatives. All derivatives are recognized on the Statements of Condition at their fair values and are reported as either derivative assets or derivative liabilities, net of cash collateral and accrued interest received from or pledged to clearing agents and/or counterparties. The fair values of derivatives are netted by the clearing agent and/or counterparty when the netting requirements have been met. If these netted amounts are positive, they are classified as an asset and, if negative, they are classified as a liability. Cash flows associated with derivatives are reflected as cash flows from operating activities on the Statements of Cash Flows unless the derivative meets the criteria to be a financing derivative. Derivatives not used for intermediary purposes are designated as either (1) a hedge of the fair value of (a) a recognized asset or liability or (b) an unrecognized firm commitment (a fair-value hedge); or (2) a non-qualifying hedge of an asset or liability for asset-liability management purposes. Changes in the fair value of a derivative that are effective as, and that are designated and qualify as, a fair-value hedge, along with changes in the fair value of the hedged asset or liability that are attributable to the hedged risk (including changes that reflect losses or gains on firm commitments), are recorded in noninterest income (loss) as “Net gains on derivatives and hedging activities” on the Statements of Income. Any hedge ineffectiveness (which represents the amount by which the change in the fair value of the derivative differs from the change in the fair value of the hedged item) is recorded in noninterest income (loss) as “Net gains on derivatives and hedging activities” on the Statements of Income. A non-qualifying hedge is a derivative hedging specific or non-specific underlying assets, liabilities, or firm commitments that is an acceptable hedging strategy under the Bank’s risk management program and Finance Agency regulatory requirements, but it does not qualify or was not designated for fair value or cash flow hedge accounting. A non-qualifying hedge introduces the potential for earnings variability because only the change in fair value of the derivative is recorded and is not offset by corresponding changes in the fair value of the non-qualifying hedged asset, liability, or firm commitment, unless such asset, liability, or firm commitment is required to be accounted for at fair value through earnings. Both the net interest on the derivative and the fair value adjustments of a non-qualifying hedge are recorded in noninterest income (loss) as “Net gains on derivatives and hedging activities” on the Statements of Income. The derivatives used in intermediary activities do not qualify for hedge accounting treatment and are separately marked-to-market through earnings. These amounts are recorded in noninterest income (loss) as “Net gains on derivatives and hedging activities” on the Statements of Income. The net result of the accounting for these derivatives does not significantly impact the Bank’s results of operations. The net settlement of interest receivables and payables related to derivatives designated as fair-value hedges are recognized as adjustments to the interest income or interest expense of the designated hedged item. The net settlement of interest receivables and payables related to intermediated derivatives for members and other non-qualifying hedges are recognized in noninterest income (loss) as “Net gains on derivatives and hedging activities” on the Statements of Income. The Bank discontinues hedge accounting prospectively when (1) it determines that the derivative is no longer expected to be effective in offsetting changes in the fair value of a hedged risk, including hedged items such as firm commitments; (2) the derivative and/or the hedged item expires or is sold, terminated, or exercised; (3) a hedged firm commitment no longer meets the definition of a firm commitment; or (4) the bank determines that designating the derivative as a hedging instrument is no longer appropriate. When hedge accounting is discontinued due to the Bank’s determination that a derivative no longer qualifies as an effective fair-value hedge of an existing hedged item, or when the bank decides to cease the specific hedging activity, the Bank will either (1) terminate the derivative, or (2) continue to carry the derivative on the Statements of Condition at its fair value, cease to adjust the hedged asset or liability for changes in fair value, and amortize the cumulative basis adjustment on the hedged item into earnings over the remaining life of the hedged item using the level-yield method. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Bank will carry the derivative at its fair value on the Statements of Condition, recognizing changes in the fair value of the derivative in current-period earnings. The Bank may issue debt, make advances, or purchase financial instruments in which a derivative instrument may be “embedded.” Upon execution of these transactions, the Bank assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the advance, debt, or purchased financial instruments (i.e., the host contract) and whether a separate, non-embedded instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that (1) the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract; and (2) a separate, stand-alone instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract, carried at fair value, and designated as a stand-alone derivative instrument pursuant to a non-qualifying hedge. However, if the entire contract (the host contract and the embedded derivative) is to be measured at fair value, with changes in fair value reported in current-period earnings (e.g., an investment security classified as “trading”), or if the Bank could not identify and measure reliably the embedded derivative for purposes of separating that derivative from its host contract, the entire contract would be carried on the Statements of Condition at fair value, and no portion of the contract could be designated as a hedging instrument. Premises, Equipment, and Software. Premises, equipment, and the cost of purchased software and certain costs incurred in developing computer software for internal use are recorded in “Other assets” on the Statements of Condition. The Bank records these items at cost less accumulated depreciation or amortization. The Bank computes depreciation and amortization using the straight-line method over the estimated useful lives of assets. The estimated useful lives in years are generally as follows: automobiles and computer hardware—three; capitalized computer software cost—thr |
