| Derivative Instruments and Hedging Activities Disclosure [Text Block] | Derivatives and Hedging Activities Hedging Activities. As a financial intermediary, the Bank is exposed to interest rate risk. This risk arises from a variety of financial instruments that the Bank enters into on a regular basis in the normal course of its business. The Bank enters into interest rate swap, swaption, cap and forward rate agreements (collectively, interest rate exchange agreements) to manage its exposure to changes in interest rates. The Bank may use these instruments to adjust the effective maturity, repricing frequency, or option characteristics of financial instruments to achieve risk management objectives. In addition, the Bank may use these instruments to hedge the variable cash flows associated with forecasted transactions. The Bank has not entered into any credit default swaps or foreign exchange-related derivatives and, as of December 31, 2019 , it was not a party to any forward rate agreements. The Bank uses interest rate exchange agreements in three ways: (1) by designating the agreement as a fair value hedge of a specific financial instrument or firm commitment; (2) by designating the agreement as a cash flow hedge of a forecasted transaction; or (3) by designating the agreement as a hedge of some other defined risk (referred to as an “economic hedge”). For example, the Bank uses interest rate exchange agreements in its overall interest rate risk management activities to adjust the interest rate sensitivity of consolidated obligations to approximate more closely the interest rate sensitivity of its assets (both advances and investments), and/or to adjust the interest rate sensitivity of advances or investments to approximate more closely the interest rate sensitivity of its liabilities. In addition to using interest rate exchange agreements to manage mismatches between the coupon features of its assets and liabilities, the Bank also uses interest rate exchange agreements to, among other things, manage embedded options in assets and liabilities, to preserve the market value of existing assets and liabilities, to hedge the duration risk of prepayable instruments, to hedge the variable cash flows associated with forecasted transactions, to offset interest rate exchange agreements entered into with members (the Bank serves as an intermediary in these transactions), and to reduce funding costs. The Bank, consistent with Finance Agency regulations, enters into interest rate exchange agreements only to reduce potential market risk exposures inherent in otherwise unhedged assets and liabilities or anticipated transactions, or to act as an intermediary between its members and the Bank’s non-member derivative counterparties. The Bank is not a derivatives dealer and it does not trade derivatives for short-term profit. At inception, the Bank formally documents the relationships between derivatives designated as hedging instruments and their hedged items, its risk management objectives and strategies for undertaking the hedge transactions, and its method for assessing the effectiveness of the hedging relationships. For fair value hedges, this process includes linking the derivatives to: (1) specific assets and liabilities on the statements of condition or (2) firm commitments. For cash flow hedges, this process includes linking the derivatives to forecasted transactions. The Bank also formally assesses (both at the inception of the hedging relationship and on a monthly basis thereafter) whether the derivatives that are used in hedging transactions have been effective in offsetting changes in the fair value of hedged items or the cash flows associated with forecasted transactions and whether those derivatives may be expected to remain effective in future periods. The Bank uses regression analyses to assess the effectiveness of its hedges. Investment Securities and Mortgage Loans Held for Portfolio — The Bank has invested in agency and non-agency MBS and residential mortgage loans. The interest rate and prepayment risk associated with these investments is managed through consolidated obligations and/or derivatives. The Bank may manage prepayment and duration risk presented by some of these investments with either callable and/or non-callable consolidated obligations and/or interest rate exchange agreements, including interest rate swaps, swaptions and caps. A substantial portion of the Bank’s held-to-maturity securities are variable-rate MBS that include caps that would limit the variable-rate coupons if short-term interest rates rise dramatically. To hedge a portion of the potential cap risk embedded in these securities, the Bank has entered into interest rate cap agreements, only one of which remained outstanding at December 31, 2019 . These derivatives are treated as economic hedges. All of the Bank's available-for-sale securities are fixed-rate agency and other highly rated debentures and agency CMBS. To hedge the interest rate risk associated with these fixed-rate investment securities, the Bank has entered into fixed-for-floating interest rate exchange agreements, which are designated as fair value hedges. The majority of the Bank's trading securities are fixed-rate U.S. Treasury Notes. To convert most of these fixed-rate investment securities to a short-term floating rate, the Bank entered into fixed-for-floating interest rate exchange agreements that are indexed to the OIS rate. These derivatives are treated as economic hedges. The interest rate swaps and swaptions that are used by the Bank to hedge the risks associated with its mortgage loan portfolio are treated as economic hedges. Advances — The Bank issues both fixed-rate and variable-rate advances. When appropriate, the Bank uses interest rate exchange agreements to adjust the interest rate sensitivity of its fixed-rate advances to approximate more closely the interest rate sensitivity of its liabilities. With issuances of putable advances, the Bank purchases from the member a put option that enables the Bank to terminate a fixed-rate advance on specified future dates. This embedded option is clearly and closely related to the host advance contract. The Bank typically hedges a putable advance by entering into a cancelable interest rate exchange agreement where the Bank pays a fixed-rate coupon and receives a variable-rate coupon, and sells an option to cancel the swap to the swap counterparty. This type of hedge is treated as a fair value hedge. The swap counterparty can cancel the interest rate exchange agreement on the call date and the Bank can cancel the putable advance and offer, subject to certain conditions, replacement funding at prevailing market rates. From time to time, a small portion of the Bank’s variable-rate advances may be subject to interest rate caps that would limit the variable-rate coupons if short-term interest rates rise above a predetermined level. To hedge the cap risk embedded in these advances, the Bank will generally enter into interest rate cap agreements. This type of hedge is treated as a fair value hedge. The Bank may hedge a firm commitment for a forward-starting advance through the use of an interest rate swap. In this case, the swap will function as the hedging instrument for both the firm commitment and the subsequent advance. The carrying value of the firm commitment will be included in the basis of the advance at the time the commitment is terminated and the advance is issued. The basis adjustment will then be amortized into interest income over the life of the advance. The Bank enters into optional advance commitments with its members. In an optional advance commitment, the Bank sells an option to the member that provides the member with the right to increase the amount of an existing advance at a specified fixed rate and term on a specified future date, provided the member has satisfied all of the customary requirements for such advance. This embedded option is clearly and closely related to the host contract. The Bank may hedge an optional advance commitment through the use of an interest rate swaption. In this case, the swaption will function as the hedging instrument for both the commitment and, if the option is exercised by the member, the subsequent advance. These swaptions are treated as fair value hedges. Consolidated Obligations — While consolidated obligations are the joint and several obligations of the FHLBanks, each FHLBank is the primary obligor for the consolidated obligations it has issued or assumed from another FHLBank. The Bank generally enters into derivative contracts to hedge the interest rate risk associated with its specific debt issuances. To manage the interest rate risk of certain of its consolidated obligations, the Bank will match the cash outflow on a consolidated obligation with the cash inflow of an interest rate exchange agreement. With issuances of fixed-rate consolidated obligation bonds, the Bank typically enters into a matching interest rate exchange agreement in which the counterparty pays fixed cash flows to the Bank that are designed to mirror in timing and amount the cash outflows the Bank pays on the consolidated obligation. In this transaction, the Bank pays a variable cash flow that closely matches the interest payments it receives on short-term or variable-rate assets, typically one-month or three-month LIBOR. These transactions are treated as fair value hedges. On occasion, the Bank may enter into fixed-for-floating interest rate exchange agreements to hedge the interest rate risk associated with certain of its consolidated obligation discount notes. The derivatives associated with the Bank’s fair value discount note hedging are indexed to the OIS rate and are treated as economic hedges. The Bank may also use interest rate exchange agreements to convert variable-rate consolidated obligation bonds from one index rate (e.g., the daily effective federal funds rate) to another index rate (e.g., one-month or three-month LIBOR). These transactions are treated as economic hedges. The Bank has not issued consolidated obligations denominated in currencies other than U.S. dollars. Forecasted Issuances of Consolidated Obligations — The Bank uses derivatives to hedge the variability of cash flows over a specified period of time as a result of the forecasted issuances and maturities of short-term, fixed-rate instruments, such as three-month consolidated obligation discount notes. Although each short-term consolidated obligation discount note has a fixed rate of interest, a portfolio of rolling consolidated obligation discount notes effectively has a variable interest rate. The variable cash flows associated with these liabilities are converted to fixed-rate cash flows by entering into receive-variable, pay-fixed interest rate swaps. The maturity dates of the cash flow streams are closely matched to the interest rate reset dates of the derivatives. These derivatives are treated as cash flow hedges. Balance Sheet Management — From time to time, the Bank may enter into interest rate basis swaps to reduce its exposure to changing spreads between one-month and three-month LIBOR. In addition, to reduce its exposure to reset risk, the Bank may occasionally enter into forward rate agreements. These derivatives are treated as economic hedges. Intermediation — The Bank offers interest rate swaps, caps and floors to its members to assist them in meeting their hedging needs. In these transactions, the Bank acts as an intermediary for its members by entering into an interest rate exchange agreement with a member and then entering into an offsetting interest rate exchange agreement with one of the Bank’s approved derivative counterparties. All interest rate exchange agreements related to the Bank’s intermediary activities with its members are accounted for as economic hedges. Other — From time to time, the Bank may enter into derivatives to hedge risks to its earnings that are not directly linked to specific assets, liabilities or forecasted transactions. These derivatives are treated as economic hedges. Impact of Derivatives and Hedging Activities. The following table summarizes the notional balances and estimated fair values of the Bank’s outstanding derivatives (inclusive of variation margin on daily settled contracts) and the amounts offset against those values in the statement of condition at December 31, 2019 and 2018 (in thousands). December 31, 2019 December 31, 2018 Notional Amount of Derivatives Estimated Fair Value Notional Amount of Derivatives Estimated Fair Value Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments under ASC 815 Interest rate swaps Advances (1) $ 10,102,510 $ 5,117 $ 134,520 $ 7,171,033 $ 4,273 $ 36,521 Available-for-sale securities (1) 16,114,507 28,049 19,718 15,981,523 8,501 55,202 Consolidated obligation bonds (1) 19,861,615 14,000 13,619 19,824,055 21,112 130,806 Consolidated obligation discount notes (2) 1,043,000 2,503 — 865,000 — 2,480 Total derivatives designated as hedging instruments under ASC 815 47,121,632 49,669 167,857 43,841,611 33,886 225,009 Derivatives not designated as hedging instruments under ASC 815 Interest rate swaps Advances 255,000 25 16 2,500 — — Available-for-sale securities 3,144 4 — 3,156 — 10 Mortgage loans held for portfolio 339,600 343 1,118 150,600 158 198 Consolidated obligation discount notes 1,000,000 — — — — — Trading securities 3,700,000 171 8 1,713,000 5 39 Intermediary transactions 842,036 5,312 2,355 1,228,345 3,742 6,245 Other 925,000 328 1,069 425,000 1,425 — Interest rate swaptions related to mortgage loans held for portfolio 145,000 381 — 185,000 1,234 — Mortgage delivery commitments 31,765 94 — 11,687 62 — Interest rate caps and floors Held-to-maturity securities 500,000 — — 1,000,000 6 — Intermediary transactions 80,000 12 12 541,000 3,178 3,178 Total derivatives not designated as hedging instruments under ASC 815 7,821,545 6,670 4,578 5,260,288 9,810 9,670 Total derivatives before collateral and netting adjustments $ 54,943,177 56,339 172,435 $ 49,101,899 43,696 234,679 Cash collateral and related accrued interest (3,440 ) (156,903 ) (9,287 ) (164,237 ) Cash received or remitted in excess of variation margin requirements (5 ) (54 ) (93 ) (13 ) Netting adjustments (11,623 ) (11,623 ) (24,438 ) (24,438 ) Total collateral and netting adjustments (3) (15,068 ) (168,580 ) (33,818 ) (188,688 ) Net derivative balances reported in statements of condition $ 41,271 $ 3,855 $ 9,878 $ 45,991 ________________________________________ (1) Derivatives designated as fair value hedges. (2) Derivatives designated as cash flow hedges. (3) Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as any cash collateral held or placed with those same counterparties. The following table presents the components of net gains (losses) on qualifying fair value and cash flow hedging relationships for the years ended December 31, 2019, 2018 and 2017 (in thousands). Interest Income (Expense) Advances Available-for-Sale Securities Consolidated Obligation Bonds Consolidated Obligation Discount Notes Net Gains (Losses) on Derivatives and Hedging Activities Other Comprehensive Income (Loss) Year Ended December 31, 2019 Total amount of the financial statement line item $ 906,671 $ 465,023 $ (711,240 ) $ (780,165 ) $ 24,687 $ (28,952 ) Gains (losses) on fair value hedging relationships included in the financial statement line item Interest rate contracts Derivatives $ (122,094 ) $ (760,621 ) $ 212,198 $ — $ — $ — Hedged items 170,055 796,381 (245,307 ) — — — Net gains (losses) on fair value hedging relationships $ 47,961 $ 35,760 $ (33,109 ) $ — $ — $ — Gains (losses) on cash flow hedging relationships included in the financial statement line item Interest rate contracts Reclassified from AOCI into interest expense $ — $ — $ — $ 1,829 $ — $ (1,829 ) Recognized in OCI — — — — — (54,777 ) Net gains (losses) on cash flow hedging relationships $ — $ — $ — $ 1,829 $ — $ (56,606 ) Year Ended December 31, 2018 (1) Total amount of the financial statement line item $ 828,929 $ 417,793 $ (659,943 ) $ (560,824 ) $ (10,256 ) $ (92,325 ) Gains (losses) on fair value hedging relationships included in the financial statement line item Interest rate contracts Derivatives $ 17,492 $ 22,474 $ (39,478 ) $ — $ 120,825 $ — Hedged items (2) — — — — (119,003 ) — Net gains (losses) on fair value hedging relationships $ 17,492 $ 22,474 $ (39,478 ) $ — $ 1,822 $ — Gains (losses) on cash flow hedging relationships included in the financial statement line item Interest rate contracts Reclassified from AOCI into interest expense $ — $ — $ — $ 950 $ — $ (950 ) Recognized in OCI — — — — — (823 ) Net gains (losses) on cash flow hedging relationships $ — $ — $ — $ 950 $ — $ (1,773 ) Year Ended December 31, 2017 (1) Total amount of the financial statement line item $ 421,588 $ 239,193 $ (327,644 ) $ (233,698 ) $ 4,668 $ 157,116 Gains (losses) on fair value hedging relationships included in the financial statement line item Interest rate contracts Derivatives $ (31,950 ) $ (104,042 ) $ 39,831 $ — $ 99,962 $ — Hedged items (2) — — — — (103,398 ) — Net gains (losses) on fair value hedging relationships $ (31,950 ) $ (104,042 ) $ 39,831 $ — $ (3,436 ) $ — Gains (losses) on cash flow hedging relationships included in the financial statement line item Interest rate contracts Reclassified from AOCI into interest expense $ — $ — $ — $ (2,375 ) $ — $ 2,375 Recognized in OCI — — — — — (2,570 ) Net losses on cash flow hedging relationships $ — $ — $ — $ (2,375 ) $ — $ (195 ) _____________________________ (1) Prior year amounts have not been reclassified to conform to the new hedge accounting presentation requirements which became effective on January 1, 2019. (2) Excludes amortization/accretion on closed fair value relationships. For the years ended December 31, 2019, 2018 and 2017, there were no amounts reclassified from AOCI into earnings as a result of the discontinuance of cash flow hedges because the original forecasted transactions occurred by the end of the originally specified time periods or within two-month periods thereafter. At December 31, 2019, $5,346,000 of deferred net losses on derivative instruments in AOCI are expected to be reclassified to earnings during the next 12 months. At December 31, 2019, the maximum length of time over which the Bank is hedging its exposure to the variability in future cash flows for forecasted transactions is 10 years. The following table presents the cumulative basis adjustments on hedged items either designated or previously designated as fair value hedges and the related amortized cost of those items as of December 31, 2019 (in thousands). Line Item in Statement of Condition of Hedged Item Amortized Cost of Hedged Asset/(Liability) (1) Basis Adjustments for Active Hedging Relationships Included in Amortized Cost Basis Adjustments for Discontinued Hedging Relationships Included in Amortized Cost Total Fair Value Hedging Basis Adjustments (2) Advances $ 10,283,221 $ 175,343 $ 4,978 $ 180,321 Available-for-sale securities 16,621,667 346,741 (985 ) 345,756 Consolidated obligation bonds (20,310,223 ) (64,027 ) (1,654 ) (65,681 ) _____________________________ (1) Reflects the amortized cost of hedged items in active or discontinued fair value hedging relationships, which includes fair value hedging basis adjustments. (2) Reflects the cumulative life-to-date unamortized hedging gains (losses) on the hedged items. The following table presents the components of net gains (losses) on derivatives and hedging activities that are reported in other income (loss) for the years ended December 31, 2019, 2018 and 2017 (in thousands). Gain (Loss) Recognized in Other Income (Loss) for the Year Ended December 31, 2019 2018 2017 Derivatives and hedged items in ASC 815 fair value hedging relationships (1) Interest rate swaps $ — $ 1,866 $ (3,414 ) Interest rate swaptions — (44 ) (22 ) Total net gain (loss) related to fair value hedge ineffectiveness — 1,822 (3,436 ) Derivatives not designated as hedging instruments under ASC 815 Net interest income (expense) on interest rate swaps (3,414 ) (1,389 ) 1,535 Interest rate swaps 28,408 (2,586 ) 3,730 Interest rate swaptions (2,728 ) (239 ) — Interest rate caps and floors 86 116 (255 ) Mortgage delivery commitments 2,097 1,912 2,329 Total net gain (loss) related to derivatives not designated as hedging instruments under ASC 815 24,449 (2,186 ) 7,339 Price alignment amount on variation margin for daily settled derivative contracts (2) 238 (9,892 ) 765 Net gains (losses) on derivatives and hedging activities reported in other income (loss) $ 24,687 $ (10,256 ) $ 4,668 _____________________________ (1) For the year ended December 31, 2019, all of the effects of derivatives and associated hedged items in ASC 815 fair value hedging relationships are reported in net interest income. (2) The amounts reported for the year ended December 31, 2019 reflect the price alignment amounts on variation margin for daily settled derivative contracts that are not designated as hedging instruments under ASC 815. The price alignment amounts on variation margin for daily settled derivative contracts that are designated as hedging instruments under ASC 815 are recorded in the same line item as the earnings effect of the hedged item. The amounts reported for the years ended December 31, 2018 and 2017 reflect the price alignment amounts on variation margin for all daily settled derivative contracts. Credit Risk Related to Derivatives. The Bank is subject to credit risk due to the risk of nonperformance by counterparties to its derivative agreements. The Bank manages derivative counterparty credit risk through the use of master netting agreements or other similar collateral exchange arrangements, credit analysis, and adherence to the requirements set forth in the Bank’s Enterprise Market Risk Management Policy, Enterprise Credit Risk Management Policy and Finance Agency regulations. The majority of the Bank's derivative transactions have been cleared through third-party central clearinghouses (as of December 31, 2019 , the notional balance of cleared transactions outstanding totaled $33.7 billion ). With cleared transactions, the Bank is exposed to credit risk in the event that the clearinghouse or the clearing member fails to meet its obligations to the Bank. The remainder of the Bank's derivative contracts have been transacted bilaterally with large financial institutions under master netting agreements or, to a much lesser extent, with member institutions (as of December 31, 2019 , the notional balance of outstanding transactions with non-member bilateral counterparties and member counterparties totaled $20.7 billion and $0.5 billion , respectively). Some of these institutions (or their affiliates) buy, sell, and distribute consolidated obligations. The notional amount of the Bank's interest rate exchange agreements does not reflect its credit risk exposure, which is much less than the notional amount. The Bank's net credit risk exposure is based on the current estimated cost, on a present value basis, of replacing at current market rates all interest rate exchange agreements with individual counterparties, if those counterparties were to default, after taking into account the value of any cash and/or securities collateral held or remitted by the Bank. For counterparties with which the Bank is in a net gain position, the Bank has credit exposure when the collateral it is holding (if any) has a value less than the amount of the gain. For counterparties with which the Bank is in a net loss position, the Bank has credit exposure when it has delivered collateral with a value greater than the amount of the loss position. The net exposure on derivative agreements is presented in Note 12. Based on the netting provisions and collateral requirements associated with its derivative agreements and the creditworthiness of its derivative counterparties, Bank management does not currently anticipate any credit losses on its derivative agreements. |
