Federal Home Loan Bank of Indianapolis 10-K 9 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 28, 2018
Document and Entity Information [Line Items]
Entity Registrant Name	Federal Home Loan Bank of Indianapolis
Entity Central Index Key	1,331,754
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		20,395,278
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float	$ 0

Statements of Condition

Statements of Condition - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks (Note 3)	$ 55,269	$ 546,612
Interest-bearing deposits	660,342	150,225
Securities purchased under agreements to resell	2,605,460	1,781,309
Federal funds sold	1,280,000	1,650,000
Available-for-sale securities (Notes 4 and 6)	7,128,758	6,059,835
Held-to-maturity securities (estimated fair values of $5,919,299 and $5,848,692, respectively) (Notes 5 and 6)	5,897,668	5,819,573
Advances (Note 7)	34,055,064	28,095,953
Mortgage loans held for portfolio, net of allowance for loan losses of $(850) and $(850), respectively (Notes 8 and 9)	10,356,341	9,501,397
Accrued interest receivable	105,314	93,716
Premises, software, and equipment, net (Note 10)	36,795	37,638
Derivative assets, net (Note 11)	128,206	134,848
Other assets	39,689	36,294
Total assets	62,348,906	53,907,400
Liabilities:
Deposits (Note 12)	564,799	524,073
Consolidated obligations (Note 13):
Discount notes	20,358,157	16,801,763
Bonds	37,895,653	33,467,279
Total consolidated obligations, net	58,253,810	50,269,042
Accrued interest payable	135,691	98,411
Affordable Housing Program payable (Note 14)	32,166	26,598
Derivative liabilities, net (Note 11)	2,718	25,225
Mandatorily redeemable capital stock (Note 15)	164,322	170,043
Other liabilities	249,894	357,812
Total liabilities	59,403,400	51,471,204
Commitments and contingencies (Note 20)
Capital stock (putable at par value of $100 per share):
Total capital stock	1,857,766	1,492,581
Retained earnings:
Unrestricted	792,783	734,982
Restricted	183,551	152,265
Total retained earnings	976,334	887,247
Total accumulated other comprehensive income (Note 16)	111,406	56,368
Total capital	2,945,506	2,436,196
Total liabilities and capital	62,348,906	53,907,400
Class B-1 issued and outstanding shares: 18,566,388 and 14,897,390, respectively
Capital stock (putable at par value of $100 per share):
Total capital stock	1,856,639	1,489,739
Class B-2 issued and outstanding shares: 11,271 and 28,416, respectively
Capital stock (putable at par value of $100 per share):
Total capital stock	$ 1,127	$ 2,842

Statements of Condition Parenth

Statements of Condition Parenthetical - USD ($)	Dec. 31, 2017	Dec. 31, 2016
HTM Securities, Fair Value	$ 5,919,299,000	$ 5,848,692,000
Allowance for credit losses	$ (850,000)	$ (850,000)
Common Stock Putable, Par Value Per Share	$ 100	$ 100
Subclass B1 [Member]
Common Stock, Shares, Issued	18,566,388	14,897,390
Common Stock, Shares, Outstanding	18,566,388	14,897,390
Subclass B2 [Member]
Common Stock, Shares, Issued	11,271	28,416
Common Stock, Shares, Outstanding	11,271	28,416

Statements of Income

Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income:
Advances	$ 404,494	$ 219,061	$ 126,216
Prepayment fees on advances, net	1,369	477	696
Interest-bearing deposits	3,397	808	217
Securities purchased under agreements to resell	6,144	6,481	1,534
Federal funds sold	44,054	10,494	2,821
Available-for-sale securities	121,049	69,106	32,858
Held-to-maturity securities	119,347	112,959	115,752
Mortgage loans held for portfolio	314,827	274,343	264,199
Other interest income (loss), net	1,955	1,162	(570)
Total interest income	1,016,636	694,891	543,723
Interest Expense:
Consolidated obligation discount notes	182,104	64,370	19,750
Consolidated obligation bonds	559,711	425,006	327,932
Deposits	4,784	709	94
Mandatorily redeemable capital stock	7,034	6,613	522
Other interest expense	0	0	0
Total interest expense	753,633	496,698	348,298
Net interest income	263,003	198,193	195,425
Provision for (reversal of) credit losses	51	(45)	(456)
Net interest income after provision for credit losses	262,952	198,238	195,881
Other Income (Loss):
Total other-than-temporary impairment losses	0	0	0
Non-credit portion reclassified to (from) other comprehensive income, net	(207)	(197)	(61)
Net other-than-temporary impairment losses, credit portion	(207)	(197)	(61)
Net gains (losses) on derivatives and hedging activities	(9,258)	2,272	2,832
Service fees	947	1,200	967
Standby letters of credit fees	747	736	657
Other, net (Note 20)	1,775	1,647	6,086
Total other income (loss)	(5,996)	5,658	10,481
Other Expenses:
Compensation and benefits	47,631	45,647	42,307
Other operating expenses	26,349	24,945	22,382
Federal Housing Finance Agency	3,328	2,955	2,703
Office of Finance	3,687	3,020	3,118
Other	1,367	1,032	1,384
Total other expenses	82,362	77,599	71,894
Income before assessments	174,594	126,297	134,468
Affordable Housing Program assessments	18,163	13,291	13,499
Net income	$ 156,431	$ 113,006	$ 120,969

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 156,431	$ 113,006	$ 120,969
Other Comprehensive Income (Loss):
Net change in unrealized gains (losses) on available-for-sale securities	53,051	39,371	(15,981)
Non-credit portion of other-than-temporary impairment losses on available-for-sale securities:
Net non-credit portion of other-than-temporary impairment losses on available-for-sale securities	2,384	(3,291)	(7,943)
Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities:
Net non-credit portion of other-than-temporary impairment losses on held-to-maturity securities	52	29	43
Pension benefits, net (Note 17)	(449)	(2,619)	99
Total other comprehensive income (loss)	55,038	33,490	(23,782)
Total comprehensive income	$ 211,469	$ 146,496	$ 97,187

Statements of Capital

Statements of Capital - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 2,436,196	$ 2,385,797	$ 2,375,270
Total comprehensive income	211,469	146,496	97,187
Proceeds from issuance of capital stock	365,185	147,831	217,160
Repurchase/redemption of capital stock			(240,335)
Shares reclassified (to) from mandatorily redeemable capital stock, net	0	(183,056)	0
Distributions on mandatorily redeemable capital stock		(1,072)
Cash dividends on capital stock	(67,344)	(59,800)	(63,485)
Ending Balance	2,945,506	2,436,196	2,385,797
Capital Stock Class B Putable [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 1,492,581	$ 1,527,806	$ 1,550,981
Beginning Balance, Shares	14,926	15,278	15,510
Proceeds from issuance of capital stock	$ 365,185	$ 147,831	$ 217,160
Proceeds from issuance of capital stock, shares	3,652	1,478	2,171
Repurchase/redemption of capital stock			$ (240,335)
Repurchase/redemption of capital stock, shares			(2,403)
Shares reclassified (to) from mandatorily redeemable capital stock, net	$ 0	$ (183,056)
Shares reclassified to mandatorily redeemable capital stock, shares		(1,830)
Ending Balance	$ 1,857,766	$ 1,492,581	$ 1,527,806
Ending Balance, Shares	18,578	14,926	15,278
Retained Earnings, Unrestricted [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 734,982	$ 705,449	$ 672,159
Total comprehensive income	125,145	90,405	96,775
Distributions on mandatorily redeemable capital stock		(1,072)
Cash dividends on capital stock	(67,344)	(59,800)	(63,485)
Ending Balance	792,783	734,982	705,449
Retained Earnings, Restricted [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	152,265	129,664	105,470
Total comprehensive income	31,286	22,601	24,194
Distributions on mandatorily redeemable capital stock		0
Cash dividends on capital stock	0	0	0
Ending Balance	183,551	152,265	129,664
Retained Earnings Total [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	887,247	835,113	777,629
Total comprehensive income	156,431	113,006	120,969
Distributions on mandatorily redeemable capital stock		(1,072)
Cash dividends on capital stock	(67,344)	(59,800)	(63,485)
Ending Balance	976,334	887,247	835,113
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	56,368	22,878	46,660
Total comprehensive income	55,038	33,490	(23,782)
Ending Balance	$ 111,406	$ 56,368	$ 22,878

Statements of Capital Parenthet

Statements of Capital Parenthetical	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Annualized cash dividend rate on capital stock (percent)	4.25%	4.25%	4.12%

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Net income		$ 156,431	$ 113,006	$ 120,969
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and depreciation		69,111	57,040	52,556
Prepayment fees on advances, net of related swap termination fees		0	(526)	(2,508)
Changes in net derivative and hedging activities		(13,643)	22,701	56,171
Net other-than-temporary impairment losses, credit portion		207	197	61
Provision for (reversal of) credit losses		51	(45)	(456)
Changes in:
Accrued interest receivable		(11,783)	(5,541)	(5,650)
Other assets		(1,867)	(2,674)	(5,853)
Accrued interest payable		37,343	16,597	4,802
Other liabilities		27,890	38,187	30,702
Total adjustments, net		107,309	125,936	129,825
Net cash provided by operating activities		263,740	238,942	250,794
Net change in:
Interest-bearing deposits		(464,287)	(39,205)	55,309
Securities purchased under agreements to resell		(824,151)	(1,781,309)	0
Federal funds sold		370,000	(1,650,000)	0
Available-for-sale Securities [Abstract]
Proceeds from maturities		1,041,227	855,927	82,567
Purchases		(2,213,866)	(2,906,310)	(635,954)
Held-to-maturity securities:
Proceeds from maturities		1,245,438	1,351,512	1,577,327
Purchases		(1,325,424)	(983,718)	(802,687)
Advances:
Principal repayments		280,448,048	146,368,448	96,180,660
Disbursements to members		(286,485,558)	(147,692,939)	(102,357,927)
Mortgage loans held for portfolio:
Principal collections		1,245,983	1,701,633	1,323,072
Purchases from members		(2,144,552)	(3,074,847)	(2,663,395)
Purchases of premises, software, and equipment		(5,176)	(4,957)	(4,494)
Loans to other Federal Home Loan Banks:
Principal repayments		100,000	300,000	0
Payments From Loans to Other Federal Home Loan Banks		(100,000)	(300,000)	0
Net cash used in investing activities		(9,112,318)	(7,855,765)	(7,245,522)
Net Change In:
Changes in deposits		73,891	22,268	(528,048)
Net payments on derivative contracts with financing elements		(16,683)	(32,898)	(57,828)
Net proceeds from issuance of consolidated obligations:
Discount notes		216,011,184	331,383,919	101,485,730
Bonds		23,856,245	31,636,349	22,234,991
Payments for matured and retired consolidated obligations:
Discount notes		(212,480,262)	(333,840,103)	(94,808,634)
Bonds		(19,379,260)	(25,997,585)	(19,862,550)
Loans from other Federal Home Loan Banks:
Proceeds from issuance of capital stock		365,185	147,831	217,160
Payments for redemption/repurchase of mandatorily redeemable capital stock		(5,721)	(28,148)	(1,610)
Payments for redemption/repurchase of capital stock		0	0	(240,335)
Dividend payments on capital stock		(67,344)	(59,800)	(63,485)
Net cash provided by financing activities		8,357,235	3,231,833	8,375,391
Net increase (decrease) in cash and due from banks		(491,343)	(4,384,990)	1,380,663
Cash and due from banks at beginning of year		546,612	4,931,602	3,550,939
Cash and due from banks at end of year		55,269	546,612	4,931,602
Supplemental Disclosures:
Interest payments		525,403	415,261	321,227
Purchases of securities, traded but not yet settled		0	120,266	179,580
Affordable Housing Program payments	[1]	12,595	17,796	19,295
Capitalized interest on certain held-to-maturity securities		3,282	975	1,483
Net Shares Reclassified to Mandatorily Redeemable Capital Stock, Value		$ 0	$ 183,056	$ 0
[1]	(1) Subsidies disbursed are reported net of returns/recaptures of previously disbursed subsidies.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	These Notes to Financial Statements should be read in conjunction with the Statements of Condition as of December 31, 2017 and 2016 , and the Statements of Income, Comprehensive Income, Capital, and Cash Flows for the years ended December 31, 2017 , 2016 , and 2015 . We use acronyms and terms throughout these Notes to Financial Statements that are defined herein or in the Glossary of Terms . Unless the context otherwise requires, the terms "Bank," "we," "us," and "our" refer to the Federal Home Loan Bank of Indianapolis or its management. Background Information The Federal Home Loan Bank of Indianapolis, a federally chartered corporation, is one of 11 regional wholesale FHLBanks in the United States. The FHLBanks are GSEs that serve the public by enhancing the availability of credit for residential mortgages and targeted community development. Even though we are part of the FHLBank System, we operate as a separate entity with our own management, employees and board of directors. Each FHLBank is a financial cooperative that provides a readily available, competitively-priced source of funds to its member institutions. Regulated financial depositories and non-captive insurance companies engaged in residential housing finance that have their principal place of business located in, or are domiciled in, our district states of Michigan or Indiana are eligible for membership in our Bank. Additionally, qualified CDFIs are eligible to be members. Housing Associates, including state and local housing authorities, that meet certain statutory and regulatory criteria may also borrow from us. While eligible to borrow, Housing Associates are not members and, as such, are not allowed to hold our capital stock. Each member must purchase a minimum amount of our capital stock based on the amount of its total mortgage assets. A member may be required to purchase additional activity-based capital stock as it engages in certain business activities with us. Members and former members own all of our capital stock. Former members (including certain non-member institutions that own our capital stock as a result of a merger with or acquisition of a member) hold our capital stock solely to support credit products or mortgage loans still outstanding on our statement of condition. All owners of our capital stock, to the extent declared by our board of directors, receive dividends on their capital stock, subject to the applicable regulations as discussed in Note 15 - Capital . See Note 21 - Related Party and Other Transactions for more information about transactions with related parties. The FHLBanks' Office of Finance was established to facilitate the issuance and servicing of the debt instruments of the FHLBanks, known as consolidated obligations, consisting of bonds and discount notes, and to prepare and publish the FHLBanks' combined quarterly and annual financial reports. Consolidated obligations are the primary source of funds for the FHLBanks. Deposits, other borrowings and capital stock sold to members provide additional funds. We primarily use these funds to: • disburse advances to members; • acquire mortgage loans from PFIs through our MPP; • maintain liquidity; and • invest in other opportunities to support the residential housing market. We also provide correspondent services, such as wire transfer, security safekeeping, and settlement services, to our members. The Finance Agency is the independent federal regulator of the FHLBanks, Freddie Mac, and Fannie Mae. The Finance Agency's stated mission is to ensure that the housing GSEs operate in a safe and sound manner so that they serve as a reliable source of liquidity and funding for housing finance and community investment. Note 1 - Summary of Significant Accounting Policies Basis of Presentation. The accompanying financial statements have been prepared in accordance with GAAP and SEC requirements. The financial statements contain all adjustments that are, in the opinion of management, necessary for a fair statement of our financial position, results of operations and cash flows for the periods presented. All such adjustments were of a normal recurring nature. Use of Estimates. When preparing financial statements in accordance with GAAP, we are required to make subjective assumptions and estimates that may affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of income and expense. The most significant estimates pertain to derivatives and hedging activity, fair value, the provision for credit losses, and OTTI. Although the reported amounts and disclosures reflect our best estimates, actual results could differ significantly from these estimates. Estimated Fair Value. The estimated fair value amounts, recorded on the statement of condition and presented in the accompanying disclosures, have been determined based on the assumptions that we believe market participants would use in pricing the asset or liability and reflect our best judgment of appropriate valuation methods. Although we use our best judgment in estimating fair value, there are inherent limitations in any valuation technique. Therefore, these estimated fair values may not be indicative of the amounts that would have been realized in market transactions on the reporting dates. See Note 19 - Estimated Fair Values for more information. Reclassifications. We have reclassified certain amounts from the prior period to conform to the current period presentation. These reclassifications had no effect on total assets, total liabilities, total capital, net income, total comprehensive income or net cash flows. Interest-Bearing Deposits, Securities Purchased under Agreements to Resell, and Federal Funds Sold. These investments provide short-term liquidity and are carried at cost. Interest-bearing deposits may include certificates of deposit and bank notes not meeting the definition of a security. Securities purchased under agreements to resell are considered short-term collateralized financings. These securities are held in safekeeping in our name by third-party custodians approved by us. If the market value of the underlying assets declines below the market value required as collateral, the counterparty must (i) place an equivalent amount of additional securities in safekeeping in our name, and/or (ii) remit an equivalent amount of cash, or the dollar value of the resale agreement will be reduced accordingly. Federal funds sold consist of short-term, unsecured loans made to investment-grade counterparties. Investment Securities. Purchases and sales of securities are recorded on a trade date basis. We classify investments as trading, HTM or AFS at the date of acquisition. We did not have any investments classified as trading during the years ended December 31, 2017 , 2016 or 2015 . HTM Securities. Securities for which we have both the positive intent and ability to hold to maturity are classified as HTM. The carrying value includes adjustments made to the cost basis of the security for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses) and OCI (non-credit losses). Certain changes in circumstances may cause us to change our intent to hold a particular security to maturity without necessarily calling into question our intent to hold other debt securities to maturity. Thus, the sale or transfer of an HTM security due to certain changes in circumstances, such as evidence of significant deterioration in the issuer's creditworthiness or changes in regulatory requirements, is not considered to be inconsistent with its original classification. Other isolated, non-recurring, and unusual events, which could not have been reasonably anticipated, may also cause us to sell or transfer an HTM security without necessarily calling into question our intent to hold other debt securities to maturity. In addition, sales of HTM debt securities that meet either of the following two conditions may be considered as maturities for purposes of the classification of securities: (i) the sale occurs near enough to its maturity date (or call date, if exercise of the call is probable) that interest-rate risk is substantially eliminated as a pricing factor and any changes in market interest rates would not have a significant effect on the security's fair value, or (ii) the sale occurs after we have already collected a substantial portion (at least 85% ) of the principal outstanding at acquisition due either to prepayments or to scheduled payments payable in equal installments (both principal and interest) over its term. AFS Securities. Securities that have readily determinable fair values and are not classified as trading or HTM are classified as AFS and carried at estimated fair value. We record changes in the fair value of these securities in OCI as net change in unrealized gains (losses) on AFS securities, except for AFS securities that have been hedged and for which the hedging relationship qualifies as a fair-value hedge. For these securities, we record the portion of the change in fair value attributable to the risk being hedged in other income (loss) as net gains (losses) on derivatives and hedging activities together with the related change in the fair value of the derivative, and record the remainder of the change in the fair value of the securities in OCI. For AFS securities that are OTTI, changes in fair value, net of any credit loss, are recorded in OCI as the non-credit portion. Premiums and Discounts. We amortize purchased premiums and accrete purchased discounts on MBS and ABS at an individual security level using the retrospective level-yield method (retrospective interest method) over the estimated remaining cash flows of each security. This method requires that we estimate prepayments over the estimated life of the securities and make a retrospective adjustment of the effective yield each time we change the estimated remaining cash flows of the securities as if the new estimates had been used since the acquisition date. Changes in interest rates are a significant assumption used in prepayment speed estimates. We amortize purchased premiums and accrete purchased discounts on all other investment securities at an individual security level using a contractual level-yield methodology, under which prepayments are only taken into account as they actually occur. Gains and Losses on Sales. We compute gains and losses on sales of investment securities using the specific identification method and include these gains and losses in other income (loss) as net realized gains from sale of securities. Investment Securities - Other-Than-Temporary Impairment. On a quarterly basis, we evaluate our individual AFS and HTM securities that have been previously OTTI or are in an unrealized loss position to determine if any such securities are OTTI. A security is in an unrealized loss position (i.e., impaired) when its estimated fair value is less than its amortized cost. We consider an impaired debt security to be OTTI under any of the following conditions: • we intend to sell the debt security; • based on available evidence, we believe it is more likely than not that we will be required to sell the debt security before the anticipated recovery of its remaining amortized cost; or • we do not expect to recover the entire amortized cost of the debt security. Recognition of OTTI. If either of the first two conditions above is met, we recognize an OTTI loss in earnings equal to the entire difference between the debt security's amortized cost and its estimated fair value as of the statement of condition date. For those impaired securities that meet neither of these two conditions, we perform a cash flow analysis to determine whether we expect to recover the entire amortized cost of each security. If the present value of the cash flows expected to be collected is less than the amortized cost of the debt security, a credit loss equal to that difference is recorded, and the carrying value of the debt security is adjusted to its estimated fair value. However, rather than recognizing the entire difference between the amortized cost and estimated 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 remaining amount, if any, related to all other factors (i.e., the non-credit component) is recognized in OCI. The credit loss on a debt security is capped at the amount of that security's unrealized loss. The new amortized cost basis of the OTTI security, which reflects the credit loss, will not be adjusted for any subsequent recoveries of fair value. The total OTTI loss is presented in other income (loss) with an offset for the portion recognized in OCI. The remaining amount represents the credit loss. Additional OTTI. Subsequent to any recognition of OTTI, if the present value of cash flows expected to be collected is less than the amortized cost basis (which reflects previous credit losses), we record an additional credit loss equal to that difference as additional OTTI. The total amount of additional OTTI (both credit and non-credit component, if any) is determined as the difference between the security's amortized cost, less the amount of OTTI recognized in AOCI prior to the determination of this additional OTTI, and its fair value. For certain AFS or HTM securities that were previously impaired and have subsequently incurred additional credit losses, an amount equal to the additional credit losses, up to the amount of non-credit losses remaining in AOCI, is reclassified out of AOCI and into other income (loss). Subsequent increases and decreases (if not an additional OTTI) in the estimated fair value of OTTI AFS securities are netted against the non-credit component of OTTI recognized previously in AOCI. For HTM securities, the OTTI in AOCI is accreted to the carrying value of each security on a prospective basis, based on the amount and timing of future projected cash flows (with no effect on earnings unless the security is subsequently sold, matures or additional OTTI is recognized). For debt securities classified as AFS, we do not accrete the OTTI in AOCI to the carrying value because the subsequent measurement basis for these securities is estimated fair value. Interest Income Recognition. As of the initial OTTI measurement date, a new accretable yield is calculated for the OTTI debt security. This yield is then used to calculate the portion of the credit losses included in the amortized cost of the security to be recognized into interest income each period over the remaining life of the security so as to match the amount and timing of future cash flows expected to be collected. On a quarterly basis, we re-evaluate the estimated cash flows and accretable yield. If there is no additional OTTI and there is either (i) a significant increase in the security's expected cash flows or (ii) a favorable change in the timing and amount of the security's expected cash flows, we adjust the accretable yield on a prospective basis. Variable Interest Entities. We do not have any special purpose entities or any other type of off-balance sheet conduits. We have investments in VIEs that consist of senior interests in private-label RMBS and ABS. The carrying amounts of the investments are included in HTM or AFS securities. We have no liabilities related to these VIEs. The maximum loss exposure on these VIEs is limited to our carrying value. On an annual basis, or more frequently as needed, we conduct an evaluation to determine whether we are the primary beneficiary of any VIE. To make this determination, we consider whether we possess both of the following characteristics: • the power to direct the VIE's activities that most significantly affect the VIE's economic performance; and • the obligation to absorb the VIE's losses, or the right to receive benefits from the VIE, that could potentially be significant to the VIE. Based on an evaluation of the above characteristics, we have determined that we are not the primary beneficiary of a VIE and, therefore, consolidation is not required for our investments in VIEs as of December 31, 2017 or 2016 . In addition, we have not provided financial or other support (explicitly or implicitly) to any VIE during the years ended December 31, 2017 , 2016 , or 2015 . Furthermore, we were not previously contractually required to provide, nor do we intend to provide, that support to any VIE in the future. Advances. We record advances at amortized cost, adjusted for unamortized premiums, discounts, prepayment fees and swap termination fees, unearned commitment fees, and fair-value hedging adjustments. We amortize/accrete premiums, discounts, hedging basis adjustments, deferred prepayment fees, and deferred swap termination fees, and recognize unearned commitment fees on advances, to interest income using a level-yield methodology. When an advance is prepaid, any remaining premium or discount is amortized at the time of prepayment. We record interest on advances to interest income as earned. Prepayment Fees. We charge a borrower a prepayment fee when the borrower repays certain advances prior to the original maturity. We report prepayment fees net of any swap termination fees and hedge accounting basis adjustments. Advance Modifications. When we fund a new advance concurrent with, or within a short period of time after, the prepayment of an original advance, we determine whether the transaction is effectively either (i) two separate transactions (the prepayment of an original advance and the disbursement of a new advance), defined as an advance extinguishment, or (ii) the continuation of the original advance as modified, defined as an advance modification. We account for the transaction as an extinguishment if both of the following criteria are met: (i) the effective yield of the new advance is at least equal to the effective yield for a comparable advance to a member with similar collection risks who is not prepaying, and (ii) modifications of the original advance are determined to be more than minor, i.e., if the present value of the cash flows under the terms of the new advance is at least 10% different from the present value of the remaining cash flows under the terms of the original advance or through an evaluation of qualitative factors which may include changes in the interest-rate exposure to the member by moving from a fixed to an adjustable rate advance. In all other instances, the transaction is accounted for as an advance modification. If the transaction is determined to be an advance extinguishment, we recognize income from nonrefundable prepayment fees, net of swap termination fees, in the period that the extinguishment occurs. Alternatively, if no prepayment fees are received (e.g., the member requests that we embed the prepayment fee into the rate of the new advance), the difference between the present value of the cash flows of the new advance and that of a current market rate advance of comparable terms is recognized in current income, and the basis of the new advance is adjusted accordingly. If the transaction is determined to be an advance modification, the income from nonrefundable prepayment fees, net of swap termination fees, associated with the modification of the original advance is not recognized in current income but is (i) included in the carrying value of the modified advance and amortized into interest income using a level-yield methodology when the prepayment fee is received up front or (ii) embedded into the rate of the modified advance and recorded as an adjustment to the interest accrual. If the modified advance is hedged in a qualifying hedge relationship, the modified advance is marked to fair value, and subsequent fair value changes attributable to the hedged risk are recorded in other income (loss). Mortgage Loans Held for Portfolio. We classify mortgage loans, for which we have 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 at cost, adjusted for premiums paid to and discounts received from PFIs, deferred loan fees or costs, hedging basis adjustments, and the allowance for loan losses. Premiums and Discounts. We defer and amortize/accrete premiums and discounts, certain loan fees or costs, and hedging basis adjustments to interest income using the contractual level-yield interest method. When a loan is prepaid, any remaining premium or discount is amortized to interest income in the period in which the loan is prepaid and derecognized. For partial prepayments, a proportionate share of any remaining premium or discount is amortized to interest income in the period in which the prepayment occurs. Non-accrual Loans. We place a conventional mortgage loan on non-accrual status if it is determined that either (i) the collection of interest or principal is doubtful, or (ii) interest or principal is past due for 90 days or more, except when the loan is well secured and in the process of collection (e.g., through credit enhancements and monthly servicer remittances on a scheduled/scheduled basis). Monthly servicer remittances on MPP loans on an actual/actual basis may also be well secured; however, servicers on actual/actual remittance do not advance principal and interest due until the payments are received from the borrower or when the loan is repaid. A government-guaranteed or -insured mortgage loan is not placed on non-accrual status when the collection of the contractual principal or interest is 90 days or more past due because of the contractual obligation of the loan servicer to pay defaulted interest at the contractual rate. For those mortgage loans placed on non-accrual status, accrued but uncollected interest is reversed against interest income (for any interest accrued in the current year) and/or the allowance for loan losses (for any interest accrued in the previous year). We record cash payments received on non-accrual loans as a direct reduction of the recorded investment in the loan. When the recorded investment has been fully collected, any additional amounts collected are recognized as interest income. A loan on non-accrual status may be restored to accrual status when it becomes current (zero days past due) and three consecutive and timely monthly payments have been made. REO. Our MPP was designed to require loan servicers to foreclose and liquidate in the servicer's name rather than in our name. Therefore, we do not take title to any foreclosed property or enter into any other legal agreement under which the borrower conveys all interest in the property to us to satisfy the loan. As the servicer progresses through the process from foreclosure to liquidation, we are paid in full for all unpaid principal and accrued interest on the loan through the normal remittance process. Upon full receipt, the mortgage loan is removed from our statement of condition. As a result of these factors, we do not classify as REO any foreclosed properties collateralizing MPP loans that were previously recorded on our statement of condition. Under the MPF Program, REO is recorded in other assets and includes assets that have been received in satisfaction of debt through foreclosures. REO is recorded at the lower of cost or fair value less estimated selling costs. We recognize 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 the transfer from mortgage loans to REO. Any subsequent gains, losses, and carrying costs are included in other expense. Loan Participations. We may sell participating interests in MPP loans acquired from our PFIs to other FHLBanks. The terms of the sale of these participating interests meet the accounting requirements for a sale and, therefore, the participating interests are de-recognized from our reported mortgage loan balances and a pro-rata portion of the fixed LRA is assumed by the participating FHLBank for its use in loss mitigation. As a result, available funds remaining in our LRA include our pro-rata portion only of the fixed LRA associated with the participating interests retained by us. The portion of the participation fees received related to our upfront costs is recognized immediately into income, while the remaining portion related to our ongoing costs is deferred and amortized to income over the remaining life of the loans. Allowance for Credit Losses. An allowance for credit losses is separately established for each identified portfolio segment if it is probable that impairment has occurred as of the statement of condition date and the amount of loss can be reasonably estimated. See Note 9 - Allowance for Credit Losses for details on each allowance methodology. Portfolio Segments. 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. We have developed and documented a systematic methodology for determining an allowance for credit losses, where applicable, for (i) credit products (advances, letters of credit, and other extensions of credit to members); (ii) term securities purchased under agreements to resell and term federal funds sold; (iii) government-guaranteed or -insured mortgage loans held for portfolio; and (iv) conventional mortgage loans held for portfolio. Classes of Financing Receivables. Classes of financing receivables generally are a disaggregation of a portfolio segment to the extent that they are needed to understand the exposure to credit risk arising from these financing receivables. We determined that no further disaggregation of our portfolio segments is needed, as the credit risk arising from these financing receivables is adequately assessed and measured at the portfolio segment level. Troubled Debt Restructuring. TDRs related to MPP loans occur when a concession is granted to a borrower for economic or legal reasons related to the borrower's financial difficulties that would not have been otherwise considered. Although we do not participate in government-sponsored loan modification programs, we do consider certain conventional loan modifications to be TDRs when the modification agreement permits the recapitalization of past due amounts, generally up to the original loan amount. If a borrower is having financial difficulty and a concession has been granted by the PFI with our approval, the loan modification is considered a TDR. No other terms of the original loan are modified, except for the possible extension of the contractual maturity date on a case-by-case basis. In no event does the borrower's original interest rate change. MPP loans discharged in Chapter 7 bankruptcy proceedings without a reaffirmation of the debt are considered TDRs unless they are covered by SMI policies. Loans discharged in Chapter 7 bankruptcy proceedings with SMI policies are also considered to be TDRs unless (i) we will not suffer more than an insignificant delay in receiving all principal and interest due or (ii) we are not relinquishing a legal right to pursue the borrower for deficiencies for those loans not affirmed. TDRs related to MPF Program loans occur when a concession is granted to a borrower for economic or legal reasons related to the borrower's financial difficulties that would not have been otherwise considered. Such TDRs generally involve modifying the borrower's monthly payment for a period of up to 36 months. MPF Program loans discharged in Chapter 7 bankruptcy proceedings without a reaffirmation of the debt are also considered TDRs. For both the MPP and the MPF Program, modifications of government loans are not considered or accounted for as TDRs because we anticipate no loss of principal or interest accrued at the original contract rate, without significant delay, due to the government-guarantee or insurance. Impairment Methodology. A loan is considered impaired when, based on current and historical information and events, it is probable that not all amounts due according to the contractual terms of the loan agreement will be collected. Loans that are considered collateral dependent are subject to individual evaluation for impairment instead of collective evaluation. Loans are considered collateral dependent if repayment is expected to be provided solely by the sale of the underlying property, i.e., there is no other available and reliable source of repayment (including LRA and SMI). We consider all impaired loans to be collateral dependent and, therefore, measure impairment based on the fair value of the underlying collateral less costs to sell. Interest income on impaired loans is recognized in the same manner as non-accrual loans. Charge-Off Policy. A charge-off is recorded to the extent that the recorded investment (including UPB, accrued interest, unamortized premiums or discounts, and hedging adjustments) in a loan will not be fully recovered. We record a charge-off on a conventional mortgage loan against the loan loss allowance upon the occurrence of a confirming event. Confirming events include, but are not limited to, the settlement of a claim against any of the credit enhancements, delinquency in excess of 180 days, and filing for bankruptcy protection. We charge-off the portion of the outstanding conventional mortgage loan balance in excess of the fair value of the underlying property, less cost to sell and adjusted for any available credit enhancements. Derivatives. We record derivative instruments, related cash collateral (including initial and variation margin received or pledged/posted) and associated accrued interest on a net basis, by clearing agent and/or by counterparty when the netting requirements have been met, as either derivative assets or derivative liabilities at their estimated fair values. For derivative instruments that meet the netting requirements, any excess cash collateral received or pledged is recognized as a derivative liability or derivative asset, respectively. Cash flows associated with derivatives are reported as cash flows from operating activities in the statement of cash flows unless the derivatives contain financing elements, in which case they are reflected as cash flows from financing activities. Derivative instruments that include non-standard terms, or require an upfront cash payment, or both, often contain a financing element. Changes in the estimated fair value of derivatives are recorded in earnings regardless of how changes in the estimated fair value of the assets or liabilities being hedged may be recorded. Designations. Each derivative is designated as one of the following: (i) a qualifying fair-value hedge of the change in fair value of a recognized asset or liability, an unrecognized firm commitment, or a forecasted transaction (a fair-value hedge); or (ii) a non-qualifying hedge (economic hedge) for asset/liability management purposes. Derivatives are recorded beginning on the trade date and typically executed and designated in a qualifying hedging relationship at the same time as the acquisition of the hedged item. We may also designate the hedging relationship upon the Bank's commitment to disburse an advance, purchase mortgage loans, or trade a consolidated obligation in which settlement occurs within the shortest period of time possible for the type of instrument based on market settlement conventions. Accounting for Qualifying Hedges. Hedging relationships must meet certain criteria to qualify for hedge accounting including, but not limited to, formal documentation of the hedging relationship and an expectation to be highly effective. Two approaches to hedge accounting include: (i) Long-haul hedge accounting - The application of long-haul hedge accounting requires us to formally assess (both at the hedge's inception and at least quarterly) whether the derivatives used in hedging transactions are highly effective in offsetting changes in the fair value of hedged items or forecasted transactions and whether those derivatives may be expected to remain highly effective in future periods. (ii) Short-cut hedge accounting - Transactions that meet certain criteria qualify for the short-cut method of hedge accounting in which an assumption can be made that the entire change in fair value of a hedged item, due to changes in the benchmark rate, exactly offsets the entire change in fair value of the related derivative. Therefore, the derivative is considered to be highly effective at ac

Recently Adopted and Issued Acc

Recently Adopted and Issued Accounting Guidance	12 Months Ended
	Dec. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Note 2 - Recently Adopted and Issued Accounting Guidance Recently Adopted Accounting Guidance. Contingent Put and Call Options in Debt Instruments (Accounting Standards Update (ASU) 2016-06) . On March 14, 2016, the FASB issued amendments to clarify the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt host contracts. The amendments require entities to apply only the four-step decision sequence when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts. Consequently, when a call (put) option is contingently exercisable, an entity does not have to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks. This amended guidance was effective for the interim and annual periods beginning on January 1, 2017. The adoption of this guidance on January 1, 2017 had no effect on our financial condition, results of operations, or cash flows. Recently Issued Accounting Guidance. Revenue from Contracts with Customers (ASU 2014-09). On May 28, 2014, the FASB issued new guidance on revenue from contracts with customers. This guidance outlines a comprehensive model for recognizing revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry specific guidance. In addition, this guidance amends the existing requirements for the recognition of a gain or loss on the transfer of nonfinancial assets that are not in a contract with a customer. This guidance applies to all contracts with customers except those that are within the scope of certain other standards, such as financial instruments, certain guarantees, insurance contracts, or lease contracts. On August 12, 2015, the FASB issued an amendment to defer the effective date of the guidance by one year. In 2016, the FASB issued additional amendments to clarify certain aspects of the guidance; however, the amendments do not change the core principle in the guidance. The guidance became effective for interim and annual periods beginning on January 1, 2018. The guidance provides entities with the option of using either of the following two methods upon adoption: (i) a full retrospective method, applied to each prior reporting period presented; or (ii) a modified retrospective method, with the cumulative effect of initially applying this guidance recognized at the date of initial adoption. The adoption of this guidance will have no effect on our financial condition, results of operations, or cash flows. Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) . On January 5, 2016, the FASB issued amended guidance on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. This guidance includes, but is not limited to, the following provisions: • equity investments (with certain exceptions) to be measured at fair value with changes in fair value recognized in net income; • separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; • separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (i.e., securities or loans and receivables) on the statement of condition or in the accompanying notes to the financial statements; and • elimination of the requirement for public entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. The guidance became effective for the interim and annual periods beginning on January 1, 2018. The amendments, in general, should be applied by means of a cumulative-effect adjustment to the statement of condition as of the beginning of the period of adoption. The adoption of this guidance will have no effect on our financial condition, results of operations, or cash flows. Classification of Certain Cash Receipts and Cash Payments (ASU 2016-15). On August 26, 2016, the FASB issued amendments to clarify existing guidance on the classification of certain cash receipts and payments on the statement of cash flows to reduce current and potential future diversity in practice regarding eight specific cash flow issues. These amendments became effective for interim and annual periods beginning on January 1, 2018. These amendments should be applied using a retrospective transition method to each period presented. The adoption of these amendments will have no effect on our financial condition, results of operations, or cash flows. Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASU 2017-07). On March 10, 2017, the FASB issued amendments to improve the presentation of net periodic pension cost and net periodic postretirement benefit cost. The amendments require that an employer disaggregate the service cost component from the other components of net pension and benefit cost. The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement. These amendments became effective for interim and annual periods beginning on January 1, 2018. The amendments should be applied retrospectively for the presentation of the service cost component and the other components of net periodic pension cost and net periodic postretirement benefit cost in the income statement and prospectively, on and after the effective date, for the capitalization of the service cost component of net periodic pension cost and net periodic postretirement benefit cost. The adoption of these amendments will have no effect on our financial condition, results of operations, or cash flows. However, the adoption will result in a reclassification within other expenses on the income statement of the non-service components of our net periodic pension cost. Leases (ASU 2016-02) . On February 25, 2016, the FASB issued guidance which requires recognition of lease assets and lease liabilities on the statement of condition and disclosure of key information about leasing arrangements. In particular, this guidance requires a lessee, in an operating or finance lease, to recognize on the statement of condition a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. However, for a lease with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize a lease asset and lease liability. Under previous guidance, a lessee was not required to recognize a lease asset and lease liability arising from an operating lease on the statement of condition. While this guidance does not fundamentally change lessor accounting, some changes have been made to align that guidance with the lessee guidance and other areas within GAAP. This guidance is effective for the interim and annual periods beginning on January 1, 2019, and early adoption is permitted. However, we plan to adopt this guidance on the effective date. The guidance requires lessors and lessees to recognize and measure leases at the beginning of the earliest period presented in the financial statements using a modified retrospective approach. Upon adoption, we expect to report higher assets and liabilities as a result of including right-of-use assets and lease liabilities on the statement of condition, but we do not expect its effect on our financial condition, results of operations, or cash flows to be material. Premium Amortization on Purchased Callable Debt Securities (ASU 2017-08). On March 30, 2017, the FASB issued amendments to shorten the amortization period for certain callable debt securities purchased at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. No change is required for securities purchased at a discount. These amendments are effective beginning on January 1, 2019. Early adoption is permitted; however, we plan to adopt the amendments on the effective date. The amendments should be applied using a modified retrospective method through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The adoption of this guidance will have no effect on our financial condition, results of operations, or cash flows. Targeted Improvements to Accounting for Hedging Activities (ASU 2017-12). On August 28, 2017, the FASB issued amended guidance to improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. This guidance requires that, for fair value hedges, the entire change in the fair value of the hedging instrument included in the assessment of hedge effectiveness be presented in the same income statement line that is used to present the earnings effect of the hedged item. For cash flow hedges, the entire change in the fair value of the hedging instrument included in the assessment of hedge effectiveness must be recorded in OCI. In addition, the amendments include certain targeted improvements to the assessment of hedge effectiveness and permit, among other things, the following: • Measurement of the change in fair value of the hedged item on the basis of the benchmark rate component of the contractual coupon cash flows determined at hedge inception. • Measurement of the hedged item in a partial-term fair value hedge of interest-rate risk by assuming the hedged item has a term that reflects only the designated cash flows being hedged. • Consideration only of how changes in the benchmark interest rate affect a decision to settle a prepayable instrument before its scheduled maturity in calculating the change in the fair value of the hedged item attributable to interest-rate risk. This guidance is effective beginning January 1, 2019. Early adoption is permitted; however, we plan to adopt the guidance on the effective date. We are in the process of evaluating this guidance; but we currently expect its adoption to have no effect on our financial condition, results of operations, or cash flows. However, the amended presentation and disclosure guidance will result in a prospective reclassification on the income statement of the change in fair value of hedging instruments and related hedged items in fair value hedging relationships from other income to interest income. Measurement of Credit Losses on Financial Instruments (ASU 2016-13). On June 16, 2016, the FASB issued amended guidance for the measurement of credit losses on financial instruments. The amendments require entities to measure expected losses over the entire estimated life of a financial instrument instead of incurred losses. Such measurement must be based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The amended guidance requires a financial asset, or a group of financial assets, measured at amortized cost basis to be presented at the net amount expected to be collected over the contractual term of the financial asset. The guidance also requires, among other provisions, the following: • The statement of income must reflect the measurement of credit losses for newly recognized financial assets, as well as the increases or decreases in expected credit losses that have taken place during the period. • Entities must determine the allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination in a manner similar to other financial assets measured at amortized cost. The initial allowance for credit losses is required to be added to the purchase price. • Entities must record credit losses relating to AFS debt securities through an allowance for credit losses. The amendments limit the allowance for credit losses to the amount by which fair value is below amortized cost. • Public entities must further disaggregate the current disclosure of credit quality indicators in relation to the amortized cost of financing receivables by the year of origination (i.e., vintage). This guidance is effective for the interim and annual periods beginning on January 1, 2020. Early adoption is permitted as of the interim and annual reporting periods beginning after December 15, 2018; however, we plan to adopt this guidance on the effective date. This guidance should be applied using a modified-retrospective approach whereby a cumulative-effect adjustment is recorded to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. In addition, the guidance requires the use of a prospective transition approach for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination and for debt securities for which OTTI had been recognized before the effective date. We are in the process of evaluating this guidance, but expect the adoption to result in an increase to the allowance for credit losses, including an allowance for debt securities, primarily due to the requirement to measure losses for the entire estimated life of the financial asset. The impact on our financial condition, results of operations, and cash flows will depend upon the composition of financial assets held at the adoption date as well as the economic conditions and forecasts at that time.

Cash and Due from Banks

Cash and Due from Banks	12 Months Ended
	Dec. 31, 2017
Cash and Due from Banks [Abstract]
Cash and Due from Banks	Note 3 - Cash and Due from Banks Compensating Balances. We maintain cash balances with commercial banks in return for certain services. These agreements contain no legal restrictions on the withdrawal of funds. The average cash balances were $ 35,592 , $ 101,311 , and $81,853 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Pass-through Deposit Reserves. We act as a pass-through correspondent for member institutions required to deposit reserves with the Federal Reserve Banks. The amount reported as cash and due from banks includes pass-through reserves deposited with the Federal Reserve Banks of $ 51,576 and $ 29,118 at December 31, 2017 and 2016 , respectively.

Available-for-Sale Securities

Available-for-Sale Securities	12 Months Ended
	Dec. 31, 2017
Available-for-sale Securities [Abstract]
Available-for-sale Securities	Note 4 - Available-for-Sale Securities Major Security Types. The following table presents our AFS securities by type of security. Gross Gross Amortized Non-Credit Unrealized Unrealized Estimated December 31, 2017 Cost (1) OTTI Gains Losses Fair Value GSE and TVA debentures $ 4,357,250 $ — $ 46,679 $ — $ 4,403,929 GSE MBS 2,460,455 — 45,840 — 2,506,295 Private-label RMBS 189,212 (68 ) 29,390 — 218,534 Total AFS securities $ 7,006,917 $ (68 ) $ 121,909 $ — $ 7,128,758 December 31, 2016 GSE and TVA debentures $ 4,693,211 $ — $ 25,624 $ (4,201 ) $ 4,714,634 GSE MBS 1,058,037 — 18,279 (234 ) 1,076,082 Private-label RMBS 242,181 (263 ) 27,201 — 269,119 Total AFS securities $ 5,993,429 $ (263 ) $ 71,104 $ (4,435 ) $ 6,059,835 (1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses) and fair-value hedge accounting adjustments. Unrealized Loss Positions. The following table presents impaired AFS securities (i.e., in an unrealized loss position), aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position. Less than 12 months 12 months or more Total Estimated Unrealized Estimated Unrealized Estimated Unrealized December 31, 2017 Fair Value Losses Fair Value Losses Fair Value Losses GSE and TVA debentures $ — $ — $ — $ — $ — $ — GSE MBS — — — — — — Private-label RMBS — — 2,494 (68 ) 2,494 (68 ) Total impaired AFS securities $ — $ — $ 2,494 $ (68 ) $ 2,494 $ (68 ) December 31, 2016 GSE and TVA debentures $ 525,722 $ (3,604 ) $ 176,104 $ (597 ) $ 701,826 $ (4,201 ) GSE MBS — — 78,704 (234 ) 78,704 (234 ) Private-label RMBS — — 3,002 (263 ) 3,002 (263 ) Total impaired AFS securities $ 525,722 $ (3,604 ) $ 257,810 $ (1,094 ) $ 783,532 $ (4,698 ) Contractual Maturity. The amortized cost and estimated fair value of non-MBS AFS securities are presented below by contractual maturity. MBS are not presented by contractual maturity because their actual maturities will likely differ from their contractual maturities as borrowers have the right to prepay their obligations with or without prepayment fees. December 31, 2017 December 31, 2016 Amortized Estimated Amortized Estimated Year of Contractual Maturity Cost Fair Value Cost Fair Value Due in 1 year or less $ 83,666 $ 83,754 $ 972,508 $ 974,215 Due after 1 year through 5 years 2,317,516 2,336,699 1,841,488 1,855,517 Due after 5 years through 10 years 1,766,440 1,791,829 1,734,156 1,740,029 Due after 10 years 189,628 191,647 145,059 144,873 Total non-MBS 4,357,250 4,403,929 4,693,211 4,714,634 Total MBS 2,649,667 2,724,829 1,300,218 1,345,201 Total AFS securities $ 7,006,917 $ 7,128,758 $ 5,993,429 $ 6,059,835 Realized Gains and Losses. There were no sales of AFS securities during the years ended December 31, 2017 , 2016 , or 2015 . As of December 31, 2017 , we had no intention of selling the AFS securities in an unrealized loss position nor did we consider it more likely than not that we will be required to sell these securities before our anticipated recovery of each security's remaining amortized cost basis.

Held-to-Maturity Securities

Held-to-Maturity Securities	12 Months Ended
	Dec. 31, 2017
Held-to-maturity Securities [Abstract]
Held-to-Maturity Securities	Note 5 - Held-to-Maturity Securities Major Security Types. The following table presents our HTM securities by type of security. Gross Gross Unrecognized Unrecognized Estimated Amortized Non-Credit Carrying Holding Holding Fair December 31, 2017 Cost (1) OTTI Value Gains Losses Value MBS and ABS: Other U.S. obligations -guaranteed MBS $ 3,299,157 $ — $ 3,299,157 $ 6,555 $ (6,690 ) $ 3,299,022 GSE MBS 2,553,193 — 2,553,193 26,727 (4,529 ) 2,575,391 Private-label RMBS 37,889 — 37,889 240 (307 ) 37,822 Private-label ABS 7,480 (51 ) 7,429 40 (405 ) 7,064 Total HTM securities $ 5,897,719 $ (51 ) $ 5,897,668 $ 33,562 $ (11,931 ) $ 5,919,299 December 31, 2016 MBS and ABS: Other U.S. obligations -guaranteed MBS $ 2,678,437 $ — $ 2,678,437 $ 5,412 $ (12,720 ) $ 2,671,129 GSE MBS 3,082,343 — 3,082,343 46,480 (8,841 ) 3,119,982 Private-label RMBS 49,748 — 49,748 61 (533 ) 49,276 Private-label ABS 9,148 (103 ) 9,045 40 (780 ) 8,305 Total HTM securities $ 5,819,676 $ (103 ) $ 5,819,573 $ 51,993 $ (22,874 ) $ 5,848,692 (1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses). Unrealized Loss Positions. The following table presents impaired HTM securities (i.e., in an unrealized loss position), aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position. Less than 12 months 12 months or more Total Estimated Unrealized Estimated Unrealized Estimated Unrealized December 31, 2017 Fair Value Losses Fair Value Losses Fair Value Losses (1) MBS and ABS: Other U.S. obligations - guaranteed MBS $ 1,140,624 $ (3,274 ) $ 886,359 $ (3,416 ) $ 2,026,983 $ (6,690 ) GSE MBS 513,244 (2,191 ) 203,401 (2,338 ) 716,645 (4,529 ) Private-label RMBS 14,712 (26 ) 11,369 (281 ) 26,081 (307 ) Private-label ABS — — 7,064 (416 ) 7,064 (416 ) Total impaired HTM securities $ 1,668,580 $ (5,491 ) $ 1,108,193 $ (6,451 ) $ 2,776,773 $ (11,942 ) December 31, 2016 MBS and ABS: Other U.S. obligations - guaranteed MBS $ 367,474 $ (997 ) $ 1,426,182 $ (11,723 ) $ 1,793,656 $ (12,720 ) GSE MBS 1,281,827 (7,915 ) 320,141 (926 ) 1,601,968 (8,841 ) Private-label RMBS 18,166 (62 ) 15,770 (471 ) 33,936 (533 ) Private-label ABS — — 8,304 (843 ) 8,304 (843 ) Total impaired HTM securities $ 1,667,467 $ (8,974 ) $ 1,770,397 $ (13,963 ) $ 3,437,864 $ (22,937 ) (1) For private-label ABS, the total of unrealized losses does not agree to total gross unrecognized holding losses at December 31, 2017 and 2016 of $405 and $780 , respectively. Total unrealized losses include non-credit-related OTTI losses recorded in AOCI of $51 and $103 , respectively, and gross unrecognized holding gains on previously OTTI securities of $40 and $40 , respectively. Contractual Maturity. MBS and ABS are not presented by contractual maturity because their actual maturities will likely differ from contractual maturities as certain borrowers have the right to prepay their obligations with or without prepayment fees.

Other-Than-Temporary Impairment

Other-Than-Temporary Impairment Analysis	12 Months Ended
	Dec. 31, 2017
Other than Temporary Impairment Losses, Investments [Abstract]
Other-Than-Temporary Impairment Analysis	Note 6 - Other-Than-Temporary Impairment OTTI Evaluation Process and Results - Private-label RMBS and ABS. As described in Note 1 - Summary of Significant Accounting Policies , on a quarterly basis we evaluate our individual AFS and HTM investment securities for OTTI. To ensure consistency in the determination of OTTI for private-label RMBS and ABS, all FHLBanks use a common framework and formal governance process to determine and approve the key OTTI modeling assumptions used for purposes of our cash flow analysis for substantially all of these securities. Our evaluation includes a projection of future cash flows based on an assessment of the structure of each security and certain assumptions (some of which are determined based upon other assumptions) such as: • the remaining payment terms for the security; • market interest rates; • expected housing price changes; and • based on underlying loan-level borrower and loan characteristics: ◦ prepayment speed; ◦ default rate; and ◦ loss severity on the collateral supporting our security. A significant modeling assumption is the forecast of future housing price changes for the relevant states and CBSAs, which are based upon an assessment of the individual housing markets. As currently defined, a CBSA must contain at least one urban area with a population of 10,000 or more people. The FHLBanks developed a short-term housing price forecast with projected changes ranging from a decrease of 5.0% to an increase of 12.0% over a twelve-month period. For the vast majority of markets, the changes range from an increase of 2.0% to an increase of 6.0% . Thereafter, a unique path is projected for each geographic area based on an internally developed framework derived from historical data. The following table presents the other significant modeling assumptions used to determine the amount of credit loss recognized in earnings during the year ended December 31, 2017 on the two private-label RMBS for which an OTTI was determined to have occurred, as well as the related current credit enhancement. Significant Modeling Assumptions Current Credit Classification (1) Prepayment Rates Default Rates Loss Severities Enhancement (2) Prime 9 % 11 % 26 % — % Subprime (3) 8 % 40 % 42 % — % (1) The classification (prime, Alt-A or subprime) is based on the model used to project the cash flows for the security, which may not be the same as the rating agency's classification at the time of origination. (2) Credit enhancement is defined as the percentage of subordinated tranches, excess spread, and over-collateralization, if any, in a security structure that will generally absorb losses before we will experience a loss on the security. A credit enhancement percentage of zero reflects a security that has no remaining credit support and is likely to have experienced an actual principal loss. (3) Modeling assumptions assume no payout from monoline bond insurers. Our cash flow analysis uses two third-party models to assess whether the entire amortized cost basis of each of our private-label RMBS and ABS will be recovered. Since the projected cash flows are based on a number of assumptions and expectations, the results of these models can vary significantly with changes in those assumptions and expectations. The scenario of cash flows determined based on the model approach reflects a best estimate scenario. The first third-party model considers borrower characteristics, collateral characteristics and the particular attributes of the loans underlying our securities, in conjunction with the assumptions. The month-by-month projections of future loan performance derived from the first model are then input into a second model that allocates the projected loan level cash flows and losses to the various security classes in the securitization structure in accordance with its prescribed cash flow and loss allocation rules. In a securitization in which the credit enhancement for the senior securities is derived from the presence of subordinate securities, losses are generally allocated first to the subordinate securities until their principal balances are reduced to zero. In performing the detailed cash flow analysis, we determine the present value of the cash flows expected to be collected, discounted at the security's effective yield. For variable-rate and hybrid private-label RMBS, we use the effective interest rate derived from a variable-rate index (e.g., 12-month LIBOR) plus the contractual spread, plus or minus a fixed spread adjustment. As the implied forward curve of the index changes over time, the effective interest rates derived from that index will also change over time. Results of OTTI Evaluation Process - Private-label RMBS and ABS. As part of our evaluation as described in Note 1 - Summary of Significant Accounting Policies , we did not have any change in intent to sell, nor were we required to sell, any OTTI security during the years ended December 31, 2017 , 2016 , or 2015 . Therefore, we performed a cash flow analysis to determine whether we expect to recover the entire amortized cost of each security. As a result of our cash flow analysis, we recognized credit losses of $207 , $197 , and $61 during the years ended December 31, 2017 , 2016 , and 2015 , respectively. We determined that the unrealized losses on the remaining private-label RMBS and ABS were temporary as we expect to recover the entire amortized cost. The following table presents a rollforward of the amounts related to credit losses recognized in earnings. The rollforward excludes accretion of credit losses for securities that have not experienced a significant increase in cash flows. Credit Loss Rollforward 2017 2016 2015 Balance at beginning of year $ 51,514 $ 60,673 $ 69,626 Additions: Additional credit losses for which OTTI was previously recognized (1) 207 197 61 Reductions: Increases in cash flows expected to be collected (accreted as interest income over the remaining lives of the applicable securities) (6,786 ) (9,356 ) (9,014 ) Balance at end of year $ 44,935 $ 51,514 $ 60,673 (1) Relates to all securities impaired prior to January 1, 2017 , 2016 , and 2015 , respectively. The following table presents the December 31, 2017 classification and balances of OTTI securities impaired prior to that date (i.e., life-to-date) but not necessarily as of that date. December 31, 2017 HTM Securities AFS Securities Estimated Estimated OTTI Life-to-Date (1) UPB Amortized Cost Carrying Value Fair Value UPB Amortized Cost Fair Value Private-label RMBS - prime $ — $ — $ — $ — $ 224,574 $ 189,212 $ 218,534 Private-label ABS - subprime 552 487 436 476 — — — Total $ 552 $ 487 $ 436 $ 476 $ 224,574 $ 189,212 $ 218,534 (1) Securities are classified based on the originator's classification at the time of origination or based on the classification by the NRSROs upon issuance. Because there is no universally accepted definition of prime, Alt-A or subprime underwriting standards, such classifications are subjective. Evaluation Process and Results - All Other AFS and HTM Securities. Other U.S. and GSE Obligations and TVA Debentures. For other U.S. obligations, GSE obligations, and TVA debentures, we determined that, based on current expectations, the strength of the issuers' guarantees through direct obligations of or support from the United States government is sufficient to protect us from any losses. As a result, all of the gross unrealized losses as of December 31, 2017 are considered temporary.

Advances

Advances	12 Months Ended
	Dec. 31, 2017
Advances [Abstract]
Advances	Note 7 - Advances We offer a wide range of fixed- and adjustable-rate advance products with different maturities, interest rates, payment characteristics and optionality. Adjustable-rate advances have interest rates that reset periodically at a fixed spread to LIBOR or another specified index. Longer-term advances may be available subject to market conditions for both fixed-rate and adjustable-rate products. The following table presents advances outstanding by year of contractual maturity. December 31, 2017 December 31, 2016 Year of Contractual Maturity Amount WAIR % Amount WAIR % Overdrawn demand and overnight deposit accounts $ — — $ — — Due in 1 year or less 16,935,411 1.46 12,598,864 0.91 Due after 1 year through 2 years 2,701,784 1.96 2,752,629 1.74 Due after 2 years through 3 years 2,682,073 1.69 1,920,962 2.10 Due after 3 years through 4 years 2,172,549 1.78 2,605,198 1.38 Due after 4 years through 5 years 2,213,319 1.93 2,009,395 1.47 Thereafter 7,464,333 1.66 6,244,912 1.20 Total advances, par value 34,169,469 1.61 28,131,960 1.22 Fair-value hedging adjustments (126,137 ) (57,716 ) Unamortized swap termination fees associated with modified advances, net of deferred prepayment fees 11,732 21,709 Total advances $ 34,055,064 $ 28,095,953 We offer our members certain advances that provide them the right, at predetermined future dates, to call (i.e., prepay) the advance prior to maturity without incurring prepayment or termination fees. Borrowers typically exercise their call options for fixed-rate advances when interest rates decline. We also offer certain adjustable-rate advances that may be contractually prepaid by the borrower at the interest-rate reset date without incurring prepayment or termination fees. All other advances may only be prepaid by paying a fee that is sufficient to make us financially indifferent to the prepayment of the advance. We also offer putable advances. Under the terms of a putable advance, we retain the right to extinguish or put the fixed-rate advance to the member on predetermined future dates and offer replacement funding at prevailing market rates, subject to certain conditions. The following table presents advances outstanding by the earlier of the year of contractual maturity or the next call date and next put date. Year of Contractual Maturity or Next Call Date Year of Contractual Maturity or Next Put Date December 31, December 31, December 31, December 31, Overdrawn demand and overnight deposit accounts $ — $ — $ — $ — Due in 1 year or less 25,067,272 19,390,714 17,032,411 12,767,364 Due after 1 year through 2 years 2,412,184 2,502,629 2,701,784 2,757,629 Due after 2 years through 3 years 1,716,873 1,856,463 3,406,673 1,915,962 Due after 3 years through 4 years 928,649 1,548,998 2,718,049 2,605,198 Due after 4 years through 5 years 1,494,529 900,095 2,524,619 2,535,895 Thereafter 2,549,962 1,933,061 5,785,933 5,549,912 Total advances, par value $ 34,169,469 $ 28,131,960 $ 34,169,469 $ 28,131,960 In accordance with the Final Membership Rule, captive insurance companies that were admitted as FHLBank members on or after September 12, 2014 repaid all of their outstanding advances and had their memberships terminated by February 19, 2017. Under the Final Membership Rule, captive insurance companies that were admitted as FHLBank members prior to September 12, 2014, and do not meet the new definition of "insurance company" or fall within another category of institution that is eligible for FHLBank membership, shall have their memberships terminated no later than February 19, 2021. Prior to termination, new or renewed extensions of credit to such members will be subject to certain restrictions relating to maturity dates and the ratio of advances to the captive insurer's total assets and may be subject to additional restrictions at our discretion. The outstanding advances to these captive insurers mature on various dates through 2025. Credit Risk Exposure and Security Terms . We lend to members according to Federal statutes, including the Bank Act. The Bank Act requires each FHLBank to hold, or have access to, collateral to fully secure its advances. At December 31, 2017 and 2016 , our top five borrowers held 45% and 43% , respectively, of total advances outstanding, at par. As security for the advances to these and our other borrowers, we held, or had access to, collateral with an estimated fair value at December 31, 2017 and 2016 that was well in excess of the advances outstanding on those dates, respectively. See Note 9 - Allowance for Credit Losses for information related to credit risk on advances and allowance methodology for credit losses.

Mortgage Loans Held for Portfol

Mortgage Loans Held for Portfolio	12 Months Ended
	Dec. 31, 2017
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans Held for Portfolio	Note 8 - Mortgage Loans Held for Portfolio Mortgage loans held for portfolio consist of residential loans acquired from our members through the MPP and participating interests purchased in 2012 - 2014 from the FHLBank of Topeka in residential loans that were originated by certain of its PFIs through their participation in the MPF Program offered by the FHLBank of Chicago. The MPP and MPF Program loans are fixed rate and either credit enhanced by PFIs, if conventional, or guaranteed or insured by government agencies. The following tables present information on mortgage loans held for portfolio by term and type. Term December 31, 2017 December 31, 2016 Fixed-rate long-term mortgages $ 8,989,545 $ 8,086,412 Fixed-rate medium-term (1) mortgages 1,134,303 1,206,978 Total mortgage loans held for portfolio, UPB 10,123,848 9,293,390 Unamortized premiums 234,519 210,116 Unamortized discounts (2,426 ) (2,383 ) Fair-value hedging adjustments 1,250 1,124 Allowance for loan losses (850 ) (850 ) Total mortgage loans held for portfolio, net $ 10,356,341 $ 9,501,397 (1) Defined as a term of 15 years or less at origination. Type December 31, 2017 December 31, 2016 Conventional $ 9,701,600 $ 8,796,407 Government -guaranteed or -insured 422,248 496,983 Total mortgage loans held for portfolio, UPB $ 10,123,848 $ 9,293,390 In December 2016, we agreed to sell a 90% participating interest in a $100 million MCC of certain newly acquired MPP loans to the FHLBank of Atlanta. Principal amounts settled in December 2016 totaled $72 million , and the remaining $18 million settled in January 2017. See Note 9 - Allowance for Credit Losses for information related to our credit risk on mortgage loans and allowance methodology for loan losses.

Allowance for Credit Losses

Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2017
Allowance for Credit Losses [Abstract]
Allowance for Credit Losses	Note 9 - Allowance for Credit Losses We have established a methodology to determine the allowance for credit losses for each of our portfolio segments: credit products (advances, letters of credit, and other extensions of credit to members); term securities purchased under agreements to resell and term federal funds sold; government-guaranteed or -insured mortgage loans held for portfolio; and conventional mortgage loans held for portfolio. Credit Products . We manage our exposure to credit products through an integrated approach that generally includes establishing a credit limit for each borrower, and an ongoing review of each borrower's financial condition, coupled with conservative collateral/lending policies to limit the risk of loss while balancing the borrower's needs for a reliable source of funding. In addition, we lend to eligible borrowers in accordance with federal statutes and Finance Agency regulations. Specifically, we comply with the Bank Act, which requires us to obtain sufficient collateral to fully secure credit products. We evaluate and update our collateral guidelines, as necessary, based on current market conditions. We accept certain investment securities, residential mortgage loans, deposits, and other real estate-related assets as collateral. In addition, certain members that qualify as CFIs are eligible to utilize expanded statutory collateral provisions for small business and agriculture loans. Under the Bank Act, our members' capital stock in our Bank serves as additional security. Collateral arrangements may vary depending upon borrower credit quality, financial condition and performance; borrowing capacity; and overall credit exposure to the borrower. To ensure that we are sufficiently protected, we evaluate and determine whether a member may retain physical possession of its collateral that is pledged to us or must specifically deliver the collateral to us or our safekeeping agent. We perfect our security interest in all pledged collateral and we can also require additional or substitute collateral to protect our security interest. We determine the estimated value of the collateral required to secure each member's credit products by applying collateral discounts, or haircuts, to the market value or UPB of the collateral, as applicable. Using a risk-based approach, we consider the amount and quality of the collateral pledged and the borrower's financial condition to be the primary indicators of credit quality on the borrower's credit products. At December 31, 2017 and 2016 , we had rights to collateral on a borrower-by-borrower basis with an estimated value in excess of our outstanding extensions of credit. At December 31, 2017 and 2016 , we did not have any credit products that were past due, on non-accrual status, or considered impaired. In addition, there were no TDRs related to credit products during the years ended December 31, 2017 , 2016 , or 2015 . Based upon the collateral held as security, our credit extension and collateral policies, our credit analysis and the repayment history on credit products, we have not recorded any allowance for credit losses on credit products, and no liability was recorded to reflect an allowance for credit losses for off-balance sheet credit exposures. For additional information about off-balance sheet credit exposure, see Note 20 - Commitments and Contingencies . Term Securities Purchased Under Agreements to Resell and Term Federal Funds Sold. These assets generally have maturities ranging from 1 to 270 days. Given their short-term nature and the credit quality of the counterparties, credit risk is minimal and, as such, we have not established an allowance for credit losses for these products. Government-Guaranteed or -Insured Mortgage Loans. We invest in fixed-rate mortgage loans that are guaranteed or insured by the FHA, Department of Veterans Affairs, Rural Housing Service of the Department of Agriculture, or HUD. The servicer provides and maintains a guaranty or insurance from the applicable government agency. The servicer is responsible for compliance with all government agency requirements and for obtaining the benefit of the applicable guaranty or insurance with respect to defaulted government-guaranteed or -insured mortgage loans. Any losses incurred on these loans that are not recovered from the insurer or guarantor are absorbed by the servicers. Therefore, we did not establish an allowance for credit losses for government-guaranteed or -insured mortgage loans at December 31, 2017 or 2016 . Conventional Mortgage Loans. We invest in conventional mortgage loans primarily through the MPP. Additionally, we hold participating interests in conventional mortgage loans that were originated by PFIs of the FHLBank of Topeka through the MPF Program. Conventional MPP. Our management of credit risk considers the several layers of loss protection that are defined in our agreements with the PFIs. Our loss protection consists of the following loss layers, in order of priority, (i) borrower equity; (ii) PMI up to coverage limits (when applicable for the acquisition of mortgages with an initial LTV ratio of over 80% at the time of purchase); (iii) available funds remaining in the LRA; and (iv) SMI coverage (as applicable) purchased by the seller from a third-party provider naming the Bank as the beneficiary, up to the policy limits. Any losses not absorbed by the loss protection are borne by the Bank. For conventional mortgage loans under our original MPP, credit enhancement is provided through allocating a portion of the periodic interest payments on the loans into an LRA. In addition, the PFI selling conventional loans to us is required to purchase SMI, paid through periodic interest payments, as an enhancement to cover credit losses over and above those covered by the LRA, but the covered losses are limited to the terms of the policy. Beginning with MPP Advantage, we discontinued the use of SMI for all loan purchases and replaced it with a fixed LRA. The fixed LRA is funded with a portion of each loan's purchase proceeds. The LRA is segregated by pools of loans and used to cover losses in a pool beyond those covered by an individual loan's PMI (as applicable), but is limited to covering losses of that specific pool only. Any excess funds are ultimately distributed to the member in accordance with a step-down schedule that is established upon execution of an MCC, subject to performance of the related pool. The following table presents the activity in the LRA, which is reported in other liabilities. LRA Activity 2017 2016 2015 Liability, beginning of year $ 125,683 $ 91,552 $ 61,949 Additions 25,350 36,341 31,573 Claims paid (617 ) (1,054 ) (1,576 ) Distributions to PFIs (1,701 ) (1,156 ) (394 ) Liability, end of year $ 148,715 $ 125,683 $ 91,552 We determine our allowance for loan losses based on our best estimate of probable losses over the loss emergence period. We use the MPP portfolio's delinquency migration (movement of loans through the various stages of delinquency) to determine whether a loss event is probable. Once a loss event is deemed to be probable, we utilize a systematic methodology that incorporates all credit enhancements and servicer advances to establish the allowance for loan losses. Although we do not reserve for any estimated losses that would be recovered from the credit enhancements, as part of the estimate of the recoverable credit enhancements, we evaluate the recovery and collectability of amounts under our PMI/SMI policies. Conventional MPF Program. Our management of credit risk in the MPF Program considers the several layers of loss protection that are defined in agreements among the FHLBank of Topeka and its PFIs. The availability of loss protection may differ slightly among MPF products. The loss layers, in order of priority, are (i) borrower equity; (ii) PMI, ( when applicable for the purchase of mortgages with an initial LTV ratio of over 80% at the time of purchase) ; (iii) FLA, which represents the first layer or portion of credit losses that we absorb after the borrower's equity, PMI, and recoverable CE fees; and (iv) the CE Obligation of a PFI, which absorbs losses in excess of the FLA in order to limit our loss exposure to that of an investor in an MBS deemed to be investment-grade. Any losses not absorbed by the loss protection are shared among the participating FHLBanks based upon the applicable percentage of participation. PFIs retain a portion of the credit risk on the loans they sell by providing credit enhancement through a direct liability to pay credit losses up to a specified amount. PFIs are paid a CE fee for assuming credit risk and, in some instances, all or a portion of the CE fee may be performance-based. To the extent the Bank is responsible for losses in a pool, it may be able to recapture CE fees paid to that PFI to offset those losses. All CE fees are paid monthly based on the remaining UPB of the loans in a pool. The allowance for MPF Program conventional loans is determined by analyzing the portfolio's delinquency migration and charge-offs over a historical period to determine the probability of default and loss severity rates. The analysis of conventional loans evaluated for impairment (i) considers loan pool-specific attribute data; (ii) applies estimated default probabilities and loss severities; and (iii) incorporates the applicable credit enhancements in order to determine our best estimate of probable losses. Collectively Evaluated Mortgage Loans. MPP. For performing conventional loans current to 179 days past due and collectively evaluated for impairment, we use a recognized third-party credit model to estimate potential ranges of credit loss exposure. The loss projection is based upon distinct underlying loan characteristics, including loan vintage (year of origination), geographic location, credit support features and other factors, and a projected migration of loans through the various stages of delinquency. For delinquent conventional loans past due 180 days or more and collectively evaluated for impairment, we evaluate the pools based on current and historical information and events. This loan loss analysis incorporates third-party modeled values and considers MPP pool-specific attribute data, estimated liquidation values of real estate collateral held, estimated costs associated with maintaining and disposing of the collateral, and credit enhancements. MPF Program. Our loan loss analysis includes collectively evaluating conventional loans for impairment within each pool. The measurement of the allowance for loan losses consists of (i) evaluating homogeneous pools of current and delinquent mortgage loans; and (ii) estimating credit losses in the pool based upon the default probability ratios, loss severity rates, FLAs and CE obligations. Additional analyses include consideration of various data observations such as past performance, current performance, loan portfolio characteristics, collateral-related characteristics, industry data and prevailing economic conditions. Individually Evaluated Mortgage Loans. The measurement of our allowance for loans individually evaluated for loss considers loan-specific attribution data similar to homogeneous pools of delinquent loans evaluated on a collective basis, including the use of loan-level property values from a third-party. We also individually evaluate any remaining exposure to delinquent MPP conventional loans paid in full by the servicers. An estimate of the loss, if any, is equal to the estimated cost associated with maintaining and disposing of the property (which includes the UPB, interest owed on the delinquent loan to date, and estimated costs associated with disposing of the collateral) less the estimated fair value of the collateral (net of estimated selling costs) and the amount of credit enhancements including the PMI, LRA and SMI. The fair value of the collateral is obtained from HUD statements, sales listings or other evidence of current expected liquidation amounts. Individually Evaluated Impaired Loans. The tables below present the conventional loans individually evaluated for impairment with and without an allowance for loan losses. Due to the minimal change in terms of modified loans (i.e., no principal forgiven), our pre-modification recorded investment in TDRs was not materially different than the post-modification recorded investment. December 31, 2017 December 31, 2016 Individually Evaluated Impaired Loans Recorded Investment UPB Related Allowance for Loan Losses Recorded Investment UPB Related Allowance for Loan Losses MPP conventional loans without allowance for loan losses (1) $ 13,261 $ 13,343 $ — $ 15,158 $ 15,219 $ — MPP conventional loans with allowance for loan losses 1,270 1,272 54 349 358 30 Total $ 14,531 $ 14,615 $ 54 $ 15,507 $ 15,577 $ 30 (1) No allowance for loan losses was recorded on these impaired loans after consideration of the underlying loan-specific attribute data, estimated liquidation value of real estate collateral held, estimated costs associated with maintaining and disposing of the collateral, and credit enhancements. Years Ended December 31, 2017 2016 2015 Individually Evaluated Impaired Loans Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized MPP conventional loans without allowance for loan losses $ 14,011 $ 675 $ 16,623 $ 758 $ 17,967 $ 872 MPP conventional loans with allowance for loan losses 1,259 69 353 39 881 105 Total $ 15,270 $ 744 $ 16,976 $ 797 $ 18,848 $ 977 Credit Quality Indicators. The tables below present the key credit quality indicators for our mortgage loans held for portfolio. Delinquency Status as of December 31, 2017 Conventional Government Total Past due: 30-59 days $ 63,670 $ 11,848 $ 75,518 60-89 days 9,944 2,121 12,065 90 days or more 19,576 2,555 22,131 Total past due 93,190 16,524 109,714 Total current 9,878,030 412,869 10,290,899 Total mortgage loans, recorded investment (1) $ 9,971,220 $ 429,393 $ 10,400,613 Delinquency Status as of December 31, 2016 Past due: 30-59 days $ 46,118 $ 17,183 $ 63,301 60-89 days 11,044 3,548 14,592 90 days or more 29,098 2,350 31,448 Total past due 86,260 23,081 109,341 Total current 8,949,441 482,316 9,431,757 Total mortgage loans, recorded investment (1) $ 9,035,701 $ 505,397 $ 9,541,098 Other Delinquency Statistics as of December 31, 2017 Conventional Government Total In process of foreclosure (2) $ 11,081 $ — $ 11,081 Serious delinquency rate (3) 0.20 % 0.59 % 0.21 % Past due 90 days or more still accruing interest (4) $ 16,603 $ 2,555 $ 19,158 On non-accrual status $ 3,464 $ — $ 3,464 Other Delinquency Statistics as of December 31, 2016 In process of foreclosure (2) $ 17,749 $ — $ 17,749 Serious delinquency rate (3) 0.32 % 0.46 % 0.33 % Past due 90 days or more still accruing interest (4) $ 25,375 $ 2,350 $ 27,725 On non-accrual status $ 4,699 $ — $ 4,699 (1) The recorded investment in a loan is the UPB of the loan, adjusted for accrued interest, net of any deferred loan fees or costs, unamortized premiums or discounts (which may include the basis adjustment related to any gain or loss on a delivery commitment prior to being funded) and direct charge-offs. The recorded investment is not net of any valuation allowance. (2) Includes loans for which the decision of foreclosure or similar alternative, such as pursuit of deed-in-lieu of foreclosure, has been reported. Loans in process of foreclosure are included in past due categories depending on their delinquency status, but are not necessarily considered to be on non-accrual status. (3) Represents loans 90 days or more past due (including loans in process of foreclosure) expressed as a percentage of the total recorded investment in mortgage loans. The percentage excludes principal and interest amounts previously paid in full by the servicers on conventional loans that are pending resolution of potential loss claims. Our servicers repurchase seriously delinquent government loans, including FHA loans, when certain criteria are met. (4) Although our past due scheduled/scheduled MPP loans are classified as loans past due 90 days or more based on the mortgagor's payment status, we do not consider these loans to be on non-accrual status. Qualitative Factors. We also assess qualitative factors in the estimation of loan losses. These factors represent a subjective management judgment based on facts and circumstances that exist as of the reporting date that is not ascribed to any specific measurable economic or credit event and is intended to address other inherent losses that may not otherwise be captured in our methodology. Allowance for Loan Losses on Mortgage Loans. Our loan loss analysis also compares, or benchmarks, our estimated losses, after credit enhancements, to actual losses occurring in the portfolio. As a result of our methodology, our allowance for loan losses reflects our best estimate of the probable losses in our original MPP, MPP Advantage, and MPF Program portfolios. The following table presents the components of the allowance for loan losses, including the credit enhancement waterfall for MPP. Components of Allowance December 31, December 31, MPP estimated incurred losses remaining after borrower's equity, before credit enhancements (1) $ 5,360 $ 8,689 Portion of estimated incurred losses recoverable from credit enhancements: PMI (995 ) (1,981 ) LRA (2) (1,262 ) (2,418 ) SMI (2,383 ) (3,590 ) Total portion recoverable from credit enhancements (4,640 ) (7,989 ) Allowance for unrecoverable PMI/SMI 30 50 Allowance for MPP loan losses 750 750 Allowance for MPF Program loan losses 100 100 Total allowance for loan losses $ 850 $ 850 (1) Based on a loss emergence period of 24 months. (2) Amounts recoverable are limited to (i) the estimated losses remaining after borrower's equity and PMI and (ii) the remaining balance in each pool's portion of the LRA. The remainder of the total LRA balance is available to cover any losses not yet incurred and to distribute any excess funds to the PFIs. The tables below present a rollforward of our allowance for loan losses, the allowance for loan losses by impairment methodology, and the recorded investment in mortgage loans by impairment methodology. Rollforward of Allowance for Loan Losses 2017 2016 2015 Balance, beginning of year $ 850 $ 1,125 $ 2,500 Charge-offs (647 ) (857 ) (1,168 ) Recoveries 596 627 249 Provision for (reversal of) loan losses 51 (45 ) (456 ) Balance, end of year $ 850 $ 850 $ 1,125 Allowance for Loan Losses by Impairment Methodology December 31, 2017 December 31, 2016 Conventional loans collectively evaluated for impairment $ 652 $ 750 Conventional loans individually evaluated for impairment (1) 198 100 Total allowance for loan losses $ 850 $ 850 Recorded Investment by Impairment Methodology December 31, 2017 December 31, 2016 Conventional loans collectively evaluated for impairment $ 9,956,689 $ 9,020,194 Conventional loans individually evaluated for impairment (1) 14,531 15,507 Total recorded investment in conventional loans $ 9,971,220 $ 9,035,701 (1) The recorded investment in our MPP conventional loans individually evaluated for impairment excludes principal previously paid in full by the servicers as of December 31, 2017 and 2016 of $2,498 and $2,814 , respectively, that remains subject to potential claims by those servicers for any losses resulting from past or future liquidations of the underlying properties. However, the MPP allowance for loan losses as of December 31, 2017 and 2016 includes $144 and $70 , respectively, for these potential claims.

Premises, Software and Equipmen

Premises, Software and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises, Software and Equipment	Note 10 - Premises, Software and Equipment The following table presents information on our premises, software and equipment. Type December 31, December 31, Premises $ 15,242 $ 14,958 Computer software 38,559 38,497 Data processing equipment 8,846 7,505 Furniture and equipment 4,539 3,920 Other 563 513 Premises, software and equipment, in service 67,749 65,393 Accumulated depreciation and amortization (36,085 ) (30,121 ) Premises, software and equipment, in service, net 31,664 35,272 Capitalized assets in progress 5,131 2,366 Premises, software and equipment, net $ 36,795 $ 37,638 For the years ended December 31, 2017 , 2016 , and 2015 , the depreciation and amortization expense for premises, software and equipment was $5,965 , $5,820 , and $5,461 , respectively, including amortization of computer software costs of $4,276 , $4,055 , and $3,633 , respectively.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Note 11 - Derivatives and Hedging Activities Nature of Business Activity. We are exposed to interest-rate risk primarily from the effect of changes in market interest rates on our interest-earning assets and our interest-bearing liabilities that finance those assets. The goal of our interest-rate risk management strategies is not to eliminate interest-rate risk, but to manage it within appropriate limits. To mitigate the risk of loss, we have established policies and procedures, which include guidelines on the amount of exposure to interest rate changes we are willing to accept. In addition, we monitor the risk to our interest income, net interest margin and average maturity of interest-earning assets and interest-bearing liabilities. Consistent with Finance Agency regulation, we enter into derivatives to (i) manage the interest-rate risk exposures inherent in our otherwise unhedged assets and funding positions, (ii) achieve our risk management objectives, and (iii) act as an intermediary between our members and counterparties. Finance Agency regulation and our Capital Markets Policy prohibit trading in, or the speculative use of, these derivative instruments and limit credit risk arising from these instruments. However, the use of derivatives is an integral part of our financial management strategy. We use derivative financial instruments when they are considered to be the most cost-effective alternative to achieve our financial and risk management objectives. The most common ways in which we use derivatives are to: • reduce funding costs by executing a derivative concurrently with the issuance of a consolidated obligation as the cost of a combined funding structure can be lower than the cost of a comparable CO bond; • reduce the interest-rate sensitivity and repricing gaps of assets and liabilities; • preserve a favorable interest-rate spread between the yield of an asset (e.g., an advance) and the cost of the related liability (e.g., CO bond used to fund advance); • mitigate the adverse earnings effects of the shortening or extension of the duration of certain assets (e.g., advances or mortgage assets) and liabilities; • protect the value of existing asset and liability positions or of commitments and forecasted transactions; • manage embedded options in assets and liabilities; and • manage our overall asset/liability structure. We reevaluate our hedging strategies from time to time and, consequently, we may adopt new strategies or change our hedging techniques. We transact most of our derivatives with large banks and major broker-dealers. Some of these banks and broker-dealers or their affiliates buy, sell, and distribute consolidated obligations. We are not a derivatives dealer and thus do not trade derivatives for short-term profit. Over-the-counter derivative transactions may be either executed with a counterparty (uncleared derivatives) or cleared through a Futures Commission Merchant (i.e., clearing agent) with a clearinghouse (cleared derivatives). Once a derivative transaction has been accepted for clearing by a clearinghouse, the derivative transaction is novated, and the executing counterparty is replaced with the clearinghouse. Types of Derivatives. We use the following derivative instruments to reduce funding costs and to manage our exposure to interest-rate risks inherent in the normal course of business. Interest-Rate Swaps. An interest-rate swap is an agreement between two entities to exchange cash flows in the future. The agreement sets forth the manner in which the cash flows will be determined and the dates on which they will be paid. One of the simplest forms of interest-rate swap involves the promise by one party to pay cash flows equivalent to the interest on a notional amount at a predetermined fixed rate for a given period of time. In return for this promise, the party receives cash flows equivalent to the interest on the same notional amount at a variable-rate index for the same period of time. The variable rate we receive or pay in most interest-rate swaps is indexed to LIBOR. Interest-Rate Cap and Floor Agreements. In an interest-rate cap agreement, a cash flow is generated if the price or rate of an underlying variable rises above a certain threshold (or "cap") price. In an interest-rate floor agreement, a cash flow is generated if the price or rate of an underlying variable falls below a certain threshold (or "floor") price. Caps may be used in conjunction with liabilities, and floors may be used in conjunction with assets. Caps and floors are designed to protect against the interest rate on a variable-rate asset or liability falling below or rising above a certain level. Interest-Rate Swaptions. A swaption is an option on a swap that gives the buyer the right, but not the obligation, to enter into a specified interest-rate swap with the following agreed upon terms with the seller: option premium, time until expiration, fixed vs. floating rates, and notional amount. When used as a hedge, a swaption can protect the buyer against sudden adverse moves in interest rates. To protect against the adverse effects of a sudden decrease in interest rates, a receiver swaption may be utilized in which the buyer has the option to enter into a swap to receive the fixed rate and pay the floating rate. To protect against the adverse effects of a sudden increase in interest rates, a payer swaption may be utilized in which the buyer has the option to enter into a swap to pay the fixed rate and receive the floating rate. Forward Contracts. Forward contracts give the buyer the right to buy or sell a specific type of asset at a specific time at a given price. We may use forward contracts in order to hedge interest-rate risk. For example, certain MDCs entered into by us are considered derivatives. We may hedge these MDCs by selling TBAs for forward settlement. Types of Hedged Items. We document at inception all relationships between the derivatives designated as hedging instruments and the hedged items, our risk management objectives and strategies for undertaking various hedge transactions, and our method of assessing effectiveness. This process includes linking all derivatives that are designated as fair-value hedges to (i) assets and liabilities on the statements of condition, or (ii) firm commitments. We also formally assess (both at the hedge's inception and at least quarterly), using regression analyses, whether the derivatives that are used in hedging transactions have been effective in offsetting changes in the fair value of the hedged items attributable to the hedged risk and whether those derivatives may be expected to remain effective in future periods. We have the following types of hedged items: Investments. We primarily invest in agency MBS and GSE debentures, which may be classified as HTM or AFS securities. The interest-rate and prepayment risks associated with these investment securities are managed through a combination of debt issuance and derivatives. We may manage the prepayment, interest-rate and duration risks by funding investment securities with consolidated obligations that contain call features or by hedging the prepayment risk with caps or floors, callable swaps or swaptions. We may also manage the risk and volatility arising from changing market prices of investment securities by matching the cash outflow on the derivatives with the cash inflow on the investment securities. On occasion, we may hold derivatives that are associated with HTM securities and are designated as economic hedges. Derivatives associated with AFS securities may qualify as a fair-value hedge or be designated as an economic hedge. Advances. We offer a wide range of fixed and variable-rate advance products with different maturities, interest rates, payment characteristics, and optionality. We may use derivatives to manage the repricing and/or options characteristics of advances in order to more closely match the characteristics of our funding liabilities. In general, whenever a member executes a fixed-rate advance or an adjustable-rate advance with embedded options, we may simultaneously execute a derivative with terms that offset the terms and embedded options in the advance. For example, we may hedge a fixed-rate advance with an interest-rate swap where we pay a fixed-rate and receive a variable-rate effectively converting the fixed-rate advance to an adjustable-rate advance. This type of hedge is typically treated as a fair-value hedge. In addition, we may hedge a callable, prepayable or putable advance by entering into a cancellable interest-rate swap. Mortgage Loans. We invest in fixed-rate mortgage loans. The prepayment options embedded in these mortgage loans can result in extensions or contractions in the expected repayment of these loans, depending on changes in prepayment speeds. We manage the interest-rate and prepayment risks associated with mortgage loans through a combination of debt issuance and derivatives. We issue both callable and noncallable debt and prepayment-linked consolidated obligations to achieve cash flow patterns and liability durations similar to those expected on the mortgage loans. Interest-rate swaps, to the extent the payments on the mortgages loans result in a simultaneous reduction of the notional amount of the swaps, may qualify for fair-value hedge accounting. We may also purchase interest-rate caps and floors, swaptions, callable swaps, calls, and puts to minimize the prepayment risk embedded in the loans. Although these derivatives are valid economic hedges against the prepayment risk of the loans, they are not specifically linked to individual loans and, therefore, do not qualify for fair-value hedge accounting. These derivatives are marked to market value through earnings. Consolidated Obligations. We may enter into derivatives to hedge the interest-rate risk associated with our debt issues. We manage the risk and volatility arising from changing market prices of a consolidated obligation by matching the cash inflow on the derivative with the cash outflow on the consolidated obligation. In a typical transaction, we issue a fixed-rate consolidated obligation and simultaneously enter into a matching derivative in which the counterparty pays fixed cash flows to us designed to match in timing and amount the cash outflows we pay on the consolidated obligation. In turn, we pay a variable cash flow to the counterparty that closely matches the interest payments we receive on short-term or variable-rate advances (typically one- or three-month LIBOR). These transactions are typically treated as fair-value hedges. Additionally, we may issue variable-rate CO bonds indexed to LIBOR, the United States prime rate, or federal funds rate and simultaneously execute interest-rate swaps to hedge the basis risk of the variable-rate debt. Firm Commitments. Certain MDCs are considered derivatives. We normally hedge these commitments by selling TBA MBS or other derivatives for forward settlement. The MDC and the TBA used in the firm commitment hedging strategy are treated as an economic hedge and are marked to market through earnings. When the MDC derivative settles, the current market value of the commitment is included with the basis of the mortgage loan and amortized accordingly. Managing Credit Risk on Derivatives. We are subject to credit risk due to the risk of nonperformance by the counterparties to our derivative transactions. We manage counterparty credit risk through credit analysis, collateral requirements and adherence to the requirements set forth in our policies, CFTC regulations, and Finance Agency regulations. See Note 19 - Estimated Fair Values for discussion regarding our fair value methodology for derivative assets and liabilities, including an evaluation of the potential for the estimated fair value of these instruments to be affected by counterparty credit risk. Uncleared Derivatives. For uncleared derivatives, the degree of credit risk depends on the extent to which master netting arrangements are included in such contracts to mitigate the risk. We require collateral agreements with our uncleared derivatives. The exposure thresholds above which collateral must be delivered vary; the threshold is zero in some cases. Additionally, collateral related to derivatives with member institutions includes collateral assigned to us as evidenced by a written security agreement and held by the member institution for our benefit. For certain of our uncleared derivatives, we have credit support agreements that contain provisions requiring us to post additional collateral with our counterparties if there is deterioration in our credit rating. If our credit rating is lowered by an NRSRO, we could be required to deliver additional collateral on uncleared derivative instruments in net liability positions. The aggregate estimated fair value of all uncleared derivative instruments with credit-risk-related contingent features that were in a net liability position (before cash collateral and related accrued interest on cash collateral) at December 31, 2017 was $644 , for which we have posted collateral, including accrued interest, with an estimated fair value of $34 in the normal course of business. In addition, we held other derivative instruments in a net liability position of $49 that are not subject to credit support agreements containing credit-risk related contingent features. If our credit rating had been lowered by an NRSRO (from an S&P equivalent of AA+ to AA), we would not have been required to deliver additional collateral to our uncleared derivative counterparties at December 31, 2017 . Cleared Derivatives. For cleared derivatives, the clearinghouse is our counterparty. We use LCH and CME as clearinghouses for all cleared derivative transactions. Collateral is required to be posted daily for changes in the value of cleared derivatives to mitigate each counterparty's credit risk. The clearinghouse notifies the clearing agent of the required initial and variation margin, and the clearing agent notifies us. The requirement that we post initial and variation margin through the clearing agent for the benefit of the clearinghouse exposes us to institutional credit risk in the event that the clearing agent or clearinghouse fails to meet its obligations. Effective January 3, 2017, CME made certain amendments to its rulebook, including changing the legal characterization of variation margin payments to be daily settled contracts, rather than cash collateral. Variation margin payments related to LCH contracts were characterized as cash collateral until January 16, 2018, when LCH changed the characterization of variation margin payments to be daily settled contracts, consistent with CME. Initial margin continues to be considered by both clearinghouses as cash collateral. The clearinghouse determines margin requirements which are generally not based on credit ratings. However, clearing agents may require additional margin to be posted by us based on credit considerations, including but not limited to any credit rating downgrades. At December 31, 2017 , we were not required by our clearing agents to post any additional margin. Financial Statement Effect and Additional Financial Information. Derivative Notional Amounts . The notional amount of derivatives serves as a factor in determining periodic interest payments, or cash flows received and paid. The notional amount of derivatives also reflects the extent of our involvement in the various classes of financial instruments but represents neither the actual amounts exchanged nor our overall exposure to credit and market risk; the overall risk is much smaller. The risks of derivatives can be measured meaningfully on a portfolio basis that takes into account the counterparties, the types of derivatives, the items being hedged and any offsets between the derivatives and the items being hedged. The following table presents the notional amount and estimated fair value of derivative assets and liabilities. Notional Estimated Fair Value Estimated Fair Value Amount of of Derivative of Derivative December 31, 2017 Derivatives Assets Liabilities Derivatives designated as hedging instruments: Interest-rate swaps $ 31,084,068 $ 298,625 $ 76,205 Total derivatives designated as hedging instruments 31,084,068 298,625 76,205 Derivatives not designated as hedging instruments: Interest-rate swaps 1,026,778 1,187 734 Swaptions — — — Interest-rate caps/floors 245,500 92 — Interest-rate forwards 72,800 37 1 MDCs 70,831 73 48 Total derivatives not designated as hedging instruments 1,415,909 1,389 783 Total derivatives before adjustments $ 32,499,977 300,014 76,988 Netting adjustments (1) (150,868 ) (150,868 ) Cash collateral and variation margin for daily settled contracts (1) (20,940 ) 76,598 Total derivatives, net $ 128,206 $ 2,718 December 31, 2016 Derivatives designated as hedging instruments: Interest-rate swaps $ 23,998,498 $ 230,705 $ 102,201 Total derivatives designated as hedging instruments 23,998,498 230,705 102,201 Derivatives not designated as hedging instruments: Interest-rate swaps 901,344 1,430 31 Swaptions 350,000 2 50 Interest-rate caps/floors 364,500 322 2 Interest-rate forwards 99,100 339 352 MDCs 99,002 303 471 Total derivatives not designated as hedging instruments 1,813,946 2,396 906 Total derivatives before adjustments $ 25,812,444 233,101 103,107 Netting adjustments (1) (133,089 ) (133,089 ) Cash collateral (1) 34,836 55,207 Total derivatives, net $ 134,848 $ 25,225 (1) Represents the application of the netting requirements that allow us to settle (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (including fair value adjustments on derivatives for which variation margin payments are characterized as daily settled contracts). Cash collateral pledged to counterparties at December 31, 2017 and 2016 totaled $16,437 and $35,422 , respectively. Cash collateral received from counterparties at December 31, 2017 and 2016 totaled $89,021 and $55,793 , respectively. Variation margin for daily settled contracts totaled $24,954 at December 31, 2017 . The following table presents separately the estimated fair value of derivative instruments meeting and not meeting netting requirements, including the effect of the related collateral received from or pledged to counterparties and variation margin for daily settled contracts. December 31, 2017 December 31, 2016 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivative instruments meeting netting requirements: Gross recognized amount Uncleared $ 118,932 $ 27,491 $ 86,606 $ 45,449 Cleared 180,972 49,448 145,853 56,835 Total gross recognized amount 299,904 76,939 232,459 102,284 Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts Uncleared (113,842 ) (24,822 ) (76,255 ) (21,047 ) Cleared (1) (57,966 ) (49,448 ) (21,998 ) (56,835 ) Total gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts (171,808 ) (74,270 ) (98,253 ) (77,882 ) Net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts Uncleared 5,090 2,669 10,351 24,402 Cleared 123,006 — 123,855 — Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts 128,096 2,669 134,206 24,402 Derivative instruments not meeting netting requirements (2) 110 49 642 823 Total derivatives, at estimated fair value $ 128,206 $ 2,718 $ 134,848 $ 25,225 (1) Variation margin for daily settled contracts totaled $24,954 at December 31, 2017 . (2) Includes MDCs and certain interest-rate forwards. The following table presents the components of net gains (losses) on derivatives and hedging activities reported in other income (loss). Years Ended December 31, Type of Hedge 2017 2016 2015 Net gain (loss) related to fair-value hedge ineffectiveness: Interest-rate swaps $ (7,414 ) $ 4,488 $ 4,146 Total net gain (loss) related to fair-value hedge ineffectiveness (7,414 ) 4,488 4,146 Net gain (loss) on derivatives not designated as hedging instruments: Economic hedges: Interest-rate swaps 122 (196 ) 1,497 Swaptions (200 ) (290 ) — Interest-rate caps/floors (228 ) 87 (251 ) Interest-rate forwards (1,728 ) (207 ) (3,372 ) Net interest settlements (416 ) (381 ) 392 MDCs 835 (1,229 ) 420 Total net gain (loss) on derivatives not designated as hedging instruments (1,615 ) (2,216 ) (1,314 ) Other (1) (229 ) — — Net gains (losses) on derivatives and hedging activities $ (9,258 ) $ 2,272 $ 2,832 (1) Consists of price alignment amounts on derivatives for which variation margin payments are characterized as daily settled contracts. The following table presents, by type of hedged item, the gains (losses) on the derivatives and the related hedged items in fair-value hedging relationships and the effect of those derivatives on net interest income. Gain (Loss) Gain (Loss) Net Fair- Effect on on on Hedged Value Hedge Net Interest Year Ended December 31, 2017 Derivative Item Ineffectiveness Income (1) Advances $ 61,439 $ (62,324 ) $ (885 ) $ (31,461 ) AFS securities 35,620 (39,843 ) (4,223 ) (48,144 ) CO bonds (46,299 ) 43,993 (2,306 ) 16,289 Total $ 50,760 $ (58,174 ) $ (7,414 ) $ (63,316 ) Year Ended December 31, 2016 Advances $ 118,029 $ (117,201 ) $ 828 $ (91,219 ) AFS securities 193,305 (194,083 ) (778 ) (94,018 ) CO bonds (30,252 ) 34,690 4,438 16,888 Total $ 281,082 $ (276,594 ) $ 4,488 $ (168,349 ) Year Ended December 31, 2015 Advances $ 22,761 $ (21,196 ) $ 1,565 $ (155,082 ) AFS securities 42,219 (46,145 ) (3,926 ) (98,063 ) CO bonds 1,696 4,811 6,507 56,976 Total $ 66,676 $ (62,530 ) $ 4,146 $ (196,169 ) (1) Includes the effect of derivatives in fair-value hedging relationships on net interest income that is recorded in the interest income/expense line item of the respective hedged items. Excludes the interest income/expense of the respective hedged items, which fully offsets the interest income/expense of the derivatives, except to the extent of any hedge ineffectiveness. Net interest settlements on derivatives that are not in fair-value hedging relationships are reported in other income (loss). These amounts do not include the effect of amortization/accretion related to fair value hedging activities.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	Note 12 - Deposits We offer demand and overnight deposits to members and qualifying non-members. In addition, we offer short-term interest-bearing deposit programs to members. A member that services mortgage loans may deposit funds collected in connection with the mortgage loans, pending disbursement of such funds to the owners of the mortgage loans. We classify these items as other deposits. Demand, overnight, and other deposits pay interest based on a daily interest rate. Time deposits pay interest based on a fixed rate determined at the origination of the deposit. The WAIR paid on interest-bearing deposits was 0.86% , 0.12% and 0.01% during the years ended December 31, 2017 , 2016 and 2015 , respectively. The following table presents interest-bearing and non-interest-bearing deposits. Type December 31, December 31, Interest-bearing: Demand and overnight $ 513,150 $ 494,880 Time 50 50 Other 23 25 Total interest-bearing 513,223 494,955 Non-interest-bearing: Other (1) 51,576 29,118 Total non-interest-bearing 51,576 29,118 Total deposits $ 564,799 $ 524,073 (1) Includes pass-through deposit reserves from members.

Consolidated Obligations

Consolidated Obligations	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Consolidated Obligations	Note 13 - Consolidated Obligations Consolidated obligations consist of CO bonds and discount notes. CO bonds may be issued to raise short, intermediate and long-term funds for the FHLBanks and are not subject to any statutory or regulatory limits on maturity. Discount notes are issued primarily to raise short-term funds and have original maturities of up to one year . These notes generally sell at less than their face amount and are redeemed at par value when they mature. The FHLBanks issue consolidated obligations through the Office of Finance as our agent under the oversight of the Finance Agency and the United States Secretary of the Treasury. In connection with each debt issuance, each FHLBank specifies the amount of debt to be issued on its behalf. Each FHLBank records as a liability the specific portion of consolidated obligations issued on its behalf and for which it is the primary obligor. In addition to being the primary obligor for all consolidated obligations issued on our behalf, we are jointly and severally liable with each of the other FHLBanks for the payment of the principal and interest on all FHLBank outstanding consolidated obligations. The par values of the FHLBanks' outstanding consolidated obligations at December 31, 2017 and 2016 totaled $1.0 trillion and $ 989.3 billion , respectively. As provided by the Bank Act and applicable regulations, consolidated obligations are backed only by the financial resources of all FHLBanks. The Finance Agency, in its discretion, may require any FHLBank to make principal or interest payments due on any consolidated obligation whether or not the consolidated obligation represents a primary liability of that FHLBank. Although an FHLBank has never paid the principal or interest payments due on a consolidated obligation on behalf of another FHLBank, if that event should occur, Finance Agency regulations provide that the paying FHLBank is entitled to reimbursement for any payments made on behalf of another FHLBank and other associated costs, including interest to be determined by the Finance Agency. If, however, the Finance Agency determines that such other FHLBank is unable to satisfy its repayment obligations to the paying FHLBank, then the Finance Agency may allocate the outstanding liability of such other FHLBank among the remaining FHLBanks on a pro-rata basis in proportion to their participation in all outstanding consolidated obligations, or in any other manner it may determine to ensure that the FHLBanks operate in a safe and sound manner. We do not believe that it is probable that we will be asked or required to make principal or interest payments on behalf of another FHLBank. Discount Notes. The following table presents our discount notes outstanding, all of which are due within one year of issuance. Discount Notes December 31, December 31, Book value $ 20,358,157 $ 16,801,763 Par value $ 20,394,192 $ 16,819,659 Weighted-average effective interest rate 1.22 % 0.51 % CO Bonds. The following table presents our CO bonds outstanding by contractual maturity. December 31, 2017 December 31, 2016 Year of Contractual Maturity Amount WAIR% Amount WAIR% Due in 1 year or less $ 14,021,190 1.27 $ 16,234,460 0.85 Due after 1 year through 2 years 9,392,470 1.46 6,122,190 0.96 Due after 2 years through 3 years 4,849,960 2.23 2,718,945 1.65 Due after 3 years through 4 years 1,294,470 2.17 1,684,530 3.17 Due after 4 years through 5 years 2,798,000 2.29 1,040,000 2.17 Thereafter 5,626,500 3.02 5,708,000 2.92 Total CO bonds, par value 37,982,590 1.80 33,508,125 1.44 Unamortized premiums 27,333 27,462 Unamortized discounts (13,782 ) (12,059 ) Unamortized concessions (14,188 ) (13,705 ) Fair-value hedging adjustments (86,300 ) (42,544 ) Total CO bonds $ 37,895,653 $ 33,467,279 Consolidated obligations are issued with either fixed-rate or variable-rate coupon payment terms that may use a variety of indices for interest-rate resets, such as LIBOR. To meet the specific needs of certain investors in CO bonds, both fixed-rate and variable-rate CO bonds may contain features that result in complex coupon payment terms and call options. When these CO bonds are issued, we may enter into derivatives containing features that offset the terms and embedded options, if any, of the CO bonds. CO bonds may also be callable. Such bonds may be redeemed in whole or in part, at our discretion, on predetermined call dates according to the terms of the offerings. The following tables present our CO bonds outstanding by redemption feature and the earlier of the year of contractual maturity or next call date. Redemption Feature December 31, December 31, Non-callable / non-putable $ 26,277,590 $ 25,627,125 Callable 11,705,000 7,881,000 Total CO bonds, par value $ 37,982,590 $ 33,508,125 Year of Contractual Maturity or Next Call Date December 31, December 31, Due in 1 year or less $ 24,449,190 $ 23,825,460 Due after 1 year through 2 years 9,098,470 4,675,190 Due after 2 years through 3 years 2,125,960 2,240,945 Due after 3 years through 4 years 584,470 1,257,530 Due after 4 years through 5 years 579,000 474,000 Thereafter 1,145,500 1,035,000 Total CO bonds, par value $ 37,982,590 $ 33,508,125 Interest-Rate Payment Types. CO bonds, beyond having fixed-rate or simple variable-rate interest payment terms, may also have the following features: • Step-up CO bonds pay interest at increasing fixed rates for specified intervals over their lives. These CO bonds generally contain provisions enabling us to call them at our option on the step-up dates; • Ratchet CO bonds pay a floating interest rate indexed on a reference range such as LIBOR. Each floating rate is subject to increasing floors, such that subsequent rates may not be lower than the previous rate; or • Conversion CO bonds have interest rates that convert from fixed to variable, or variable to fixed, or from one index to another, on predetermined dates according to the terms of the offerings. The following table presents CO bonds outstanding by interest-rate payment type. Interest-Rate Payment Type December 31, December 31, Fixed-rate $ 24,747,590 $ 18,928,125 Step-up 285,000 655,000 Simple variable-rate 12,950,000 13,905,000 Ratchet — 20,000 Total CO bonds, par value $ 37,982,590 $ 33,508,125

Affordable Housing Program

Affordable Housing Program	12 Months Ended
	Dec. 31, 2017
Affordable Housing Program [Abstract]
Affordable Housing Program	Note 14 - Affordable Housing Program The Bank Act requires each FHLBank to establish an AHP, in which the FHLBank provides subsidies in the form of direct grants and below-market-rate advances to members that use the funds to assist in the purchase, construction, or rehabilitation of housing for very low-, low-, and moderate-income households. Annually, the FHLBanks must set aside for the AHP the greater of the aggregate of $100 million or 10% of each FHLBank's net earnings. For purposes of the AHP calculation, net earnings is defined in a Finance Agency Advisory Bulletin as income before assessments, plus interest expense related to MRCS. The following table summarizes the activity in our AHP funding obligation. AHP Activity 2017 2016 2015 Liability at beginning of year $ 26,598 $ 31,103 $ 36,899 Assessment (expense) 18,163 13,291 13,499 Subsidy usage, net (1) (12,595 ) (17,796 ) (19,295 ) Liability at end of year $ 32,166 $ 26,598 $ 31,103 (1) Subsidies disbursed are reported net of returns/recaptures of previously disbursed subsidies. We made no AHP-related advances during the years ended December 31, 2017 , 2016 or 2015 and had no outstanding principal at December 31, 2017 or 2016 .

Capital

Capital	12 Months Ended
	Dec. 31, 2017
Capital [Abstract]
Capital	Note 15 - Capital We are a cooperative whose member and former member institutions own all of our capital stock. Former members (including certain non-member institutions that own our capital stock as a result of a merger with or acquisition of a member) own our capital stock solely to support credit products or mortgage loans still outstanding on our statement of condition. Member shares cannot be purchased or sold except between us and our members or, with our written approval, among our members, at the par value of one hundred dollars per share, as mandated by our capital plan and Finance Agency regulation. Our capital plan divides our Class B stock into two sub-series: Class B-1 and Class B-2. Class B-2 stock consists solely of required stock that is subject to a redemption request. The Class B-2 dividend is presently calculated at 80% of the amount of the Class B-1 dividend; this ratio can only be changed by amendment of our capital plan by our board of directors with approval of the Finance Agency. Our board of directors may, but is not required to, declare and pay dividends on our Class B stock in either cash or capital stock or a combination thereof, as long as we are in compliance with Finance Agency rules. The amount of the dividend to be paid is based on the average number of shares of each sub-series held by the member during the dividend payment period (applicable quarter). Stock Redemption and Repurchase. In accordance with the Bank Act, our Class B stock is considered putable by the member. Members can redeem Class B stock, subject to certain restrictions, by giving five years' written notice. Any member that withdraws from membership may not be readmitted as a member for a period of five years from the divestiture date for all capital stock that was held as a condition of membership, as set forth in our capital plan, unless the member has canceled or revoked its notice of withdrawal prior to the end of the five -year redemption period. This restriction does not apply if the member is transferring its membership from one FHLBank to another on an uninterrupted basis. We may repurchase, at our sole discretion, any member's Class B stock that exceeds the required minimum amount. However, there are significant statutory and regulatory restrictions on our right to repurchase, or obligation to redeem, the outstanding stock. As a result, whether or not a member may have its Class B stock repurchased or redeemed will depend, in part, on whether we are in compliance with those restrictions. Consistent with our capital plan, we are not required to redeem activity-based stock until the expiration of the notice of redemption, or until the activity to which the capital stock relates no longer remains outstanding, whichever is later. If activity-based stock becomes excess stock (i.e., the amount of stock held by a member or former member in excess of our stock ownership requirement for that institution) as a result of an activity no longer remaining outstanding, we may redeem the excess stock at our discretion, subject to the statutory and regulatory restrictions on capital stock redemption. A member may cancel or revoke its written notice of redemption or its notice of withdrawal from membership prior to the five-year redemption period. However, our capital plan provides that we will charge a cancellation fee to a member that cancels or revokes its withdrawal notice. Our board of directors may change the cancellation fee with at least 15 days prior written notice to members. At December 31, 2017 and 2016 , certain members had requested redemptions of their Class B stock, but the related stock totaling $5,144 at December 31, 2017 and 2016 was not considered mandatorily redeemable and reclassified to MRCS because the requesting members may revoke their requests, without substantial penalty, throughout the five -year waiting period. Therefore, these requests are not considered sufficiently substantive in nature. However, we consider redemption requests related to merger, acquisition or charter termination, as well as involuntary terminations from membership, to be sufficiently substantive when made and, therefore, the related stock is considered mandatorily redeemable and reclassified to MRCS. Mandatorily Redeemable Capital Stock. The following table presents the activity in our MRCS. MRCS Activity 2017 2016 2015 Liability at beginning of year $ 170,043 $ 14,063 $ 15,673 Reclassifications from capital stock — 183,056 — Redemptions/repurchases (5,721 ) (28,148 ) (1,610 ) Accrued distributions — 1,072 — Liability at end of year $ 164,322 $ 170,043 $ 14,063 As a result of, and effective with, the Final Membership Rule in February 2016, we reclassified all of the outstanding Class B stock of our captive insurance company members totaling $178,898 to MRCS. In accordance with the Final Membership Rule, captive insurance companies that were admitted as FHLBank members on or after September 12, 2014 had their memberships terminated by February 19, 2017. As a result, all of their outstanding Class B stock, totaling $3,021 at December 31, 2016, was repurchased on or before February 19, 2017. Captive insurance companies that were admitted as FHLBank members prior to September 12, 2014, and do not meet the new definition of "insurance company" or fall within another category of institution that is eligible for FHLBank membership, shall have their memberships terminated no later than February 19, 2021. Upon termination, their outstanding Class B stock will be repurchased or redeemed in accordance with the Final Membership Rule. The following table presents MRCS by contractual year of redemption. The year of redemption is the later of: (i) the final year of the five-year redemption period, or (ii) the first year in which a non-member no longer has an activity-based stock requirement. MRCS Contractual Year of Redemption December 31, 2017 December 31, 2016 Year 1 (1) $ 7,963 $ 8,630 Year 2 13 5,054 Year 3 — 13 Year 4 4,158 — Year 5 — 4,158 Thereafter (2) 152,188 152,188 Total MRCS $ 164,322 $ 170,043 (1) Balances at December 31, 2017 and 2016 include $2,909 and $5,609 , respectively, of Class B stock that had reached the end of the five-year redemption period but will not be redeemed until the associated credit products and other obligations are no longer outstanding. (2) Represents the five-year redemption period of Class B stock held by certain captive insurance companies which begins immediately upon their termination of memberships no later than February 19, 2021, in accordance with the Final Membership Rule. When a member's membership status changes to a non-member, the member's capital stock is reclassified to MRCS. If such change occurs during a quarterly period, but not at the beginning or the end of a quarterly period, any dividends for that quarterly period are allocated between distributions from retained earnings for the shares held as capital stock during that period and interest expense for the shares held as MRCS during that period. Therefore, the distributions from retained earnings represent dividends to former members for only the portion of the period that they were members. The amounts recorded to interest expense represent dividends to former members for the portion of that period and subsequent periods that they were not members. The following table presents the distributions related to MRCS. Years Ended December 31, MRCS Distributions 2017 2016 2015 Recorded as interest expense $ 7,034 $ 6,613 $ 522 Recorded as distributions from retained earnings — 1,072 — Total $ 7,034 $ 7,685 $ 522 Restricted Retained Earnings. In 2011, we entered into a JCE Agreement with all of the other FHLBanks to enhance the capital position of each FHLBank. In accordance with the JCE Agreement, we allocate 20% of our net income to a separate restricted retained earnings account until the balance of that account equals at least 1% of the average balance of our outstanding consolidated obligations for the previous quarter. These restricted retained earnings are not available from which to pay dividends except to the extent the restricted retained earnings balance exceeds 1.5% of the average balance of our outstanding consolidated obligations for the previous quarter. Capital Requirements. We are subject to three capital requirements under our capital plan and Finance Agency regulations: (i) Risk-based capital. We must maintain at all times permanent capital, defined as Class B stock (including MRCS) and retained earnings, in an amount at least equal to the sum of our credit risk, market risk, and operations risk capital requirements, all of which are calculated in accordance with Finance Agency regulations. The Finance Agency may require us to maintain a greater amount of permanent capital than is required by the risk-based capital requirements as defined. (ii) Total regulatory capital. We are required to maintain at all times a total capital-to-assets ratio of at least 4% . Total regulatory capital is the sum of permanent capital, any general loss allowance, if consistent with GAAP and not established for specific assets, and other amounts from sources determined by the Finance Agency as available to absorb losses. For regulatory capital purposes, AOCI is not considered capital. (iii) Leverage capital. We are required to maintain at all times a leverage capital-to-assets ratio of at least 5% . Leverage capital is defined as the sum of (i) permanent capital weighted 1.5 times and (ii) all other capital without a weighting factor. As presented in the following table, we were in compliance with the Finance Agency's capital requirements at December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Regulatory Capital Requirements Required Actual Required Actual Risk-based capital $ 903,806 $ 2,998,422 $ 760,946 $ 2,549,871 Total regulatory capital-to-asset ratio 4.00 % 4.81 % 4.00 % 4.73 % Total regulatory capital $ 2,493,956 $ 2,998,422 $ 2,156,296 $ 2,549,871 Leverage ratio 5.00 % 7.21 % 5.00 % 7.10 % Leverage capital $ 3,117,445 $ 4,497,633 $ 2,695,370 $ 3,824,806

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
AOCI Attributable to Parent [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 16 - Accumulated Other Comprehensive Income (Loss) The following table presents a summary of the changes in the components of AOCI. AOCI Rollforward Unrealized Gains (Losses) on AFS Securities Non-Credit OTTI on AFS Securities Non-Credit OTTI on HTM Securities Pension Benefits Total AOCI Balance, December 31, 2014 $ 16,078 $ 38,172 $ (175 ) $ (7,415 ) $ 46,660 OCI before reclassifications: Net change in unrealized gains (losses) (15,981 ) (7,766 ) — — (23,747 ) Net change in fair value — (238 ) — — (238 ) Accretion of non-credit losses — — 43 — 43 Reclassifications from OCI to net income: Non-credit portion of OTTI losses — 61 — — 61 Pension benefits, net — — — 99 99 Total other comprehensive income (loss) (15,981 ) (7,943 ) 43 99 (23,782 ) Balance, December 31, 2015 $ 97 $ 30,229 $ (132 ) $ (7,316 ) $ 22,878 OCI before reclassifications: Net change in unrealized gains (losses) 39,371 (3,332 ) — — 36,039 Net change in fair value — (156 ) — — (156 ) Accretion of non-credit losses — — 29 — 29 Reclassifications from OCI to net income: Non-credit portion of OTTI losses — 197 — — 197 Pension benefits, net — — — (2,619 ) (2,619 ) Total other comprehensive income (loss) 39,371 (3,291 ) 29 (2,619 ) 33,490 Balance, December 31, 2016 $ 39,468 $ 26,938 $ (103 ) $ (9,935 ) $ 56,368 OCI before reclassifications: Net change in unrealized gains (losses) 53,051 2,189 — — 55,240 Net change in fair value — 29 — — 29 Accretion of non-credit losses — — 10 — 10 Reclassifications from OCI to net income: Non-credit portion of OTTI losses — 166 42 — 208 Pension benefits, net — — — (449 ) (449 ) Total other comprehensive income (loss) 53,051 2,384 52 (449 ) 55,038 Balance, December 31, 2017 $ 92,519 $ 29,322 $ (51 ) $ (10,384 ) $ 111,406

Employee Retirement and Deferre

Employee Retirement and Deferred Compensation Plans	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Employee Retirement and Deferred Compensation Plans	Note 17 - Employee and Director Retirement and Deferred Compensation Plans Qualified Defined Benefit Pension Plan. We participate in a tax-qualified, defined-benefit pension plan for financial institutions administered by Pentegra Retirement Services. This DB plan is treated as a multiemployer plan for accounting purposes but operates as a multiple-employer plan under the Employee Retirement Income Security Act of 1974 and the Internal Revenue Code. As a result, certain multiemployer plan disclosures are not applicable. Under the DB plan, contributions made by a participating employer may be used to provide benefits to employees of other participating employers because assets contributed by an employer are not segregated in a separate account or restricted to provide benefits to employees of that employer only. Also, in the event that a participating employer is unable to meet its contribution or funding requirements, the required contributions for the other participating employers (including us) could increase proportionately. The DB plan covers our officers and employees who meet certain eligibility requirements, including an employment date prior to February 1, 2010 . The DB plan operates on a fiscal year from July 1 through June 30 and files one Form 5500 on behalf of all participating employers. The Employer Identification Number is 13-5645888 and the three digit plan number is 333 . There are no collective bargaining agreements in place. The DB plan's annual valuation process includes calculating its funded status and separately calculating the funded status of each participating employer. The funded status is calculated as the market value of plan assets divided by the funding target ( 100% of the present value of all benefit liabilities accrued at that date utilizing the discount rate prescribed by statute). The calculation of the funding target as of July 1, 2017, 2016 and 2015 incorporated a higher discount rate in accordance with MAP-21, which resulted in a lower funding target and a higher funded status. Over time, the favorable impact of MAP-21 is expected to decline. As permitted by the Employee Retirement Income Security Act of 1974 , the DB plan accepts contributions for the prior plan year up to eight and a half months after the asset valuation date. As a result, the market value of plan assets at the valuation date ( July 1 ) will increase by any subsequent contributions designated for the immediately preceding plan year ended June 30 . The most recent Form 5500 available for the DB plan is for the plan year ended June 30, 2016 . Our contributions to the DB plan for the fiscal years ended December 31, 2017 , 2016 and 2015 were not more than 5% of the total contributions to the DB plan for the plan years ended June 30, 2016 , 2015 and 2014 , respectively. The following table presents a summary of net pension costs charged to compensation and benefits expense and the DB plan's funded status. DB Plan Net Pension Cost and Funded Status 2017 2016 2015 Net pension cost charged to compensation and benefits expense for the year ended December 31 $ 4,450 $ 5,772 $ 5,412 DB plan funded status as July 1 111 % (a) 104 % (b) 107 % Our funded status as of July 1 117 % 113 % 118 % (a) The DB plan's funded status as of July 1, 2017 is preliminary and may increase because the participating employers were permitted to make designated contributions for the plan year ended June 30, 2017 through March 15, 2018 . Any such contributions will be included in the final valuation as of July 1, 2017 . The final funded status as of July 1, 2017 will not be available until the Form 5500 for the plan year ended June 30, 2018 is filed (no later than April 2019 ). (b) The DB plan's final funded status as of July 1, 2016 will not be available until the Form 5500 for the plan year ended June 30, 2017 is filed (no later than April 2018 ). Qualified Defined Contribution Plan. We participate in a tax-qualified, defined contribution plan for financial institutions administered by Pentegra Retirement Services. This DC plan covers our officers and employees who meet certain eligibility requirements. Our contribution is equal to a percentage of voluntary employee contributions, subject to certain limitations. We contributed $1,577 , $1,488 , and $1,344 in the years ended December 31, 2017 , 2016 , and 2015 , respectively. Nonqualified Supplemental Defined Benefit Retirement Plan. We participate in a single-employer, non-qualified, unfunded supplemental executive retirement plan for financial institutions administered by Pentegra Retirement Services. This SERP restores all of the defined benefits to participating employees who have had their qualified defined benefits limited by Internal Revenue Service regulations. Since the SERP is a non-qualified unfunded plan, no contributions are required to be made. However, we may elect to make contributions to a related grantor trust that was established to indirectly fund the SERP in order to maintain a desired funding level. Payments of benefits may be made from the related grantor trust or from our general assets. The following table presents the changes in our SERP benefit obligation. Change in benefit obligation 2017 2016 2015 Projected benefit obligation at beginning of year $ 20,022 $ 15,099 $ 14,074 Service cost 1,035 808 839 Interest cost 738 735 665 Actuarial loss 1,712 4,055 1,485 Benefits paid (331 ) (675 ) (1,964 ) Projected benefit obligation at end of year $ 23,176 $ 20,022 $ 15,099 The measurement date used to determine the benefit obligation was December 31. The following table presents the key assumptions used for the actuarial calculations to determine the benefit obligation. December 31, 2017 December 31, 2016 Discount rate 3.00 % 4.00 % Compensation increases 5.50 % 5.50 % The discount rate represents a weighted average that was determined by a discounted cash-flow approach, which incorporates the timing of each expected future benefit payment. We estimate future benefit payments based on the census data of the SERP's participants, benefit formulas and provisions, and valuation assumptions reflecting the probability of decrement and survival. We then determine the present value of the future benefit payments by using duration-based interest-rate yields from the Citi Pension Discount Curve as of the measurement date, and solving for the single discount rate that produces the same present value of the future benefit payments. The accumulated benefit obligation for the SERP, which excludes projected future salary increases, was $16,704 and $13,744 as of December 31, 2017 and 2016 , respectively. The unfunded benefit obligation is reported in other liabilities. Although there are no plan assets, the assets in the grantor trust, included as a component of other assets, had a total fair value of $20,071 and $17,536 at December 31, 2017 and 2016 , respectively. The following table presents the components of the net periodic benefit cost and the amounts recognized in OCI for the SERP. Years Ended December 31, 2017 2016 2015 Net periodic benefit cost: Service cost $ 1,035 $ 808 $ 839 Interest cost 738 735 665 Amortization of prior service benefit — — (11 ) Amortization of net actuarial loss 1,263 1,436 1,595 Net periodic benefit cost recognized in compensation and benefits 3,036 2,979 3,088 Amounts recognized in OCI: Actuarial loss 1,712 4,055 1,485 Amortization of net actuarial loss (1,263 ) (1,436 ) (1,595 ) Amortization of prior service benefit — — 11 Net loss (income) recognized in OCI 449 2,619 (99 ) Total recognized in compensation and benefits and in OCI $ 3,485 $ 5,598 $ 2,989 The following table presents the key assumptions used for the actuarial calculations to determine net periodic benefit cost for the SERP. Years Ended December 31, 2017 2016 2015 Discount rate 4.00 % 4.20 % 3.90 % Compensation increases 5.50 % 5.50 % 5.50 % The following table presents the components of the pension benefits reported in AOCI related to the SERP. December 31, 2017 December 31, 2016 Net actuarial loss $ (10,384 ) $ (9,935 ) Net pension benefits reported in AOCI $ (10,384 ) $ (9,935 ) The following table presents the amounts that will be amortized from AOCI into net periodic benefit cost during the year ending December 31, 2018 . Year Ending December 31, 2018 Net actuarial loss $ 1,291 Net amount to be amortized $ 1,291 The net periodic benefit cost for the SERP, including the net amount to be amortized, for the year ending December 31, 2018 is projected to be approximately $2,904 . The following table presents the estimated future benefit payments reflecting scheduled benefit payments for retired participants and the estimated payments to active participants, weighted based on the probability of the participant retiring, the value of the participant's benefits, and the actual form of payment elected by the participant. For the Years Ending December 31, 2018 $ 2,652 2019 4,058 2020 2,259 2021 1,716 2022 7,240 2023 - 2027 4,316 Nonqualified Supplemental Executive Thrift Plan. Effective January 1, 2016, we offer the SETP, a voluntary, non-qualified, unfunded deferred compensation plan that permits certain officers and approved employees of the Bank to elect to defer certain components of their compensation. The SETP is intended to constitute a deferred compensation arrangement that complies with Section 409A of the Internal Revenue Code, as amended. The SETP provides that, subject to certain limitations, the Bank will make matching contributions to the participant's deferred contribution account each plan year. For the years ended December 31, 2017 and 2016 , we contributed $52 and $47 , respectively, to the SETP and our obligation at December 31, 2017 and 2016 was $660 and $248 , respectively. Directors' Deferred Compensation Plan. Effective January 1, 2016, we offer the DDCP, a voluntary, non-qualified, unfunded deferred compensation plan that permits our directors to defer all or a portion of the fees payable to them for a calendar year for their services as directors. The DDCP is intended to constitute a deferred compensation arrangement that complies with Section 409A of the Internal Revenue Code, as amended. Any duly elected and serving member of our board may participate in the DDCP. We make no matching contributions under the DDCP. Our obligation under the DDCP at December 31, 2017 and 2016 was $967 and $333 , respectively. The following table presents the compensation earned and deferred by our directors under the DDCP. Years Ended December 31, 2017 2016 Compensation earned $ 1,768 $ 1,620 Compensation deferred 538 319

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Information	Note 18 - Segment Information We report based on two operating segments: • Traditional, which consists of credit products (including advances, letters of credit, and lines of credit), investments (including federal funds sold, securities purchased under agreements to resell, AFS securities and HTM securities), and correspondent services and deposits; and • Mortgage loans, which consists of mortgage loans purchased from our members through our MPP and participating interests purchased in 2012 - 2014 from the FHLBank of Topeka in mortgage loans that were originated by certain of its PFIs under the MPF Program. These segments reflect our 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 we provide services to members. We measure the performance of each segment based upon the net interest spread of the underlying portfolio(s). Therefore, each segment's performance begins with net interest income. Traditional net interest income is derived primarily from the difference, or spread, between the interest income earned on advances and investments and the borrowing costs related to those assets, net interest settlements related to interest-rate swaps, and related premium and discount amortization. Traditional also includes the costs related to holding deposits for members and other miscellaneous borrowings as well as all other miscellaneous income and expense not associated with mortgage loans. Mortgage loan net interest income is derived primarily from the difference, or spread, between the interest income earned on mortgage loans, including the premium and discount amortization, and the borrowing costs related to those loans. Direct other income and expense also affect each segment's results. The traditional segment includes the direct earnings impact of derivatives and hedging activities related to advances and investments as well as all other income and expense not associated with mortgage loans. The mortgage loans segment includes the direct earnings impact of derivatives and hedging activities as well as direct compensation, benefits and other expenses (including an allocation for indirect overhead) associated with operating the MPP and MPF Program and volume-driven costs associated with master servicing and quality control fees. The assessments related to AHP have been allocated to each segment based upon its proportionate share of income before assessments. The following table presents our financial performance by operating segment. Year Ended December 31, 2017 Traditional Mortgage Loans Total Net interest income $ 193,278 $ 69,725 $ 263,003 Provision for (reversal of) credit losses — 51 51 Other income (loss) (5,110 ) (886 ) (5,996 ) Other expenses 69,644 12,718 82,362 Income before assessments 118,524 56,070 174,594 Affordable Housing Program assessments 12,556 5,607 18,163 Net income $ 105,968 $ 50,463 $ 156,431 Year Ended December 31, 2016 Traditional Mortgage Loans Total Net interest income $ 144,695 $ 53,498 $ 198,193 Provision for (reversal of) credit losses — (45 ) (45 ) Other income (loss) 6,674 (1,016 ) 5,658 Other expenses 65,746 11,853 77,599 Income before assessments 85,623 40,674 126,297 Affordable Housing Program assessments 9,224 4,067 13,291 Net income $ 76,399 $ 36,607 $ 113,006 Year Ended December 31, 2015 Traditional Mortgage Loans Total Net interest income $ 128,175 $ 67,250 $ 195,425 Provision for (reversal of) credit losses — (456 ) (456 ) Other income (loss) 13,272 (2,791 ) 10,481 Other expenses 62,211 9,683 71,894 Income before assessments 79,236 55,232 134,468 Affordable Housing Program assessments 7,976 5,523 13,499 Net income $ 71,260 $ 49,709 $ 120,969 We have not symmetrically allocated assets to each segment based upon financial results as it is impracticable to measure the performance of our segments from a total assets perspective. As a result, there is asymmetrical information presented in the tables above including, among other items, the allocation of depreciation without an allocation of the depreciable assets, derivatives and hedging earnings adjustments with no corresponding allocation to derivative assets, if any, and the recording of interest income with no allocation to accrued interest receivable. The following table presents asset balances by operating segment. By Date Traditional Mortgage Loans Total December 31, 2017 $ 51,992,565 $ 10,356,341 $ 62,348,906 December 31, 2016 44,406,003 9,501,397 53,907,400

Estimated Fair Values

Estimated Fair Values	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Estimated Fair Value	Note 19 - Estimated Fair Values We estimate fair value amounts by using available market and other pertinent information and the most appropriate valuation methods. Although we use our best judgment in estimating the fair values of financial instruments, there are inherent limitations in any valuation technique. Therefore, these estimated fair values may not be indicative of the amounts that would have been realized in market transactions at the reporting dates. Certain estimates of the fair value of financial assets and liabilities are highly subjective and require judgments regarding significant factors such as the amount and timing of future cash flows, prepayment speeds, interest-rate volatility, and the discount rates that appropriately reflect market and credit risks. The use of different assumptions could have a material effect on the fair value estimates. Fair Value Hierarchy . GAAP establishes a fair value hierarchy and requires us to maximize the use of significant observable inputs and minimize the use of significant unobservable inputs when measuring estimated fair value. The inputs are evaluated, and an overall level for the estimated fair value measurement is determined. This overall level is an indication of the extent of the market observability of the estimated fair value measurement for the asset or liability. The fair value hierarchy prioritizes the inputs used to measure fair value into three broad levels: Level 1 Inputs. Quoted prices (unadjusted) for identical assets or liabilities in an active market that we can access on the measurement date. Level 2 Inputs. Inputs other than quoted prices within level 1 that are observable inputs for the asset or liability, either directly or indirectly. If the asset or liability has a specified or contractual term, a level 2 input must be observable for substantially the full term of the asset or liability. Level 2 inputs include (i) quoted prices for similar assets or liabilities in active markets; (ii) quoted prices for identical or similar assets or liabilities in markets that are not active; (iii) inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates and yield curves that are observable at commonly quoted intervals and implied volatilities); and (iv) inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3 Inputs. Unobservable inputs for the asset or liability. We review the fair value hierarchy classifications on a quarterly basis. Changes in the observability of the inputs may result in a reclassification of certain assets or liabilities. Such reclassifications are reported as transfers in/out at estimated fair value as of the beginning of the quarter in which the changes occur. There were no such reclassifications during the years ended December 31, 2017 , 2016 , or 2015 . The following tables present the carrying value and estimated fair value of our financial instruments. The total of the estimated fair values does not represent an estimate of our overall market value as a going concern, which would take into account, among other considerations, future business opportunities and the net profitability of assets and liabilities. December 31, 2017 Estimated Fair Value Carrying Netting Financial Instruments Value Total Level 1 Level 2 Level 3 Adjustment (1) Assets: Cash and due from banks $ 55,269 $ 55,269 $ 55,269 $ — $ — $ — Interest-bearing deposits 660,342 660,342 659,926 416 — — Securities purchased under agreements to resell 2,605,460 2,605,461 — 2,605,461 — — Federal funds sold 1,280,000 1,280,000 — 1,280,000 — — AFS securities 7,128,758 7,128,758 — 6,910,224 218,534 — HTM securities 5,897,668 5,919,299 — 5,874,413 44,886 — Advances 34,055,064 34,001,397 — 34,001,397 — — Mortgage loans held for portfolio, net 10,356,341 10,426,213 — 10,413,134 13,079 — Accrued interest receivable 105,314 105,314 — 105,314 — — Derivative assets, net 128,206 128,206 — 300,014 — (171,808 ) Grantor trust assets (2) 21,698 21,698 21,698 — — — Liabilities: Deposits 564,799 564,799 — 564,799 — — Consolidated Obligations: Discount notes 20,358,157 20,394,192 — 20,394,192 — — Bonds 37,895,653 37,998,928 — 37,998,928 — — Accrued interest payable 135,691 135,691 — 135,691 — — Derivative liabilities, net 2,718 2,718 — 76,988 — (74,270 ) MRCS 164,322 164,322 164,322 — — — December 31, 2016 Estimated Fair Value Carrying Netting Financial Instruments Value Total Level 1 Level 2 Level 3 Adjustment (1) Assets: Cash and due from banks $ 546,612 $ 546,612 $ 546,612 $ — $ — $ — Interest-bearing deposits 150,225 150,225 150,072 153 — — Securities purchased under agreements to resell 1,781,309 1,781,309 — 1,781,309 — — Federal funds sold 1,650,000 1,650,000 — 1,650,000 — — AFS securities 6,059,835 6,059,835 — 5,790,716 269,119 — HTM securities 5,819,573 5,848,692 — 5,791,111 57,581 — Advances 28,095,953 28,059,477 — 28,059,477 — — Mortgage loans held for portfolio, net 9,501,397 9,587,394 — 9,567,140 20,254 — Accrued interest receivable 93,716 93,716 — 93,716 — — Derivative assets, net 134,848 134,848 — 233,101 — (98,253 ) Grantor trust assets (2) 18,117 18,117 18,117 — — — Liabilities: Deposits 524,073 524,073 — 524,073 — — Consolidated Obligations: Discount notes 16,801,763 16,819,659 — 16,819,659 — — Bonds 33,467,279 33,614,346 — 33,614,346 — — Accrued interest payable 98,411 98,411 — 98,411 — — Derivative liabilities, net 25,225 25,225 — 103,107 — (77,882 ) MRCS 170,043 170,043 170,043 — — — (1) Represents the application of the netting requirements that allow the settlement of (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts). (2) Included in other assets. Summary of Valuation Techniques and Significant Inputs. Cash and Due from Banks. The estimated fair value equals the carrying value. Interest-Bearing Deposits. The estimated fair value equals the carrying value. Securities Purchased Under Agreements to Resell. The estimated fair value of overnight securities purchased under agreements to resell approximates the carrying value. The estimated fair value of term securities purchased under agreements to resell is determined by calculating the present value of the future cash flows. The discount rates used in these calculations are the rates for securities with similar terms. Federal Funds Sold. The estimated fair value of overnight federal funds sold approximates the carrying value. The estimated fair value of term federal funds sold is determined by calculating the present value of the expected future cash flows. The discount rates used in these calculations are the rates for federal funds with similar terms. AFS and HTM Securities - MBS. The estimated fair value incorporates prices from multiple third-party pricing vendors, when available. These pricing vendors use various proprietary models to price MBS. The inputs to those models are derived from various sources, including, but not limited to, benchmark yields, reported trades, dealer estimates, issuer spreads, benchmark securities, bids, offers, and other market-related data. Because many private-label RMBS do not trade on a daily basis, the pricing vendors use other available information, as applicable, such as benchmark curves, benchmarking of like securities, sector groupings and matrix pricing to determine the prices for individual securities. We conduct reviews of the pricing vendors' processes, methodologies and control procedures to confirm and further augment our understanding of the vendors' prices for agency and private-label RMBS. Each pricing vendor has an established challenge process in place for all MBS valuations, which facilitates resolution of potentially erroneous prices identified by us. Our valuation technique for estimating the fair values of MBS initially requires the establishment of a "median" price for each security. All prices that are within a specified tolerance threshold of the median price are then included in the "cluster" of prices that are averaged to compute a "default" price. All prices that are outside the threshold (i.e., outliers) are subject to further analysis (including, but not limited to, comparison to prices provided by an additional third-party valuation service, prices for similar securities, and/or non-binding dealer estimates) to determine if an outlier is a better estimate of fair value. If so, then the outlier (or the other price as appropriate) is used as the final price rather than the default price. In all cases, the final price is used to determine the estimated fair value of the security. As of December 31, 2017 , two or three prices were received for substantially all of our MBS. Based on the lack of significant market activity and observable inputs for private-label RMBS and home equity loan ABS, the recurring fair value measurements for those securities were classified as level 3 within the fair value hierarchy as of December 31, 2017 and 2016 . AFS and HTM Securities - non-MBS. The estimated fair value is determined using market-observable price quotes from third-party pricing vendors, such as the Composite Bloomberg Bond Trader screen, thus falling under the market approach. Advances. We determine the estimated fair value by calculating the present value of expected future cash flows from the advances (excluding the amount of the accrued interest receivable). The discount rates used in these calculations are equivalent to the replacement advance rates for advances with similar terms. In accordance with the Finance Agency's regulations, advances with a maturity or repricing period greater than six months require a prepayment fee sufficient to make us financially indifferent to the borrower's decision to prepay the advances. Therefore, the estimated fair value of advances appropriately excludes prepayment risk. The inputs used to determine the estimated fair value of advances are as follows: • LIBOR swap curve - we use the LIBOR swap curve, which represents the fixed rates on which fixed-rate payments are swapped in exchange for payments of three-month LIBOR; • Volatility assumption - to estimate the fair value of advances with optionality, we use market-based expectations of future interest-rate volatility implied from current market prices for certain benchmark options; • Spread adjustment to the LIBOR swap curve - the spreads are calculated for various structures of advances using current internal advance pricing indications; or • CO curve - for cost-of-funds floating-rate advances that do not use the inputs above, we use the CO curve, which represents the fixed rates at which the FHLBanks can currently issue debt of various maturities. Mortgage Loans Held for Portfolio. The estimated fair value of performing mortgage loans is determined based on quoted market prices for similar mortgage loans, if available, or modeled prices. The modeled pricing starts with prices for new MBS issued by GSEs or similar new mortgage loans, adjusted for underlying assumptions or characteristics. Prices are then interpolated for differences in coupon between our mortgage loans and the referenced MBS or mortgage loans. The prices of the referenced MBS and the mortgage loans are highly dependent upon the underlying prepayment and other assumptions. Changes in the prepayment assumptions can have a material effect on the fair value estimates. The estimated fair value for certain single-family nonperforming loans represents an estimate of the prices we would receive if we were to sell these loans in the nonperforming whole-loan market. These nonperforming loans are 90 days or greater delinquent. We use pricing indications provided by a third-party vendor that transacts whole loan sales within this market segment as an estimate of fair value for these loans. These nonperforming loans are classified as level 3 in the fair value hierarchy. We record non-recurring fair value adjustments to reflect partial charge-offs on impaired mortgage loans. We estimate the fair value of these assets using a current property value obtained from a third-party. Accrued interest receivable and payable. The estimated fair value equals the carrying value. Derivative assets/liabilities. We base the estimated fair values of derivatives with similar terms on market prices when available. However, active markets do not exist for many of our derivatives. Consequently, fair values for these instruments are generally estimated using standard valuation techniques such as discounted cash-flow analysis and comparisons to similar instruments. In limited instances, fair value estimates for derivatives are obtained from dealers and are corroborated by using a pricing model and observable market data (e.g., the LIBOR or OIS curves). A discounted cash flow analysis utilizes market-observable inputs (inputs that are actively quoted and can be validated to external sources). Inputs by class of derivative are as follows: Interest-rate related: • LIBOR curve to project, but OIS curve to discount, cash flows for collateralized interest-rate swaps; and • Volatility assumption - market-based expectations of future interest-rate volatility implied from current market prices for similar options. TBAs: • TBA securities prices - market-based prices are determined by coupon, maturity and expected term until settlement. MDCs: • TBA securities prices - prices are then adjusted for differences in coupon, average loan rate and seasoning. The estimated fair values of our derivative assets and liabilities include accrued interest receivable/payable and related cash collateral, including initial and variation margin, posted to/received from counterparties. The estimated fair values of the accrued interest receivable/payable and cash collateral equal their carrying values due to their short-term nature. We adjust the estimated fair values of our derivatives for counterparty nonperformance risk, particularly credit risk, as appropriate. We compute our nonperformance risk adjustment by using observable credit default swap spreads and estimated probability default rates applied to our exposure after considering collateral held or placed. Grantor Trust Assets. Grantor trust assets, included as a component of other assets, are carried at estimated fair value based on quoted market prices as of the last business day of the reporting period. Deposits. The estimated fair values are generally equal to their carrying values because the deposits are primarily overnight instruments or due on demand. We determine the estimated fair values of term deposits by calculating the present value of expected future cash flows from the deposits and excluding accrued interest payable. The discount rates used in these calculations are the costs of deposits with similar terms. Consolidated Obligations. We assume the estimated fair value of discount notes is equal to par value due to their short-term nature. We determine the estimated fair value of CO bonds by using prices received from up to three designated third-party pricing vendors. These pricing vendors use various proprietary models. The inputs to those models are derived from various sources including, but not limited to, benchmark yields, reported trades, dealer estimates, issuer spreads, benchmark securities, bids, offers, and other market-related data. Since many CO bonds do not trade on a daily basis, the pricing vendors use other available information, as applicable, such as benchmark curves, benchmarking of like securities, sector groupings and matrix pricing to determine the prices for individual CO bonds. We conduct reviews of the three pricing vendors' processes, methodologies and control procedures to confirm and further augment our understanding of the vendors' prices. Each pricing vendor has an established challenge process in place for all valuations, which facilitates the resolution of potentially erroneous prices identified by us. As of December 31, 2017 , three prices were received for substantially all of our CO bonds, and the final prices for substantially all of those bonds were computed by averaging the three prices. Mandatorily Redeemable Capital Stock. The estimated fair value of capital stock subject to mandatory redemption is equal to its par value and includes, if applicable, an estimated dividend earned at the time of reclassification from capital to liabilities until that amount is paid. In the ordinary course of business, our stock can only be acquired and redeemed at par value. It is not traded, and no market mechanism exists for the exchange of our stock outside the cooperative structure of our Bank. Estimated Fair Value Measurements . The following tables present, by level within the fair value hierarchy, the estimated fair value of our financial assets and liabilities that are recorded at estimated fair value on a recurring or non-recurring basis on our statement of condition. Netting December 31, 2017 Total Level 1 Level 2 Level 3 Adjustment (1) AFS securities: GSE and TVA debentures $ 4,403,929 $ — $ 4,403,929 $ — $ — GSE MBS 2,506,295 — 2,506,295 — — Private-label RMBS 218,534 — — 218,534 — Total AFS securities 7,128,758 — 6,910,224 218,534 — Derivative assets: Interest-rate related 128,096 — 299,904 — (171,808 ) Interest-rate forwards 37 — 37 — — MDCs 73 — 73 — — Total derivative assets, net 128,206 — 300,014 — (171,808 ) Grantor trust assets (2) 21,698 21,698 — — — Total assets at recurring estimated fair value $ 7,278,662 $ 21,698 $ 7,210,238 $ 218,534 $ (171,808 ) Derivative liabilities: Interest-rate related $ 2,669 $ — $ 76,939 $ — $ (74,270 ) Interest-rate forwards 1 — 1 — — MDCs 48 — 48 — — Total derivative liabilities, net 2,718 — 76,988 — (74,270 ) Total liabilities at recurring estimated fair value $ 2,718 $ — $ 76,988 $ — $ (74,270 ) Mortgage loans held for portfolio (3) $ 2,637 $ — $ — $ 2,637 $ — Total assets at non-recurring estimated fair value $ 2,637 $ — $ — $ 2,637 $ — Netting December 31, 2016 Total Level 1 Level 2 Level 3 Adjustment (1) AFS securities: GSE and TVA debentures $ 4,714,634 $ — $ 4,714,634 $ — $ — GSE MBS 1,076,082 — 1,076,082 — — Private-label RMBS 269,119 — — 269,119 — Total AFS securities 6,059,835 — 5,790,716 269,119 — Derivative assets: Interest-rate related 134,206 — 232,459 — (98,253 ) Interest-rate forwards 339 — 339 — — MDCs 303 — 303 — — Total derivative assets, net 134,848 — 233,101 — (98,253 ) Grantor trust assets (2) 18,117 18,117 — — — Total assets at recurring estimated fair value $ 6,212,800 $ 18,117 $ 6,023,817 $ 269,119 $ (98,253 ) Derivative liabilities: Interest-rate related $ 24,402 $ — $ 102,284 $ — $ (77,882 ) Interest-rate forwards 352 — 352 — — MDCs 471 — 471 — — Total derivative liabilities, net 25,225 — 103,107 — (77,882 ) Total liabilities at recurring estimated fair value $ 25,225 $ — $ 103,107 $ — $ (77,882 ) Mortgage loans held for portfolio (4) $ 3,492 $ — $ — $ 3,492 $ — Total assets at non-recurring estimated fair value $ 3,492 $ — $ — $ 3,492 $ — (1) Represents the application of the netting requirements that allow us to settle (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts). (2) Included in other assets. (3) Amounts are as of the date the fair value adjustment was recorded during the year ended December 31, 2017 . (4) Amounts are as of the date the fair value adjustment was recorded during the year ended December 31, 2016 . Level 3 Disclosures for All Assets and Liabilities that are Measured at Fair Value on a Recurring Basis. The table below presents a rollforward of our AFS private-label RMBS measured at estimated fair value on a recurring basis using level 3 significant inputs. The estimated fair values were determined using a pricing source, such as a dealer quote or comparable security price, for which the significant unobservable inputs used to determine the price were not readily available. Level 3 Rollforward - AFS private-label RMBS 2017 2016 2015 Balance, beginning of year $ 269,119 $ 319,186 $ 401,050 Total realized and unrealized gains (losses): Accretion of credit losses in interest income 6,778 9,348 8,708 Net losses on changes in fair value in other income (loss) (166 ) (197 ) (61 ) Net change in fair value not in excess of cumulative non-credit losses in OCI 29 (156 ) (238 ) Unrealized gains (losses) in OCI 2,189 (3,332 ) (7,766 ) Reclassification of non-credit portion in OCI to other income (loss) 166 197 61 Purchases, issuances, sales and settlements: Settlements (59,581 ) (55,927 ) (82,568 ) Balance, end of year $ 218,534 $ 269,119 $ 319,186 Net gains (losses) included in earnings attributable to changes in fair value relating to assets still held at end of year $ 6,612 $ 8,291 $ 8,647

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 20 - Commitments and Contingencies The following table presents our off-balance-sheet commitments at their notional amounts. December 31, 2017 Type of Commitment Expire within one year Expire after one year Total Letters of credit outstanding $ 102,344 $ 121,381 $ 223,725 Unused lines of credit (1) 1,084,234 — 1,084,234 Commitments to fund additional advances (2) 4,050 — 4,050 Commitments to fund or purchase mortgage loans, net (3) 70,831 — 70,831 Unsettled CO bonds, at par 28,000 — 28,000 (1) Maximum line of credit amount per member is $50,000 . (2) Generally for periods up to six months. (3) Generally for periods up to 91 days. Commitments to Extend Credit. A standby letter of credit is a financing arrangement between us and one of our members for which we charge the member a commitment fee. If we are required to make a payment for a beneficiary's draw, the payment amount is converted into a collateralized advance to the member. Substantially all of these standby letters of credit, including related commitments, range from 3 months to 20 years, although some are renewable at our option. The carrying value of guarantees (commitment fees) related to standby letters of credit is recorded in other liabilities and totaled $2,867 at December 31, 2017 . Lines of credit allow members to fund short-term cash needs (up to one year) without submitting a new application for each request for funds. We monitor the creditworthiness of our standby letters of credit and lines of credit based on an evaluation of the financial condition of our members. In addition, commitments to extend credit are fully collateralized at the time of issuance. We have established parameters for the measurement, review, classification, and monitoring of credit risk related to these two products. Based on credit analyses performed by us as well as collateral requirements, we have not deemed it necessary to record any additional liability for these commitments. See Note 7 - Advances and Note 9 - Allowance for Credit Losses for more information. Commitments to Fund or Purchase Mortgage Loans. Commitments that unconditionally obligate us to fund or purchase mortgage loans are generally for periods not to exceed 91 days . Such commitments are reported as derivative assets or derivative liabilities at their estimated fair value and are reported net of participating interests sold to other FHLBanks. Pledged Collateral. At December 31, 2017 and 2016 , we had pledged cash collateral, at par, of $16,437 and $35,421 , respectively, to counterparties and clearing agents. Additionally, at December 31, 2017 , variation margin for daily settled contracts totaled $24,954 . At December 31, 2017 and 2016 , we had not pledged any securities as collateral. Lease Commitments. Net rental and related costs totaled $ 287 , $ 212 , and $ 185 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Total future minimum lease payments were $2,253 at December 31, 2017 . Legal Proceedings. We are subject to legal proceedings arising in the normal course of business. We record an accrual for a loss contingency when it is probable that a loss for which we could be liable has been incurred and the amount can be reasonably estimated. After consultation with legal counsel, management does not anticipate that the ultimate liability, if any, arising out of these proceedings could have a material effect on our financial condition, results of operations or cash flows. In 2010, we filed a complaint asserting claims against several entities for negligent misrepresentation and violations of state and federal securities law occurring in connection with the sale of private-label RMBS to us. In 2013, 2014 and 2015, we executed confidential settlement agreements with certain defendants in this litigation, pursuant to which we have dismissed pending claims against, and provided legal releases to, certain entities with respect to all applicable securities at issue in the litigation, in consideration of our receipt of cash payments from or on behalf of those defendants. We had previously dismissed the complaint as to the other named defendants. As a result, all proceedings in the RMBS litigation we filed have been concluded. Cash settlement payments, net of legal fees and litigation expenses, totaled $530 , $60 , and $4,732 for the years ended December 31, 2017 , 2016 , and 2015 , respectively, and were recorded in other income. Additional discussion of other commitments and contingencies is provided in Note 7 - Advances ; Note 8 - Mortgage Loans Held for Portfolio ; Note 11 - Derivatives and Hedging Activities ; Note 13 - Consolidated Obligations ; Note 15 - Capital ; and Note 19 - Estimated Fair Values .

Transactions with Related Parti

Transactions with Related Parties	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Transactions with Related Parties and Other Entities	Note 21 - Related Party and Other Transactions Transactions with Related Parties. We are a cooperative whose members and former members (or legal successors) own all of our outstanding capital stock. Former members (including certain non-members) are required to maintain their investment in our capital stock until their outstanding business transactions with us have matured or are paid off and their capital stock is redeemed in accordance with our capital plan and regulatory requirements. See Note 15 - Capital for more information. Under GAAP, transactions with related parties include transactions with principal owners, i.e, owners of more than 10% of the voting interests of the entity. Due to the statutory limits on members' voting rights and the number of members in our Bank, no shareholder owned more than 10 percent of the total voting interests as of and for the three-year period ended December 31, 2017 . Therefore, the Bank had no transactions with principal owners for any of the periods presented. Under GAAP, transactions with related parties also include transactions with management. Management is defined as persons who are responsible for achieving the objectives of the entity and who have the authority to establish policies and make decisions by which those objectives are to be pursued. For this purpose, management typically includes those who serve on our board of directors. The Bank provides, in the ordinary course of its business, products and services to members whose officers or directors may also serve as directors of the Bank, i.e., directors' financial institutions. However, Finance Agency regulations require that transactions with directors' financial institutions be made on the same terms as those with any other member. Therefore, all of our transactions with directors' financial institutions are subject to the same eligibility and credit criteria, as well as the same conditions, as comparable transactions with all other members. The following table presents the aggregate outstanding balances with directors' financial institutions and their balance as a percent of the total balance on our statement of condition. December 31, 2017 December 31, 2016 Balances with Directors' Financial Institutions Par value % of Total Par value % of Total Capital stock $ 40,564 2 % $ 50,810 3 % Advances 588,108 2 % 627,105 2 % The par values at December 31, 2017 reflect changes in the composition of directors' financial institutions effective January 1, 2017, due to changes in our board membership resulting from the 2016 director election. The following table presents transactions with directors' financial institutions, taking into account the beginning and ending dates of the directors' terms, merger activity and other changes in the composition of directors' financial institutions. Years Ended December 31, Transactions with Directors' Financial Institutions 2017 2016 2015 Net capital stock issuances (redemptions and repurchases) $ 3,912 $ 1,516 $ (12,588 ) Net advances (repayments) 79,751 11,274 112,976 Mortgage loan purchases 33,274 38,728 39,590 Transactions with Members and Former Members. Substantially all advances are made to members, and all whole mortgage loans held for portfolio are purchased from members. We also maintain demand deposit accounts for members, primarily to facilitate settlement activities that are directly related to advances or mortgage loan purchases. Such transactions with members are entered into in the ordinary course of business. In addition, we may purchase investments in federal funds sold, securities purchased under agreements to resell, certificates of deposit, and MBS from members or their affiliates. All purchases are transacted at market prices without preference to the status of the counterparty or the issuer of the security as a member, nonmember, or affiliate thereof. Under our AHP, we provide subsidies to members, which may be in the form of direct grants or below-market-rate advances. All AHP subsidies are made in the ordinary course of business. Under our Community Investment Program and our Community Investment Cash Advances program, we provide subsidies in the form of below-market-rate advances to members or standby letters of credit to members for community lending and economic development projects. All Community Investment Cash Advances subsidies are made in the ordinary course of business. Transactions with Other FHLBanks. Occasionally, we loan (or borrow) short-term funds to (from) other FHLBanks. The following table presents the loans to other FHLBanks. Years Ended December 31, Loans to other FHLBanks 2017 2016 2015 Disbursements $ (100,000 ) $ (300,000 ) $ — Principal repayments 100,000 300,000 — There were no borrowings from other FHLBanks during the years ended December 31, 2017 , 2016 , or 2015 . There were no loans to or borrowings from other FHLBanks outstanding at December 31, 2017 or 2016 . In December 2016, we agreed to sell a 90% participating interest in a $100 million MCC of certain newly acquired MPP loans to the FHLBank of Atlanta. Principal amounts settled in December 2016 totaled $72 million , and the remaining $18 million settled in January 2017. Transactions with the Office of Finance. Our proportionate share of the cost of operating the Office of Finance is identified in the Statements of Income.

Summary of Significant Accoun30

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation, Policy	Basis of Presentation. The accompanying financial statements have been prepared in accordance with GAAP and SEC requirements. The financial statements contain all adjustments that are, in the opinion of management, necessary for a fair statement of our financial position, results of operations and cash flows for the periods presented.
Reclassifications, Policy	Reclassifications. We have reclassified certain amounts from the prior period to conform to the current period presentation. These reclassifications had no effect on total assets, total liabilities, total capital, net income, total comprehensive income or net cash flows.
Use of Estimates, Policy	Use of Estimates. When preparing financial statements in accordance with GAAP, we are required to make subjective assumptions and estimates that may affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of income and expense. The most significant estimates pertain to derivatives and hedging activity, fair value, the provision for credit losses, and OTTI. Although the reported amounts and disclosures reflect our best estimates, actual results could differ significantly from these estimates. Estimated Fair Value. The estimated fair value amounts, recorded on the statement of condition and presented in the accompanying disclosures, have been determined based on the assumptions that we believe market participants would use in pricing the asset or liability and reflect our best judgment of appropriate valuation methods. Although we use our best judgment in estimating fair value, there are inherent limitations in any valuation technique. Therefore, these estimated fair values may not be indicative of the amounts that would have been realized in market transactions on the reporting dates.
Interest-Bearing Deposits, Securities Purchased under Agreements to Resell, and Federal Funds Sold, Policy	Interest-Bearing Deposits, Securities Purchased under Agreements to Resell, and Federal Funds Sold. These investments provide short-term liquidity and are carried at cost. Interest-bearing deposits may include certificates of deposit and bank notes not meeting the definition of a security. Securities purchased under agreements to resell are considered short-term collateralized financings. These securities are held in safekeeping in our name by third-party custodians approved by us. If the market value of the underlying assets declines below the market value required as collateral, the counterparty must (i) place an equivalent amount of additional securities in safekeeping in our name, and/or (ii) remit an equivalent amount of cash, or the dollar value of the resale agreement will be reduced accordingly. Federal funds sold consist of short-term, unsecured loans made to investment-grade counterparties.
Investment Securities, Policy	Investment Securities. Purchases and sales of securities are recorded on a trade date basis. We classify investments as trading, HTM or AFS at the date of acquisition. We did not have any investments classified as trading during the years ended December 31, 2017 , 2016 or 2015 . HTM Securities. Securities for which we have both the positive intent and ability to hold to maturity are classified as HTM. The carrying value includes adjustments made to the cost basis of the security for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses) and OCI (non-credit losses). Certain changes in circumstances may cause us to change our intent to hold a particular security to maturity without necessarily calling into question our intent to hold other debt securities to maturity. Thus, the sale or transfer of an HTM security due to certain changes in circumstances, such as evidence of significant deterioration in the issuer's creditworthiness or changes in regulatory requirements, is not considered to be inconsistent with its original classification. Other isolated, non-recurring, and unusual events, which could not have been reasonably anticipated, may also cause us to sell or transfer an HTM security without necessarily calling into question our intent to hold other debt securities to maturity. In addition, sales of HTM debt securities that meet either of the following two conditions may be considered as maturities for purposes of the classification of securities: (i) the sale occurs near enough to its maturity date (or call date, if exercise of the call is probable) that interest-rate risk is substantially eliminated as a pricing factor and any changes in market interest rates would not have a significant effect on the security's fair value, or (ii) the sale occurs after we have already collected a substantial portion (at least 85% ) of the principal outstanding at acquisition due either to prepayments or to scheduled payments payable in equal installments (both principal and interest) over its term. AFS Securities. Securities that have readily determinable fair values and are not classified as trading or HTM are classified as AFS and carried at estimated fair value. We record changes in the fair value of these securities in OCI as net change in unrealized gains (losses) on AFS securities, except for AFS securities that have been hedged and for which the hedging relationship qualifies as a fair-value hedge. For these securities, we record the portion of the change in fair value attributable to the risk being hedged in other income (loss) as net gains (losses) on derivatives and hedging activities together with the related change in the fair value of the derivative, and record the remainder of the change in the fair value of the securities in OCI. For AFS securities that are OTTI, changes in fair value, net of any credit loss, are recorded in OCI as the non-credit portion. Premiums and Discounts. We amortize purchased premiums and accrete purchased discounts on MBS and ABS at an individual security level using the retrospective level-yield method (retrospective interest method) over the estimated remaining cash flows of each security. This method requires that we estimate prepayments over the estimated life of the securities and make a retrospective adjustment of the effective yield each time we change the estimated remaining cash flows of the securities as if the new estimates had been used since the acquisition date. Changes in interest rates are a significant assumption used in prepayment speed estimates. We amortize purchased premiums and accrete purchased discounts on all other investment securities at an individual security level using a contractual level-yield methodology, under which prepayments are only taken into account as they actually occur. Gains and Losses on Sales. We compute gains and losses on sales of investment securities using the specific identification method and include these gains and losses in other income (loss) as net realized gains from sale of securities.
Impairment of Investments, Policy	Investment Securities - Other-Than-Temporary Impairment. On a quarterly basis, we evaluate our individual AFS and HTM securities that have been previously OTTI or are in an unrealized loss position to determine if any such securities are OTTI. A security is in an unrealized loss position (i.e., impaired) when its estimated fair value is less than its amortized cost. We consider an impaired debt security to be OTTI under any of the following conditions: • we intend to sell the debt security; • based on available evidence, we believe it is more likely than not that we will be required to sell the debt security before the anticipated recovery of its remaining amortized cost; or • we do not expect to recover the entire amortized cost of the debt security. Recognition of OTTI. If either of the first two conditions above is met, we recognize an OTTI loss in earnings equal to the entire difference between the debt security's amortized cost and its estimated fair value as of the statement of condition date. For those impaired securities that meet neither of these two conditions, we perform a cash flow analysis to determine whether we expect to recover the entire amortized cost of each security. If the present value of the cash flows expected to be collected is less than the amortized cost of the debt security, a credit loss equal to that difference is recorded, and the carrying value of the debt security is adjusted to its estimated fair value. However, rather than recognizing the entire difference between the amortized cost and estimated 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 remaining amount, if any, related to all other factors (i.e., the non-credit component) is recognized in OCI. The credit loss on a debt security is capped at the amount of that security's unrealized loss. The new amortized cost basis of the OTTI security, which reflects the credit loss, will not be adjusted for any subsequent recoveries of fair value. The total OTTI loss is presented in other income (loss) with an offset for the portion recognized in OCI. The remaining amount represents the credit loss. Additional OTTI. Subsequent to any recognition of OTTI, if the present value of cash flows expected to be collected is less than the amortized cost basis (which reflects previous credit losses), we record an additional credit loss equal to that difference as additional OTTI. The total amount of additional OTTI (both credit and non-credit component, if any) is determined as the difference between the security's amortized cost, less the amount of OTTI recognized in AOCI prior to the determination of this additional OTTI, and its fair value. For certain AFS or HTM securities that were previously impaired and have subsequently incurred additional credit losses, an amount equal to the additional credit losses, up to the amount of non-credit losses remaining in AOCI, is reclassified out of AOCI and into other income (loss). Subsequent increases and decreases (if not an additional OTTI) in the estimated fair value of OTTI AFS securities are netted against the non-credit component of OTTI recognized previously in AOCI. For HTM securities, the OTTI in AOCI is accreted to the carrying value of each security on a prospective basis, based on the amount and timing of future projected cash flows (with no effect on earnings unless the security is subsequently sold, matures or additional OTTI is recognized). For debt securities classified as AFS, we do not accrete the OTTI in AOCI to the carrying value because the subsequent measurement basis for these securities is estimated fair value. Interest Income Recognition. As of the initial OTTI measurement date, a new accretable yield is calculated for the OTTI debt security. This yield is then used to calculate the portion of the credit losses included in the amortized cost of the security to be recognized into interest income each period over the remaining life of the security so as to match the amount and timing of future cash flows expected to be collected. On a quarterly basis, we re-evaluate the estimated cash flows and accretable yield. If there is no additional OTTI and there is either (i) a significant increase in the security's expected cash flows or (ii) a favorable change in the timing and amount of the security's expected cash flows, we adjust the accretable yield on a prospective basis.
Variable Interest Entity, Policy	Variable Interest Entities. We do not have any special purpose entities or any other type of off-balance sheet conduits. We have investments in VIEs that consist of senior interests in private-label RMBS and ABS. The carrying amounts of the investments are included in HTM or AFS securities. We have no liabilities related to these VIEs. The maximum loss exposure on these VIEs is limited to our carrying value. On an annual basis, or more frequently as needed, we conduct an evaluation to determine whether we are the primary beneficiary of any VIE. To make this determination, we consider whether we possess both of the following characteristics: • the power to direct the VIE's activities that most significantly affect the VIE's economic performance; and • the obligation to absorb the VIE's losses, or the right to receive benefits from the VIE, that could potentially be significant to the VIE.
Advances, Policy	Advances. We record advances at amortized cost, adjusted for unamortized premiums, discounts, prepayment fees and swap termination fees, unearned commitment fees, and fair-value hedging adjustments. We amortize/accrete premiums, discounts, hedging basis adjustments, deferred prepayment fees, and deferred swap termination fees, and recognize unearned commitment fees on advances, to interest income using a level-yield methodology. When an advance is prepaid, any remaining premium or discount is amortized at the time of prepayment. We record interest on advances to interest income as earned. Prepayment Fees. We charge a borrower a prepayment fee when the borrower repays certain advances prior to the original maturity. We report prepayment fees net of any swap termination fees and hedge accounting basis adjustments. Advance Modifications. When we fund a new advance concurrent with, or within a short period of time after, the prepayment of an original advance, we determine whether the transaction is effectively either (i) two separate transactions (the prepayment of an original advance and the disbursement of a new advance), defined as an advance extinguishment, or (ii) the continuation of the original advance as modified, defined as an advance modification. We account for the transaction as an extinguishment if both of the following criteria are met: (i) the effective yield of the new advance is at least equal to the effective yield for a comparable advance to a member with similar collection risks who is not prepaying, and (ii) modifications of the original advance are determined to be more than minor, i.e., if the present value of the cash flows under the terms of the new advance is at least 10% different from the present value of the remaining cash flows under the terms of the original advance or through an evaluation of qualitative factors which may include changes in the interest-rate exposure to the member by moving from a fixed to an adjustable rate advance. In all other instances, the transaction is accounted for as an advance modification. If the transaction is determined to be an advance extinguishment, we recognize income from nonrefundable prepayment fees, net of swap termination fees, in the period that the extinguishment occurs. Alternatively, if no prepayment fees are received (e.g., the member requests that we embed the prepayment fee into the rate of the new advance), the difference between the present value of the cash flows of the new advance and that of a current market rate advance of comparable terms is recognized in current income, and the basis of the new advance is adjusted accordingly. If the transaction is determined to be an advance modification, the income from nonrefundable prepayment fees, net of swap termination fees, associated with the modification of the original advance is not recognized in current income but is (i) included in the carrying value of the modified advance and amortized into interest income using a level-yield methodology when the prepayment fee is received up front or (ii) embedded into the rate of the modified advance and recorded as an adjustment to the interest accrual. If the modified advance is hedged in a qualifying hedge relationship, the modified advance is marked to fair value, and subsequent fair value changes attributable to the hedged risk are recorded in other income (loss).
Mortgage Loans Held for Portfolio, Policy	Mortgage Loans Held for Portfolio. We classify mortgage loans, for which we have 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 at cost, adjusted for premiums paid to and discounts received from PFIs, deferred loan fees or costs, hedging basis adjustments, and the allowance for loan losses. Premiums and Discounts. We defer and amortize/accrete premiums and discounts, certain loan fees or costs, and hedging basis adjustments to interest income using the contractual level-yield interest method. When a loan is prepaid, any remaining premium or discount is amortized to interest income in the period in which the loan is prepaid and derecognized. For partial prepayments, a proportionate share of any remaining premium or discount is amortized to interest income in the period in which the prepayment occurs. Non-accrual Loans. We place a conventional mortgage loan on non-accrual status if it is determined that either (i) the collection of interest or principal is doubtful, or (ii) interest or principal is past due for 90 days or more, except when the loan is well secured and in the process of collection (e.g., through credit enhancements and monthly servicer remittances on a scheduled/scheduled basis). Monthly servicer remittances on MPP loans on an actual/actual basis may also be well secured; however, servicers on actual/actual remittance do not advance principal and interest due until the payments are received from the borrower or when the loan is repaid. A government-guaranteed or -insured mortgage loan is not placed on non-accrual status when the collection of the contractual principal or interest is 90 days or more past due because of the contractual obligation of the loan servicer to pay defaulted interest at the contractual rate. For those mortgage loans placed on non-accrual status, accrued but uncollected interest is reversed against interest income (for any interest accrued in the current year) and/or the allowance for loan losses (for any interest accrued in the previous year). We record cash payments received on non-accrual loans as a direct reduction of the recorded investment in the loan. When the recorded investment has been fully collected, any additional amounts collected are recognized as interest income. A loan on non-accrual status may be restored to accrual status when it becomes current (zero days past due) and three consecutive and timely monthly payments have been made. REO. Our MPP was designed to require loan servicers to foreclose and liquidate in the servicer's name rather than in our name. Therefore, we do not take title to any foreclosed property or enter into any other legal agreement under which the borrower conveys all interest in the property to us to satisfy the loan. As the servicer progresses through the process from foreclosure to liquidation, we are paid in full for all unpaid principal and accrued interest on the loan through the normal remittance process. Upon full receipt, the mortgage loan is removed from our statement of condition. As a result of these factors, we do not classify as REO any foreclosed properties collateralizing MPP loans that were previously recorded on our statement of condition. Under the MPF Program, REO is recorded in other assets and includes assets that have been received in satisfaction of debt through foreclosures. REO is recorded at the lower of cost or fair value less estimated selling costs. We recognize 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 the transfer from mortgage loans to REO. Any subsequent gains, losses, and carrying costs are included in other expense. Loan Participations. We may sell participating interests in MPP loans acquired from our PFIs to other FHLBanks. The terms of the sale of these participating interests meet the accounting requirements for a sale and, therefore, the participating interests are de-recognized from our reported mortgage loan balances and a pro-rata portion of the fixed LRA is assumed by the participating FHLBank for its use in loss mitigation. As a result, available funds remaining in our LRA include our pro-rata portion only of the fixed LRA associated with the participating interests retained by us. The portion of the participation fees received related to our upfront costs is recognized immediately into income, while the remaining portion related to our ongoing costs is deferred and amortized to income over the remaining life of the loans.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for Credit Losses. An allowance for credit losses is separately established for each identified portfolio segment if it is probable that impairment has occurred as of the statement of condition date and the amount of loss can be reasonably estimated. See Note 9 - Allowance for Credit Losses for details on each allowance methodology. Portfolio Segments. 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. We have developed and documented a systematic methodology for determining an allowance for credit losses, where applicable, for (i) credit products (advances, letters of credit, and other extensions of credit to members); (ii) term securities purchased under agreements to resell and term federal funds sold; (iii) government-guaranteed or -insured mortgage loans held for portfolio; and (iv) conventional mortgage loans held for portfolio. Classes of Financing Receivables. Classes of financing receivables generally are a disaggregation of a portfolio segment to the extent that they are needed to understand the exposure to credit risk arising from these financing receivables. We determined that no further disaggregation of our portfolio segments is needed, as the credit risk arising from these financing receivables is adequately assessed and measured at the portfolio segment level. Troubled Debt Restructuring. TDRs related to MPP loans occur when a concession is granted to a borrower for economic or legal reasons related to the borrower's financial difficulties that would not have been otherwise considered. Although we do not participate in government-sponsored loan modification programs, we do consider certain conventional loan modifications to be TDRs when the modification agreement permits the recapitalization of past due amounts, generally up to the original loan amount. If a borrower is having financial difficulty and a concession has been granted by the PFI with our approval, the loan modification is considered a TDR. No other terms of the original loan are modified, except for the possible extension of the contractual maturity date on a case-by-case basis. In no event does the borrower's original interest rate change. MPP loans discharged in Chapter 7 bankruptcy proceedings without a reaffirmation of the debt are considered TDRs unless they are covered by SMI policies. Loans discharged in Chapter 7 bankruptcy proceedings with SMI policies are also considered to be TDRs unless (i) we will not suffer more than an insignificant delay in receiving all principal and interest due or (ii) we are not relinquishing a legal right to pursue the borrower for deficiencies for those loans not affirmed. TDRs related to MPF Program loans occur when a concession is granted to a borrower for economic or legal reasons related to the borrower's financial difficulties that would not have been otherwise considered. Such TDRs generally involve modifying the borrower's monthly payment for a period of up to 36 months. MPF Program loans discharged in Chapter 7 bankruptcy proceedings without a reaffirmation of the debt are also considered TDRs. For both the MPP and the MPF Program, modifications of government loans are not considered or accounted for as TDRs because we anticipate no loss of principal or interest accrued at the original contract rate, without significant delay, due to the government-guarantee or insurance. Impairment Methodology. A loan is considered impaired when, based on current and historical information and events, it is probable that not all amounts due according to the contractual terms of the loan agreement will be collected. Loans that are considered collateral dependent are subject to individual evaluation for impairment instead of collective evaluation. Loans are considered collateral dependent if repayment is expected to be provided solely by the sale of the underlying property, i.e., there is no other available and reliable source of repayment (including LRA and SMI). We consider all impaired loans to be collateral dependent and, therefore, measure impairment based on the fair value of the underlying collateral less costs to sell. Interest income on impaired loans is recognized in the same manner as non-accrual loans. Charge-Off Policy. A charge-off is recorded to the extent that the recorded investment (including UPB, accrued interest, unamortized premiums or discounts, and hedging adjustments) in a loan will not be fully recovered. We record a charge-off on a conventional mortgage loan against the loan loss allowance upon the occurrence of a confirming event. Confirming events include, but are not limited to, the settlement of a claim against any of the credit enhancements, delinquency in excess of 180 days, and filing for bankruptcy protection. We charge-off the portion of the outstanding conventional mortgage loan balance in excess of the fair value of the underlying property, less cost to sell and adjusted for any available credit enhancements. The allowance for MPF Program conventional loans is determined by analyzing the portfolio's delinquency migration and charge-offs over a historical period to determine the probability of default and loss severity rates. The analysis of conventional loans evaluated for impairment (i) considers loan pool-specific attribute data; (ii) applies estimated default probabilities and loss severities; and (iii) incorporates the applicable credit enhancements in order to determine our best estimate of probable losses. Collectively Evaluated Mortgage Loans. MPP. For performing conventional loans current to 179 days past due and collectively evaluated for impairment, we use a recognized third-party credit model to estimate potential ranges of credit loss exposure. The loss projection is based upon distinct underlying loan characteristics, including loan vintage (year of origination), geographic location, credit support features and other factors, and a projected migration of loans through the various stages of delinquency. For delinquent conventional loans past due 180 days or more and collectively evaluated for impairment, we evaluate the pools based on current and historical information and events. This loan loss analysis incorporates third-party modeled values and considers MPP pool-specific attribute data, estimated liquidation values of real estate collateral held, estimated costs associated with maintaining and disposing of the collateral, and credit enhancements. MPF Program. Our loan loss analysis includes collectively evaluating conventional loans for impairment within each pool. The measurement of the allowance for loan losses consists of (i) evaluating homogeneous pools of current and delinquent mortgage loans; and (ii) estimating credit losses in the pool based upon the default probability ratios, loss severity rates, FLAs and CE obligations. Additional analyses include consideration of various data observations such as past performance, current performance, loan portfolio characteristics, collateral-related characteristics, industry data and prevailing economic conditions. Individually Evaluated Mortgage Loans. The measurement of our allowance for loans individually evaluated for loss considers loan-specific attribution data similar to homogeneous pools of delinquent loans evaluated on a collective basis, including the use of loan-level property values from a third-party. We also individually evaluate any remaining exposure to delinquent MPP conventional loans paid in full by the servicers. An estimate of the loss, if any, is equal to the estimated cost associated with maintaining and disposing of the property (which includes the UPB, interest owed on the delinquent loan to date, and estimated costs associated with disposing of the collateral) less the estimated fair value of the collateral (net of estimated selling costs) and the amount of credit enhancements including the PMI, LRA and SMI. The fair value of the collateral is obtained from HUD statements, sales listings or other evidence of current expected liquidation amounts.
Derivatives, Policy	Derivatives. We record derivative instruments, related cash collateral (including initial and variation margin received or pledged/posted) and associated accrued interest on a net basis, by clearing agent and/or by counterparty when the netting requirements have been met, as either derivative assets or derivative liabilities at their estimated fair values. For derivative instruments that meet the netting requirements, any excess cash collateral received or pledged is recognized as a derivative liability or derivative asset, respectively. Cash flows associated with derivatives are reported as cash flows from operating activities in the statement of cash flows unless the derivatives contain financing elements, in which case they are reflected as cash flows from financing activities. Derivative instruments that include non-standard terms, or require an upfront cash payment, or both, often contain a financing element. Changes in the estimated fair value of derivatives are recorded in earnings regardless of how changes in the estimated fair value of the assets or liabilities being hedged may be recorded. Designations. Each derivative is designated as one of the following: (i) a qualifying fair-value hedge of the change in fair value of a recognized asset or liability, an unrecognized firm commitment, or a forecasted transaction (a fair-value hedge); or (ii) a non-qualifying hedge (economic hedge) for asset/liability management purposes. Derivatives are recorded beginning on the trade date and typically executed and designated in a qualifying hedging relationship at the same time as the acquisition of the hedged item. We may also designate the hedging relationship upon the Bank's commitment to disburse an advance, purchase mortgage loans, or trade a consolidated obligation in which settlement occurs within the shortest period of time possible for the type of instrument based on market settlement conventions. Accounting for Qualifying Hedges. Hedging relationships must meet certain criteria to qualify for hedge accounting including, but not limited to, formal documentation of the hedging relationship and an expectation to be highly effective. Two approaches to hedge accounting include: (i) Long-haul hedge accounting - The application of long-haul hedge accounting requires us to formally assess (both at the hedge's inception and at least quarterly) whether the derivatives used in hedging transactions are highly effective in offsetting changes in the fair value of hedged items or forecasted transactions and whether those derivatives may be expected to remain highly effective in future periods. (ii) Short-cut hedge accounting - Transactions that meet certain criteria qualify for the short-cut method of hedge accounting in which an assumption can be made that the entire change in fair value of a hedged item, due to changes in the benchmark rate, exactly offsets the entire change in fair value of the related derivative. Therefore, the derivative is considered to be highly effective at achieving offsetting changes in fair values of the hedged asset or liability. For all existing hedging relationships entered into prior to April 1, 2008, we continue to use the short-cut method of accounting provided they still meet the assumption of "no ineffectiveness." We no longer apply this method to any other hedging relationships. Changes in the fair value of a derivative that is designated and qualifies 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 firm commitments), are recorded in other income (loss) as net gains (losses) on derivatives and hedging activities. As a result, for fair-value hedges, 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 attributable to the hedged risk) is recorded in other income (loss) as net gains (losses) on derivatives and hedging activities. Accounting for Non-Qualifying Hedges. An economic hedge is defined as a derivative that hedges specific or non-specific underlying assets, liabilities, or firm commitments and does not qualify, or was not designated, for hedge accounting. As a result, we recognize only the net interest settlement and the change in fair value of these derivatives in other income (loss) as net gains (losses) on derivatives and hedging activities with no offsetting fair value adjustments in earnings for the hedged assets, liabilities, or firm commitments. An economic hedge by definition, therefore, introduces the potential for earnings variability. Accrued Interest Receivables and Payables. The difference between the interest receivable and payable on a derivative designated as a qualifying hedge is recognized as an adjustment to the income or expense of the designated hedged item. Discontinuance of Hedge Accounting. We discontinue hedge accounting prospectively when: (i) the hedging relationship ceases to be highly effective; (ii) the derivative and/or the hedged item expires or is sold, terminated, or exercised; (iii) a hedged firm commitment no longer meets the definition of a firm commitment; or (iv) we elect to discontinue hedge accounting. When hedge accounting is discontinued, we either terminate the derivative or continue to carry the derivative 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 interest income over the remaining life of the hedged item using a level-yield methodology. Embedded Derivatives. We may issue consolidated obligations, disburse advances, or purchase financial instruments in which a derivative instrument is embedded. In order to determine whether an embedded derivative must be bifurcated from the host instrument and separately valued, we must assess, upon execution of the transaction, whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the consolidated obligation, advance or purchased financial instrument (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. If we determine that (i) the embedded derivative has economic characteristics that are not clearly and closely related to the economic characteristics of the host contract and (ii) 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 an economic hedge, and the host contract is accounted for based on the guidance applicable to instruments of that type that are not hedged. However, if (i) the entire contract (the host contract and the embedded derivative) is required to be measured at fair value, with changes in fair value reported in earnings (such as an investment security classified as trading), or (ii) we cannot reliably identify and measure the embedded derivative for purposes of separating that derivative from its host contract, the entire contract is carried at fair value, and no portion of the contract is designated as a hedging instrument.
Financial Instruments Meeting Netting Requirements, Policy	We present certain financial instruments, including our derivative asset and liability positions as well as cash collateral received or pledged, on a net basis when we have a legal right of offset and all other requirements for netting are met (collectively referred to as the netting requirements). The net exposure for these financial instruments can change on a daily basis; therefore, there may be a delay between the time a change in the exposure is identified and additional collateral is requested, and the time the additional collateral is received or pledged. Likewise, there may be a delay before excess collateral is returned. For derivative instruments that meet the netting requirements, any excess cash collateral received or pledged is recognized as a derivative liability or derivative asset, respectively.
Premises, Software, and Equipment, Policy	Premises, Software, and Equipment. We record premises, software, and equipment at cost, less accumulated depreciation and amortization, and compute depreciation and amortization using the straight-line method over their respective estimated useful lives, which range from 1 to 40 years. We capitalize improvements and major renewals, but expense maintenance and repairs when incurred. We depreciate building improvements using the straight-line method over the shorter of the estimated useful life of the improvement or the remaining life of the building. In addition, we capitalize software development costs for internal use software with an estimated economic useful life of at least one year. If capitalized, we use the straight-line method for computing amortization. We include any gain or loss on disposal (other than abandonment) of premises, software, and equipment in other income (loss). Any loss on abandonment of premises, software, and equipment is included in other operating expenses.
Consolidated Obligations, Policy	Consolidated Obligations. Consolidated obligations are recorded at amortized cost, adjusted for concessions, accretion of discounts, amortization of premiums, principal payments, and fair-value hedging adjustments. Discounts and Premiums. We accrete/amortize the discounts and premiums as well as hedging basis adjustments on CO bonds to interest expense using the level-yield interest method over the term to contractual maturity of the corresponding CO bonds. Any remaining unamortized premium or discount is recognized upon prepayment. Concessions. Concessions are paid to dealers in connection with the issuance of certain consolidated obligations. The Office of Finance prorates the amount of our concession based upon the percentage of the debt issued on our behalf. We record concessions paid on consolidated obligations as a direct deduction from their carrying amounts, consistent with the presentation of discounts on consolidated obligations. The concessions are deferred and amortized, using the level-yield interest method, to interest expense over the term to contractual maturity of the corresponding consolidated obligations. Any remaining unamortized concessions are recognized upon prepayment.
Mandatorily Redeemable Capital Stock, Policy	Mandatorily Redeemable Capital Stock. When a member withdraws or attains non-member status by merger or acquisition, charter termination, relocation or other involuntary termination from membership, the member's shares are then subject to redemption, at which time a five-year redemption period commences. Since the shares meet the definition of a mandatorily redeemable financial instrument, the shares are reclassified from capital to liabilities as MRCS at estimated fair value, which is equal to par value. Dividends declared on shares classified as a liability are accrued at the expected dividend rate and reported as interest expense. We reclassify MRCS from liabilities to capital when non-members subsequently become members through either acquisition, merger, or election. After the reclassification, dividends declared on that capital stock are no longer classified as interest expense.
Pension and Other Postretirement Plans, Pensions, Policy [Policy Text Block]	Employee Retirement and Deferred Compensation Plans. We recognize the minimum required contribution to the DB plan as expense ratably over the plan year to which it relates. Without a prefunding election, any contribution made in excess of the minimum required contribution is recorded as an expense in the quarterly reporting period in which the contribution is made.
Restricted Retained Earnings, Policy	Restricted Retained Earnings. In accordance with the Bank's JCE Agreement, we allocate 20% of our net income each quarter to a separate restricted retained earnings account until the balance of that account equals at least 1% of the average balance of our outstanding consolidated obligations for the previous quarter.
Gains on Litigation Settlements, Policy	Gains on Litigation Settlements. Litigation settlement gains, net of related legal fees and litigation expenses, are recorded in other income when realized. A litigation settlement gain is considered realized when we receive cash or assets that are readily convertible to known amounts of cash or claims to cash. In addition, a settlement gain is considered realized when we enter into a signed agreement not subject to appeal, the counterparty has the ability to pay, and the amount to be received can be reasonably estimated. Prior to being realized, we consider potential litigation settlement gains to be gain contingencies and, therefore, they are not recorded in the statement of income.
Finance Agency Expenses, Policy	Finance Agency Expenses. The portion of the Finance Agency's expenses and working capital fund not allocated to Freddie Mac and Fannie Mae is allocated among the FHLBanks as assessments, which are based on the ratio of each FHLBank's minimum required regulatory capital to the aggregate minimum required regulatory capital of every FHLBank.
Office of Finance Expenses, Policy	Office of Finance Expenses. Our proportionate share of the Office of Finance's operating and capital expenditures is calculated based upon two components as follows: (i) two-thirds based on our share of total consolidated obligations outstanding and (ii) one-third based on equal pro rata allocation. We record our share of these expenditures in other expenses.
Assessments, Policy	Assessments. The Bank Act requires each FHLBank to establish and fund an AHP, which provides subsidies to members to assist in the purchase, construction, or rehabilitation of housing for very low- to moderate-income households. Each period, we charge/(credit) the required funding for AHP to earnings and increase/(decrease) the associated liability. We typically make the AHP subsidy available to members as a grant. As an alternative, we can issue AHP advances at interest rates below the customary interest rate for non-subsidized advances.
Fair Value of Financial Instruments, Policy	We estimate fair value amounts by using available market and other pertinent information and the most appropriate valuation methods. Although we use our best judgment in estimating the fair values of financial instruments, there are inherent limitations in any valuation technique. Therefore, these estimated fair values may not be indicative of the amounts that would have been realized in market transactions at the reporting dates. Certain estimates of the fair value of financial assets and liabilities are highly subjective and require judgments regarding significant factors such as the amount and timing of future cash flows, prepayment speeds, interest-rate volatility, and the discount rates that appropriately reflect market and credit risks. The use of different assumptions could have a material effect on the fair value estimates. Fair Value Hierarchy . GAAP establishes a fair value hierarchy and requires us to maximize the use of significant observable inputs and minimize the use of significant unobservable inputs when measuring estimated fair value. The inputs are evaluated, and an overall level for the estimated fair value measurement is determined. This overall level is an indication of the extent of the market observability of the estimated fair value measurement for the asset or liability. The fair value hierarchy prioritizes the inputs used to measure fair value into three broad levels: Level 1 Inputs. Quoted prices (unadjusted) for identical assets or liabilities in an active market that we can access on the measurement date. Level 2 Inputs. Inputs other than quoted prices within level 1 that are observable inputs for the asset or liability, either directly or indirectly. If the asset or liability has a specified or contractual term, a level 2 input must be observable for substantially the full term of the asset or liability. Level 2 inputs include (i) quoted prices for similar assets or liabilities in active markets; (ii) quoted prices for identical or similar assets or liabilities in markets that are not active; (iii) inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates and yield curves that are observable at commonly quoted intervals and implied volatilities); and (iv) inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3 Inputs. Unobservable inputs for the asset or liability.
Fair Value Transfer, Policy	We review the fair value hierarchy classifications on a quarterly basis. Changes in the observability of the inputs may result in a reclassification of certain assets or liabilities. Such reclassifications are reported as transfers in/out at estimated fair value as of the beginning of the quarter in which the changes occur.
Segment Reporting, Policy	We report based on two operating segments: • Traditional, which consists of credit products (including advances, letters of credit, and lines of credit), investments (including federal funds sold, securities purchased under agreements to resell, AFS securities and HTM securities), and correspondent services and deposits; and • Mortgage loans, which consists of mortgage loans purchased from our members through our MPP and participating interests purchased in 2012 - 2014 from the FHLBank of Topeka in mortgage loans that were originated by certain of its PFIs under the MPF Program. These segments reflect our 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 we provide services to members. We measure the performance of each segment based upon the net interest spread of the underlying portfolio(s). Therefore, each segment's performance begins with net interest income. Traditional net interest income is derived primarily from the difference, or spread, between the interest income earned on advances and investments and the borrowing costs related to those assets, net interest settlements related to interest-rate swaps, and related premium and discount amortization. Traditional also includes the costs related to holding deposits for members and other miscellaneous borrowings as well as all other miscellaneous income and expense not associated with mortgage loans. Mortgage loan net interest income is derived primarily from the difference, or spread, between the interest income earned on mortgage loans, including the premium and discount amortization, and the borrowing costs related to those loans. Direct other income and expense also affect each segment's results. The traditional segment includes the direct earnings impact of derivatives and hedging activities related to advances and investments as well as all other income and expense not associated with mortgage loans. The mortgage loans segment includes the direct earnings impact of derivatives and hedging activities as well as direct compensation, benefits and other expenses (including an allocation for indirect overhead) associated with operating the MPP and MPF Program and volume-driven costs associated with master servicing and quality control fees. The assessments related to AHP have been allocated to each segment based upon its proportionate share of income before assessments.
Cash Flows, Policy	Cash Flows. We consider cash and due from banks on the statement of condition as cash and cash equivalents within the statement of cash flows because of their highly liquid nature. Federal funds sold, securities purchased under agreements to resell, and interest-bearing deposits are not treated as cash and cash equivalents, but instead are treated as short-term investments. Accordingly, their associated cash flows are reported in the investing activities section of the statement of cash flows.

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Available-for-sale Securities [Line Items]
Available-for-Sale (AFS) Securities by Major Security Type	The following table presents our AFS securities by type of security. Gross Gross Amortized Non-Credit Unrealized Unrealized Estimated December 31, 2017 Cost (1) OTTI Gains Losses Fair Value GSE and TVA debentures $ 4,357,250 $ — $ 46,679 $ — $ 4,403,929 GSE MBS 2,460,455 — 45,840 — 2,506,295 Private-label RMBS 189,212 (68 ) 29,390 — 218,534 Total AFS securities $ 7,006,917 $ (68 ) $ 121,909 $ — $ 7,128,758 December 31, 2016 GSE and TVA debentures $ 4,693,211 $ — $ 25,624 $ (4,201 ) $ 4,714,634 GSE MBS 1,058,037 — 18,279 (234 ) 1,076,082 Private-label RMBS 242,181 (263 ) 27,201 — 269,119 Total AFS securities $ 5,993,429 $ (263 ) $ 71,104 $ (4,435 ) $ 6,059,835 (1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses) and fair-value hedge accounting adjustments.
Available-for-sale Securities [Member]
Available-for-sale Securities [Line Items]
AFS Securities in a Continuous Unrealized Loss Position	The following table presents impaired AFS securities (i.e., in an unrealized loss position), aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position. Less than 12 months 12 months or more Total Estimated Unrealized Estimated Unrealized Estimated Unrealized December 31, 2017 Fair Value Losses Fair Value Losses Fair Value Losses GSE and TVA debentures $ — $ — $ — $ — $ — $ — GSE MBS — — — — — — Private-label RMBS — — 2,494 (68 ) 2,494 (68 ) Total impaired AFS securities $ — $ — $ 2,494 $ (68 ) $ 2,494 $ (68 ) December 31, 2016 GSE and TVA debentures $ 525,722 $ (3,604 ) $ 176,104 $ (597 ) $ 701,826 $ (4,201 ) GSE MBS — — 78,704 (234 ) 78,704 (234 ) Private-label RMBS — — 3,002 (263 ) 3,002 (263 ) Total impaired AFS securities $ 525,722 $ (3,604 ) $ 257,810 $ (1,094 ) $ 783,532 $ (4,698 )
AFS Securities by Contractual Maturity	The amortized cost and estimated fair value of non-MBS AFS securities are presented below by contractual maturity. MBS are not presented by contractual maturity because their actual maturities will likely differ from their contractual maturities as borrowers have the right to prepay their obligations with or without prepayment fees. December 31, 2017 December 31, 2016 Amortized Estimated Amortized Estimated Year of Contractual Maturity Cost Fair Value Cost Fair Value Due in 1 year or less $ 83,666 $ 83,754 $ 972,508 $ 974,215 Due after 1 year through 5 years 2,317,516 2,336,699 1,841,488 1,855,517 Due after 5 years through 10 years 1,766,440 1,791,829 1,734,156 1,740,029 Due after 10 years 189,628 191,647 145,059 144,873 Total non-MBS 4,357,250 4,403,929 4,693,211 4,714,634 Total MBS 2,649,667 2,724,829 1,300,218 1,345,201 Total AFS securities $ 7,006,917 $ 7,128,758 $ 5,993,429 $ 6,059,835

Held-to-Maturity Securities (Ta

Held-to-Maturity Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
HTM Securities by Major Security Type	The following table presents our HTM securities by type of security. Gross Gross Unrecognized Unrecognized Estimated Amortized Non-Credit Carrying Holding Holding Fair December 31, 2017 Cost (1) OTTI Value Gains Losses Value MBS and ABS: Other U.S. obligations -guaranteed MBS $ 3,299,157 $ — $ 3,299,157 $ 6,555 $ (6,690 ) $ 3,299,022 GSE MBS 2,553,193 — 2,553,193 26,727 (4,529 ) 2,575,391 Private-label RMBS 37,889 — 37,889 240 (307 ) 37,822 Private-label ABS 7,480 (51 ) 7,429 40 (405 ) 7,064 Total HTM securities $ 5,897,719 $ (51 ) $ 5,897,668 $ 33,562 $ (11,931 ) $ 5,919,299 December 31, 2016 MBS and ABS: Other U.S. obligations -guaranteed MBS $ 2,678,437 $ — $ 2,678,437 $ 5,412 $ (12,720 ) $ 2,671,129 GSE MBS 3,082,343 — 3,082,343 46,480 (8,841 ) 3,119,982 Private-label RMBS 49,748 — 49,748 61 (533 ) 49,276 Private-label ABS 9,148 (103 ) 9,045 40 (780 ) 8,305 Total HTM securities $ 5,819,676 $ (103 ) $ 5,819,573 $ 51,993 $ (22,874 ) $ 5,848,692 (1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses).
Held-to-maturity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
HTM Securities in a Continuous Unrealized Loss Position	The following table presents impaired HTM securities (i.e., in an unrealized loss position), aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position. Less than 12 months 12 months or more Total Estimated Unrealized Estimated Unrealized Estimated Unrealized December 31, 2017 Fair Value Losses Fair Value Losses Fair Value Losses (1) MBS and ABS: Other U.S. obligations - guaranteed MBS $ 1,140,624 $ (3,274 ) $ 886,359 $ (3,416 ) $ 2,026,983 $ (6,690 ) GSE MBS 513,244 (2,191 ) 203,401 (2,338 ) 716,645 (4,529 ) Private-label RMBS 14,712 (26 ) 11,369 (281 ) 26,081 (307 ) Private-label ABS — — 7,064 (416 ) 7,064 (416 ) Total impaired HTM securities $ 1,668,580 $ (5,491 ) $ 1,108,193 $ (6,451 ) $ 2,776,773 $ (11,942 ) December 31, 2016 MBS and ABS: Other U.S. obligations - guaranteed MBS $ 367,474 $ (997 ) $ 1,426,182 $ (11,723 ) $ 1,793,656 $ (12,720 ) GSE MBS 1,281,827 (7,915 ) 320,141 (926 ) 1,601,968 (8,841 ) Private-label RMBS 18,166 (62 ) 15,770 (471 ) 33,936 (533 ) Private-label ABS — — 8,304 (843 ) 8,304 (843 ) Total impaired HTM securities $ 1,667,467 $ (8,974 ) $ 1,770,397 $ (13,963 ) $ 3,437,864 $ (22,937 ) (1) For private-label ABS, the total of unrealized losses does not agree to total gross unrecognized holding losses at December 31, 2017 and 2016 of $405 and $780 , respectively. Total unrealized losses include non-credit-related OTTI losses recorded in AOCI of $51 and $103 , respectively, and gross unrecognized holding gains on previously OTTI securities of $40 and $40 , respectively.

Other-Than-Temporary Impairme33

Other-Than-Temporary Impairment Analysis (Tables)	12 Months Ended
	Dec. 31, 2017
Other than Temporary Impairment Losses, Investments [Abstract]
Schedule of Significant Inputs In Measuring Other Than Temporary Impairments Recognized In Earnings	The following table presents the other significant modeling assumptions used to determine the amount of credit loss recognized in earnings during the year ended December 31, 2017 on the two private-label RMBS for which an OTTI was determined to have occurred, as well as the related current credit enhancement. Significant Modeling Assumptions Current Credit Classification (1) Prepayment Rates Default Rates Loss Severities Enhancement (2) Prime 9 % 11 % 26 % — % Subprime (3) 8 % 40 % 42 % — % (1) The classification (prime, Alt-A or subprime) is based on the model used to project the cash flows for the security, which may not be the same as the rating agency's classification at the time of origination. (2) Credit enhancement is defined as the percentage of subordinated tranches, excess spread, and over-collateralization, if any, in a security structure that will generally absorb losses before we will experience a loss on the security. A credit enhancement percentage of zero reflects a security that has no remaining credit support and is likely to have experienced an actual principal loss. (3) Modeling assumptions assume no payout from monoline bond insurers.
Rollforward of the Amounts Related to Credit Losses Recognized into Earnings	The following table presents a rollforward of the amounts related to credit losses recognized in earnings. The rollforward excludes accretion of credit losses for securities that have not experienced a significant increase in cash flows. Credit Loss Rollforward 2017 2016 2015 Balance at beginning of year $ 51,514 $ 60,673 $ 69,626 Additions: Additional credit losses for which OTTI was previously recognized (1) 207 197 61 Reductions: Increases in cash flows expected to be collected (accreted as interest income over the remaining lives of the applicable securities) (6,786 ) (9,356 ) (9,014 ) Balance at end of year $ 44,935 $ 51,514 $ 60,673 (1) Relates to all securities impaired prior to January 1, 2017 , 2016 , and 2015 , respectively.
Total Securities Other-than-Temporarily Impaired during the Life of the Security	The following table presents the December 31, 2017 classification and balances of OTTI securities impaired prior to that date (i.e., life-to-date) but not necessarily as of that date. December 31, 2017 HTM Securities AFS Securities Estimated Estimated OTTI Life-to-Date (1) UPB Amortized Cost Carrying Value Fair Value UPB Amortized Cost Fair Value Private-label RMBS - prime $ — $ — $ — $ — $ 224,574 $ 189,212 $ 218,534 Private-label ABS - subprime 552 487 436 476 — — — Total $ 552 $ 487 $ 436 $ 476 $ 224,574 $ 189,212 $ 218,534 (1) Securities are classified based on the originator's classification at the time of origination or based on the classification by the NRSROs upon issuance. Because there is no universally accepted definition of prime, Alt-A or subprime underwriting standards, such classifications are subjective.

Advances (Tables)

Advances (Tables)	12 Months Ended
	Dec. 31, 2017
Advances [Abstract]
Federal Home Loan Bank, Advances [Table Text Block]	The following table presents advances outstanding by year of contractual maturity. December 31, 2017 December 31, 2016 Year of Contractual Maturity Amount WAIR % Amount WAIR % Overdrawn demand and overnight deposit accounts $ — — $ — — Due in 1 year or less 16,935,411 1.46 12,598,864 0.91 Due after 1 year through 2 years 2,701,784 1.96 2,752,629 1.74 Due after 2 years through 3 years 2,682,073 1.69 1,920,962 2.10 Due after 3 years through 4 years 2,172,549 1.78 2,605,198 1.38 Due after 4 years through 5 years 2,213,319 1.93 2,009,395 1.47 Thereafter 7,464,333 1.66 6,244,912 1.20 Total advances, par value 34,169,469 1.61 28,131,960 1.22 Fair-value hedging adjustments (126,137 ) (57,716 ) Unamortized swap termination fees associated with modified advances, net of deferred prepayment fees 11,732 21,709 Total advances $ 34,055,064 $ 28,095,953 We offer our members certain advances that provide them the right, at predetermined future dates, to call (i.e., prepay) the advance prior to maturity without incurring prepayment or termination fees. Borrowers typically exercise their call options for fixed-rate advances when interest rates decline. We also offer certain adjustable-rate advances that may be contractually prepaid by the borrower at the interest-rate reset date without incurring prepayment or termination fees. All other advances may only be prepaid by paying a fee that is sufficient to make us financially indifferent to the prepayment of the advance. We also offer putable advances. Under the terms of a putable advance, we retain the right to extinguish or put the fixed-rate advance to the member on predetermined future dates and offer replacement funding at prevailing market rates, subject to certain conditions. The following table presents advances outstanding by the earlier of the year of contractual maturity or the next call date and next put date. Year of Contractual Maturity or Next Call Date Year of Contractual Maturity or Next Put Date December 31, December 31, December 31, December 31, Overdrawn demand and overnight deposit accounts $ — $ — $ — $ — Due in 1 year or less 25,067,272 19,390,714 17,032,411 12,767,364 Due after 1 year through 2 years 2,412,184 2,502,629 2,701,784 2,757,629 Due after 2 years through 3 years 1,716,873 1,856,463 3,406,673 1,915,962 Due after 3 years through 4 years 928,649 1,548,998 2,718,049 2,605,198 Due after 4 years through 5 years 1,494,529 900,095 2,524,619 2,535,895 Thereafter 2,549,962 1,933,061 5,785,933 5,549,912 Total advances, par value $ 34,169,469 $ 28,131,960 $ 34,169,469 $ 28,131,960 In accordance with the Final Membership Rule, captive insurance companies that were admitted as FHLBank members on or after September 12, 2014 repaid all of their outstanding advances and had their memberships terminated by February 19, 2017. Under the Final Membership Rule, captive insurance companies that were admitted as FHLBank members prior to September 12, 2014, and do not meet the new definition of "insurance company" or fall within another category of institution that is eligible for FHLBank membership, shall have their memberships terminated no later than February 19, 2021. Prior to termination, new or renewed extensions of credit to such members will be subject to certain restrictions relating to maturity dates and the ratio of advances to the captive insurer's total assets and may be subject to additional restrictions at our discretion. The outstanding advances to these captive insurers mature on various dates through 2025.

Mortgage Loans Held for Portf35

Mortgage Loans Held for Portfolio (Tables)	12 Months Ended
	Dec. 31, 2017
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans Held for Portfolio	The following tables present information on mortgage loans held for portfolio by term and type. Term December 31, 2017 December 31, 2016 Fixed-rate long-term mortgages $ 8,989,545 $ 8,086,412 Fixed-rate medium-term (1) mortgages 1,134,303 1,206,978 Total mortgage loans held for portfolio, UPB 10,123,848 9,293,390 Unamortized premiums 234,519 210,116 Unamortized discounts (2,426 ) (2,383 ) Fair-value hedging adjustments 1,250 1,124 Allowance for loan losses (850 ) (850 ) Total mortgage loans held for portfolio, net $ 10,356,341 $ 9,501,397 (1) Defined as a term of 15 years or less at origination. Type December 31, 2017 December 31, 2016 Conventional $ 9,701,600 $ 8,796,407 Government -guaranteed or -insured 422,248 496,983 Total mortgage loans held for portfolio, UPB $ 10,123,848 $ 9,293,390

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Allowance for Credit Losses [Abstract]
Changes in Lender Risk Account	The following table presents the activity in the LRA, which is reported in other liabilities. LRA Activity 2017 2016 2015 Liability, beginning of year $ 125,683 $ 91,552 $ 61,949 Additions 25,350 36,341 31,573 Claims paid (617 ) (1,054 ) (1,576 ) Distributions to PFIs (1,701 ) (1,156 ) (394 ) Liability, end of year $ 148,715 $ 125,683 $ 91,552
Individually Evaluated Impaired Loan Statistics by Product Class Level [Table Text Block]	The tables below present the conventional loans individually evaluated for impairment with and without an allowance for loan losses. Due to the minimal change in terms of modified loans (i.e., no principal forgiven), our pre-modification recorded investment in TDRs was not materially different than the post-modification recorded investment. December 31, 2017 December 31, 2016 Individually Evaluated Impaired Loans Recorded Investment UPB Related Allowance for Loan Losses Recorded Investment UPB Related Allowance for Loan Losses MPP conventional loans without allowance for loan losses (1) $ 13,261 $ 13,343 $ — $ 15,158 $ 15,219 $ — MPP conventional loans with allowance for loan losses 1,270 1,272 54 349 358 30 Total $ 14,531 $ 14,615 $ 54 $ 15,507 $ 15,577 $ 30 (1) No allowance for loan losses was recorded on these impaired loans after consideration of the underlying loan-specific attribute data, estimated liquidation value of real estate collateral held, estimated costs associated with maintaining and disposing of the collateral, and credit enhancements.
Impaired Financing Receivables [Table Text Block]	Years Ended December 31, 2017 2016 2015 Individually Evaluated Impaired Loans Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized MPP conventional loans without allowance for loan losses $ 14,011 $ 675 $ 16,623 $ 758 $ 17,967 $ 872 MPP conventional loans with allowance for loan losses 1,259 69 353 39 881 105 Total $ 15,270 $ 744 $ 16,976 $ 797 $ 18,848 $ 977
Recorded Investment in Delinquent Mortgage Loans	Credit Quality Indicators. The tables below present the key credit quality indicators for our mortgage loans held for portfolio. Delinquency Status as of December 31, 2017 Conventional Government Total Past due: 30-59 days $ 63,670 $ 11,848 $ 75,518 60-89 days 9,944 2,121 12,065 90 days or more 19,576 2,555 22,131 Total past due 93,190 16,524 109,714 Total current 9,878,030 412,869 10,290,899 Total mortgage loans, recorded investment (1) $ 9,971,220 $ 429,393 $ 10,400,613 Delinquency Status as of December 31, 2016 Past due: 30-59 days $ 46,118 $ 17,183 $ 63,301 60-89 days 11,044 3,548 14,592 90 days or more 29,098 2,350 31,448 Total past due 86,260 23,081 109,341 Total current 8,949,441 482,316 9,431,757 Total mortgage loans, recorded investment (1) $ 9,035,701 $ 505,397 $ 9,541,098 Other Delinquency Statistics as of December 31, 2017 Conventional Government Total In process of foreclosure (2) $ 11,081 $ — $ 11,081 Serious delinquency rate (3) 0.20 % 0.59 % 0.21 % Past due 90 days or more still accruing interest (4) $ 16,603 $ 2,555 $ 19,158 On non-accrual status $ 3,464 $ — $ 3,464 Other Delinquency Statistics as of December 31, 2016 In process of foreclosure (2) $ 17,749 $ — $ 17,749 Serious delinquency rate (3) 0.32 % 0.46 % 0.33 % Past due 90 days or more still accruing interest (4) $ 25,375 $ 2,350 $ 27,725 On non-accrual status $ 4,699 $ — $ 4,699 (1) The recorded investment in a loan is the UPB of the loan, adjusted for accrued interest, net of any deferred loan fees or costs, unamortized premiums or discounts (which may include the basis adjustment related to any gain or loss on a delivery commitment prior to being funded) and direct charge-offs. The recorded investment is not net of any valuation allowance. (2) Includes loans for which the decision of foreclosure or similar alternative, such as pursuit of deed-in-lieu of foreclosure, has been reported. Loans in process of foreclosure are included in past due categories depending on their delinquency status, but are not necessarily considered to be on non-accrual status. (3) Represents loans 90 days or more past due (including loans in process of foreclosure) expressed as a percentage of the total recorded investment in mortgage loans. The percentage excludes principal and interest amounts previously paid in full by the servicers on conventional loans that are pending resolution of potential loss claims. Our servicers repurchase seriously delinquent government loans, including FHA loans, when certain criteria are met. (4) Although our past due scheduled/scheduled MPP loans are classified as loans past due 90 days or more based on the mortgagor's payment status, we do not consider these loans to be on non-accrual status.
Impact of MPP Risk Sharing Structure on Allowance for Credit Losses	The following table presents the components of the allowance for loan losses, including the credit enhancement waterfall for MPP. Components of Allowance December 31, December 31, MPP estimated incurred losses remaining after borrower's equity, before credit enhancements (1) $ 5,360 $ 8,689 Portion of estimated incurred losses recoverable from credit enhancements: PMI (995 ) (1,981 ) LRA (2) (1,262 ) (2,418 ) SMI (2,383 ) (3,590 ) Total portion recoverable from credit enhancements (4,640 ) (7,989 ) Allowance for unrecoverable PMI/SMI 30 50 Allowance for MPP loan losses 750 750 Allowance for MPF Program loan losses 100 100 Total allowance for loan losses $ 850 $ 850 (1) Based on a loss emergence period of 24 months. (2) Amounts recoverable are limited to (i) the estimated losses remaining after borrower's equity and PMI and (ii) the remaining balance in each pool's portion of the LRA. The remainder of the total LRA balance is available to cover any losses not yet incurred and to distribute any excess funds to the PFIs.
Rollforward of Allowance for Credit Losses on Mortgage Loans	The tables below present a rollforward of our allowance for loan losses, the allowance for loan losses by impairment methodology, and the recorded investment in mortgage loans by impairment methodology. Rollforward of Allowance for Loan Losses 2017 2016 2015 Balance, beginning of year $ 850 $ 1,125 $ 2,500 Charge-offs (647 ) (857 ) (1,168 ) Recoveries 596 627 249 Provision for (reversal of) loan losses 51 (45 ) (456 ) Balance, end of year $ 850 $ 850 $ 1,125
Allowance for Credit Losses and Recorded Investment by Impairment Methodology	Allowance for Loan Losses by Impairment Methodology December 31, 2017 December 31, 2016 Conventional loans collectively evaluated for impairment $ 652 $ 750 Conventional loans individually evaluated for impairment (1) 198 100 Total allowance for loan losses $ 850 $ 850 Recorded Investment by Impairment Methodology December 31, 2017 December 31, 2016 Conventional loans collectively evaluated for impairment $ 9,956,689 $ 9,020,194 Conventional loans individually evaluated for impairment (1) 14,531 15,507 Total recorded investment in conventional loans $ 9,971,220 $ 9,035,701 (1) The recorded investment in our MPP conventional loans individually evaluated for impairment excludes principal previously paid in full by the servicers as of December 31, 2017 and 2016 of $2,498 and $2,814 , respectively, that remains subject to potential claims by those servicers for any losses resulting from past or future liquidations of the underlying properties. However, the MPP allowance for loan losses as of December 31, 2017 and 2016 includes $144 and $70 , respectively, for these potential claims.

Premises, Software and Equipm37

Premises, Software and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of premises, software and equipment	The following table presents information on our premises, software and equipment. Type December 31, December 31, Premises $ 15,242 $ 14,958 Computer software 38,559 38,497 Data processing equipment 8,846 7,505 Furniture and equipment 4,539 3,920 Other 563 513 Premises, software and equipment, in service 67,749 65,393 Accumulated depreciation and amortization (36,085 ) (30,121 ) Premises, software and equipment, in service, net 31,664 35,272 Capitalized assets in progress 5,131 2,366 Premises, software and equipment, net $ 36,795 $ 37,638

Derivatives and Hedging Activ38

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments	The following table presents the notional amount and estimated fair value of derivative assets and liabilities. Notional Estimated Fair Value Estimated Fair Value Amount of of Derivative of Derivative December 31, 2017 Derivatives Assets Liabilities Derivatives designated as hedging instruments: Interest-rate swaps $ 31,084,068 $ 298,625 $ 76,205 Total derivatives designated as hedging instruments 31,084,068 298,625 76,205 Derivatives not designated as hedging instruments: Interest-rate swaps 1,026,778 1,187 734 Swaptions — — — Interest-rate caps/floors 245,500 92 — Interest-rate forwards 72,800 37 1 MDCs 70,831 73 48 Total derivatives not designated as hedging instruments 1,415,909 1,389 783 Total derivatives before adjustments $ 32,499,977 300,014 76,988 Netting adjustments (1) (150,868 ) (150,868 ) Cash collateral and variation margin for daily settled contracts (1) (20,940 ) 76,598 Total derivatives, net $ 128,206 $ 2,718 December 31, 2016 Derivatives designated as hedging instruments: Interest-rate swaps $ 23,998,498 $ 230,705 $ 102,201 Total derivatives designated as hedging instruments 23,998,498 230,705 102,201 Derivatives not designated as hedging instruments: Interest-rate swaps 901,344 1,430 31 Swaptions 350,000 2 50 Interest-rate caps/floors 364,500 322 2 Interest-rate forwards 99,100 339 352 MDCs 99,002 303 471 Total derivatives not designated as hedging instruments 1,813,946 2,396 906 Total derivatives before adjustments $ 25,812,444 233,101 103,107 Netting adjustments (1) (133,089 ) (133,089 ) Cash collateral (1) 34,836 55,207 Total derivatives, net $ 134,848 $ 25,225 (1) Represents the application of the netting requirements that allow us to settle (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (including fair value adjustments on derivatives for which variation margin payments are characterized as daily settled contracts). Cash collateral pledged to counterparties at December 31, 2017 and 2016 totaled $16,437 and $35,422 , respectively. Cash collateral received from counterparties at December 31, 2017 and 2016 totaled $89,021 and $55,793 , respectively. Variation margin for daily settled contracts totaled $24,954 at December 31, 2017 .
Offsetting Derivative Assets and Liabilities	The following table presents separately the estimated fair value of derivative instruments meeting and not meeting netting requirements, including the effect of the related collateral received from or pledged to counterparties and variation margin for daily settled contracts. December 31, 2017 December 31, 2016 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivative instruments meeting netting requirements: Gross recognized amount Uncleared $ 118,932 $ 27,491 $ 86,606 $ 45,449 Cleared 180,972 49,448 145,853 56,835 Total gross recognized amount 299,904 76,939 232,459 102,284 Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts Uncleared (113,842 ) (24,822 ) (76,255 ) (21,047 ) Cleared (1) (57,966 ) (49,448 ) (21,998 ) (56,835 ) Total gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts (171,808 ) (74,270 ) (98,253 ) (77,882 ) Net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts Uncleared 5,090 2,669 10,351 24,402 Cleared 123,006 — 123,855 — Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts 128,096 2,669 134,206 24,402 Derivative instruments not meeting netting requirements (2) 110 49 642 823 Total derivatives, at estimated fair value $ 128,206 $ 2,718 $ 134,848 $ 25,225 (1) Variation margin for daily settled contracts totaled $24,954 at December 31, 2017 . (2) Includes MDCs and certain interest-rate forwards.
Components of Net Gains (Losses) on Derivatives and Hedging Activities	The following table presents the components of net gains (losses) on derivatives and hedging activities reported in other income (loss). Years Ended December 31, Type of Hedge 2017 2016 2015 Net gain (loss) related to fair-value hedge ineffectiveness: Interest-rate swaps $ (7,414 ) $ 4,488 $ 4,146 Total net gain (loss) related to fair-value hedge ineffectiveness (7,414 ) 4,488 4,146 Net gain (loss) on derivatives not designated as hedging instruments: Economic hedges: Interest-rate swaps 122 (196 ) 1,497 Swaptions (200 ) (290 ) — Interest-rate caps/floors (228 ) 87 (251 ) Interest-rate forwards (1,728 ) (207 ) (3,372 ) Net interest settlements (416 ) (381 ) 392 MDCs 835 (1,229 ) 420 Total net gain (loss) on derivatives not designated as hedging instruments (1,615 ) (2,216 ) (1,314 ) Other (1) (229 ) — — Net gains (losses) on derivatives and hedging activities $ (9,258 ) $ 2,272 $ 2,832 (1) Consists of price alignment amounts on derivatives for which variation margin payments are characterized as daily settled contracts.
Effect of Fair Value Hedge-Related Derivative Instruments	The following table presents, by type of hedged item, the gains (losses) on the derivatives and the related hedged items in fair-value hedging relationships and the effect of those derivatives on net interest income. Gain (Loss) Gain (Loss) Net Fair- Effect on on on Hedged Value Hedge Net Interest Year Ended December 31, 2017 Derivative Item Ineffectiveness Income (1) Advances $ 61,439 $ (62,324 ) $ (885 ) $ (31,461 ) AFS securities 35,620 (39,843 ) (4,223 ) (48,144 ) CO bonds (46,299 ) 43,993 (2,306 ) 16,289 Total $ 50,760 $ (58,174 ) $ (7,414 ) $ (63,316 ) Year Ended December 31, 2016 Advances $ 118,029 $ (117,201 ) $ 828 $ (91,219 ) AFS securities 193,305 (194,083 ) (778 ) (94,018 ) CO bonds (30,252 ) 34,690 4,438 16,888 Total $ 281,082 $ (276,594 ) $ 4,488 $ (168,349 ) Year Ended December 31, 2015 Advances $ 22,761 $ (21,196 ) $ 1,565 $ (155,082 ) AFS securities 42,219 (46,145 ) (3,926 ) (98,063 ) CO bonds 1,696 4,811 6,507 56,976 Total $ 66,676 $ (62,530 ) $ 4,146 $ (196,169 ) (1) Includes the effect of derivatives in fair-value hedging relationships on net interest income that is recorded in the interest income/expense line item of the respective hedged items. Excludes the interest income/expense of the respective hedged items, which fully offsets the interest income/expense of the derivatives, except to the extent of any hedge ineffectiveness. Net interest settlements on derivatives that are not in fair-value hedging relationships are reported in other income (loss). These amounts do not include the effect of amortization/accretion related to fair value hedging activities.

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Summary of Deposits, by Type	The following table presents interest-bearing and non-interest-bearing deposits. Type December 31, December 31, Interest-bearing: Demand and overnight $ 513,150 $ 494,880 Time 50 50 Other 23 25 Total interest-bearing 513,223 494,955 Non-interest-bearing: Other (1) 51,576 29,118 Total non-interest-bearing 51,576 29,118 Total deposits $ 564,799 $ 524,073 (1) Includes pass-through deposit reserves from members.

Consolidated Obligations (Table

Consolidated Obligations (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Discount Notes	Discount Notes. The following table presents our discount notes outstanding, all of which are due within one year of issuance. Discount Notes December 31, December 31, Book value $ 20,358,157 $ 16,801,763 Par value $ 20,394,192 $ 16,819,659 Weighted-average effective interest rate 1.22 % 0.51 %
CO Bonds Outstanding	The following table presents our CO bonds outstanding by contractual maturity. December 31, 2017 December 31, 2016 Year of Contractual Maturity Amount WAIR% Amount WAIR% Due in 1 year or less $ 14,021,190 1.27 $ 16,234,460 0.85 Due after 1 year through 2 years 9,392,470 1.46 6,122,190 0.96 Due after 2 years through 3 years 4,849,960 2.23 2,718,945 1.65 Due after 3 years through 4 years 1,294,470 2.17 1,684,530 3.17 Due after 4 years through 5 years 2,798,000 2.29 1,040,000 2.17 Thereafter 5,626,500 3.02 5,708,000 2.92 Total CO bonds, par value 37,982,590 1.80 33,508,125 1.44 Unamortized premiums 27,333 27,462 Unamortized discounts (13,782 ) (12,059 ) Unamortized concessions (14,188 ) (13,705 ) Fair-value hedging adjustments (86,300 ) (42,544 ) Total CO bonds $ 37,895,653 $ 33,467,279
CO Bonds by Redemption Feature	The following tables present our CO bonds outstanding by redemption feature and the earlier of the year of contractual maturity or next call date. Redemption Feature December 31, December 31, Non-callable / non-putable $ 26,277,590 $ 25,627,125 Callable 11,705,000 7,881,000 Total CO bonds, par value $ 37,982,590 $ 33,508,125
CO Bonds by Contractual Maturity or Next Call Date	Year of Contractual Maturity or Next Call Date December 31, December 31, Due in 1 year or less $ 24,449,190 $ 23,825,460 Due after 1 year through 2 years 9,098,470 4,675,190 Due after 2 years through 3 years 2,125,960 2,240,945 Due after 3 years through 4 years 584,470 1,257,530 Due after 4 years through 5 years 579,000 474,000 Thereafter 1,145,500 1,035,000 Total CO bonds, par value $ 37,982,590 $ 33,508,125
Schedule of Long-term Debt By Interest Rate Payment Terms	The following table presents CO bonds outstanding by interest-rate payment type. Interest-Rate Payment Type December 31, December 31, Fixed-rate $ 24,747,590 $ 18,928,125 Step-up 285,000 655,000 Simple variable-rate 12,950,000 13,905,000 Ratchet — 20,000 Total CO bonds, par value $ 37,982,590 $ 33,508,125

Affordable Housing Program (Tab

Affordable Housing Program (Tables)	12 Months Ended
	Dec. 31, 2017
Affordable Housing Program [Abstract]
Schedule of Activity in Affordable Housing Program Obligation	The following table summarizes the activity in our AHP funding obligation. AHP Activity 2017 2016 2015 Liability at beginning of year $ 26,598 $ 31,103 $ 36,899 Assessment (expense) 18,163 13,291 13,499 Subsidy usage, net (1) (12,595 ) (17,796 ) (19,295 ) Liability at end of year $ 32,166 $ 26,598 $ 31,103 (1) Subsidies disbursed are reported net of returns/recaptures of previously disbursed subsidies.

Capital (Tables)

Capital (Tables)	12 Months Ended
	Dec. 31, 2017
Capital [Abstract]
Schedule of Mandatorily Redeemable Capital Stock	The following table presents the activity in our MRCS. MRCS Activity 2017 2016 2015 Liability at beginning of year $ 170,043 $ 14,063 $ 15,673 Reclassifications from capital stock — 183,056 — Redemptions/repurchases (5,721 ) (28,148 ) (1,610 ) Accrued distributions — 1,072 — Liability at end of year $ 164,322 $ 170,043 $ 14,063
Schedule of Mandatorily Redeemable Capital Stock by Contractual Year of Redemption	MRCS Contractual Year of Redemption December 31, 2017 December 31, 2016 Year 1 (1) $ 7,963 $ 8,630 Year 2 13 5,054 Year 3 — 13 Year 4 4,158 — Year 5 — 4,158 Thereafter (2) 152,188 152,188 Total MRCS $ 164,322 $ 170,043 (1) Balances at December 31, 2017 and 2016 include $2,909 and $5,609 , respectively, of Class B stock that had reached the end of the five-year redemption period but will not be redeemed until the associated credit products and other obligations are no longer outstanding. (2) Represents the five-year redemption period of Class B stock held by certain captive insurance companies which begins immediately upon their termination of memberships no later than February 19, 2021, in accordance with the Final Membership Rule.
Schedule of Distributions on Mandatorily Redeemable Capital Stock	The following table presents the distributions related to MRCS. Years Ended December 31, MRCS Distributions 2017 2016 2015 Recorded as interest expense $ 7,034 $ 6,613 $ 522 Recorded as distributions from retained earnings — 1,072 — Total $ 7,034 $ 7,685 $ 522
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	As presented in the following table, we were in compliance with the Finance Agency's capital requirements at December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Regulatory Capital Requirements Required Actual Required Actual Risk-based capital $ 903,806 $ 2,998,422 $ 760,946 $ 2,549,871 Total regulatory capital-to-asset ratio 4.00 % 4.81 % 4.00 % 4.73 % Total regulatory capital $ 2,493,956 $ 2,998,422 $ 2,156,296 $ 2,549,871 Leverage ratio 5.00 % 7.21 % 5.00 % 7.10 % Leverage capital $ 3,117,445 $ 4,497,633 $ 2,695,370 $ 3,824,806

Accumulated Other Comprehensi43

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
AOCI Attributable to Parent [Abstract]
Schedule of Changes in the Components of AOCI	The following table presents a summary of the changes in the components of AOCI. AOCI Rollforward Unrealized Gains (Losses) on AFS Securities Non-Credit OTTI on AFS Securities Non-Credit OTTI on HTM Securities Pension Benefits Total AOCI Balance, December 31, 2014 $ 16,078 $ 38,172 $ (175 ) $ (7,415 ) $ 46,660 OCI before reclassifications: Net change in unrealized gains (losses) (15,981 ) (7,766 ) — — (23,747 ) Net change in fair value — (238 ) — — (238 ) Accretion of non-credit losses — — 43 — 43 Reclassifications from OCI to net income: Non-credit portion of OTTI losses — 61 — — 61 Pension benefits, net — — — 99 99 Total other comprehensive income (loss) (15,981 ) (7,943 ) 43 99 (23,782 ) Balance, December 31, 2015 $ 97 $ 30,229 $ (132 ) $ (7,316 ) $ 22,878 OCI before reclassifications: Net change in unrealized gains (losses) 39,371 (3,332 ) — — 36,039 Net change in fair value — (156 ) — — (156 ) Accretion of non-credit losses — — 29 — 29 Reclassifications from OCI to net income: Non-credit portion of OTTI losses — 197 — — 197 Pension benefits, net — — — (2,619 ) (2,619 ) Total other comprehensive income (loss) 39,371 (3,291 ) 29 (2,619 ) 33,490 Balance, December 31, 2016 $ 39,468 $ 26,938 $ (103 ) $ (9,935 ) $ 56,368 OCI before reclassifications: Net change in unrealized gains (losses) 53,051 2,189 — — 55,240 Net change in fair value — 29 — — 29 Accretion of non-credit losses — — 10 — 10 Reclassifications from OCI to net income: Non-credit portion of OTTI losses — 166 42 — 208 Pension benefits, net — — — (449 ) (449 ) Total other comprehensive income (loss) 53,051 2,384 52 (449 ) 55,038 Balance, December 31, 2017 $ 92,519 $ 29,322 $ (51 ) $ (10,384 ) $ 111,406

Employee Retirement and Defer44

Employee Retirement and Deferred Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Schedule of Net Funded Status	The following table presents a summary of net pension costs charged to compensation and benefits expense and the DB plan's funded status. DB Plan Net Pension Cost and Funded Status 2017 2016 2015 Net pension cost charged to compensation and benefits expense for the year ended December 31 $ 4,450 $ 5,772 $ 5,412 DB plan funded status as July 1 111 % (a) 104 % (b) 107 % Our funded status as of July 1 117 % 113 % 118 % (a) The DB plan's funded status as of July 1, 2017 is preliminary and may increase because the participating employers were permitted to make designated contributions for the plan year ended June 30, 2017 through March 15, 2018 . Any such contributions will be included in the final valuation as of July 1, 2017 . The final funded status as of July 1, 2017 will not be available until the Form 5500 for the plan year ended June 30, 2018 is filed (no later than April 2019 ). (b) The DB plan's final funded status as of July 1, 2016 will not be available until the Form 5500 for the plan year ended June 30, 2017 is filed (no later than April 2018 ).
Schedule of Changes in Projected Benefit Obligations	The following table presents the changes in our SERP benefit obligation. Change in benefit obligation 2017 2016 2015 Projected benefit obligation at beginning of year $ 20,022 $ 15,099 $ 14,074 Service cost 1,035 808 839 Interest cost 738 735 665 Actuarial loss 1,712 4,055 1,485 Benefits paid (331 ) (675 ) (1,964 ) Projected benefit obligation at end of year $ 23,176 $ 20,022 $ 15,099
Schedule of Assumptions Used	The following table presents the key assumptions used for the actuarial calculations to determine net periodic benefit cost for the SERP. Years Ended December 31, 2017 2016 2015 Discount rate 4.00 % 4.20 % 3.90 % Compensation increases 5.50 % 5.50 % 5.50 % The measurement date used to determine the benefit obligation was December 31. The following table presents the key assumptions used for the actuarial calculations to determine the benefit obligation. December 31, 2017 December 31, 2016 Discount rate 3.00 % 4.00 % Compensation increases 5.50 % 5.50 %
Schedule of Net Benefit Costs	The following table presents the components of the net periodic benefit cost and the amounts recognized in OCI for the SERP. Years Ended December 31, 2017 2016 2015 Net periodic benefit cost: Service cost $ 1,035 $ 808 $ 839 Interest cost 738 735 665 Amortization of prior service benefit — — (11 ) Amortization of net actuarial loss 1,263 1,436 1,595 Net periodic benefit cost recognized in compensation and benefits 3,036 2,979 3,088 Amounts recognized in OCI: Actuarial loss 1,712 4,055 1,485 Amortization of net actuarial loss (1,263 ) (1,436 ) (1,595 ) Amortization of prior service benefit — — 11 Net loss (income) recognized in OCI 449 2,619 (99 ) Total recognized in compensation and benefits and in OCI $ 3,485 $ 5,598 $ 2,989
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The following table presents the components of the pension benefits reported in AOCI related to the SERP. December 31, 2017 December 31, 2016 Net actuarial loss $ (10,384 ) $ (9,935 ) Net pension benefits reported in AOCI $ (10,384 ) $ (9,935 )
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year	The following table presents the amounts that will be amortized from AOCI into net periodic benefit cost during the year ending December 31, 2018 . Year Ending December 31, 2018 Net actuarial loss $ 1,291 Net amount to be amortized $ 1,291
Schedule of Expected Benefit Payments	The following table presents the estimated future benefit payments reflecting scheduled benefit payments for retired participants and the estimated payments to active participants, weighted based on the probability of the participant retiring, the value of the participant's benefits, and the actual form of payment elected by the participant. For the Years Ending December 31, 2018 $ 2,652 2019 4,058 2020 2,259 2021 1,716 2022 7,240 2023 - 2027 4,316
Deferred Compensation Arrangement with Individual Disclosure, Postretirement Benefits [Table Text Block]	The following table presents the compensation earned and deferred by our directors under the DDCP. Years Ended December 31, 2017 2016 Compensation earned $ 1,768 $ 1,620 Compensation deferred 538 319

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Financial Performance by Operating Segment	The following table presents our financial performance by operating segment. Year Ended December 31, 2017 Traditional Mortgage Loans Total Net interest income $ 193,278 $ 69,725 $ 263,003 Provision for (reversal of) credit losses — 51 51 Other income (loss) (5,110 ) (886 ) (5,996 ) Other expenses 69,644 12,718 82,362 Income before assessments 118,524 56,070 174,594 Affordable Housing Program assessments 12,556 5,607 18,163 Net income $ 105,968 $ 50,463 $ 156,431 Year Ended December 31, 2016 Traditional Mortgage Loans Total Net interest income $ 144,695 $ 53,498 $ 198,193 Provision for (reversal of) credit losses — (45 ) (45 ) Other income (loss) 6,674 (1,016 ) 5,658 Other expenses 65,746 11,853 77,599 Income before assessments 85,623 40,674 126,297 Affordable Housing Program assessments 9,224 4,067 13,291 Net income $ 76,399 $ 36,607 $ 113,006 Year Ended December 31, 2015 Traditional Mortgage Loans Total Net interest income $ 128,175 $ 67,250 $ 195,425 Provision for (reversal of) credit losses — (456 ) (456 ) Other income (loss) 13,272 (2,791 ) 10,481 Other expenses 62,211 9,683 71,894 Income before assessments 79,236 55,232 134,468 Affordable Housing Program assessments 7,976 5,523 13,499 Net income $ 71,260 $ 49,709 $ 120,969
Schedule of Segment Assets by Segment	The following table presents asset balances by operating segment. By Date Traditional Mortgage Loans Total December 31, 2017 $ 51,992,565 $ 10,356,341 $ 62,348,906 December 31, 2016 44,406,003 9,501,397 53,907,400

Estimated Fair Values (Tables)

Estimated Fair Values (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	The following tables present the carrying value and estimated fair value of our financial instruments. The total of the estimated fair values does not represent an estimate of our overall market value as a going concern, which would take into account, among other considerations, future business opportunities and the net profitability of assets and liabilities. December 31, 2017 Estimated Fair Value Carrying Netting Financial Instruments Value Total Level 1 Level 2 Level 3 Adjustment (1) Assets: Cash and due from banks $ 55,269 $ 55,269 $ 55,269 $ — $ — $ — Interest-bearing deposits 660,342 660,342 659,926 416 — — Securities purchased under agreements to resell 2,605,460 2,605,461 — 2,605,461 — — Federal funds sold 1,280,000 1,280,000 — 1,280,000 — — AFS securities 7,128,758 7,128,758 — 6,910,224 218,534 — HTM securities 5,897,668 5,919,299 — 5,874,413 44,886 — Advances 34,055,064 34,001,397 — 34,001,397 — — Mortgage loans held for portfolio, net 10,356,341 10,426,213 — 10,413,134 13,079 — Accrued interest receivable 105,314 105,314 — 105,314 — — Derivative assets, net 128,206 128,206 — 300,014 — (171,808 ) Grantor trust assets (2) 21,698 21,698 21,698 — — — Liabilities: Deposits 564,799 564,799 — 564,799 — — Consolidated Obligations: Discount notes 20,358,157 20,394,192 — 20,394,192 — — Bonds 37,895,653 37,998,928 — 37,998,928 — — Accrued interest payable 135,691 135,691 — 135,691 — — Derivative liabilities, net 2,718 2,718 — 76,988 — (74,270 ) MRCS 164,322 164,322 164,322 — — — December 31, 2016 Estimated Fair Value Carrying Netting Financial Instruments Value Total Level 1 Level 2 Level 3 Adjustment (1) Assets: Cash and due from banks $ 546,612 $ 546,612 $ 546,612 $ — $ — $ — Interest-bearing deposits 150,225 150,225 150,072 153 — — Securities purchased under agreements to resell 1,781,309 1,781,309 — 1,781,309 — — Federal funds sold 1,650,000 1,650,000 — 1,650,000 — — AFS securities 6,059,835 6,059,835 — 5,790,716 269,119 — HTM securities 5,819,573 5,848,692 — 5,791,111 57,581 — Advances 28,095,953 28,059,477 — 28,059,477 — — Mortgage loans held for portfolio, net 9,501,397 9,587,394 — 9,567,140 20,254 — Accrued interest receivable 93,716 93,716 — 93,716 — — Derivative assets, net 134,848 134,848 — 233,101 — (98,253 ) Grantor trust assets (2) 18,117 18,117 18,117 — — — Liabilities: Deposits 524,073 524,073 — 524,073 — — Consolidated Obligations: Discount notes 16,801,763 16,819,659 — 16,819,659 — — Bonds 33,467,279 33,614,346 — 33,614,346 — — Accrued interest payable 98,411 98,411 — 98,411 — — Derivative liabilities, net 25,225 25,225 — 103,107 — (77,882 ) MRCS 170,043 170,043 170,043 — — — (1) Represents the application of the netting requirements that allow the settlement of (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts). (2) Included in other assets.
Estimated Fair Value Measurements on Recurring and Nonrecurring Basis	The following tables present, by level within the fair value hierarchy, the estimated fair value of our financial assets and liabilities that are recorded at estimated fair value on a recurring or non-recurring basis on our statement of condition. Netting December 31, 2017 Total Level 1 Level 2 Level 3 Adjustment (1) AFS securities: GSE and TVA debentures $ 4,403,929 $ — $ 4,403,929 $ — $ — GSE MBS 2,506,295 — 2,506,295 — — Private-label RMBS 218,534 — — 218,534 — Total AFS securities 7,128,758 — 6,910,224 218,534 — Derivative assets: Interest-rate related 128,096 — 299,904 — (171,808 ) Interest-rate forwards 37 — 37 — — MDCs 73 — 73 — — Total derivative assets, net 128,206 — 300,014 — (171,808 ) Grantor trust assets (2) 21,698 21,698 — — — Total assets at recurring estimated fair value $ 7,278,662 $ 21,698 $ 7,210,238 $ 218,534 $ (171,808 ) Derivative liabilities: Interest-rate related $ 2,669 $ — $ 76,939 $ — $ (74,270 ) Interest-rate forwards 1 — 1 — — MDCs 48 — 48 — — Total derivative liabilities, net 2,718 — 76,988 — (74,270 ) Total liabilities at recurring estimated fair value $ 2,718 $ — $ 76,988 $ — $ (74,270 ) Mortgage loans held for portfolio (3) $ 2,637 $ — $ — $ 2,637 $ — Total assets at non-recurring estimated fair value $ 2,637 $ — $ — $ 2,637 $ — Netting December 31, 2016 Total Level 1 Level 2 Level 3 Adjustment (1) AFS securities: GSE and TVA debentures $ 4,714,634 $ — $ 4,714,634 $ — $ — GSE MBS 1,076,082 — 1,076,082 — — Private-label RMBS 269,119 — — 269,119 — Total AFS securities 6,059,835 — 5,790,716 269,119 — Derivative assets: Interest-rate related 134,206 — 232,459 — (98,253 ) Interest-rate forwards 339 — 339 — — MDCs 303 — 303 — — Total derivative assets, net 134,848 — 233,101 — (98,253 ) Grantor trust assets (2) 18,117 18,117 — — — Total assets at recurring estimated fair value $ 6,212,800 $ 18,117 $ 6,023,817 $ 269,119 $ (98,253 ) Derivative liabilities: Interest-rate related $ 24,402 $ — $ 102,284 $ — $ (77,882 ) Interest-rate forwards 352 — 352 — — MDCs 471 — 471 — — Total derivative liabilities, net 25,225 — 103,107 — (77,882 ) Total liabilities at recurring estimated fair value $ 25,225 $ — $ 103,107 $ — $ (77,882 ) Mortgage loans held for portfolio (4) $ 3,492 $ — $ — $ 3,492 $ — Total assets at non-recurring estimated fair value $ 3,492 $ — $ — $ 3,492 $ — (1) Represents the application of the netting requirements that allow us to settle (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts). (2) Included in other assets. (3) Amounts are as of the date the fair value adjustment was recorded during the year ended December 31, 2017 . (4) Amounts are as of the date the fair value adjustment was recorded during the year ended December 31, 2016 .
Reconciliation of AFS Private-label RMBS Measured at Estimated Fair Value on a Recurring Basis using Level 3 Significant Inputs	The table below presents a rollforward of our AFS private-label RMBS measured at estimated fair value on a recurring basis using level 3 significant inputs. The estimated fair values were determined using a pricing source, such as a dealer quote or comparable security price, for which the significant unobservable inputs used to determine the price were not readily available. Level 3 Rollforward - AFS private-label RMBS 2017 2016 2015 Balance, beginning of year $ 269,119 $ 319,186 $ 401,050 Total realized and unrealized gains (losses): Accretion of credit losses in interest income 6,778 9,348 8,708 Net losses on changes in fair value in other income (loss) (166 ) (197 ) (61 ) Net change in fair value not in excess of cumulative non-credit losses in OCI 29 (156 ) (238 ) Unrealized gains (losses) in OCI 2,189 (3,332 ) (7,766 ) Reclassification of non-credit portion in OCI to other income (loss) 166 197 61 Purchases, issuances, sales and settlements: Settlements (59,581 ) (55,927 ) (82,568 ) Balance, end of year $ 218,534 $ 269,119 $ 319,186 Net gains (losses) included in earnings attributable to changes in fair value relating to assets still held at end of year $ 6,612 $ 8,291 $ 8,647

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Off-Balance Sheet Commitments	The following table presents our off-balance-sheet commitments at their notional amounts. December 31, 2017 Type of Commitment Expire within one year Expire after one year Total Letters of credit outstanding $ 102,344 $ 121,381 $ 223,725 Unused lines of credit (1) 1,084,234 — 1,084,234 Commitments to fund additional advances (2) 4,050 — 4,050 Commitments to fund or purchase mortgage loans, net (3) 70,831 — 70,831 Unsettled CO bonds, at par 28,000 — 28,000 (1) Maximum line of credit amount per member is $50,000 . (2) Generally for periods up to six months. (3) Generally for periods up to 91 days.

Transactions with Related Par48

Transactions with Related Parties and Other Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transaction [Line Items]
Loans to Other Federal Home Loan Banks and Principal Repayments	Transactions with Other FHLBanks. Occasionally, we loan (or borrow) short-term funds to (from) other FHLBanks. The following table presents the loans to other FHLBanks. Years Ended December 31, Loans to other FHLBanks 2017 2016 2015 Disbursements $ (100,000 ) $ (300,000 ) $ — Principal repayments 100,000 300,000 —
Directors' Financial Institutions [Member]
Related Party Transaction [Line Items]
Outstanding Balances with Respect to Transactions with Related Parties	The following table presents the aggregate outstanding balances with directors' financial institutions and their balance as a percent of the total balance on our statement of condition. December 31, 2017 December 31, 2016 Balances with Directors' Financial Institutions Par value % of Total Par value % of Total Capital stock $ 40,564 2 % $ 50,810 3 % Advances 588,108 2 % 627,105 2 % The par values at December 31, 2017 reflect changes in the composition of directors' financial institutions effective January 1, 2017, due to changes in our board membership resulting from the 2016 director election. The following table presents transactions with directors' financial institutions, taking into account the beginning and ending dates of the directors' terms, merger activity and other changes in the composition of directors' financial institutions. Years Ended December 31, Transactions with Directors' Financial Institutions 2017 2016 2015 Net capital stock issuances (redemptions and repurchases) $ 3,912 $ 1,516 $ (12,588 ) Net advances (repayments) 79,751 11,274 112,976 Mortgage loan purchases 33,274 38,728 39,590

Summary of Significant Accoun49

Summary of Significant Accounting Policies (Details)	12 Months Ended	78 Months Ended
	Dec. 31, 2017Component	Dec. 31, 2017
Summary of Significant Accounting Policies [Line Items]
Percentage of quarterly net income allocated to separate restricted retained earnings account		20.00%
Number of components calculating proportionate share of Office of Finance operating and capital expenditures	2
Percentage used to calculate proportionate share of Office of Finance operating and capital expenditures based on share of total Consolidated Obligations outstanding	67.00%
Percentage used to calculate proportionate share of Office of Finance operating and capital expenditures based on equal pro-rata allocation	33.00%
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Percent of debt security paid down for effective maturity	85.00%	85.00%
Percentage of difference between present value of cash flows under terms of new advances and present value of remaining cash flows under terms of original advance	10.00%
Estimated useful life	1 year
Restricted retained earnings as percentage of average balance of outstanding consolidated obligations for previous quarter		1.00%
Restricted retained earnings as percentage of average balance of outstanding consolidated obligations for previous quarter when available to pay dividends		1.50%
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Estimated useful life	40 years

Cash and Due from Banks (Detail

Cash and Due from Banks (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and Due from Banks [Abstract]
Average cash balances with commercial banks	$ 35,592	$ 101,311	$ 81,853
Pass-through reserves deposited with Federal Reserve Banks	$ 51,576	$ 29,118

Available-for-Sale Securities -

Available-for-Sale Securities - Major Security Types (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities [Line Items]
Amortized Cost Basis	[1]	$ 7,006,917	$ 5,993,429
Non-Credit OTTI		(68)	(263)
Gross unrealized gains		121,909	71,104
Gross unrealized losses		0	(4,435)
Estimated Fair Value - AFS Securities		7,128,758	6,059,835
GSE and TVA Debentures [Member]
Available-for-sale Securities [Line Items]
Amortized Cost Basis	[1]	4,357,250	4,693,211
Non-Credit OTTI		0	0
Gross unrealized gains		46,679	25,624
Gross unrealized losses		0	(4,201)
Estimated Fair Value - AFS Securities		4,403,929	4,714,634
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale Securities [Line Items]
Amortized Cost Basis	[1]	2,460,455	1,058,037
Non-Credit OTTI		0	0
Gross unrealized gains		45,840	18,279
Gross unrealized losses		0	(234)
Estimated Fair Value - AFS Securities		2,506,295	1,076,082
RMBS [Member] | Private-Label RMBS [Member]
Available-for-sale Securities [Line Items]
Amortized Cost Basis	[1]	189,212	242,181
Non-Credit OTTI		(68)	(263)
Gross unrealized gains		29,390	27,201
Gross unrealized losses		0	0
Estimated Fair Value - AFS Securities		$ 218,534	$ 269,119
[1]	(1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses) and fair-value hedge accounting adjustments.

Available-for-Sale Securities52

Available-for-Sale Securities - Unrealized Loss Positions (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities [Line Items]
Less than 12 Months, Estimated Fair Value	$ 0	$ 525,722
Less than 12 Months, Unrealized Losses	0	(3,604)
12 Months or More, Estimated Fair Value	2,494	257,810
12 Months or More, Unrealized Losses	(68)	(1,094)
Total Estimated Fair Value	2,494	783,532
Unrealized Losses	(68)	(4,698)
GSE and TVA Debentures [Member]
Available-for-sale Securities [Line Items]
Less than 12 Months, Estimated Fair Value	0	525,722
Less than 12 Months, Unrealized Losses	0	(3,604)
12 Months or More, Estimated Fair Value	0	176,104
12 Months or More, Unrealized Losses	0	(597)
Total Estimated Fair Value	0	701,826
Unrealized Losses	0	(4,201)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale Securities [Line Items]
Less than 12 Months, Estimated Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Estimated Fair Value	0	78,704
12 Months or More, Unrealized Losses	0	(234)
Total Estimated Fair Value	0	78,704
Unrealized Losses	0	(234)
Private-Label RMBS [Member] | RMBS [Member]
Available-for-sale Securities [Line Items]
Less than 12 Months, Estimated Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Estimated Fair Value	2,494	3,002
12 Months or More, Unrealized Losses	(68)	(263)
Total Estimated Fair Value	2,494	3,002
Unrealized Losses	$ (68)	$ (263)

Available-for-Sale Securities53

Available-for-Sale Securities - Redemption Terms (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities [Line Items]
Amortized Cost Basis	[1]	$ 7,006,917	$ 5,993,429
Estimated Fair Value - AFS Securities		7,128,758	6,059,835
Non-MBS [Member]
Available-for-sale Securities [Line Items]
Due in 1 year or less, Amortized Cost		83,666	972,508
Due after 1 year through 5 years, Amortized Cost		2,317,516	1,841,488
Due after 5 years through 10 years, Amortized Cost		1,766,440	1,734,156
Due after 10 years, Amortized Cost		189,628	145,059
Amortized Cost Basis		4,357,250	4,693,211
Due in 1 year or less, Estimated Fair Value		83,754	974,215
Due after 1 year through 5 years, Estimated Fair Value		2,336,699	1,855,517
Due after 5 years through 10 years, Estimated Fair Value		1,791,829	1,740,029
Due after 10 years, Fair Value		191,647	144,873
Estimated Fair Value - AFS Securities		4,403,929	4,714,634
MBS [Member]
Available-for-sale Securities [Line Items]
Amortized Cost Basis		2,649,667	1,300,218
Estimated Fair Value - AFS Securities		$ 2,724,829	$ 1,345,201
[1]	(1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses) and fair-value hedge accounting adjustments.

Held-to-Maturity Securities - M

Held-to-Maturity Securities - Major Security Types (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[1]	$ 5,897,719	$ 5,819,676
Non-Credit OTTI		(51)	(103)
Carrying Value		5,897,668	5,819,573
Gross Unrecognized Holding Gains		33,562	51,993
Gross Unrecognized Holding Losses		(11,931)	(22,874)
Estimated Fair Value		5,919,299	5,848,692
Residential Mortgage Backed Securities Other US Obligations [Member] [Domain]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[1]	3,299,157	2,678,437
Non-Credit OTTI		0	0
Carrying Value		3,299,157	2,678,437
Gross Unrecognized Holding Gains		6,555	5,412
Gross Unrecognized Holding Losses		(6,690)	(12,720)
Estimated Fair Value		3,299,022	2,671,129
GSE MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[1]	2,553,193	3,082,343
Non-Credit OTTI		0	0
Carrying Value		2,553,193	3,082,343
Gross Unrecognized Holding Gains		26,727	46,480
Gross Unrecognized Holding Losses		(4,529)	(8,841)
Estimated Fair Value		2,575,391	3,119,982
Asset-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[1]	7,480	9,148
Non-Credit OTTI		(51)	(103)
Carrying Value		7,429	9,045
Gross Unrecognized Holding Gains		40	40
Gross Unrecognized Holding Losses		(405)	(780)
Estimated Fair Value		7,064	8,305
RMBS [Member] | Private-Label RMBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[1]	37,889	49,748
Non-Credit OTTI		0	0
Carrying Value		37,889	49,748
Gross Unrecognized Holding Gains		240	61
Gross Unrecognized Holding Losses		(307)	(533)
Estimated Fair Value		$ 37,822	$ 49,276
[1]	(1) Includes adjustments made to the cost basis of an investment for accretion, amortization, collection of principal, and, if applicable, OTTI recognized in earnings (credit losses).

Held-to-Maturity Securities - U

Held-to-Maturity Securities - Unrealized Loss Position (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Estimated Fair Value		$ 1,668,580	$ 1,667,467
Less than 12 Months, Unrealized Losses		(5,491)	(8,974)
12 Months or More, Estimated Fair Value		1,108,193	1,770,397
12 Months or More, Unrealized Losses		(6,451)	(13,963)
Total Estimated Fair Value		2,776,773	3,437,864
Unrealized Losses	[1]	(11,942)	(22,937)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		(11,931)	(22,874)
Non-Credit OTTI		(51)	(103)
Gross Unrecognized Holding Gains		33,562	51,993
Other U.S. obligations -guaranteed MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Estimated Fair Value		1,140,624	367,474
Less than 12 Months, Unrealized Losses		(3,274)	(997)
12 Months or More, Estimated Fair Value		886,359	1,426,182
12 Months or More, Unrealized Losses		(3,416)	(11,723)
Total Estimated Fair Value		2,026,983	1,793,656
Unrealized Losses	[1]	(6,690)	(12,720)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		(6,690)	(12,720)
Non-Credit OTTI		0	0
Gross Unrecognized Holding Gains		6,555	5,412
GSE MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Estimated Fair Value		513,244	1,281,827
Less than 12 Months, Unrealized Losses		(2,191)	(7,915)
12 Months or More, Estimated Fair Value		203,401	320,141
12 Months or More, Unrealized Losses		(2,338)	(926)
Total Estimated Fair Value		716,645	1,601,968
Unrealized Losses	[1]	(4,529)	(8,841)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		(4,529)	(8,841)
Non-Credit OTTI		0	0
Gross Unrecognized Holding Gains		26,727	46,480
Asset-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Estimated Fair Value		0	0
Less than 12 Months, Unrealized Losses		0	0
12 Months or More, Estimated Fair Value		7,064	8,304
12 Months or More, Unrealized Losses		(416)	(843)
Total Estimated Fair Value		7,064	8,304
Unrealized Losses	[1]	(416)	(843)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		(405)	(780)
Non-Credit OTTI		(51)	(103)
Gross Unrecognized Holding Gains		40	40
RMBS [Member] | Private-Label RMBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Estimated Fair Value		14,712	18,166
Less than 12 Months, Unrealized Losses		(26)	(62)
12 Months or More, Estimated Fair Value		11,369	15,770
12 Months or More, Unrealized Losses		(281)	(471)
Total Estimated Fair Value		26,081	33,936
Unrealized Losses	[1]	(307)	(533)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		(307)	(533)
Non-Credit OTTI		0	0
Gross Unrecognized Holding Gains		$ 240	$ 61
[1]	(1) For private-label ABS, the total of unrealized losses does not agree to total gross unrecognized holding losses at December 31, 2017 and 2016 of $405 and $780, respectively. Total unrealized losses include non-credit-related OTTI losses recorded in AOCI of $51 and $103, respectively, and gross unrecognized holding gains on previously OTTI securities of $40 and $40, respectively.

Other-Than-Temporary Impairme56

Other-Than-Temporary Impairment Analysis - Narratives (Details) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2017securities	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Other than Temporary Impairment, Disclosure [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses | $	[1]		$ (207)	$ (197)	$ (61)
Number of Third Party Models to Assess Recovery of Amortized Cost Basis of Securities		2	2
Core Based Statistical Areas Current Requirements Number of Urban Areas		1	1
Core Based Statistical Areas Current REquirements Urban Area Population		10,000	10,000
Projected Change In The Twelve Month Housing Price Percentage Rate, Maximum Decrease		(5.00%)	(5.00%)
Projected Change In The Twelve Month Housing Price Percentage Rate, Maximum Increase		12.00%	12.00%
Projected Change In The Short Term Housing Price Percentage Rate Minimum Increase In Vast Majority Of Markets		2.00%	2.00%
Projected Change In The Short-term Housing Price Percentage Rate, Maximum Increase In Vast Majority of Markets		6.00%	6.00%
Number of Securities, Other Than Temporary Impairment Credit Losses Recognized | securities		2
[1]	Relates to all securities impaired prior to January 1, 2017, 2016, and 2015, respectively.

Other-Than-Temporary Impairme57

Other-Than-Temporary Impairment Analysis Other-Than-Temporary Impairment - Significant Modeling Assumptions (Details) - Private-Label RMBS [Member] - RMBS [Member]	3 Months Ended		12 Months Ended
	Dec. 31, 2017	[2]	Dec. 31, 2017	[2]
Subprime [Member]
Schedule of Significant Inputs In Measuring Other Than Temporary Impairments Measured in Earnings [Line Items]
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Prepayment Speed Weighted Average			8.00%	[1]
Other Than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Qualitative Disclosures, Weighted Average Default Rate	40.00%	[1]
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Loss Severity Weighted Average			42.00%	[1]
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Credit Enhancements Weighted Average	0.00%	[1],[3]	0.00%	[1],[3]
Prime [Member]
Schedule of Significant Inputs In Measuring Other Than Temporary Impairments Measured in Earnings [Line Items]
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Prepayment Speed Weighted Average			9.00%
Other Than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Qualitative Disclosures, Weighted Average Default Rate	11.00%
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Loss Severity Weighted Average			26.00%
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Credit Enhancements Weighted Average	0.00%	[3]	0.00%	[3]
[1]	Modeling assumptions assume no payout from monoline bond insurers.
[2]	The classification (prime, Alt-A or subprime) is based on the model used to project the cash flows for the security, which may not be the same as the rating agency's classification at the time of origination.
[3]	Credit enhancement is defined as the percentage of subordinated tranches, excess spread, and over-collateralization, if any, in a security structure that will generally absorb losses before we will experience a loss on the security. A credit enhancement percentage of zero reflects a security that has no remaining credit support and is likely to have experienced an actual principal loss.

Other-Than-Temporary Impairme58

Other-Than-Temporary Impairment Analysis - Rollforward of the Cumulative Credit Losses (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance at Beginning of Year		$ 51,514	$ 60,673	$ 69,626
Additional credit losses for which OTTI was previously recognized (1)	[1]	207	197	61
Increases in cash flows expected to be collected (accreted as interest income over the remaining lives of the applicable securities)		(6,786)	(9,356)	(9,014)
Balance at End of Year		$ 44,935	$ 51,514	$ 60,673
[1]	Relates to all securities impaired prior to January 1, 2017, 2016, and 2015, respectively.

Other-Than-Temporary Impairme59

Other-Than-Temporary Impairment Analysis - Securities with OTTI Losses (Details) $ in Thousands	Dec. 31, 2017USD ($)	[1]
Held-to-maturity Securities [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Life-to-Date, UPB	$ 552
OTTI Life-to-Date, Amortized Cost	487
OTTI Life-to-Date, Carrying Value	436
OTTI Life-to-Date, Estimated Fair Value	476
Available-for-sale Securities [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Life-to-Date, UPB	224,574
OTTI Life-to-Date, Amortized Cost	189,212
OTTI Life-to-Date, Estimated Fair Value	218,534
Home Equity Loan ABS [Member] | Held-to-maturity Securities [Member] | Subprime [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Life-to-Date, UPB	552
OTTI Life-to-Date, Amortized Cost	487
OTTI Life-to-Date, Carrying Value	436
OTTI Life-to-Date, Estimated Fair Value	476
Home Equity Loan ABS [Member] | Available-for-sale Securities [Member] | Subprime [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Life-to-Date, UPB	0
OTTI Life-to-Date, Amortized Cost	0
OTTI Life-to-Date, Estimated Fair Value	0
Private-Label RMBS [Member] | Held-to-maturity Securities [Member] | RMBS [Member] | Prime [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Life-to-Date, UPB	0
OTTI Life-to-Date, Amortized Cost	0
OTTI Life-to-Date, Carrying Value	0
OTTI Life-to-Date, Estimated Fair Value	0
Private-Label RMBS [Member] | Available-for-sale Securities [Member] | RMBS [Member] | Prime [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Life-to-Date, UPB	224,574
OTTI Life-to-Date, Amortized Cost	189,212
OTTI Life-to-Date, Estimated Fair Value	$ 218,534
[1]	Securities are classified based on the originator's classification at the time of origination or based on the classification by the NRSROs upon issuance. Because there is no universally accepted definition of prime, Alt-A or subprime underwriting standards, such classifications are subjective.

Advances - Advances by Year of

Advances - Advances by Year of Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Maturity, Rolling Year, Par Value [Abstract]
Overdrawn demand and overnight deposit accounts	$ 0	$ 0
Federal Home Loan Bank, Advances, Maturities Summary, in Next Rolling Twelve Months	16,935,411	12,598,864
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Two	2,701,784	2,752,629
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Three	2,682,073	1,920,962
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Four	2,172,549	2,605,198
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Five	2,213,319	2,009,395
Federal Home Loan Bank, Advances, Maturities Summary, after Rolling Year Five	7,464,333	6,244,912
Total advances, par value	34,169,469	28,131,960
Fair-value hedging adjustments	(126,137)	(57,716)
Unamortized swap termination fees associated with modified advances, net of deferred prepayment fees	11,732	21,709
Total advances	$ 34,055,064	$ 28,095,953
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Rolling Year [Abstract]
Overdrawn demand and overnight deposit accounts	0.00%	0.00%
Due in 1 year or less	1.46%	0.91%
Due after 1 year through 2 years	1.96%	1.74%
Due after 2 years through 3 years	1.69%	2.10%
Due after 3 years through 4 years	1.78%	1.38%
Due after 4 years through 5 years	1.93%	1.47%
Thereafter	1.66%	1.20%
Total advances, par value	1.61%	1.22%

Advances - Earlier of Contractu

Advances - Earlier of Contractual Maturity or Next Call Date and Year of Contractual Maturity or Next Put Date (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, Rolling Year, Par Value [Abstract]
Overdrawn demand and overnight deposit accounts	$ 0	$ 0
Due in 1 year or less	25,067,272	19,390,714
Due after 1 year through 2 years	2,412,184	2,502,629
Due after 2 years through 3 years	1,716,873	1,856,463
Due after 3 years through 4 years	928,649	1,548,998
Due after 4 years through 5 years	1,494,529	900,095
Thereafter	2,549,962	1,933,061
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, Rolling Year, Par Value [Abstract]
Due in 1 year or less	17,032,411	12,767,364
Due after 1 year through 2 years	2,701,784	2,757,629
Due after 2 years through 3 years	3,406,673	1,915,962
Due after 3 years through 4 years	2,718,049	2,605,198
Due after 4 years through 5 years	2,524,619	2,535,895
Thereafter	5,785,933	5,549,912
Total advances, par value	$ 34,169,469	$ 28,131,960
Percent of Advances Par Value Held by Top Five Borrowers	45.00%	43.00%

Mortgage Loans Held for Portf62

Mortgage Loans Held for Portfolio (Details) - USD ($)		1 Months Ended		12 Months Ended
		Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
Mortgage Loans on Real Estate [Line Items]
Principal Amount of Mortgage Loans Sold		$ 18,000,000	$ 72,000,000
Mortgage Loans Held for Portfolio, UPB			9,293,390,000	$ 10,123,848,000
Unamortized premiums			210,116,000	234,519,000
Unamortized discounts			(2,383,000)	(2,426,000)
Fair-value hedging adjustments			1,124,000	1,250,000
Allowance for loan losses			(850,000)	(850,000)
Total mortgage loans held for portfolio, net			9,501,397,000	10,356,341,000
US Government Agency Insured Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage Loans Held for Portfolio, UPB			496,983,000	422,248,000
Fixed-rate Long-term Mortgages [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage Loans Held for Portfolio, UPB			8,086,412,000	8,989,545,000
Fixed-rate Medium-term Mortgages [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage Loans Held for Portfolio, UPB	[1]		1,206,978,000	$ 1,134,303,000
Fixed-rate Medium-term Mortgages [Member] | Maximum [Member]
Mortgage Loans on Real Estate [Line Items]
Original term				15 years
Conventional [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage Loans Held for Portfolio, UPB			$ 8,796,407,000	$ 9,701,600,000
[1]	(1) Defined as a term of 15 years or less at origination.

Allowance for Credit Losses - C

Allowance for Credit Losses - Credit Enhancements (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		$ 850,000	$ 850,000
LRA Activity
Balance of LRA, beginning of period		125,683,000	91,552,000	$ 61,949,000
Additions		25,350,000	36,341,000	31,573,000
Claim paid		(617,000)	(1,054,000)	(1,576,000)
Distributions		(1,701,000)	(1,156,000)	(394,000)
Balance of LRA, end of period		148,715,000	125,683,000	91,552,000
Conventional Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		850,000	850,000	$ 1,125,000	$ 2,500,000
MPP [Member] | Conventional Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Estimated losses remaining after borrower's equity, before credit enhancements	[1]	5,360,000	8,689,000
Portion of estimated losses recoverable		(4,640,000)	(7,989,000)
Allowance for unrecoverable PMI/SMI		30,000	50,000
Allowance for loan losses		750,000	750,000
MPP [Member] | Conventional Loan [Member] | PMI [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of estimated losses recoverable		(995,000)	(1,981,000)
MPP [Member] | Conventional Loan [Member] | LRA [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of estimated losses recoverable	[2]	(1,262,000)	(2,418,000)
MPP [Member] | Conventional Loan [Member] | SMI [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of estimated losses recoverable		(2,383,000)	(3,590,000)
MPF [Member] | Conventional Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		$ 100,000	$ 100,000
Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Initial loan-to-value ratio for conventional loan loss protection - over		80.00%
Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loss emergence period		24 months
[1]	Based on a loss emergence period of 24 months.
[2]	Amounts recoverable are limited to (i) the estimated losses remaining after borrower's equity and PMI and (ii) the remaining balance in each pool's portion of the LRA. The remainder of the total LRA balance is available to cover any losses not yet incurred and to distribute any excess funds to the PFIs.

Allowance for Credit Losses - I

Allowance for Credit Losses - Impaired Debt (Details) - MPP [Member] - Conventional [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Conventional loans without allowance for loan losses, Recorded Investment	[1]	$ 13,261	$ 15,158
Conventional loans with allowance for loan losses, Recorded Investment		1,270	349
Impaired Financing Receivable, Recorded Investment		14,531	15,507
Conventional loans without allowance for loan losses, UPB	[1]	13,343	15,219
Conventional loans with allowance for loan losses, UPB		1,272	358
Impaired Financing Receivable, Unpaid Principal Balance		14,615	15,577
Allowance for loan losses		54	30
Conventional Loans without Allowance, Average Recorded Investment		14,011	16,623	$ 17,967
Conventional Loans without Allowance, Interest Income Recognized		675	758	872
Conventional Loans with Allowance, Average Recorded Investment		1,259	353	881
Conventional Loans with Allowance, Interest Income Recognized		69	39	105
Impaired Financing Receivable, Average Recorded Investment		15,270	16,976	18,848
Impaired Financing Receivable, Interest Income, Accrual Method		$ 744	$ 797	$ 977
[1]	No allowance for loan losses was recorded on these impaired loans after consideration of the underlying loan-specific attribute data, estimated liquidation value of real estate collateral held, estimated costs associated with maintaining and disposing of the collateral, and credit enhancements.

Allowance for Credit Losses -65

Allowance for Credit Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total past due		$ 109,714	$ 109,341
Total current loans		10,290,899	9,431,757
Total recorded investment	[1]	10,400,613	9,541,098
Mortgage Loans in Process of Foreclosure, Amount	[2]	$ 11,081	$ 17,749
Serious delinquency rate	[3]	0.21%	0.33%
Past due 90 days or more still accruing interest	[4]	$ 19,158	$ 27,725
On non-accrual status		$ 3,464	4,699
Period loan receivable becomes nonaccrual status		90 days
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		$ 75,518	63,301
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		12,065	14,592
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		22,131	31,448
US Government Agency Insured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		16,524	23,081
Total current loans		412,869	482,316
Total recorded investment	[1]	429,393	505,397
Mortgage Loans in Process of Foreclosure, Amount	[2]	$ 0	$ 0
Serious delinquency rate	[3]	0.59%	0.46%
Past due 90 days or more still accruing interest	[4]	$ 2,555	$ 2,350
On non-accrual status		0	0
US Government Agency Insured Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		11,848	17,183
US Government Agency Insured Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		2,121	3,548
US Government Agency Insured Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		2,555	2,350
Conventional [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		93,190	86,260
Total current loans		9,878,030	8,949,441
Total recorded investment	[1]	9,971,220	9,035,701
Mortgage Loans in Process of Foreclosure, Amount	[2]	$ 11,081	$ 17,749
Serious delinquency rate	[3]	0.20%	0.32%
Past due 90 days or more still accruing interest	[4]	$ 16,603	$ 25,375
On non-accrual status		3,464	4,699
Conventional [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		63,670	46,118
Conventional [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		9,944	11,044
Conventional [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total past due		$ 19,576	$ 29,098
[1]	The recorded investment in a loan is the UPB of the loan, adjusted for accrued interest, net of any deferred loan fees or costs, unamortized premiums or discounts (which may include the basis adjustment related to any gain or loss on a delivery commitment prior to being funded) and direct charge-offs. The recorded investment is not net of any valuation allowance.
[2]	Includes loans for which the decision of foreclosure or similar alternative, such as pursuit of deed-in-lieu of foreclosure, has been reported. Loans in process of foreclosure are included in past due categories depending on their delinquency status, but are not necessarily considered to be on non-accrual status.
[3]	Represents loans 90 days or more past due (including loans in process of foreclosure) expressed as a percentage of the total recorded investment in mortgage loans. The percentage excludes principal and interest amounts previously paid in full by the servicers on conventional loans that are pending resolution of potential loss claims. Our servicers repurchase seriously delinquent government loans, including FHA loans, when certain criteria are met.
[4]	Although our past due scheduled/scheduled MPP loans are classified as loans past due 90 days or more based on the mortgagor's payment status, we do not consider these loans to be on non-accrual status.

Allowance for Credit Losses - A

Allowance for Credit Losses - Allowance for Loan Losses on Mortgage Loans (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		$ 850,000	$ 850,000		$ 850,000	$ 850,000
Total recorded investment	[1]				10,400,613,000	9,541,098,000
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses on mortgage loans, beginning of period		850,000
Provision for (reversal of) credit losses		51,000	(45,000)	$ (456,000)
Allowance for loan losses on mortgage loans, end of period		850,000	850,000
Conventional Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Conventional loans collectively evaluated for impairment					652,000	750,000
Loans individually evaluated for impairment	[2]				198,000	100,000
Allowance for loan losses		850,000	1,125,000	2,500,000	850,000	850,000
Loans collectively evaluated for impairment					9,956,689,000	9,020,194,000
Loans individually evaluated for impairment	[2]				14,531,000	15,507,000
Total recorded investment	[1]				9,971,220,000	9,035,701,000
Principal paid in full by servicers					2,498,000	2,814,000
Potential claims included in allowance					144,000	70,000
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses on mortgage loans, beginning of period		850,000	1,125,000	2,500,000
Allowance for Loan and Lease Losses, Write-offs		(647,000)	(857,000)	(1,168,000)
Allowance for Loan and Lease Loss, Recovery of Bad Debts		596,000	627,000	249,000
Provision for (reversal of) credit losses		51,000	(45,000)	(456,000)
Allowance for loan losses on mortgage loans, end of period		850,000	850,000	$ 1,125,000
MPP [Member] | Conventional Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		750,000	750,000		750,000	750,000
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses on mortgage loans, beginning of period		750,000
Allowance for loan losses on mortgage loans, end of period		750,000	750,000
MPF [Member] | Conventional Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		100,000	100,000		$ 100,000	$ 100,000
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses on mortgage loans, beginning of period		100,000
Allowance for loan losses on mortgage loans, end of period		$ 100,000	$ 100,000
[1]	The recorded investment in a loan is the UPB of the loan, adjusted for accrued interest, net of any deferred loan fees or costs, unamortized premiums or discounts (which may include the basis adjustment related to any gain or loss on a delivery commitment prior to being funded) and direct charge-offs. The recorded investment is not net of any valuation allowance.
[2]	The recorded investment in our MPP conventional loans individually evaluated for impairment excludes principal previously paid in full by the servicers as of December 31, 2017 and 2016 of $2,498 and $2,814, respectively, that remains subject to potential claims by those servicers for any losses resulting from past or future liquidations of the underlying properties. However, the MPP allowance for loan losses as of December 31, 2017 and 2016 includes $144 and $70, respectively, for these potential claims.

Premises, Software and Equipm67

Premises, Software and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Premises	$ 15,242	$ 14,958
Computer software	38,559	38,497
Data processing equipment	8,846	7,505
Furniture and equipment	4,539	3,920
Other	563	513
Premises, software and equipment, in service	67,749	65,393
Accumulated depreciation and amortization	(36,085)	(30,121)
Premises, software and equipment, in service, net	31,664	35,272
Capitalized assets in progress	5,131	2,366
Premises, software and equipment, net	36,795	37,638
Capitalized Computer Software, Amortization	4,276	4,055	$ 3,633
Depreciation and Amortization Expense for Premises, Software and Equipment	$ 5,965	$ 5,820	$ 5,461

Derivatives and Hedging Activ68

Derivatives and Hedging Activities - Derivatives in Statement of Condition (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		$ 32,499,977	$ 25,812,444
Derivatives before adjustments, assets		300,014	233,101
Derivatives before adjustments, liabilities		76,988	103,107
Derivative Asset Gross Netting Adjustment and Cash Collateral		(171,808)	(98,253)
Netting adjustments	[1]	(150,868)	(133,089)
Derivative Asset Fair Value Gross Asset and Right to Reclaim Cash Offset	[1]	(20,940)	34,836
Total derivatives, at estimated fair value		128,206	134,848
Netting adjustments	[1]	(150,868)	(133,089)
Derivative, Collateral, Right to Reclaim Cash		16,437	35,422
Total derivatives, at estimated fair value		2,718	25,225
Cash collateral received		89,021	55,793
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	[1]	76,598	55,207
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[2]	(171,808)	(98,253)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[2]	74,270	77,882
Variation Margin for Daily Settled Contracts, Net		24,954
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		31,084,068	23,998,498
Derivatives before adjustments, assets		298,625	230,705
Derivatives before adjustments, liabilities		76,205	102,201
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		31,084,068	23,998,498
Derivatives before adjustments, assets		298,625	230,705
Derivatives before adjustments, liabilities		76,205	102,201
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		1,415,909	1,813,946
Derivatives before adjustments, assets		1,389	2,396
Derivatives before adjustments, liabilities		783	906
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		1,026,778	901,344
Derivatives before adjustments, assets		1,187	1,430
Derivatives before adjustments, liabilities		734	31
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		0	350,000
Derivatives before adjustments, assets		0	2
Derivatives before adjustments, liabilities		0	50
Not Designated as Hedging Instrument [Member] | Interest Rate Caps / Floors [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		245,500	364,500
Derivatives before adjustments, assets		92	322
Derivatives before adjustments, liabilities		0	2
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		72,800	99,100
Derivatives before adjustments, assets		37	339
Derivatives before adjustments, liabilities		1	352
Cleared
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[3]	57,966	21,998
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[3]	49,448	56,835
Mortgages [Member] | Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		70,831	99,002
Derivatives before adjustments, assets		73	303
Derivatives before adjustments, liabilities		$ 48	$ 471
[1]	Represents the application of the netting requirements that allow us to settle (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (including fair value adjustments on derivatives for which variation margin payments are characterized as daily settled contracts). Cash collateral pledged to counterparties at December 31, 2017 and 2016 totaled $16,437 and $35,422, respectively. Cash collateral received from counterparties at December 31, 2017 and 2016 totaled $89,021 and $55,793, respectively. Variation margin for daily settled contracts totaled $24,954 at December 31, 2017.
[2]	Represents the application of the netting requirements that allow the settlement of (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts).
[3]	Variation margin for daily settled contracts totaled $24,954 at December 31, 2017.

Derivatives and Hedging Activ69

Derivatives and Hedging Activities - Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Offsetting Derivative Asset [Abstract]
Gross recognized amount		$ 299,904	$ 232,459
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	171,808	98,253
Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts		128,096	134,206
Derivative instruments not meeting netting requirements	[2]	110	642
Total derivatives, at estimated fair value		128,206	134,848
Offsetting Derivative Liabilities [Abstract]
Gross recognized amount		76,939	102,284
Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts	[1]	(74,270)	(77,882)
Derivative Asset Gross Netting Adjustment and Cash Collateral		(171,808)	(98,253)
Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts		2,669	24,402
Derivative instruments not meeting netting requirements	[2]	49	823
Total derivatives, at estimated fair value		2,718	25,225
Uncleared
Offsetting Derivative Asset [Abstract]
Gross recognized amount		118,932	86,606
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset		(113,842)	(76,255)
Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts		5,090	10,351
Offsetting Derivative Liabilities [Abstract]
Gross recognized amount		27,491	45,449
Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts		(24,822)	(21,047)
Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts		2,669	24,402
Cleared
Offsetting Derivative Asset [Abstract]
Gross recognized amount		180,972	145,853
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[3]	(57,966)	(21,998)
Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts		123,006	123,855
Offsetting Derivative Liabilities [Abstract]
Gross recognized amount		49,448	56,835
Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts	[3]	(49,448)	(56,835)
Total net amounts after netting adjustments, cash collateral and variation margin for daily settled contracts		$ 0	$ 0
[1]	Represents the application of the netting requirements that allow the settlement of (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts).
[2]	Includes MDCs and certain interest-rate forwards.
[3]	Variation margin for daily settled contracts totaled $24,954 at December 31, 2017.

Derivatives and Hedging Activ70

Derivatives and Hedging Activities - Derivatives in Statement of Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) related to fair-value hedge ineffectiveness		$ (7,414)	$ 4,488	$ 4,146
Total net gain (loss) for derivatives not designated as hedging instruments		(1,615)	(2,216)	(1,314)
Derivative Instruments, Other Gain (Loss)	[1]	(229)	0
Net Gains (Losses) on Derivatives and Hedging Activities		(9,258)	2,272	2,832
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) related to fair-value hedge ineffectiveness		(7,414)	4,488	4,146
Total net gain (loss) for derivatives not designated as hedging instruments		122	(196)	1,497
Interest Rate Swaption [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) for derivatives not designated as hedging instruments		(200)	(290)	0
Interest Rate Caps / Floors [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) for derivatives not designated as hedging instruments		(228)	87	(251)
Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) for derivatives not designated as hedging instruments		(1,728)	(207)	(3,372)
Net Interest Settlements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) for derivatives not designated as hedging instruments		(416)	(381)	392
Mortgages [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gain (loss) for derivatives not designated as hedging instruments		$ 835	$ (1,229)	$ 420
[1]	Consists of price alignment amounts on derivatives for which variation margin payments are characterized as daily settled contracts.

Derivatives and Hedging Activ71

Derivatives and Hedging Activities - Derivatives in Statement of Income and Impact on Interest) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		$ 50,760	$ 281,082	$ 66,676
Gain (Loss) on Hedged Item		(58,174)	(276,594)	(62,530)
Net Fair Value Hedge Ineffectiveness		(7,414)	4,488	4,146
Effect on Net Interest Income	[1]	(63,316)	(168,349)	(196,169)
Advances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		61,439	118,029	22,761
Gain (Loss) on Hedged Item		(62,324)	(117,201)	(21,196)
Net Fair Value Hedge Ineffectiveness		(885)	828	1,565
Effect on Net Interest Income	[1]	(31,461)	(91,219)	(155,082)
Consolidated Obligation Bonds Member
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		(46,299)	(30,252)	1,696
Gain (Loss) on Hedged Item		43,993	34,690	4,811
Net Fair Value Hedge Ineffectiveness		(2,306)	4,438	6,507
Effect on Net Interest Income	[1]	16,289	16,888	56,976
Available-for-sale Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		35,620	193,305	42,219
Gain (Loss) on Hedged Item		(39,843)	(194,083)	(46,145)
Net Fair Value Hedge Ineffectiveness		(4,223)	(778)	(3,926)
Effect on Net Interest Income	[1]	$ (48,144)	$ (94,018)	$ (98,063)
[1]	(1) Includes the effect of derivatives in fair-value hedging relationships on net interest income that is recorded in the interest income/expense line item of the respective hedged items. Excludes the interest income/expense of the respective hedged items, which fully offsets the interest income/expense of the derivatives, except to the extent of any hedge ineffectiveness. Net interest settlements on derivatives that are not in fair-value hedging relationships are reported in other income (loss). These amounts do not include the effect of amortization/accretion related to fair value hedging activities.

Derivatives and Hedging Activ72

Derivatives and Hedging Activities - Narrative (Details) $ in Thousands	Dec. 31, 2017USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative, Net Liability Position, Aggregate Fair Value	$ 644
Collateral Already Posted, Aggregate Fair Value	34
Derivative, Net Liability Position, Aggregate Fair Value, Not Subject to Credit Support Agreement	$ 49

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Weighted-average interest rates paid on interest-bearing deposits		0.86%	0.12%	0.01%
Interest-bearing:
Demand and overnight		$ 513,150	$ 494,880
Time		50	50
Interest-bearing Domestic Deposit, Other		23	25
Total interest-bearing		513,223	494,955
Non-interest-bearing:
Other (1)	[1]	51,576	29,118
Total non-interest-bearing		51,576	29,118
Total deposits		$ 564,799	$ 524,073
[1]	(1) Includes pass-through deposit reserves from members.

Consolidated Obligations (Detai

Consolidated Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule of Short-term and Long-term Debt [Line Items]
Obligation with Joint and Several Liability Arrangement, Amount Outstanding	$ 1,000,000,000	$ 989,300,000
Discount Notes original maturities	1 year
Book value	$ 20,358,157	16,801,763
Par value	$ 20,394,192	$ 16,819,659
Weighted-average effective interest rate	1.22%	0.51%
Federal Home Loan Bank Consolidated Obligations Bonds Maturities Summary Next Rolling Twelve Months Par	$ 14,021,190	$ 16,234,460
Federal Home Loan Bank Consolidated Obligations Bonds Maturities Summary in Rolling Year Two Par	9,392,470	6,122,190
Federal Home Loan Bank Consolidated Obligations Bonds Maturities Summary in Rolling Year Three Par	4,849,960	2,718,945
Federal Home Loan Bank Consolidated Obligations Bonds Maturities Summary in Rolling Year Four Par	1,294,470	1,684,530
Federal Home Loan Bank Consolidated Obligations Bonds Maturities Summary in Rolling Year Five Par	2,798,000	1,040,000
Federal Home Loan Bank Consolidated Obligations Bonds Maturities Summary After Rolling Year Five Par	5,626,500	5,708,000
Total CO bonds, par value	37,982,590	33,508,125
Unamortized premiums	27,333	27,462
Debt Instrument, Unamortized Discount	(13,782)	(12,059)
Unamortized Debt Issuance Expense	(14,188)	(13,705)
Fair-value hedging adjustments	(86,300)	(42,544)
Bonds	$ 37,895,653	$ 33,467,279
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate Maturing in Next Twelve Rolling Months	1.27%	0.85%
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate Maturing in Rolling Year Two	1.46%	0.96%
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate Maturing in Rolling Year Three	2.23%	1.65%
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate Maturing in Rolling Year Four	2.17%	3.17%
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate Maturing in Rolling Year Five	2.29%	2.17%
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate Maturing After Rolling Year Five	3.02%	2.92%
Federal Home Loan Bank Consolidated Obligations Bonds Weighted Average Interest Rate	1.80%	1.44%
Federal Home Loan Bank Consolidated Obligations Bonds Earlier of Contractual Maturity or Next Call Date in Next Rolling Twelve Months	$ 24,449,190	$ 23,825,460
Federal Home Loan Bank Consolidated Obligations Bonds Earlier of Contractual Maturity or Next Call Date in Rolling Year Two	9,098,470	4,675,190
Federal Home Loan Bank Consolidated Obligations Bonds Earlier of Contractual Maturity or Next Call Date in Rolling Year Three	2,125,960	2,240,945
Federal Home Loan Bank Consolidated Obligations Bonds Earlier of Contractual Maturity or Next Call Date in Rolling Year Four	584,470	1,257,530
Federal Home Loan Bank Consolidated Obligations Bonds Earlier of Contractual Maturity or Next Call Date in Rolling Year Five	579,000	474,000
Federal Home Loan Bank Consolidated Obligations Bonds Earlier of Contractual Maturity or Next Call Date After Rolling Year Five	1,145,500	1,035,000
Federal Home Loan Bank Consolidated Obligations With No Related Option Feature [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Total CO bonds, par value	26,277,590	25,627,125
Federal Home Loan Bank Consolidated Obligations Callable Option [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Total CO bonds, par value	$ 11,705,000	$ 7,881,000
Maximum [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Discount Notes original maturities	1 year

Consolidated Obligations (CO Bo

Consolidated Obligations (CO Bonds by Interest-rate Payment Type) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Fixed-rate	$ 24,747,590	$ 18,928,125
Step-up	285,000	655,000
Simple variable-rate	12,950,000	13,905,000
Ratchet	0	20,000
Total CO bonds, par value	$ 37,982,590	$ 33,508,125

Affordable Housing Program (Det

Affordable Housing Program (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Affordable Housing Program [Abstract]
Minimum amount required to set aside for AHP		$ 100,000
Percentage of net earnings required to set aside for AHP		10.00%
Affordable Housing Program Funding Obligation [Roll Forward]
Balance at beginning of year		$ 26,598	$ 31,103	$ 36,899
Annual assessment (expense)		18,163	13,291	13,499
Subsidy usage, net	[1]	(12,595)	(17,796)	(19,295)
Balance at end of year		$ 32,166	$ 26,598	$ 31,103
[1]	(1) Subsidies disbursed are reported net of returns/recaptures of previously disbursed subsidies.

Capital Narrative (Details)

Capital Narrative (Details) $ in Thousands	12 Months Ended	78 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Capital [Abstract]
Class B-2 Dividend as a Percent of Class B-1 Dividend	80.00%
Class B stock redemption period	5 years
Minimum days of written notice from Board of Directors to change cancellation fee	15 days
Capital Stock Not Considered MRCS Subject to Redemption Request	$ 5,144	$ 5,144
JCE Agreement Requirements [Line Items]
Percentage of net income allocated to restricted retained earnings account		20.00%
Minimum [Member]
JCE Agreement Requirements [Line Items]
Restricted Retained Earnings as Percentage of Average Balance of Outstanding Consolidated Obligations for Previous Quarter		1.00%
Restricted Retained Earnings as Percentage of Average Balance of Outstanding Consolidated Obligations for Previous Quarter When Available to Pay Dividends		1.50%

Capital Mandatorily Redeemable

Capital Mandatorily Redeemable Capital Stock Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 01, 2016
Mandatorily Redeemable Capital Stock Acitvity [Roll Forward]
Balance at beginning of year	$ 170,043	$ 14,063	$ 15,673
Net Shares Reclassified to Mandatorily Redeemable Capital Stock, Value	0	183,056	0
Repayments of Mandatory Redeemable Capital Securities	5,721	28,148	1,610
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Accrued Dividends	$ 0	1,072	$ 0
Class B Stock of Captive Insurance Company Members Reclassified to MRCS				$ 178,898
Financial Instruments Subject to Mandatory Redemption Past Contractual Redemption Date Due to Outstanding Activity To Be Repurchased or Redeemed No Later Than February 19 2017		$ 3,021

Capital MRCS Contractual Year R

Capital MRCS Contractual Year Redemption (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount [Abstract]
Year 1	[1]	$ 7,963	$ 8,630
Year 2		13	5,054
Year 3		0	13
Year 4		4,158	0
Year 5		0	4,158
financial instruments subject to mandatory redemption, redeemable after year five	[2]	152,188	152,188
Total MRCS		164,322	170,043	$ 14,063	$ 15,673
Financial Instruments Subject to Mandatory Redemption, Past Contractual Redemption Date, Due to Outstanding Activity		$ 2,909	$ 5,609
[1]	(1) Balances at December 31, 2017 and 2016 include $2,909 and $5,609, respectively, of Class B stock that had reached the end of the five-year redemption period but will not be redeemed until the associated credit products and other obligations are no longer outstanding.
[2]	(2) Represents the five-year redemption period of Class B stock held by certain captive insurance companies which begins immediately upon their termination of memberships no later than February 19, 2021, in accordance with the Final Membership Rule.

Capital MRCS Distributions (Det

Capital MRCS Distributions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
MRCS Distributions [Abstract]
Interest Expense, Capital Securities	$ 7,034	$ 6,613	$ 522
Retained Earnings, Appropriated, Transfers To (From)	0	1,072	0
Distributions on Mandatorily Redeemable Securities	$ 7,034	$ 7,685	$ 522

Capital Regulatory Capital Requ

Capital Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Regulatory Capital Requirements [Abstract]
Number of Finance Agency Regulatory Capital Requirements	3
Multiplier for Determining Permanent Capital in Leverage Capital Calculation	1.5
Federal Home Loan Bank, Risk-Based Capital, Required	$ 903,806	$ 760,946
Federal Home Loan Bank, Risk-Based Capital, Actual	$ 2,998,422	$ 2,549,871
Regulatory Capital Ratio, Required	4.00%	4.00%
Federal Home Loan Bank, Regulatory Capital Ratio, Actual	4.81%	4.73%
Federal Home Loan Bank, Regulatory Capital, Required	$ 2,493,956	$ 2,156,296
Federal Home Loan Bank, Regulatory Capital, Actual	$ 2,998,422	$ 2,549,871
Leverage Ratio, Required	5.00%	5.00%
Federal Home Loan Bank, Leverage Ratio, Actual	7.21%	7.10%
Federal Home Loan Bank, Leverage Capital, Required	$ 3,117,445	$ 2,695,370
Federal Home Loan Bank, Leverage Capital, Actual	$ 4,497,633	$ 3,824,806

Accumulated Other Comprehensi82

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income [Roll Forward]
AOCI Balance, Beginning	$ 56,368
Net change in unrealized gains (losses)	53,051	$ 39,371	$ (15,981)
Pension benefits, net	(449)	(2,619)	99
Other Comprehensive Income (Loss)	55,038	33,490	(23,782)
AOCI Balance, Ending	111,406	56,368
Unrealized Gains (Losses) on Securities [Member] | Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income [Roll Forward]
AOCI Balance, Beginning	39,468	97	16,078
Net change in unrealized gains (losses)	53,051	39,371	(15,981)
Other Comprehensive Income (Loss)	53,051	39,371	(15,981)
AOCI Balance, Ending	92,519	39,468	97
Non-Credit OTTI [Member] | Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income [Roll Forward]
AOCI Balance, Beginning	26,938	30,229	38,172
Net change in unrealized gains (losses)	2,189	(3,332)	(7,766)
Net change in fair value not in excess of cumulative non-credit losses	29	(156)	(238)
Reclassification of non-credit portion to other income (loss)	166	197	61
Other Comprehensive Income (Loss)	2,384	(3,291)	(7,943)
AOCI Balance, Ending	29,322	26,938	30,229
Non-Credit OTTI [Member] | Held-to-maturity Securities [Member]
Accumulated Other Comprehensive Income [Roll Forward]
AOCI Balance, Beginning	(103)	(132)	(175)
Accretion of non-credit portion	10	29	43
Other Comprehensive Loss, Held-to-maturity Security, Reclassification Adjustment from AOCI for Noncredit Portion of OTTI, before Tax	42
Other Comprehensive Income (Loss)	52	29	43
AOCI Balance, Ending	(51)	(103)	(132)
Pension Benefits [Member]
Accumulated Other Comprehensive Income [Roll Forward]
AOCI Balance, Beginning	(9,935)	(7,316)	(7,415)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax	(449)	(2,619)	99
Other Comprehensive Income (Loss)	(449)	(2,619)	99
AOCI Balance, Ending	(10,384)	(9,935)	(7,316)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income [Roll Forward]
AOCI Balance, Beginning	56,368	22,878	46,660
Net change in unrealized gains (losses)	55,240	36,039	(23,747)
Net change in fair value not in excess of cumulative non-credit losses	29	(156)	(238)
Accretion of non-credit portion	10	29	43
Reclassification of non-credit portion to other income (loss)	208	197	61
Pension benefits, net	(449)	(2,619)	99
Other Comprehensive Income (Loss)	55,038	33,490	(23,782)
AOCI Balance, Ending	$ 111,406	$ 56,368	$ 22,878

Employee Retirement and Defer83

Employee Retirement and Deferred Compensation Plans - Qualified Defined Benefit Multiemployer Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016		Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Jun. 30, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer Plan Number	333
Maximum percentage of contributions by participating employer					5.00%		5.00%	5.00%
Multiemployer Plans, Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Entity Tax Identification Number	135,645,888
Pentegra Defined Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net pension cost charged to compensation and benefits expense for the year ended December 31	$ 4,450		$ 5,772			$ 5,412
DB Plan funded status as July 1	111.00%	[1]	104.00%	[2]		107.00%
Our funded status as of July 1	117.00%		113.00%			118.00%
[1]	(a) The DB plan's funded status as of July 1, 2017 is preliminary and may increase because the participating employers were permitted to make designated contributions for the plan year ended June 30, 2017 through March 15, 2018. Any such contributions will be included in the final valuation as of July 1, 2017. The final funded status as of July 1, 2017 will not be available until the Form 5500 for the plan year ended June 30, 2018 is filed (no later than April 2019).
[2]	(b) The DB plan's final funded status as of July 1, 2016 will not be available until the Form 5500 for the plan year ended June 30, 2017 is filed (no later than April 2018).

Employee Retirement and Defer84

Employee Retirement and Deferred Compensation Plans Employee Retirement and Deferred Compensation Plans - Qualified Defined Contribution Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Employer contribution amount	$ 1,577	$ 1,488	$ 1,344

Employee Retirement and Defer85

Employee Retirement and Deferred Compensation Plans - Nonqualified Defined Benefit Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net loss (income) recognized in OCI	$ 449	$ 2,619	$ (99)
Supplemental Executive Retirement Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	20,022	15,099	14,074
Service cost	1,035	808	839
Interest cost	738	735	665
Actuarial (gain) loss	1,712	4,055	1,485
Benefits paid	(331)	(675)	(1,964)
Projected benefit obligation at end of year	$ 23,176	$ 20,022	15,099
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	3.00%	4.00%
Compensation increases	5.50%	5.50%
Accumulated benefit obligation	$ 16,704	$ 13,744
Grantor trust assets (2)	20,071	17,536
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1,035	808	839
Interest cost	738	735	665
Amortization of prior service benefit	0	0	(11)
Amortization of net actuarial loss	(1,263)	(1,436)	(1,595)
Net pension cost charged to compensation and benefits expense for the year ended December 31	3,036	2,979	3,088
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Actuarial loss	1,712	4,055	1,485
Net loss (income) recognized in OCI	449	2,619	(99)
Total recognized in compensation and benefits and in OCI	$ 3,485	$ 5,598	$ 2,989
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.00%	4.20%	3.90%
Compensation increases	5.50%	5.50%	5.50%
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net Actuarial Loss	$ (10,384)	$ (9,935)
Net pension benefits reported in AOCI	(10,384)	$ (9,935)
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
Net actuarial loss (gain)	1,291
Net amount to be amortized	1,291
Expected net periodic benefit cost in next fiscal year	2,904
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2,018	2,652
2,019	4,058
2,020	2,259
2,021	1,716
2,022	7,240
2023-2027	$ 4,316

Employee Retirement and Defer86

Employee Retirement and Deferred Compensation Plans Employee Retirement and Deferred Compensation Plans - Nonqualified Deferred Compensation Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Nonqualified Supplemental Executive Thrift Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 52	$ 47
Deferred Compensation Arrangement with Individual, Recorded Liability	660	248
Directors' Deferred Compensation Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Noninterest Expense Directors Fees	1,768	1,620
Deferred Compensation Arrangement with Individual, Recorded Liability	967	333
Compensation Deferred by Directors Under the DDCP	$ 538	$ 319

Segment Information (Details)

Segment Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Operating_Segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | Operating_Segment	2
Net interest income	$ 263,003	$ 198,193	$ 195,425
Provision for (reversal of) credit losses	51	(45)	(456)
Other income (loss)	(5,996)	5,658	10,481
Other expenses	82,362	77,599	71,894
Income before assessments	174,594	126,297	134,468
Affordable Housing Programs assessments	18,163	13,291	13,499
Net Income	156,431	113,006	120,969
Assets	62,348,906	53,907,400
Traditional [Member]
Segment Reporting Information [Line Items]
Net interest income	193,278	144,695	128,175
Provision for (reversal of) credit losses	0	0	0
Other income (loss)	(5,110)	6,674	13,272
Other expenses	69,644	65,746	62,211
Income before assessments	118,524	85,623	79,236
Affordable Housing Programs assessments	12,556	9,224	7,976
Net Income	105,968	76,399	71,260
Assets	51,992,565	44,406,003
Mortgage Loans [Member]
Segment Reporting Information [Line Items]
Net interest income	69,725	53,498	67,250
Provision for (reversal of) credit losses	51	(45)	(456)
Other income (loss)	(886)	(1,016)	(2,791)
Other expenses	12,718	11,853	9,683
Income before assessments	56,070	40,674	55,232
Affordable Housing Programs assessments	5,607	4,067	5,523
Net Income	50,463	36,607	$ 49,709
Assets	$ 10,356,341	$ 9,501,397

Estimated Fair Values - Carryin

Estimated Fair Values - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Variation Margin for Daily Settled Contracts, Net		$ 24,954
Assets:
Cash and Due from Banks		55,269	$ 546,612
AFS Securities		7,128,758	6,059,835
HTM Securities, Carrying Value		5,897,668	5,819,573
HTM Securities, Fair Value		5,919,299	5,848,692
Accrued interest receivable		105,314	93,716
Derivative Asset		128,206	134,848
Netting adjustments and cash collateral, assets	[1]	(171,808)	(98,253)
Liabilities:
Accrued interest payable		135,691	98,411
Derivative Liability		2,718	25,225
MRCS		164,322	170,043	$ 14,063	$ 15,673
Netting adjustments and cash collateral, liabilities	[1]	(74,270)	(77,882)
Level 1 [Member]
Assets:
Cash and Due from Banks		55,269	546,612
Interest-bearing Deposits, Fair Value Disclosure		659,926	150,072
Securities Purchased Under Agreements to Resell, Fair Value Disclosure		0	0
Federal Funds Sold, Fair Value Disclosure		0	0
AFS Securities		0	0
HTM Securities, Fair Value		0	0
Advances		0	0
Mortgage loans held for portfolio, net		0	0
Accrued interest receivable		0	0
Derivative Asset		0	0
Grantor trust assets (2)	[2]	21,698	18,117
Liabilities:
Deposits		0	0
Accrued interest payable		0	0
Derivative Liability		0	0
MRCS		164,322	170,043
Level 2 [Member]
Assets:
Cash and Due from Banks		0	0
Interest-bearing Deposits, Fair Value Disclosure		416	153
Securities Purchased Under Agreements to Resell, Fair Value Disclosure		2,605,461	1,781,309
Federal Funds Sold, Fair Value Disclosure		1,280,000	1,650,000
AFS Securities		6,910,224	5,790,716
HTM Securities, Fair Value		5,874,413	5,791,111
Advances		34,001,397	28,059,477
Mortgage loans held for portfolio, net		10,413,134	9,567,140
Accrued interest receivable		105,314	93,716
Derivative Asset		300,014	233,101
Grantor trust assets (2)	[2]	0	0
Liabilities:
Deposits		564,799	524,073
Accrued interest payable		135,691	98,411
Derivative Liability		76,988	103,107
MRCS		0	0
Level 3 [Member]
Assets:
Cash and Due from Banks		0	0
Interest-bearing Deposits, Fair Value Disclosure		0	0
Securities Purchased Under Agreements to Resell, Fair Value Disclosure		0	0
Federal Funds Sold, Fair Value Disclosure		0	0
AFS Securities		218,534	269,119
HTM Securities, Fair Value		44,886	57,581
Advances		0	0
Mortgage loans held for portfolio, net		13,079	20,254
Accrued interest receivable		0	0
Derivative Asset		0	0
Grantor trust assets (2)	[2]	0	0
Liabilities:
Deposits		0	0
Accrued interest payable		0	0
Derivative Liability		0	0
MRCS		0	0
Reported Value Measurement [Member]
Assets:
Cash and Due from Banks		55,269	546,612
Interest-bearing Deposits, Fair Value Disclosure		660,342	150,225
Securities Purchased Under Agreements to Resell, Fair Value Disclosure		2,605,460	1,781,309
Federal Funds Sold, Fair Value Disclosure		1,280,000	1,650,000
AFS Securities		7,128,758	6,059,835
HTM Securities, Carrying Value		5,897,668	5,819,573
Advances		34,055,064	28,095,953
Mortgage loans held for portfolio, net		10,356,341	9,501,397
Accrued interest receivable		105,314	93,716
Derivative Asset		128,206	134,848
Grantor trust assets (2)	[2]	21,698	18,117
Liabilities:
Deposits		564,799	524,073
Accrued interest payable		135,691	98,411
Derivative Liability		2,718	25,225
MRCS		164,322	170,043
Fair Value [Member]
Assets:
Cash and Due from Banks		55,269	546,612
Interest-bearing Deposits, Fair Value Disclosure		660,342	150,225
Securities Purchased Under Agreements to Resell, Fair Value Disclosure		2,605,461	1,781,309
Federal Funds Sold, Fair Value Disclosure		1,280,000	1,650,000
AFS Securities		7,128,758	6,059,835
HTM Securities, Fair Value		5,919,299	5,848,692
Advances		34,001,397	28,059,477
Mortgage loans held for portfolio, net		10,426,213	9,587,394
Accrued interest receivable		105,314	93,716
Derivative Asset		128,206	134,848
Grantor trust assets (2)	[2]	21,698	18,117
Liabilities:
Deposits		564,799	524,073
Accrued interest payable		135,691	98,411
Derivative Liability		2,718	25,225
MRCS		164,322	170,043
Consolidated Obligation Discount Notes [Member] | Level 1 [Member]
Liabilities:
Discount notes		0	0
Consolidated Obligation Discount Notes [Member] | Level 2 [Member]
Liabilities:
Discount notes		20,394,192	16,819,659
Consolidated Obligation Discount Notes [Member] | Level 3 [Member]
Liabilities:
Discount notes		0	0
Consolidated Obligation Discount Notes [Member] | Reported Value Measurement [Member]
Liabilities:
Discount notes		20,358,157	16,801,763
Consolidated Obligation Discount Notes [Member] | Fair Value [Member]
Liabilities:
Discount notes		20,394,192	16,819,659
Consolidated Obligation Bonds Member | Level 1 [Member]
Liabilities:
Bonds		0	0
Consolidated Obligation Bonds Member | Level 2 [Member]
Liabilities:
Bonds		37,998,928	33,614,346
Consolidated Obligation Bonds Member | Level 3 [Member]
Liabilities:
Bonds		0	0
Consolidated Obligation Bonds Member | Reported Value Measurement [Member]
Liabilities:
Bonds		37,895,653	33,467,279
Consolidated Obligation Bonds Member | Fair Value [Member]
Liabilities:
Bonds		$ 37,998,928	$ 33,614,346
[1]	Represents the application of the netting requirements that allow the settlement of (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts).
[2]	Included in other assets.

Estimated Fair Values - Estimat

Estimated Fair Values - Estimated Fair Value on Recurring and Nonrecurring Basis (Details) - USD ($)		Dec. 31, 2017		Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		$ 7,128,758,000		$ 6,059,835,000
Derivative Asset [Abstract]
Derivative Asset		128,206,000		134,848,000
Netting adjustments and cash collateral, assets	[1]	(171,808,000)		(98,253,000)
Derivative Liability [Abstract]
Derivative Liability		2,718,000		25,225,000
Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts	[1]	(74,270,000)		(77,882,000)
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Mortgage loans held for portfolio, net		0		0
Derivative Asset [Abstract]
Derivative Asset		0		0
Grantor trust assets (2)	[2]	21,698,000		18,117,000
Derivative Liability [Abstract]
Derivative Liability		0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		6,910,224,000		5,790,716,000
Mortgage loans held for portfolio, net		10,413,134,000		9,567,140,000
Derivative Asset [Abstract]
Derivative Asset		300,014,000		233,101,000
Grantor trust assets (2)	[2]	0		0
Derivative Liability [Abstract]
Derivative Liability		76,988,000		103,107,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		218,534,000		269,119,000
Mortgage loans held for portfolio, net		13,079,000		20,254,000
Derivative Asset [Abstract]
Derivative Asset		0		0
Grantor trust assets (2)	[2]	0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
GSE and TVA Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		4,403,929,000		4,714,634,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		2,506,295,000		1,076,082,000
Private-Label RMBS [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		218,534,000		269,119,000
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		7,128,758,000		6,059,835,000
Derivative Asset [Abstract]
Derivative Asset		128,206,000		134,848,000
Netting adjustments and cash collateral, assets	[3]	(171,808,000)		(98,253,000)
Grantor trust assets (2)	[4]	21,698,000		18,117,000
Total assets at estimated fair value		7,278,662,000		6,212,800,000
Derivative Liability [Abstract]
Derivative Liability		2,718,000		25,225,000
Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts	[3]	(74,270,000)		(77,882,000)
Total liabilities at estimated fair value		2,718,000		25,225,000
Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Derivative Asset [Abstract]
Derivative Asset		0		0
Grantor trust assets (2)	[4]	21,698,000		18,117,000
Total assets at estimated fair value		21,698,000		18,117,000
Derivative Liability [Abstract]
Derivative Liability		0		0
Total liabilities at estimated fair value		0		0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		6,910,224,000		5,790,716,000
Derivative Asset [Abstract]
Derivative Asset		300,014,000		233,101,000
Grantor trust assets (2)	[4]	0		0
Total assets at estimated fair value		7,210,238,000		6,023,817,000
Derivative Liability [Abstract]
Derivative Liability		76,988,000		103,107,000
Total liabilities at estimated fair value		76,988,000		103,107,000
Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		218,534,000		269,119,000
Derivative Asset [Abstract]
Derivative Asset		0		0
Grantor trust assets (2)	[4]	0		0
Total assets at estimated fair value		218,534,000		269,119,000
Derivative Liability [Abstract]
Derivative Liability		0		0
Total liabilities at estimated fair value		0		0
Recurring [Member] | Interest Rate Related [Member]
Derivative Asset [Abstract]
Derivative Asset		128,096,000		134,206,000
Netting adjustments and cash collateral, assets	[3]	(171,808,000)		(98,253,000)
Derivative Liability [Abstract]
Derivative Liability		2,669,000		24,402,000
Gross amounts of netting adjustments, cash collateral and variation margin for daily settled contracts	[3]	(74,270,000)		(77,882,000)
Recurring [Member] | Interest Rate Related [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Asset [Abstract]
Derivative Asset		0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
Recurring [Member] | Interest Rate Related [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Asset [Abstract]
Derivative Asset		299,904,000		232,459,000
Derivative Liability [Abstract]
Derivative Liability		76,939,000		102,284,000
Recurring [Member] | Interest Rate Related [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Asset [Abstract]
Derivative Asset		0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
Recurring [Member] | Forward Contracts [Member]
Derivative Asset [Abstract]
Derivative Asset		37,000		339,000
Derivative Liability [Abstract]
Derivative Liability		1,000		352,000
Recurring [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Asset [Abstract]
Derivative Asset		0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
Recurring [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Asset [Abstract]
Derivative Asset		37,000		339,000
Derivative Liability [Abstract]
Derivative Liability		1,000		352,000
Recurring [Member] | Forward Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Asset [Abstract]
Derivative Asset		0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
Recurring [Member] | Forward Contracts [Member] | Mortgages [Member]
Derivative Asset [Abstract]
Derivative Asset		73,000		303,000
Derivative Liability [Abstract]
Derivative Liability		48,000		471,000
Recurring [Member] | Forward Contracts [Member] | Mortgages [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Asset [Abstract]
Derivative Asset		0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
Recurring [Member] | Forward Contracts [Member] | Mortgages [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Asset [Abstract]
Derivative Asset		73,000		303,000
Derivative Liability [Abstract]
Derivative Liability		48,000		471,000
Recurring [Member] | Forward Contracts [Member] | Mortgages [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Asset [Abstract]
Derivative Asset		0		0
Derivative Liability [Abstract]
Derivative Liability		0		0
Recurring [Member] | GSE and TVA Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		4,403,929,000		4,714,634,000
Recurring [Member] | GSE and TVA Debentures [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Recurring [Member] | GSE and TVA Debentures [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		4,403,929,000		4,714,634,000
Recurring [Member] | GSE and TVA Debentures [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		2,506,295,000		1,076,082,000
Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		2,506,295,000		1,076,082,000
Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Recurring [Member] | Private-Label RMBS [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		218,534,000		269,119,000
Recurring [Member] | Private-Label RMBS [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Recurring [Member] | Private-Label RMBS [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		0		0
Recurring [Member] | Private-Label RMBS [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value - AFS Securities		218,534,000		269,119,000
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		2,637,000	[5]	3,492,000	[6]
Derivative Asset [Abstract]
Total assets at estimated fair value		2,637,000		3,492,000
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		0	[5]	0	[6]
Derivative Asset [Abstract]
Total assets at estimated fair value		0		0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		0	[5]	0	[6]
Derivative Asset [Abstract]
Total assets at estimated fair value		0		0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		2,637,000	[5]	3,492,000	[6]
Derivative Asset [Abstract]
Total assets at estimated fair value		$ 2,637,000		$ 3,492,000
[1]	Represents the application of the netting requirements that allow the settlement of (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts).
[2]	Included in other assets.
[3]	Represents the application of the netting requirements that allow us to settle (i) positive and negative positions and (ii) cash collateral and related accrued interest held or placed, with the same clearing agent and/or counterparty (includes fair value adjustments on derivatives of $24,954 at December 31, 2017 for which variation margin payments are characterized as daily settled contracts).
[4]	Included in other assets.
[5]	Amounts are as of the date the fair value adjustment was recorded during the year ended December 31, 2017.
[6]	Amounts are as of the date the fair value adjustment was recorded during the year ended December 31, 2016.

Estimated Fair Values - Level 3

Estimated Fair Values - Level 3 Reconciliation (Details) - Available-for-sale Securities [Member] - RMBS [Member] - Private Label Residential Mortgage Backed Securities [Member] - Recurring [Member] - Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 269,119	$ 319,186	$ 401,050
Accretion of credit losses in interest income	6,778	9,348	8,708
Net gains (losses) on changes in fair value in Other Income (Loss)	(166)	(197)	(61)
Net change in fair value not in excess of cumulative non-credit losses in OCI	29	(156)	(238)
Unrealized gains (losses) in OCI	2,189	(3,332)	(7,766)
Reclassification of non-credit portion in OCI to other income (loss)	166	197	61
Settlements	(59,581)	(55,927)	(82,568)
Balance, end of period	218,534	269,119	319,186
Net gains (losses) included in earnings attributable to changes in fair value relating to assets still held at end of period	$ 6,612	$ 8,291	$ 8,647

Commitments and Contingencies91

Commitments and Contingencies (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Carrying value of guarantees related to standby letters of credit		$ 249,894,000	$ 357,812,000
Cash collateral pledged		16,437,000	35,421,000
Variation Margin for Daily Settled Contracts, Net		24,954,000
Net rental and related costs		287,000	212,000	$ 185,000
Future Minimum Lease Payments		2,253,000
Proceeds from legal settlements, net of legal fees and litigation expenses		$ 530,000	$ 60,000	$ 4,732,000
Maximum [Member]
Loss Contingencies [Line Items]
Original terms of these standby letters of credit		20 years
Period of time commitments unconditionally obligate to fund or purchase mortgage loans and participation interests		91 days
Minimum [Member]
Loss Contingencies [Line Items]
Original terms of these standby letters of credit		3 months
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Off-balance-sheet commitments expire within one year		$ 102,344,000
Off-balance-sheet commitments expire after one year		121,381,000
Off-balance-sheet commitments, Total		223,725,000
Maximum line of credit amount		50,000
Carrying value of guarantees related to standby letters of credit		$ 2,867,000
Period of time for short-term cash needs		1 year
Commitments to Extend Credit [Member]
Loss Contingencies [Line Items]
Off-balance-sheet commitments expire within one year	[1]	$ 1,084,234,000
Off-balance-sheet commitments expire after one year	[1]	0
Off-balance-sheet commitments, Total	[1]	1,084,234,000
Loan Origination Commitments [Member]
Loss Contingencies [Line Items]
Off-balance-sheet commitments expire within one year	[2]	4,050,000
Off-balance-sheet commitments expire after one year	[2]	0
Off-balance-sheet commitments, Total	[2]	$ 4,050,000
Period for Advance Commitments		6 months
Forward Contracts [Member] | Mortgages [Member]
Loss Contingencies [Line Items]
Off-balance-sheet commitments expire within one year	[3]	$ 70,831,000
Off-balance-sheet commitments expire after one year	[3]	0
Off-balance-sheet commitments, Total	[3]	70,831,000
Consolidated Obligation Bonds Member
Loss Contingencies [Line Items]
Off-balance-sheet commitments expire within one year		28,000,000
Off-balance-sheet commitments expire after one year		0
Off-balance-sheet commitments, Total		$ 28,000,000
Commitments to Invest in Mortgage Loans [Member]
Loss Contingencies [Line Items]
Period for Advance Commitments		91 days
[1]	(1) Maximum line of credit amount per member is $50,000.
[2]	(2) Generally for periods up to six months.
[3]	(3) Generally for periods up to 91 days.

Transactions with Related Par92

Transactions with Related Parties and Other Entities (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Total advances, par value		$ 28,131,960	$ 34,169,469	$ 28,131,960
Mortgage loans acquired			2,144,552	3,074,847	$ 2,663,395
Payments From Loans to Other Federal Home Loan Banks			(100,000)	(300,000)	0
Proceeds from Loans to Other Federal Home Loan Banks			100,000	300,000	0
Principal Amount of Mortgage Loans Sold	$ 18,000	72,000
Directors' Financial Institutions [Member]
Related Party Transaction [Line Items]
Capital Stock, including MRCS, par value		$ 50,810	$ 40,564	$ 50,810
Capital Stock, including MRCS, % of Total		3.00%	2.00%	3.00%
Total advances, par value		$ 627,105	$ 588,108	$ 627,105
Advances, % of Total		2.00%	2.00%	2.00%
Net Capital Stock Issuances To Directors' Financial Institutions			$ 3,912	$ 1,516	(12,588)
Net Advances to Directors Financial Institutions			79,751	11,274	112,976
Mortgage Loans Purchased from Directors Financial Institutions			$ 33,274	$ 38,728
Mortgage loans acquired					$ 39,590