Federal Home Loan Bank of Dallas 10-K 22 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 11, 2016	Jun. 30, 2015
Entity Information [Line Items]
Entity Registrant Name	Federal Home Loan Bank of Dallas
Entity Central Index Key	1,331,757
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		15,733,717
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, 2015	Dec. 31, 2014
ASSETS
Cash and due from banks		$ 837,202	$ 1,507,708
Interest-bearing deposits		260	266
Securities purchased under agreements to resell (Note 12)		1,000,000	350,000
Federal funds sold (Notes 18 and 19)		2,171,000	5,613,000
Trading securities (Notes 3, 12 and 17) ($35,985 pledged at December 31, 2014, which could be rehypothecated)		211,056	408,563
Available-for-sale securities (Notes 4,12 and 17) ($300,184 pledged at December 31, 2015, which could be rehypothecated)		9,713,191	6,388,502
Held-to-maturity securities (a) (Note 5)	[1]	3,228,011	4,662,013
Advances (Notes 6, 8 and 18)		24,746,802	18,942,400
Mortgage loans held for portfolio, net of allowance for credit losses of $141 and $143 in 2015 and 2014, respectively (Notes 7, 8 and 18)		55,117	71,411
Loans to Other Federal Home Loan Banks		0	0
Accrued interest receivable		69,676	65,168
Premises and equipment, net		18,520	18,368
Derivative assets (Notes 12 and 13)		23,080	10,454
Other assets		9,379	8,015
TOTAL ASSETS		42,083,294	38,045,868
Deposits (Notes 9 and 18)
Interest-bearing		1,045,939	797,390
Non-interest bearing		19	24
Total deposits		1,045,958	797,414
Debt and Capital Lease Obligations [Abstract]
Discount notes		20,541,329	19,131,832
Bonds		18,025,959	16,078,700
Total consolidated obligations		38,567,288	35,210,532
Mandatorily redeemable capital stock (Note 14)		8,929	5,059
Accrued interest payable		38,972	39,726
Affordable Housing Program (Note 11)		22,710	25,998
Derivative liabilities (Notes 12 and 13)		6,964	21,521
Other liabilities (Note 4)		193,161	26,705
Total liabilities		$ 39,883,982	$ 36,126,955
Commitments and contingencies (Notes 11,13,15 and 17)
Capital
Total Class B Capital Stock		$ 1,540,132	$ 1,222,738
Retained earnings
Unrestricted		699,213	650,224
Restricted		62,990	49,552
Total retained earnings		762,203	699,776
Accumulated other comprehensive income (loss) (Note 20)		(103,023)	(3,601)
Total capital		2,199,312	1,918,913
TOTAL LIABILITIES AND CAPITAL		42,083,294	38,045,868
Capital Stock - Class B putable ($100 par value) issued and outstanding shares: 12,227,376 in 2014
Capital
Total Class B Capital Stock		0	1,222,738
Capital Stock - Class B-1 putable ($100 par value) issued and outstanding shares: 6,324,540 in 2015
Capital
Total Class B Capital Stock		632,454	0
Retained earnings
Total capital		632,454	0
Capital Stock - Class B-2 putable ($100 par value) issued and outstanding shares 9,076,781 in 2015
Capital
Total Class B Capital Stock		907,678	0
Retained earnings
Total capital		$ 907,678	$ 0
[1]	(a) Fair values: $3,262,283 and $4,727,130 at December 31, 2015 and 2014, respectively.

Statements of Condition Parenth

Statements of Condition Parenthetical - USD ($)	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Held-to-maturity Securities, Fair Value	$ 3,262,283,000	$ 4,727,130,000
Loans and Leases Receivable, Allowance	141,000	143,000
Trading Securities Pledged as Collateral	0
Derivative, Collateral, Right to Reclaim Securities	$ 300,184,000	$ 35,985,000
CAPITAL (Notes 14 and 18)
Common Stock, Par or Stated Value Per Share	$ 100
Common Class B [Member]
CAPITAL (Notes 14 and 18)
Common Stock, Shares, Issued	0	12,227,376
Common Stock, Shares, Outstanding	0	12,227,376
Common Stock, Par or Stated Value Per Share	$ 100	$ 100
Capital Stock Class B-1 - Membership/Excess
CAPITAL (Notes 14 and 18)
Common Stock, Shares, Issued	6,324,540	0
Common Stock, Shares, Outstanding	6,324,540	0
Common Stock, Par or Stated Value Per Share	$ 100	$ 100
Capital Stock Class B-2 - Activity
CAPITAL (Notes 14 and 18)
Common Stock, Shares, Issued	9,076,781	0
Common Stock, Shares, Outstanding	9,076,781	0
Common Stock, Par or Stated Value Per Share	$ 100	$ 100

Statements of Income

Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
INTEREST INCOME
Advances	$ 122,717	$ 122,199	$ 140,550
Prepayment fees on advances, net	11,475	9,789	17,347
Interest-bearing deposits	767	642	1,149
Securities purchased under agreements to resell	2,301	630	1,268
Federal funds sold	7,498	2,913	1,979
Trading securities	1,140	454	327
Available-for-sale securities	42,147	22,225	22,780
Held-to-maturity securities	28,799	40,351	52,530
Mortgage loans held for portfolio	3,644	4,628	5,908
Total interest income	220,488	203,831	243,838
Consolidated obligations
Bonds	76,888	72,804	89,009
Discount notes	21,727	10,344	6,812
Deposits	263	79	129
Mandatorily redeemable capital stock	16	15	23
Other borrowings	5	6	8
Total interest expense	98,899	83,248	95,981
NET INTEREST INCOME	121,589	120,583	147,857
OTHER INCOME (LOSS)
Total other-than-temporary impairment losses on held-to-maturity securities	(287)	(1,386)	0
Net non-credit impairment losses on held-to-maturity securities recognized in other comprehensive income	254	1,349	0
Credit component of other-than-temporary impairment losses on held-to-maturity securities	(33)	(37)	0
Service fees	2,303	2,508	2,705
Net gains (losses) on trading securities	(1,792)	625	1,249
Net gains (losses) on derivatives and hedging activities	6,483	(423)	4,481
Realized gains on sales of held-to-maturity securities	14,514	0	0
Realized gains on sales of available-for-sale-securities	3,922	0	0
Gains on early extinguishment of debt	0	962	7,285
Letter of credit fees	4,415	4,832	4,658
Noninterest Income, Other Operating Income	(38)	(425)	314
Total other income	29,774	8,042	20,692
OTHER EXPENSE
Compensation and benefits	43,668	39,584	40,103
Other operating expenses	27,471	30,408	25,972
Finance Agency	2,415	2,298	2,372
Office of Finance	2,707	2,344	2,454
Other	441	91	12
Total other expense	76,702	74,725	70,913
INCOME BEFORE ASSESSMENTS	74,661	53,900	97,636
Affordable Housing Program assessments	7,468	5,391	9,766
NET INCOME	$ 67,193	$ 48,509	$ 87,870

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
NET INCOME	$ 67,193	$ 48,509	$ 87,870
OTHER COMPREHENSIVE INCOME (LOSS)
Net unrealized gains (losses) on available-for-sale securities, net of unrealized gains and losses relating to hedged interest rate risk included in net income	(100,768)	23,280	(23,395)
Reclassification adjustment for realized gains on sales of available-for-sale securities included in net income	3,922	0	0
Unrealized loss on cash flow hedge	(1,424)	0	0
Reclassification adjustment for losses on cash flow hedge included in net income	(577)	0	0
Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities	(254)	(1,349)	0
Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities	6,227	7,200	8,237
Postretirement benefit plan
Prior service cost	0	0	(211)
Amortization of prior service cost (credit) included in net periodic benefit cost	8	2	(17)
Actuarial loss (gain)	222	(2)	1,067
Amortization of net actuarial gain included in net periodic benefit cost	(88)	(91)	(77)
Total other comprehensive income (loss)	(99,422)	29,040	(14,396)
TOTAL COMPREHENSIVE INCOME (LOSS)	$ (32,229)	$ 77,549	$ 73,474

Statements of Capital

Statements of Capital - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,918,913	$ 1,746,504	$ 1,770,634
Issuance of Class B-1 and Class B-2 stock	1,464,306
Retirement of Class B Stock	(1,464,306)
Proceeds from sale of capital stock	1,206,487	1,177,333	979,815
Repurchase/redemption of capital stock	(886,643)	(1,079,169)	(1,050,878)
Shares reclassified to mandatorily redeemable capital stock	(7,044)	(3,130)	(26,325)
Comprehensive income (loss)
Net income	67,193	48,509	87,870
Other comprehensive income (loss)	(99,422)	29,040	(14,396)
Dividends on capital stock
Cash	(164)	(169)	(172)
Mandatorily redeemable capital stock	(8)	(5)	(44)
Ending balance	$ 2,199,312	$ 1,918,913	$ 1,746,504
Capital Stock Class B-1 - Membership/Excess
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares	0	0	0
Beginning balance	$ 0	$ 0	$ 0
Issuance of Class B-1 and Class B-2 stock, shares	5,379
Issuance of Class B-1 and Class B-2 stock	$ 537,936
Proceeds from sale of capital stock, shares	7	0	0
Proceeds from sale of capital stock	$ 728	$ 0	$ 0
Net transfers of shares between Class B-1 and Class B-2 stock, shares	3,304
Net transfers of shares between Class B-1 and Class B-2 stock	$ 330,344
Repurchase/redemption of capital stock, shares	(2,321)	0	0
Repurchase/redemption of capital stock	$ (232,150)	$ 0	$ 0
Shares reclassified to mandatorily redeemable capital stock, shares	(57)	0	0
Shares reclassified to mandatorily redeemable capital stock	$ (5,700)	$ 0	$ 0
Dividends on capital stock
Stock, shares	13	0	0
Stock	$ 1,296	$ 0	$ 0
Ending balance, shares	6,325	0	0
Ending balance	$ 632,454	$ 0	$ 0
Capital Stock Class B-2 - Activity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares	0	0	0
Beginning balance	$ 0	$ 0	$ 0
Issuance of Class B-1 and Class B-2 stock, shares	9,264
Issuance of Class B-1 and Class B-2 stock	$ 926,370
Proceeds from sale of capital stock, shares	3,117	0	0
Proceeds from sale of capital stock	$ 311,652	$ 0	$ 0
Net transfers of shares between Class B-1 and Class B-2 stock, shares	(3,304)
Net transfers of shares between Class B-1 and Class B-2 stock	$ (330,344)
Repurchase/redemption of capital stock, shares	0	0	0
Repurchase/redemption of capital stock	$ 0	$ 0	$ 0
Shares reclassified to mandatorily redeemable capital stock, shares	0	0	0
Shares reclassified to mandatorily redeemable capital stock	$ 0	$ 0	$ 0
Dividends on capital stock
Stock, shares	0	0	0
Stock	$ 0	$ 0	$ 0
Ending balance, shares	9,077	0	0
Ending balance	$ 907,678	$ 0	$ 0
Capital Stock Putable | Common Class B [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares	12,227	11,237	12,170
Beginning balance	$ 1,222,738	$ 1,123,675	$ 1,216,986
Issuance of Class B-1 and Class B-2 stock, shares	0
Issuance of Class B-1 and Class B-2 stock	$ 0
Retirement of Class B Stock, shares	(14,643)
Retirement of Class B Stock	$ (1,464,306)
Proceeds from sale of capital stock, shares	8,941	11,773	9,798
Proceeds from sale of capital stock	$ 894,107	$ 1,177,333	$ 979,815
Repurchase/redemption of capital stock, shares	(6,545)	(10,792)	(10,509)
Repurchase/redemption of capital stock	$ (654,493)	$ (1,079,169)	$ (1,050,878)
Shares reclassified to mandatorily redeemable capital stock, shares	(13)	(31)	(263)
Shares reclassified to mandatorily redeemable capital stock	$ (1,344)	$ (3,130)	$ (26,325)
Dividends on capital stock
Stock, shares	33	40	41
Stock	$ 3,298	$ 4,029	$ 4,077
Ending balance, shares	0	12,227	11,237
Ending balance	$ 0	$ 1,222,738	$ 1,123,675
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	699,776	655,470	571,893
Comprehensive income (loss)
Net income	67,193	48,509	87,870
Dividends on capital stock
Cash	(164)	(169)	(172)
Mandatorily redeemable capital stock	(8)	(5)	(44)
Stock	(4,594)	(4,029)	(4,077)
Ending balance	762,203	699,776	655,470
Retained Earnings, Restricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	49,552	39,850	22,276
Comprehensive income (loss)
Net income	13,438	9,702	17,574
Dividends on capital stock
Ending balance	62,990	49,552	39,850
Retained Earnings, Unrestricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	650,224	615,620	549,617
Comprehensive income (loss)
Net income	53,755	38,807	70,296
Dividends on capital stock
Cash	(164)	(169)	(172)
Mandatorily redeemable capital stock	(8)	(5)	(44)
Stock	(4,594)	(4,029)	(4,077)
Ending balance	699,213	650,224	615,620
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(3,601)	(32,641)	(18,245)
Comprehensive income (loss)
Other comprehensive income (loss)	(99,422)	29,040	(14,396)
Dividends on capital stock
Ending balance	$ (103,023)	$ (3,601)	$ (32,641)

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING ACTIVITIES
Net income	$ 67,193	$ 48,509	$ 87,870
Depreciation and amortization
Net premiums and discounts on advances, consolidated obligations, investments and mortgage loans	93,416	79,024	36,626
Concessions on consolidated obligations	3,818	2,111	1,732
Premises, equipment and computer software costs	3,920	3,563	4,620
Non-cash interest on mandatorily redeemable capital stock	14	14	18
Net decrease (increase) in trading securities	1,640	(823)	(1,017)
Losses due to change in net fair value adjustment on derivative and hedging activities	51,448	92,002	78,538
Gains on early extinguishment of debt	0	(962)	(7,285)
Gains on sales of held-to-maturity securities	(14,514)	0	0
Gains on sales of available-for-sale securities	(3,922)	0	0
Credit component of other-than-temporary impairment losses on held-to-maturity securities	33	37	0
Net losses on disposition of premises, equipment and computer software	64	76	0
Decrease (increase) in accrued interest receivable	(4,508)	(743)	8,221
Decrease (increase) in other assets	(1,652)	3,206	(716)
Increase (decrease) in Affordable Housing Program (AHP) liability	(3,288)	(5,866)	2,244
Decrease in accrued interest payable	(753)	(7,310)	(6,905)
Increase in other liabilities	1,708	1,158	1,132
Total adjustments	127,424	165,487	117,208
Net cash provided by operating activities	194,617	213,996	205,078
INVESTING ACTIVITIES
Net decrease in interest-bearing deposits, including swap collateral pledged	115,587	185,321	403,590
Net decrease (increase) in securities purchased under agreements to resell	(650,000)	(350,000)	3,000,000
Net decrease (increase) in federal funds sold	3,442,000	(4,145,000)	751,000
Net decrease (increase) in short-term trading securities held for investment	195,666	599,854	(998,884)
Proceeds from maturities of available-for-sale securities	40,120	26,497	0
Purchases of available-for-sale securities	(4,355,315)	(986,971)	0
Proceeds from sales of available-for-sale securities	959,791	0	0
Proceeds from sales of held-to-maturity securities	821,323	0	0
Proceeds from maturities of long-term held-to-maturity securities	747,985	1,005,647	1,722,602
Purchases of long-term held-to-maturity securities	(110,000)	(453,459)	(1,694,237)
Principal collected on advances	720,391,854	444,676,288	472,889,692
Advances made	(726,246,510)	(447,675,939)	(470,756,800)
Principal collected on mortgage loans held for portfolio	16,364	19,542	30,019
Purchases of premises, equipment and computer software	(4,930)	(2,820)	(1,484)
Net cash provided by (used in) investing activities	(4,636,065)	(7,101,040)	5,345,498
FINANCING ACTIVITIES
Net increase (decrease) in deposits, including swap collateral held	249,910	(90,522)	(289,778)
Net payments on derivative contracts with financing elements	(146,123)	(191,320)	(208,017)
Net proceeds from issuance of consolidated obligations
Discount notes	674,400,185	399,156,245	143,194,013
Bonds	18,145,483	11,387,763	7,901,643
Debt issuance costs	(2,905)	(2,492)	(1,067)
Payments for maturing and retiring consolidated obligations
Discount notes	(672,993,302)	(386,010,247)	(144,193,430)
Bonds	(16,198,790)	(16,862,596)	(11,864,577)
Proceeds from issuance of capital stock	1,206,487	1,177,333	979,815
Proceeds from issuance of mandatorily redeemable capital stock	2	5	18
Payments for redemption of mandatorily redeemable capital stock	(3,198)	(1,160)	(27,845)
Payments for repurchase/redemption of capital stock	(886,643)	(1,079,169)	(1,050,878)
Cash dividends paid	(164)	(169)	(172)
Net cash provided by (used in) financing activities	3,770,942	7,483,671	(5,560,275)
Net increase (decrease) in cash and cash equivalents	(670,506)	596,627	(9,699)
Cash and cash equivalents at beginning of the year	1,507,708	911,081	920,780
Cash and cash equivalents at end of the year	837,202	1,507,708	911,081
Supplemental Disclosures
Interest paid	102,415	115,042	145,979
AHP payments, net	10,756	11,257	7,522
Stock dividends issued	4,594	4,029	4,077
Dividends paid through issuance of mandatorily redeemable capital stock	8	5	44
Capital stock reclassified to mandatorily redeemable capital stock, net	$ 7,044	$ 3,130	$ 26,325

Background Information

Background Information	12 Months Ended
	Dec. 31, 2015
Background Information [Abstract]
Nature of Operations [Text Block]	Background Information The Federal Home Loan Bank of Dallas (the “Bank”), a federally chartered corporation, is one of 11 district Federal Home Loan Banks (each individually a “FHLBank” and collectively the “FHLBanks,” and, together with the Federal Home Loan Banks Office of Finance (“Office of Finance”), a joint office of the FHLBanks, the “FHLBank System”) that were created by the Federal Home Loan Bank Act of 1932 (as amended, the “FHLB Act”). The FHLBanks serve the public by enhancing the availability of credit for residential mortgages and targeted community development. The Bank serves eligible financial institutions in Arkansas, Louisiana, Mississippi, New Mexico and Texas (collectively, the Ninth District of the FHLBank System). The Bank provides a readily available, competitively priced source of funds to its member institutions. The Bank is a cooperative whose member institutions own the capital stock of the Bank. Regulated depository institutions and insurance companies engaged in residential housing finance and Community Development Financial Institutions that are certified under the Community Development Banking and Financial Institutions Act of 1994 may apply for membership in the Bank. All members must purchase stock in the Bank. Housing associates, including state and local housing authorities, that meet certain statutory criteria may also borrow from the Bank; while eligible to borrow, housing associates are not members of the Bank and, as such, are not required or allowed to hold capital stock. The Federal Housing Finance Agency (“Finance Agency”), an independent agency in the executive branch of the U.S. government, supervises and regulates the FHLBanks and the Office of Finance. The Finance Agency’s stated mission is to ensure that the housing government-sponsored enterprises ("GSEs"), including the FHLBanks, 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. Consistent with this mission, the Finance Agency establishes policies and regulations covering the operations of the FHLBanks. Each FHLBank operates as a separate entity with its own management, employees, and board of directors. The Bank does not have any special purpose entities or any other type of off-balance sheet conduits. The Office of Finance facilitates the issuance and servicing of the FHLBanks’ debt instruments (known as consolidated obligations). As provided by the FHLB Act and Finance Agency regulation, the FHLBanks’ consolidated obligations are backed only by the financial resources of all 11 FHLBanks. Consolidated obligations are the joint and several obligations of all the FHLBanks and are the FHLBanks’ primary source of funds. Deposits, other borrowings, and the proceeds from capital stock issued to members provide other funds. The Bank primarily uses these funds to provide loans (known as advances) to its members. The Bank’s credit services also include letters of credit issued or confirmed on behalf of members; in addition, the Bank offers interest rate swaps, caps and floors to its members. Further, the Bank provides its members with a variety of correspondent banking services, including overnight and term deposit accounts, wire transfer services, securities safekeeping and securities pledging services.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Significant Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Use of Estimates and Assumptions. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make assumptions and estimates. These assumptions and estimates may affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of income and expenses. Significant estimates include the valuations of the Bank’s investment securities, as well as its derivative instruments and any associated hedged items. Actual results could differ from these estimates. Federal Funds Sold, Securities Purchased Under Agreements to Resell and Interest-Bearing Deposits. These investments are carried at cost. Investment Securities. The Bank records investment securities on trade date. The Bank carries investment securities for which it has both the ability and intent to hold to maturity (held-to-maturity securities) at cost, adjusted for the amortization of premiums and accretion of discounts using the level-yield method. The carrying amount of held-to-maturity securities is further adjusted for any other-than-temporary impairment charges, as described below. The Bank classifies certain investment securities that it may sell before maturity as available-for-sale and carries them at fair value. For available-for-sale securities that have been hedged (with fixed-for-floating interest rate swaps) and qualify as fair value hedges, the Bank records the portion of the change in value related 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 records the remainder of the change in value of the securities in other comprehensive income as “net unrealized gains (losses) on available-for-sale securities.” The Bank classifies certain other investments as trading and carries them at fair value. The Bank records changes in the fair value of these investments in other income (loss) in the statements of income. Although the securities are classified as trading, the Bank does not engage in active or speculative trading practices. The Bank computes the amortization and accretion of premiums and discounts on mortgage-backed securities ("MBS") for which prepayments are probable and reasonably estimable using the level-yield method over the estimated lives of the securities. This method requires a retrospective adjustment of the effective yield each time the Bank changes the estimated life as if the new estimate had been known since the original acquisition date of the securities. The Bank computes the amortization and accretion of premiums and discounts on other investments using the level-yield method to the contractual maturity of the securities. The Bank computes gains and losses on sales of investment securities using the specific identification method and includes these gains and losses in other income (loss) in the statements of income. The Bank treats securities purchased under agreements to resell as collateralized financings. The Bank evaluates outstanding available-for-sale and held-to-maturity securities for other-than-temporary impairment on at least a quarterly basis. An investment security is impaired if the fair value of the investment is less than its amortized cost. Amortized cost includes adjustments (if any) made to the cost basis of an investment for accretion, amortization, the credit portion of previous other-than-temporary impairments and hedging. The Bank considers the impairment of a debt security to be other than temporary if the Bank (i) intends to sell the security, (ii) more likely than not will be required to sell the security before recovering its amortized cost basis, or (iii) does not expect to recover the security’s entire amortized cost basis (even if the Bank does not intend to sell the security). Further, an impairment is considered to be other than temporary if the Bank’s best estimate of the present value of cash flows expected to be collected from the debt security is less than the amortized cost basis of the security (any such shortfall is referred to as a “credit loss”). If an other-than-temporary impairment (“OTTI”) occurs because the Bank intends to sell an impaired debt security, or more likely than not will be required to sell the security before recovery of its amortized cost basis, the impairment is recognized currently in earnings in an amount equal to the entire difference between fair value and amortized cost. In instances in which a determination is made that a credit loss exists but the Bank does not intend to sell the debt security and it is not more likely than not that the Bank will be required to sell the debt security before the anticipated recovery of its remaining amortized cost basis, the other-than-temporary impairment (i.e., the difference between the security’s then-current carrying amount and its estimated fair value) is separated into (i) the amount of the total impairment related to the credit loss (i.e., the credit component) and (ii) the amount of the total impairment related to all other factors (i.e., the non-credit component). The credit component is recognized in earnings and the non-credit component is recognized in other comprehensive income. The total other-than-temporary impairment is presented in the statement of income with an offset for the amount of the total other-than-temporary impairment that is recognized in other comprehensive income. The non-credit component of any OTTI losses recognized in other comprehensive income for debt securities classified as held-to-maturity is accreted over the remaining life of the debt security (in a prospective manner based on the amount and timing of future estimated cash flows) as an increase in the carrying value of the security unless and until the security is sold, the security matures, or there is an additional other-than-temporary impairment that is recognized in earnings. In instances in which an additional other-than-temporary impairment is recognized in earnings, the amount of the credit loss is reclassified from accumulated other comprehensive income (loss) ("AOCI") to earnings. Further, if an additional other-than-temporary impairment is recognized in earnings and the held-to-maturity security’s then-current carrying amount exceeds its fair value, an additional non-credit impairment is concurrently recognized in other comprehensive income. Conversely, if an additional other-than-temporary impairment is recognized in earnings and the held-to-maturity security’s then-current carrying value is less than its fair value, the carrying value of the security is not increased. In periods subsequent to the recognition of an OTTI loss, the other-than-temporarily impaired debt security is accounted for as if it had been purchased on the measurement date of the other-than-temporary impairment at an amount equal to the previous amortized cost basis less the other-than-temporary impairment recognized in earnings. The difference between the new amortized cost basis and the cash flows expected to be collected is accreted as interest income over the remaining life of the security in a prospective manner based on the amount and timing of future estimated cash flows. In instances when there is a significant increase in a security's expected cash flows, the amount to be accreted is adjusted prospectively. Advances. The Bank reports advances at their principal amount outstanding, net of unearned commitment fees and deferred prepayment fees, if any, as discussed below. The Bank credits interest on advances to income as earned. Mortgage Loans Held for Portfolio. Through the Mortgage Partnership Finance ® (“MPF” ® ) program offered by the FHLBank of Chicago, the Bank invested in government-guaranteed/insured mortgage loans (i.e., those insured or guaranteed by the Federal Housing Administration (“FHA”) or the Department of Veterans Affairs (“DVA”)) and conventional residential mortgage loans during the period from 1998 to mid-2003. These mortgage loans were originated by certain of its member institutions that participated in the MPF program ("Participating Financial Institutions" or “PFIs”). Under its then existing arrangement with the FHLBank of Chicago, the Bank retained title to the mortgage loans, subject to any participation interest in such loans that was sold to the FHLBank of Chicago; the interest in the loans retained by the Bank ranged from 1 percent to 49 percent. Additionally, during the period from 1998 to 2000, the Bank also acquired from the FHLBank of Chicago a percentage interest (ranging up to 75 percent) in certain MPF loans originated by PFIs of other FHLBanks. The Bank manages the liquidity, interest rate and prepayment risk of these loans, while the PFIs retain the servicing activities. The Bank and the PFIs share in the credit risk of the loans with the Bank assuming the first loss obligation limited by the First Loss Account (“FLA”), and the PFIs assuming credit losses in excess of the FLA, up to the amount of the credit enhancement obligation as specified in the master agreement (“Second Loss Credit Enhancement”). The Bank assumes all losses in excess of the Second Loss Credit Enhancement. The Bank classifies mortgage loans held for portfolio as held for investment and, accordingly, reports them at their principal amount outstanding net of deferred premiums and discounts. The Bank credits interest on mortgage loans to income as earned. The Bank amortizes premiums and accretes discounts to interest income using the contractual method. The contractual method uses the cash flows required by the loan contracts, as adjusted for any actual prepayments, to apply the interest method. Future prepayments of principal are not anticipated under this method. The Bank has the ability and intent to hold these mortgage loans until maturity. Allowance for Credit Losses. An allowance for credit losses is separately established for each of the Bank’s identified portfolio segments, if necessary, to provide for probable losses inherent in its financing receivables portfolio and other off-balance sheet credit exposures as of the balance sheet date. To the extent necessary, an allowance for credit losses for off-balance sheet credit exposures is recorded as a liability. See Note 8 — Allowance for Credit Losses for information regarding the determination of the allowance for credit losses. A portfolio segment is defined as the level at which an entity develops and documents a systematic method for determining its allowance for credit losses. The Bank has developed and documented a systematic methodology for determining an allowance for credit losses for the following portfolio segments: (1) advances and other extensions of credit to members, collectively referred to as “extensions of credit to members;” (2) government-guaranteed/insured mortgage loans held for portfolio; and (3) conventional mortgage loans held for portfolio. Classes of financing receivables are generally a disaggregation of a portfolio segment and are determined on the basis of their initial measurement attribute, the risk characteristics of the financing receivable and an entity’s method for monitoring and assessing credit risk. Because the credit risk arising from the Bank’s financing receivables is assessed and measured at the portfolio segment level, the Bank does not have separate classes of financing receivables within each of its portfolio segments. The Bank places a conventional mortgage loan on nonaccrual status when the collection of the contractual principal or interest is 90 days or more past due. When a mortgage loan is placed on nonaccrual status, accrued but uncollected interest is reversed against interest income. The Bank records cash payments received on nonaccrual loans first as interest income until it recovers all interest, and then as a reduction of principal. A loan on nonaccrual status is restored to accrual status when none of its contractual principal and interest is due and unpaid, and the Bank expects repayment of the remaining contractual interest and principal. Government-guaranteed/insured loans are not placed on nonaccrual status. A loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect all amounts due according to the contractual terms of the loan agreement. Collateral-dependent loans that are on nonaccrual status are measured for impairment based on the fair value of the underlying property less estimated selling costs. Loans are considered collateral-dependent if repayment is expected to be provided solely by the sale of the underlying property; that is, there is no other available and reliable source of repayment. A collateral-dependent loan is impaired if the fair value of the underlying collateral is insufficient to recover the unpaid principal balance on the loan. Interest income on impaired loans is recognized in the same manner as it is for nonaccrual loans noted above. The Bank evaluates whether to record a charge-off on a conventional mortgage loan when the loan becomes 180 days or more past due or upon the occurrence of a confirming event, whichever occurs first. Confirming events include, but are not limited to, the occurrence of foreclosure or notification of a claim against any of the credit enhancements. A charge-off is recorded if the recorded investment in the loan will not be recovered. Real Estate Owned. Real estate owned includes assets that have been received in satisfaction of debt or as a result of actual or in-substance foreclosures. Real estate owned is initially recorded at fair value less estimated costs to sell (and subsequently carried at the lower of cost or fair value less estimated costs to sell) and is included in other assets in the statements of condition. If the fair value of the real estate owned less estimated costs to sell is less than the recorded investment in the mortgage loan at the date of transfer, the Bank recognizes a charge-off to the allowance for loan losses. Subsequent realized gains and realized or unrealized losses are included in other income (loss) in the statements of income. Premises and Equipment. The Bank records premises and equipment at cost less accumulated depreciation and amortization. At December 31, 2015 and 2014 , the Bank’s accumulated depreciation and amortization relating to premises and equipment was $33,416,000 and $34,991,000 , respectively. The Bank computes depreciation using the straight-line method over the estimated useful lives of assets ranging from 3 to 39 years. It amortizes leasehold improvements on the straight-line basis over the shorter of the estimated useful life of the improvement or the remaining term of the lease. The Bank capitalizes improvements and major renewals but expenses ordinary maintenance and repairs when incurred. Depreciation and amortization expense was $2,176,000 , $2,050,000 and $2,449,000 during the years ended December 31, 2015, 2014 and 2013 , respectively. The Bank includes gains and losses on disposal of premises and equipment, if any, in other income (loss) under the caption “other, net.” Computer Software. The cost of purchased computer software and certain costs incurred in developing computer software for internal use are capitalized and amortized over future periods. As of December 31, 2015 and 2014 , the Bank had $2,081,000 and $1,287,000 , respectively, in unamortized computer software costs included in other assets. Amortization of computer software costs charged to expense was $1,744,000 , $1,513,000 and $2,171,000 for the years ended December 31, 2015, 2014 and 2013 , respectively. Derivatives and Hedging Activities. The Bank accounts for derivatives and hedging activities in accordance with the guidance in Topic 815 of the Financial Accounting Standards Board’s ("FASB") Accounting Standards Codification entitled “Derivatives and Hedging” (“ASC 815”). All derivatives are recognized on the statements of condition at their fair values, including accrued interest receivable and payable. For purposes of reporting derivative assets and derivative liabilities, the Bank offsets the fair value amounts recognized for derivative instruments (including the right to reclaim cash collateral and the obligation to return cash collateral) where a legally enforceable right of setoff exists. Changes in the fair value of a derivative that is effective as — and 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 gains or losses on firm commitments), are recorded in current period earnings. 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.” Net interest income/expense associated with derivatives that qualify for fair value hedge accounting under ASC 815 is recorded as a component of net interest income. If fair value hedging relationships meet certain criteria specified in ASC 815, they are eligible for hedge accounting and the offsetting changes in fair value of the hedged items may be recorded in earnings. The application of hedge accounting generally requires the Bank to evaluate the effectiveness of the fair value hedging relationships on an ongoing basis and to calculate the changes in fair value of the derivatives and related hedged items independently. This is commonly known as the “long-haul” method of accounting. Transactions that meet more stringent criteria qualify for the “shortcut” method of hedge accounting in which an assumption can be made that the change in fair value of a hedged item exactly offsets the change in value of the related derivative. The Bank considers hedges of committed advances to be eligible for the shortcut method of accounting as long as the settlement of the committed advance occurs within the shortest period possible for that type of instrument based on market settlement conventions, the fair value of the swap is zero at the inception of the hedging relationship, and the transaction meets all of the other criteria for shortcut accounting specified in ASC 815. The Bank has defined the market settlement convention to be five business days or less for advances. Changes in the fair value of a derivative that is designated and qualifies as a cash flow hedge, to the extent that the hedge is effective, are recorded in AOCI until earnings are affected by the variability of the cash flows of the hedged transaction. Any ineffective portion of a cash flow hedge (which represents the amount by which the change in the fair value of the derivative differs from the change in fair value of a hypothetical derivative having terms that match identically the critical terms of the hedged forecasted transaction) is recognized in other income (loss) as “net gains (losses) on derivatives and hedging activities.” An economic hedge is defined as a derivative hedging specific or non-specific assets or liabilities that does not qualify or was not designated for hedge accounting under ASC 815, but is an acceptable hedging strategy under the Bank’s Enterprise Market Risk Management Policy. These hedging strategies also comply with Finance Agency regulatory requirements prohibiting speculative derivative transactions. An economic hedge by definition introduces the potential for earnings variability as changes in the fair value of a derivative designated as an economic hedge are recorded in current period earnings with no offsetting fair value adjustment to an asset or liability. Both the net interest income/expense and the fair value changes associated with derivatives in economic hedging relationships are recorded in other income (loss) as “net gains (losses) on derivatives and hedging activities.” The Bank records the changes in fair value of all derivatives (and, in the case of fair value hedges, the hedged items) beginning on the trade date. Cash flows associated with derivatives are reported as cash flows from operating activities in the statements of cash flows, unless the derivatives contain an other-than-insignificant financing element, in which case the cash flows are reported as cash flows from financing activities. The Bank may issue debt, make advances, or purchase financial instruments in which a derivative instrument is “embedded” and the financial instrument that embodies the embedded derivative instrument is not remeasured at fair value with changes in fair value reported in earnings as they occur. Upon execution of these transactions, the Bank assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the financial instrument (i.e., the host contract) and whether a separate, non-embedded instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that (1) the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract and (2) a separate, stand-alone instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract, carried at fair value, and designated as either (1) a hedging instrument in a fair value hedge or (2) a stand-alone derivative instrument pursuant to an economic hedge. However, if the entire contract were to be measured at fair value, with changes in fair value reported in current earnings, or if the Bank could not reliably identify and measure the embedded derivative for purposes of separating that derivative from its host contract, the entire contract would be carried on the statement of condition at fair value and no portion of the contract would be separately accounted for as a derivative. The Bank discontinues hedge accounting prospectively when: (1) management determines that the derivative is no longer effective in offsetting changes in the fair value or cash flows of a hedged item; (2) the derivative and/or the hedged item expires or is sold, terminated, or exercised; (3) it is no longer probable that a forecasted transaction will occur within the originally specified time frame; (4) a hedged firm commitment no longer meets the definition of a firm commitment; or (5) management determines that designating the derivative as a hedging instrument in accordance with ASC 815 is no longer appropriate. In all cases in which hedge accounting is discontinued and the derivative remains outstanding, the Bank will carry the derivative at its fair value on the statement of condition, recognizing any additional changes in the fair value of the derivative in current period earnings. When fair value hedge accounting for a specific derivative is discontinued due to the Bank’s determination that such derivative no longer qualifies for hedge accounting treatment or because the derivative is terminated, the Bank will cease to adjust the hedged asset or liability for changes in fair value and amortize the cumulative basis adjustment on the formerly hedged item into earnings over its remaining term using the level-yield method. When hedge accounting is discontinued because the hedged item no longer meets the definition of a firm commitment, the Bank continues to carry the derivative on the statement of condition at its fair value, removing from the statement of condition any asset or liability that was recorded to recognize the firm commitment and recording it as a gain or loss in current period earnings. When cash flow hedge accounting for a specific derivative is discontinued due to the Bank's determination that such derivative no longer qualifies for hedge accounting treatment or because the derivative is terminated, the Bank will reclassify the cumulative fair value gains or losses recorded in AOCI as of the discontinuance date from AOCI into earnings when earnings are affected by the original forecasted transaction, except in cases where the cash flow hedge is discontinued because the forecasted transaction is no longer probable (i.e., the forecasted transaction will not occur in the originally expected period or within an additional two-month period of time thereafter). In such cases, any fair value gains or losses recorded in AOCI as of the determination date are immediately reclassified to earnings as a component of "gains (losses) on derivatives and hedging activities." Similarly, if the Bank expects at any time that continued reporting of a net loss in AOCI would lead to recognizing a net loss on the combination of the hedging instrument and hedged transaction in one or more future periods, the amount that is not expected to be recovered is immediately reclassified to earnings as a component of "gains (losses) on derivatives and hedging activities." Mandatorily Redeemable Capital Stock. The Bank reclassifies shares of capital stock from the capital section to the liability section of its statement of condition at the point in time when a member submits a written redemption notice, gives notice of its intent to withdraw from membership, or becomes a non-member by merger or acquisition, charter termination, or involuntary termination from membership, as the shares of capital stock then meet the definition of a mandatorily redeemable financial instrument. Shares of capital stock meeting this definition are reclassified to liabilities at fair value. Following reclassification of the stock, any dividends paid or accrued on such shares are recorded as interest expense in the statement of income. Repurchase or redemption of these mandatorily redeemable financial instruments is reported as a cash outflow in the financing activities section of the statement of cash flows. If a member cancels a written redemption or withdrawal notice, the Bank reclassifies the shares subject to the cancellation notice from liabilities back to equity. Following this reclassification to equity, dividends on the capital stock are once again recorded as a reduction of retained earnings. Although mandatorily redeemable capital stock is excluded from capital for financial reporting purposes, it is considered capital for regulatory purposes. See Note 14 for more information, including restrictions on stock redemption. Affordable Housing Program. The FHLB Act requires each FHLBank to establish and fund an Affordable Housing Program (“AHP”) (see Note 11). The Bank charges the required funding for AHP to earnings and establishes a liability. The Bank makes AHP funds available to members in the form of direct grants to assist in the purchase, construction, or rehabilitation of housing for very low-, low-, and moderate-income households. Prepayment Fees. The Bank charges a prepayment fee when members/borrowers prepay certain advances before their original maturities. The Bank records prepayment fees received from members/borrowers net of hedging adjustments included in the book basis of the prepaid advance, if any, as interest income on advances in the statements of income either immediately (as prepayment fees on advances) or over time (as interest income on advances), as further described below. In cases in which the Bank funds a new advance concurrent with or within a short period of time before or after the prepayment of an existing advance, the Bank evaluates whether the new advance meets the accounting criteria to qualify as a modification of an existing advance. If the new advance qualifies as a modification of the existing advance, the net prepayment fee on the prepaid advance is deferred, recorded in the basis of the modified advance, and amortized into interest income over the life of the modified advance using the level-yield method. This amortization is recorded in interest income on advances. If the Bank determines that the advance should be treated as a new advance, or in instances where no new advance is funded, it records the net fees as “prepayment fees on advances” in the interest income section of the statements of income. Commitment Fees. The Bank defers commitment fees for advances and amortizes them to interest income using the level-yield method over the life of the advance. The Bank records commitment fees for letters of credit as a deferred credit when it receives the fees and amortizes them over the term of the letter of credit using the straight-line method. Concessions on Consolidated Obligations. The Bank defers and amortizes, using the level-yield method, the amounts paid to securities dealers in connection with the sale of consolidated obligation bonds over the term to maturity of the related bonds. The Office of Finance prorates the amount of the concession to the Bank based upon the percentage of the debt issued that is assumed by the Bank. Unamortized concessions were $1,266,000 and $2,179,000 at December 31, 2015 and 2014 , respectively, and are included in other assets on the statements of condition. As discussed in Note 2, the unamortized concessions will be reclassified as a reduction in the balance of consolidated obligation bonds effective January 1, 2016. Amortization of such concessions is included in consolidated obligation bond interest expense and totaled $2,544,000 , $2,111,000 and $1,732,000 during the years ended December 31, 2015, 2014 and 2013 , respectively. The Bank charges to expense as incurred the concessions applicable to the sale of consolidated obligation discount notes because of the short maturities of these notes. Concessions related to the sale of discount notes totaling $1,274,000 , $870,000 and $209,000 are included in interest expense on consolidated obligation discount notes in the statements of income for the years ended December 31, 2015, 2014 and 2013 , respectively. Discounts and Premiums on Consolidated Obligations. The Bank expenses the discounts on consolidated obligation discount notes using the level-yield method over the term to maturity of the related notes. It accretes the discounts and amortizes the premiums on consolidated obligation bonds to expense using the level-yield method over the term to maturity of the bonds. Finance Agency and Office of Finance Expenses. The Bank is assessed its proportionate share of the costs of operating the Finance Agency and the Office of Finance. The assessment for the FHLBanks’ portion of the Finance Agency’s operating and capital expenditures is allocated among the FHLBanks based on the ratio between each FHLBank’s minimum required regulatory capital and the aggregate minimum required regulatory capital of all FHLBanks determined as of June 30 of each year. The expenses of the Office of Finance are shared on a pro rata basis with two-thirds based on each FHLBank’s total consolidated obligations outstanding (as of the current month-end) and one-third divided equally among all of the FHLBanks. These costs are included in the other expense section of the statements of income. Estimated Fair Values. Some of the Bank’s financial instruments (e.g., advances) lack an available trading market characterized by transactions between a willing buyer and a willing seller engaging in an exchange transaction. Therefore, the Bank uses internal models employing assumptions regarding interest rates, volatilities, prepayments, and other factors to perform present-value calculations when disclosing estimated fair values for these financial instruments. The Bank assumes that book value approximates fair value for certain financial instruments with three months or less to repricing or maturity. For a discussion of the Bank's valuation techniques and the estimated fair values of its financial instruments, see Note 16. Cash Flows. In the statements of cash flows, the Bank considers cash and due from banks as cash and cash equivalents.

Recently Issued Accounting Guid

Recently Issued Accounting Guidance	12 Months Ended
	Dec. 31, 2015
Recently Issued Accounting Guidance [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Recently Issued Accounting Guidance Asset Classification and Charge-offs. On April 9, 2012, the Finance Agency issued Advisory Bulletin 2012-02, "Framework for Adversely Classifying Loans, Other Real Estate Owned, and Other Assets and Listing Assets for Special Mention" ("AB 2012-02"). The guidance establishes a standard and uniform methodology for classifying assets and prescribes the timing of asset charge-offs, excluding investment securities. The guidance in AB 2012-02 is generally consistent with the Uniform Retail Credit Classification and Account Management Policy issued by the federal banking regulators in June 2000. The adoption of the accounting guidance in AB 2012-02, which was effective January 1, 2015, did not have a significant impact on the Bank's results of operations or financial condition. Foreclosure of Residential Real Estate. On January 17, 2014, the FASB issued ASU 2014-04 " Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure" ("ASU 2014-04"), which clarifies when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. ASU 2014-04 states that an in substance repossession or foreclosure occurs, and a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan, upon either (i) the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure or (ii) the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or a similar legal agreement. Additionally, ASU 2014-04 requires interim and annual disclosure of both (i) the amount of foreclosed residential real estate property held by the creditor and (ii) the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure according to local requirements of the applicable jurisdiction. For public business entities, the guidance in ASU 2014-04 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2014 (January 1, 2015 for the Bank) and may be applied either retrospectively by means of a cumulative-effect adjustment to residential consumer mortgage loans and foreclosed residential real estate properties existing as of the beginning of the annual period for which the guidance is effective or prospectively to all instances of an entity receiving physical possession of residential real estate property collateralized by consumer mortgage loans that occur after the date of adoption. Early adoption was permitted. The Bank adopted this guidance effective January 1, 2015. The adoption of this guidance did not have a significant impact on the Bank's results of operations or financial condition. Revenue from Contracts with Customers. On May 28, 2014, the FASB issued ASU 2014-09 "Revenue from Contracts with Customers" ("ASU 2014-09"), which outlines a comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance. In addition, ASU 2014-09 amends the existing requirements for the recognition of a gain or loss on the transfer of non-financial assets that are not in a contract with a customer. ASU 2014-09 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, and lease contracts. The guidance in ASU 2014-09 was effective for fiscal years, and interim periods within those years, beginning after December 15, 2016 (January 1, 2017 for the Bank). Early application was not permitted. On August 12, 2015, the FASB issued ASU 2015-14 "Deferral of Effective Date," which deferred the effective date of ASU 2014-09 by one year. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Bank has not yet determined the date that it will adopt ASU 2014-09 or the effect, if any, that the adoption of ASU 2014-09 will have on its results of operations or financial condition. Repurchase-to-Maturity Transactions and Repurchase Financings. On June 12, 2014, the FASB issued ASU 2014-11 "Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures" ("ASU 2014-11"), which changes the accounting for repurchase-to-maturity transactions and linked repurchase financings to secured borrowing accounting, which is consistent with the accounting for other repurchase agreements. In addition, ASU 2014-11 requires disclosures about transfers accounted for as sales in transactions that are economically similar to repurchase agreements and about the types of collateral pledged in repurchase agreements and similar transactions accounted for as secured borrowings. The accounting changes in ASU 2014-11 and the disclosures for certain transactions accounted for as a sale are effective for public companies for the first interim or annual period beginning after December 15, 2014 (January 1, 2015 for the Bank). For public business entities, the disclosures for transactions accounted for as secured borrowings are required to be presented for annual periods beginning after December 15, 2014 (January 1, 2015 for the Bank), and interim periods beginning after March 15, 2015 (April 1, 2015 for the Bank). Earlier application for a public business entity was prohibited. The adoption of this guidance did not have any impact on the Bank's results of operations or financial condition. Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure. On August 8, 2014, the FASB issued ASU 2014-14 "Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure" ("ASU 2014-14"), which requires that government-guaranteed mortgage loans be derecognized and that a separate other receivable be recognized upon foreclosure if the following conditions are met: (i) the loan has a government guarantee that is not separable from the loan before foreclosure, (ii) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim, and (iii) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. For public business entities, the guidance in ASU 2014-14 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2014 (January 1, 2015 for the Bank) and may be applied using either the modified retrospective transition method or the prospective transition method. Early adoption was permitted. The Bank adopted this guidance effective January 1, 2015. The adoption of this guidance did not have a significant impact on the Bank's results of operations or financial condition. Simplifying the Presentation of Debt Issuance Costs. On April 7, 2015, the FASB issued ASU 2015-03 "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03"). ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the statement of condition as a direct deduction from that debt liability, consistent with the presentation of a debt discount. For public business entities, the guidance in ASU 2015-03 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 (January 1, 2016 for the Bank). Early adoption was permitted for financial statements that had not been previously issued. The guidance is required to be applied on a retrospective basis to each individual period presented on the statement of condition. The Bank adopted this guidance effective January 1, 2016. The adoption of this guidance did not have a material impact on the Bank's financial condition and it did not have any impact on the Bank's results of operations. On August 18, 2015, the FASB issued ASU 2015-1 5 "Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements" ("ASU 2015-15"). ASU 2015-15 clarifies that, given the absence of authoritative guidance within ASU 2015-03 for debt issuance costs related to line-of-credit arrangements, the SEC staff would not object to an entity deferring and presenting debt issuance costs related to line-of-credit arrangements as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The Bank adopted this guidance effective January 1, 2016. The adoption of this guidance did not have any impact on the Bank's results of operations or financial condition. Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. On April 15, 2015, the FASB issued ASU 2015-05 "Customer's Accounting for Fees Paid in a Cloud Computing Arrangement" ("ASU 2015-05"), which clarifies when fees paid in a cloud computing arrangement pertain to the acquisition of a software license, services, or both. For public business entities, the guidance in ASU 2015-05 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 (January 1, 2016 for the Bank). Early adoption was permitted. The Bank could elect to adopt ASU 2015-05 either (i) prospectively to all arrangements entered into or materially modified after the effective date or (ii) retrospectively. The Bank elected to adopt this guidance prospectively. The adoption of this guidance has not had any impact on the Bank's results of operations or financial condition. Recognition and Measurement of Financial Assets and Financial Liabilities . On January 5, 2016, the FASB issued ASU 2016-01 "Recognition and Measurement of Financial Assets and Financial Liabilities" ("ASU 2016-01"), which makes targeted improvements to existing U.S. GAAP by: (i) requiring certain equity investments to be measured at fair value with changes in fair value recognized in earnings, (ii) simplifying the impairment assessment of equity investments without readily determinable fair values, (iii) requiring public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, (iv) requiring separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the statement of condition or in the accompanying notes to the financial statements, (v) eliminating the requirement to disclose the fair value of financial instruments measured at amortized cost for organizations that are not public business entities, (vi) eliminating the requirement for public business 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 statement of condition, (vii) requiring a reporting organization to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (also referred to as “own credit”) when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments, and (viii) clarifying that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. For public business entities, the guidance in ASU 2016-01 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 (January 1, 2018 for the Bank). Early adoption is permitted for certain provisions. The adoption of ASU 2016-01 is not expected to have a material impact on the Bank's results of operations or financial condition. Leases . On February 25, 2016, the FASB issued ASU 2016-02 "Leases" (“ASU 2016-02”), which requires entities that lease assets (lessees) to recognize in the statement of condition assets and liabilities for the rights and obligations created by those leases. Specifically, ASU 2016-02 requires a lessee of operating or finance leases to recognize a right-of-use asset and a liability to make lease payments for leases with terms of more than 12 months. Lessor accounting will remain largely unchanged from current U.S. GAAP. ASU 2016-02 also requires extensive quantitative and qualitative disclosures to help financial statement users understand the amount, timing and uncertainty of cash flows arising from leases. For public business entities, the guidance in ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018 (January 1, 2019 for the Bank). Early adoption is permitted. The Bank has not yet determined the effect that the adoption of ASU 2016-02 will have on its results of operations or financial condition. Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships. On March 10, 2016, the FASB issued ASU 2016-05, " Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships" ("ASU 2016-05"), which clarifies the hedge accounting impact when there is a change in one of the counterparties to the derivative contract (i.e., a novation). ASU 2016-05 clarifies that a change in the counterparty to a derivative contract, in and of itself, does not require the dedesignation of a hedging relationship. An entity will, however, still need to evaluate whether it is probable that the counterparty will perform under the contract as part of its ongoing effectiveness assessment for hedge accounting. For public business entities, the guidance in ASU 2016-05 is effective for fiscal years beginning after December 15, 2016 (January 1, 2017 for the Bank), and interim periods within those fiscal years. Early adoption is permitted. Entities have the option to adopt ASU 2016-05 on a prospective basis to new derivative contract novations or on a modified retrospective basis. The Bank intends to adopt this guidance prospectively. The adoption of ASU 2016-05 is not expected to have a material impact on the Bank's results of operations or financial condition.

Trading Securities

Trading Securities	12 Months Ended
	Dec. 31, 2015
Trading Securities [Abstract]
Trading Securities Disclosure [Text Block]	Trading Securities Major Security Types. Trading securities as of December 31, 2015 and 2014 were as follows (in thousands): December 31, 2015 December 31, 2014 U.S. Treasury Notes $ 202,199 $ — U.S. Treasury Bills — 399,794 Other 8,857 8,769 Total $ 211,056 $ 408,563 Other trading securities consist solely of mutual fund investments associated with the Bank's non-qualified deferred compensation plans. Net gains (losses) on trading securities during the years ended December 31, 2015, 2014 and 2013 included changes in net unrealized holding gain (loss) of $(1,983,000) , $418,000 and $1,249,000 for securities that were held on December 31, 2015, 2014 and 2013 , respectively.

Available-for-Sale Securities

Available-for-Sale Securities	12 Months Ended
	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Available-for-Sale Securities Disclosure [Text Block]	Available-for-Sale Securities Major Security Types. Available-for-sale securities as of December 31, 2015 were as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 498,185 $ 1,315 $ 1,748 $ 497,752 GSE obligations 5,328,125 12,597 1,775 5,338,947 Other 372,532 10 1,002 371,540 6,198,842 13,922 4,525 6,208,239 GSE commercial MBS 3,596,627 766 92,441 3,504,952 Total $ 9,795,469 $ 14,688 $ 96,966 $ 9,713,191 Included in the table above are GSE commercial MBS that were purchased but which had not yet settled as of December 31, 2015 . The amount due of $164,889,000 is included in other liabilities on the statement of condition at that date. Available-for-sale securities as of December 31, 2014 were as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 49,666 $ 308 $ — $ 49,974 GSE obligations 4,890,484 31,066 — 4,921,550 Other 411,145 701 535 411,311 5,351,295 32,075 535 5,382,835 GSE commercial MBS 1,014,795 322 9,450 1,005,667 Total $ 6,366,090 $ 32,397 $ 9,985 $ 6,388,502 Other debentures are comprised of securities issued by the Private Export Funding Corporation ("PEFCO"). These debentures are fully secured by U.S. government-guaranteed obligations and the payment of interest on the debentures is guaranteed by an agency of the U.S. government. The amortized cost of the Bank's available-for-sale securities includes hedging adjustments. The following table summarizes (in thousands, except number of positions) the available-for-sale securities with unrealized losses as of December 31, 2015 . The unrealized losses are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Debentures U.S. government-guaranteed obligations 7 $ 229,793 $ 1,748 — $ — $ — 7 $ 229,793 $ 1,748 GSE obligations 28 802,283 1,775 — — — 28 802,283 1,775 Other 22 279,138 522 8 48,567 480 30 327,705 1,002 GSE commercial MBS 80 2,401,148 63,602 29 849,297 28,839 109 3,250,445 92,441 Total 137 $ 3,712,362 $ 67,647 37 $ 897,864 $ 29,319 174 $ 4,610,226 $ 96,966 The following table summarizes (in thousands, except number of positions) the available-for-sale securities with unrealized losses as of December 31, 2014 . The unrealized losses are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Debentures Other 18 $ 163,153 $ 535 — $ — $ — 18 $ 163,153 $ 535 GSE commercial MBS 29 863,159 9,450 — — — 29 863,159 9,450 Total 47 $ 1,026,312 $ 9,985 — $ — $ — 47 $ 1,026,312 $ 9,985 At December 31, 2015 , the gross unrealized losses on the Bank’s available-for-sale securities were $96,966,000 . All of the Bank's available-for-sale securities are either guaranteed by the U.S. government, issued by GSEs or fully secured by collateral that is guaranteed by the U.S government. As of December 31, 2015 , the U.S. government and the issuers of the Bank’s holdings of GSE debentures and GSE commercial MBS were rated triple-A by Moody’s Investors Service (“Moody’s”) and Fitch Ratings, Ltd. (“Fitch”) and AA+ by Standard and Poor’s (“S&P”). The Bank's holdings of PEFCO debentures were rated triple-A by Moody's and Fitch, and A by S&P at that date. Based upon the Bank's assessment of the strength of the government guaranty, the Bank expects that the U.S. government-guaranteed debentures that were in an unrealized loss position at December 31, 2015 would not be settled at an amount less than the Bank's amortized cost bases in the investments. In addition, based upon the Bank's assessment of the creditworthiness of the issuers of the GSE debentures and the credit ratings assigned by each of the nationally recognized statistical rating organizations (“NRSROs”), the Bank expects that its holdings of GSE debentures that were in an unrealized loss position at December 31, 2015 would not be settled at an amount less than the Bank's amortized cost bases in these investments. Further, based upon the Bank's assessment of the strength of the GSEs' guarantees of the Bank's holdings of GSE commercial MBS and the credit ratings assigned by each of the NRSROs, the Bank expects that its holdings of GSE commercial MBS that were in an unrealized loss position at December 31, 2015 would not be settled at an amount less than the Bank’s amortized cost bases in these investments. Finally, based upon PEFCO's creditworthiness, the U.S. government's guaranty of the payment of principal and interest on the collateral securing the PEFCO debentures, and the guaranty of the payment of interest on the debentures by an agency of the U.S. government, the Bank expects that its holdings of PEFCO debentures that were in an unrealized loss position at December 31, 2015 would not be settled at an amount less than the Bank’s amortized cost bases in these investments. Because the current market value deficits associated with the Bank's available-for-sale securities are not attributable to credit quality, and because the Bank does not intend to sell the investments and it is not more likely than not that the Bank will be required to sell the investments before recovery of their amortized cost bases, the Bank does not consider any of these investments to be other-than-temporarily impaired at December 31, 2015 . Redemption Terms. The amortized cost and estimated fair value of available-for-sale securities by contractual maturity at December 31, 2015 and 2014 are presented below (in thousands). December 31, 2015 December 31, 2014 Maturity Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Debentures Due in one year or less $ 133,117 $ 133,077 $ 87,379 $ 87,418 Due after one year through five years 3,637,966 3,643,909 4,224,231 4,245,122 Due after five years through ten years 2,313,112 2,316,854 1,039,685 1,050,295 Due after ten years 114,647 114,399 — — 6,198,842 6,208,239 5,351,295 5,382,835 GSE commercial MBS 3,596,627 3,504,952 1,014,795 1,005,667 Total $ 9,795,469 $ 9,713,191 $ 6,366,090 $ 6,388,502 Interest Rate Payment Terms. The following table provides interest rate payment terms for investment securities classified as available-for-sale at December 31, 2015 and 2014 (in thousands): December 31, 2015 December 31, 2014 Amortized cost of available-for-sale securities other than MBS Fixed-rate $ 6,123,842 $ 5,276,295 Variable-rate 75,000 75,000 6,198,842 5,351,295 Amortized cost of fixed-rate multi-family MBS 3,596,627 1,014,795 Total $ 9,795,469 $ 6,366,090 At December 31, 2015 and 2014 , substantially all of the Bank’s fixed-rate available-for-sale securities were swapped to a variable rate. Sales of Securities. During the year ended December 31, 2015 , the Bank sold available-for-sale securities with an amortized cost (determined by the specific identification method) of $955,869,000 . Proceeds from the sales totaled $959,791,000 , resulting in realized gains of $3,922,000 . There were no sales of available-for-sale securities during the years ended December 31, 2014 or 2013 .

Held-to-Maturity Securities

Held-to-Maturity Securities	12 Months Ended
	Dec. 31, 2015
Held-to-maturity Securities, Unclassified [Abstract]
Held-to-Maturity Securities Disclosure [Text Block]	Held-to-Maturity Securities Major Security Types. Held-to-maturity securities as of December 31, 2015 were as follows (in thousands): Amortized Cost OTTI Recorded in AOCI Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 21,546 $ — $ 21,546 $ 15 $ 151 $ 21,410 State housing agency obligations 110,000 — 110,000 — — 110,000 131,546 — 131,546 15 151 131,410 Mortgage-backed securities U.S. government-guaranteed residential MBS 4,040 — 4,040 11 — 4,051 GSE residential MBS 2,909,065 — 2,909,065 22,457 766 2,930,756 Non-agency residential MBS 142,920 21,376 121,544 16,118 2,963 134,699 GSE commercial MBS 61,816 — 61,816 — 449 61,367 3,117,841 21,376 3,096,465 38,586 4,178 3,130,873 Total $ 3,249,387 $ 21,376 $ 3,228,011 $ 38,601 $ 4,329 $ 3,262,283 Held-to-maturity securities as of December 31, 2014 were as follows (in thousands): Amortized Cost OTTI Recorded in AOCI Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 27,119 $ — $ 27,119 $ 143 $ — $ 27,262 Mortgage-backed securities U.S. government-guaranteed residential MBS 6,642 — 6,642 34 — 6,676 GSE residential MBS 4,424,542 — 4,424,542 46,767 398 4,470,911 Non-agency residential MBS 169,240 27,349 141,891 21,982 3,469 160,404 GSE commercial MBS 61,819 — 61,819 58 — 61,877 4,662,243 27,349 4,634,894 68,841 3,867 4,699,868 Total $ 4,689,362 $ 27,349 $ 4,662,013 $ 68,984 $ 3,867 $ 4,727,130 The following table summarizes (in thousands, except number of positions) the held-to-maturity securities with unrealized losses as of December 31, 2015 . The unrealized losses include other-than-temporary impairments recorded in AOCI and gross unrecognized holding losses (or, in the case of the Bank's holdings of non-agency residential MBS, gross unrecognized holding gains) and are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Debentures U.S. government-guaranteed obligations 2 $ 12,683 $ 151 — $ — $ — 2 $ 12,683 $ 151 Mortgage-backed securities GSE residential MBS 19 503,000 697 1 44,782 69 20 547,782 766 Non-agency residential MBS — — — 24 107,302 9,060 24 107,302 9,060 GSE commercial MBS — — — 3 61,366 449 3 61,366 449 Total 21 $ 515,683 $ 848 28 $ 213,450 $ 9,578 49 $ 729,133 $ 10,426 The following table summarizes (in thousands, except number of positions) the held-to-maturity securities with unrealized losses as of December 31, 2014 . The unrealized losses include other-than-temporary impairments recorded in AOCI and gross unrecognized holding losses (or, in the case of the Bank's holdings of non-agency residential MBS, gross unrecognized holding gains) and are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Mortgage-backed securities GSE residential MBS 1 $ 10,798 $ 5 17 $ 485,626 $ 393 18 $ 496,424 $ 398 Non-agency residential MBS 1 6,874 223 24 131,265 9,917 25 138,139 10,140 Total 2 $ 17,672 $ 228 41 $ 616,891 $ 10,310 43 $ 634,563 $ 10,538 At December 31, 2015 , the gross unrealized losses on the Bank’s held-to-maturity securities were $10,426,000 , of which $9,060,000 were attributable to its holdings of non-agency (i.e., private label) residential MBS and $1,366,000 were attributable to securities that are guaranteed by the U.S. government or issued and guaranteed by GSEs. As of December 31, 2015 , the U.S. government and the issuers of the Bank's holdings of GSE MBS were rated triple-A by Moody's and Fitch and AA+ by S&P. Based upon the Bank's assessment of the strength of the government guaranty, the Bank expects that the U.S. government-guaranteed debentures that were in an unrealized loss position at December 31, 2015 would not be settled at an amount less than the Bank's amortized cost bases in the investments. In addition, based upon the Bank’s assessment of the strength of the GSEs' guarantees and the credit ratings assigned by the NRSROs, the Bank expects that its holdings of GSE MBS that were in an unrealized loss position at December 31, 2015 would not be settled at an amount less than the Bank’s amortized cost bases in these investments. Because the current market value deficits associated with these securities are not attributable to credit quality, and because the Bank does not intend to sell the investments and it is not more likely than not that the Bank will be required to sell the investments before recovery of their amortized cost bases, the Bank does not consider any of these investments to be other-than-temporarily impaired at December 31, 2015 . The deterioration in the U.S. housing markets that occurred primarily during the period from 2007 through 2011, as reflected during that period by declines in the values of residential real estate and higher levels of delinquencies, defaults and losses on residential mortgages, including the mortgages underlying the Bank’s non-agency residential MBS ("RMBS"), generally increased the risk that the Bank may not ultimately recover the entire cost bases of some of its non-agency RMBS. However, based on its analysis of the securities in this portfolio, the Bank believes that the unrealized losses as of December 31, 2015 were principally the result of liquidity risk related discounts in the non-agency RMBS market and do not accurately reflect the currently likely future credit performance of the securities. Because the ultimate receipt of contractual payments on the Bank’s non-agency RMBS will depend upon the credit and prepayment performance of the underlying loans and the credit enhancements for the senior securities owned by the Bank, the Bank closely monitors these investments in an effort to determine whether the credit enhancement associated with each security is sufficient to protect against potential losses of principal and interest on the underlying mortgage loans. The credit enhancement for each of the Bank’s non-agency RMBS is provided by a senior/subordinate structure, and none of the securities owned by the Bank are insured by third-party bond insurers. More specifically, each of the Bank’s non-agency RMBS represents a single security class within a securitization that has multiple classes of securities. Each security class has a distinct claim on the cash flows from the underlying mortgage loans, with the subordinate securities having a junior claim relative to the more senior securities. The Bank’s non-agency RMBS have a senior claim on the cash flows from the underlying mortgage loans. To assess whether the entire amortized cost bases of its 27 non-agency RMBS holdings are likely to be recovered, the Bank performed a cash flow analysis for each security as of the end of each calendar quarter in 2015 using two third-party models. The first model considers borrower characteristics and the particular attributes of the loans underlying the Bank’s securities, in conjunction with assumptions about future changes in home prices and interest rates, to project prepayments, defaults and loss severities. A significant input to the first model is the forecast of future housing price changes for the relevant states and core based statistical areas (“CBSAs”), which are based upon an assessment of the individual housing markets. (The term “CBSA” refers collectively to metropolitan and micropolitan statistical areas as defined by the U.S. Office of Management and Budget; as currently defined, a CBSA must contain at least one urban area of 10,000 or more people.) The Bank’s housing price forecast as of December 31, 2015 assumed changes in home prices ranging from declines of 3 percent to increases of 8 percent over the 12-month period beginning October 1, 2015 . For the vast majority of markets, the changes were projected to range from increases of 2 percent to 5 percent . Thereafter, home price changes for each market were projected to return (at varying rates and over varying transition periods based on historical housing price patterns) to their long-term historical equilibrium levels. Following these transition periods, the constant long-term annual rates of appreciation for the vast majority of markets were projected to range between 2 percent and 5 percent . The month-by-month projections of future loan performance derived from the first model, which reflect projected prepayments, defaults and loss severities, 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 balance is reduced to zero. Based on the results of its cash flow analyses, the Bank determined it was not likely that it would fully recover the remaining amortized cost basis of one of its previously other-than-temporarily impaired non-agency RMBS and, accordingly, this security was deemed to be other-than-temporarily impaired as of December 31, 2015 . The difference between the present value of the cash flows expected to be collected from this security and its amortized cost basis (i.e., the credit loss) totaled $5,000 at December 31, 2015 . Because the Bank does not intend to sell the investment and it is not more likely than not that the Bank will be required to sell the investment before recovery of its remaining amortized cost basis, only the amount related to the credit loss was recognized in earnings. None of the Bank's other non-agency RMBS were deemed to be other-than-temporarily impaired in 2015 . For the security for which an other-than-temporary impairment was determined to have occurred as of the end of each calendar quarter in 2015 , the following table presents a summary of the significant inputs used to measure the amount of the credit loss recognized in earnings for the fourth quarter (dollars in thousands): Significant Inputs (2) Year of Securitization Collateral Type (1) Unpaid Principal Balance as of December 31, 2015 Projected Prepayment Rate Projected Default Rate Projected Loss Severity Current Credit Enhancement as of December 31, 2015 (3) 2005 Alt-A/Option ARM $ 10,762 7.7 % 18.6 % 32.2 % 32.0 % ________________________________________ (1) Although the other-than-temporarily impaired security was not labeled as Alt-A at the time of issuance, based upon its current collateral and performance characteristics, it was analyzed using Alt-A assumptions. (2) The prepayment rate reflects the weighted average of projected future voluntary prepayments. The default rate reflects the total balance of loans projected to default as a percentage of the current unpaid principal balance of the underlying loan pool. The loss severity reflects the total projected loan losses as a percentage of the total balance of loans that are projected to default. (3) The current credit enhancement percentage reflects the ability of subordinated classes of securities to absorb principal losses and interest shortfalls before the senior class held by the Bank is impacted (i.e., the losses, expressed as a percentage of the outstanding principal balances, that could be incurred in the underlying loan pool before the security held by the Bank would be impacted, assuming that all of those losses occurred on the measurement date). Depending upon the timing and amount of losses in the underlying loan pool, it is possible that the senior class held by the Bank could bear losses in scenarios where the cumulative loan losses do not exceed the current credit enhancement percentage. In addition to the security that was determined to be other-than-temporarily impaired at December 31, 2015, 14 of the Bank's holdings of non-agency RMBS were determined to be other-than-temporarily impaired in periods prior to 2013. The following table presents a rollforward for the years ended December 31, 2015, 2014 and 2013 of the amount related to credit losses on the Bank’s non-agency RMBS holdings for which a portion of an other-than-temporary impairment was recognized in other comprehensive income (loss) (in thousands). Year Ended December 31, 2015 2014 2013 Balance of credit losses, beginning of year $ 12,512 $ 12,901 $ 13,039 Credit losses on securities for which an other-than-temporary impairment was not previously recognized — 37 — Credit losses on securities for which an other-than-temporary impairment was previously recognized 33 — — Increases in cash flows expected to be collected (accreted as interest income over the remaining lives of the applicable securities) (849 ) (426 ) (138 ) Balance of credit losses, end of year 11,696 12,512 12,901 Cumulative principal shortfalls on securities held at end of year (1,668 ) (1,210 ) (684 ) Cumulative amortization of the time value of credit losses at end of year 350 293 233 Credit losses included in the amortized cost bases of other-than-temporarily impaired securities at end of year $ 10,378 $ 11,595 $ 12,450 Redemption Terms. The amortized cost, carrying value and estimated fair value of held-to-maturity securities by contractual maturity at December 31, 2015 and 2014 are presented below (in thousands). The expected maturities of some debentures could differ from the contractual maturities presented because issuers may have the right to call such debentures prior to their final stated maturities. December 31, 2015 December 31, 2014 Maturity Amortized Cost Carrying Value Estimated Fair Value Amortized Cost Carrying Value Estimated Fair Value Debentures Due after one year through five years $ 8,712 $ 8,712 $ 8,727 $ 12,544 $ 12,544 $ 12,649 Due after five years through ten years 12,834 12,834 12,683 14,575 14,575 14,613 Due after ten years 110,000 110,000 110,000 — — — 131,546 131,546 131,410 27,119 27,119 27,262 Mortgage-backed securities 3,117,841 3,096,465 3,130,873 4,662,243 4,634,894 4,699,868 Total $ 3,249,387 $ 3,228,011 $ 3,262,283 $ 4,689,362 $ 4,662,013 $ 4,727,130 The amortized cost of the Bank’s mortgage-backed securities classified as held-to-maturity includes net purchase discounts of $13,139,000 and $26,510,000 at December 31, 2015 and 2014 , respectively. Interest Rate Payment Terms. The following table provides interest rate payment terms for investment securities classified as held-to-maturity at December 31, 2015 and 2014 (in thousands): 2015 2014 Amortized cost of variable-rate held-to-maturity securities other than MBS $ 131,546 $ 27,119 Amortized cost of held-to-maturity MBS Fixed-rate pass-through securities 228 276 Collateralized mortgage obligations Fixed-rate 453 624 Variable-rate 3,055,344 4,599,524 Variable-rate multi-family MBS 61,816 61,819 3,117,841 4,662,243 Total $ 3,249,387 $ 4,689,362 All of the Bank’s variable-rate collateralized mortgage obligations classified as held-to-maturity securities have coupon rates that are subject to interest rate caps, none of which were reached during the years ended December 31, 2015 or 2014 . Sales of Securities. During the year ended December 31, 2015 , the Bank sold held-to-maturity securities with an amortized cost (determined by the specific identification method) of $806,809,000 . Proceeds from the sales totaled $821,323,000 , resulting in realized gains of $14,514,000 . For each of these securities, the Bank had previously collected at least 85 percent of the principal outstanding at the time of acquisition. As such, the sales were considered maturities for purposes of security classification. There were no sales of held-to-maturity securities during the years ended December 31, 2014 or 2013 .

Advances

Advances	12 Months Ended
	Dec. 31, 2015
Advances [Abstract]
Advances [Text Block]	Advances Redemption Terms. At December 31, 2015 and 2014 , the Bank had advances outstanding at interest rates ranging from 0.21 percent to 8.27 percent and 0.05 percent to 8.48 percent , respectively, as summarized below (dollars in thousands). 2015 2014 Contractual Maturity Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate Overdrawn demand deposit accounts $ — — % $ 79,477 4.04 % Due in one year or less 12,431,831 0.44 11,908,892 0.31 Due after one year through two years 5,886,049 0.77 1,085,057 1.46 Due after two years through three years 1,375,560 2.11 1,590,017 2.39 Due after three years through four years 613,243 2.01 1,085,640 2.40 Due after four years through five years 1,129,859 1.53 417,243 2.22 Due after five years 1,732,577 1.44 901,184 2.99 Amortizing advances 1,480,532 3.15 1,727,505 3.45 Total par value 24,649,651 0.93 % 18,795,015 1.14 % Premiums 22 — Deferred prepayment fees (16,113 ) (17,903 ) Commitment fees (131 ) (139 ) Hedging adjustments 113,373 165,427 Total $ 24,746,802 $ 18,942,400 The balances of overdrawn demand deposit accounts were fully collateralized at December 31, 2014 and were repaid at the beginning of 2015 . Amortizing advances require repayment according to predetermined amortization schedules. The Bank offers advances to members that may be prepaid on specified dates without the member incurring prepayment or termination fees (prepayable and callable advances). The prepayment of other advances requires the payment of a fee to the Bank (prepayment fee) if necessary to make the Bank financially indifferent to the prepayment of the advance. At December 31, 2015 and 2014 , the Bank had aggregate prepayable and callable advances totaling $5,895,751,000 and $487,699,000 , respectively. The following table summarizes advances outstanding at December 31, 2015 and 2014 , by the earlier of contractual maturity or next call date, or the first date on which prepayable advances can be repaid without a prepayment fee (in thousands): Contractual Maturity or Next Call Date December 31, 2015 December 31, 2014 Overdrawn demand deposit accounts $ — $ 79,477 Due in one year or less 18,135,949 11,993,262 Due after one year through two years 1,727,927 1,053,687 Due after two years through three years 1,375,559 1,590,017 Due after three years through four years 605,243 1,085,640 Due after four years through five years 613,459 414,243 Due after five years 710,982 851,184 Amortizing advances 1,480,532 1,727,505 Total par value $ 24,649,651 $ 18,795,015 The Bank also offers putable advances. With a putable advance, the Bank purchases a put option from the member that allows the Bank to terminate the fixed-rate advance on specified dates and offer, subject to certain conditions, replacement funding at prevailing market rates. At December 31, 2015 and 2014 , the Bank had putable advances outstanding totaling $1,097,071,000 and $1,454,071,000 , respectively. The following table summarizes advances at December 31, 2015 and 2014 , by the earlier of contractual maturity or next possible put date (in thousands): Contractual Maturity or Next Put Date 2015 2014 Overdrawn demand deposit accounts $ — $ 79,477 Due in one year or less 13,523,902 13,258,963 Due after one year through two years 5,489,429 1,062,557 Due after two years through three years 715,109 990,896 Due after three years through four years 578,243 397,190 Due after four years through five years 1,129,859 377,243 Due after five years 1,732,577 901,184 Amortizing advances 1,480,532 1,727,505 Total par value $ 24,649,651 $ 18,795,015 Credit Concentrations. Due to the composition of its shareholders, the Bank’s potential credit risk from advances is concentrated in commercial banks and savings institutions. No borrower represented more than 10 percent of advances outstanding at December 31, 2015, 2014 or 2013. Interest Rate Payment Terms. The following table provides interest rate payment terms for advances outstanding at December 31, 2015 and 2014 (in thousands): 2015 2014 Fixed-rate Due in one year or less $ 12,236,879 $ 11,573,066 Due after one year 6,463,464 6,694,902 Total fixed-rate 18,700,343 18,267,968 Variable-rate Due in one year or less 208,590 426,477 Due after one year 5,740,718 100,570 Total variable-rate 5,949,308 527,047 Total par value $ 24,649,651 $ 18,795,015 At December 31, 2015 and 2014 , 26 percent and 27 percent, respectively, of the Bank’s fixed-rate advances were swapped to a variable rate. Prepayment Fees. When a member/borrower prepays an advance, the Bank could suffer lower future income if the principal portion of the prepaid advance is reinvested in lower-yielding assets. To protect against this risk, the Bank generally charges a prepayment fee that makes it financially indifferent to a borrower’s decision to prepay an advance. As discussed in Note 1, the Bank records prepayment fees received from members/borrowers on prepaid advances net of any associated hedging adjustments on those advances. Gross advance prepayment fees received from members/borrowers during the years ended December 31, 2015, 2014 and 2013 were $27,724,000 , $26,035,000 and $92,037,000 , respectively. During the years ended December 31, 2015, 2014 and 2013 , the Bank deferred $6,398,000 , $5,835,000 and $1,449,000 of these gross advance prepayment fees.

Mortgage Loans Held for Portfol

Mortgage Loans Held for Portfolio	12 Months Ended
	Dec. 31, 2015
Mortgage Loans Held for Portfolio [Abstract]
Mortgage Loans on Real Estate, by Loan Disclosure [Text Block]	Mortgage Loans Held for Portfolio Mortgage loans held for portfolio represent held-for-investment loans acquired through the MPF program (see Note 1). The following table presents information as of December 31, 2015 and 2014 for mortgage loans held for portfolio (in thousands): 2015 2014 Fixed-rate medium-term* single-family mortgages $ 4,570 $ 9,332 Fixed-rate long-term single-family mortgages 50,404 61,838 Premiums 352 473 Discounts (68 ) (89 ) Total mortgage loans held for portfolio $ 55,258 $ 71,554 ________________________________________ *Medium-term is defined as an original term of 15 years or less. The unpaid principal balance of mortgage loans held for portfolio at December 31, 2015 and 2014 was comprised of government-guaranteed/insured loans totaling $29,741,000 and $37,404,000 , respectively, and conventional loans totaling $25,233,000 and $33,766,000 , respectively. PFIs are paid a credit enhancement fee (“CE fee”) as an incentive to minimize credit losses, to share in the risk of loss on MPF loans and to pay for supplemental mortgage insurance, rather than paying a guaranty fee to other secondary market purchasers. CE fees are paid monthly and are determined based on the remaining unpaid principal balance of the MPF loans. The required credit enhancement obligation varies depending upon the MPF product type. CE fees, payable to a PFI as compensation for assuming credit risk, are recorded as a reduction to mortgage loan interest income when paid by the Bank. During the years ended December 31, 2015, 2014 and 2013 , mortgage loan interest income was reduced by CE fees totaling $21,000 , $26,000 and $36,000 , respectively. The Bank also pays performance-based CE fees that are based on the actual performance of the pool of MPF loans under each individual master commitment. To the extent that losses in the current month exceed accrued performance-based CE fees, the remaining losses may be recovered from future performance-based CE fees payable to the PFI. During the years ended December 31, 2015, 2014 and 2013 , performance-based CE fees that were forgone and not paid to the Bank’s PFIs totaled $18,000 , $24,000 and $31,000 , respectively.

Allowance for Credit Losses

Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2015
Allowance for Credit Losses [Abstract]
Allowance for Credit Losses [Text Block]	Allowance for Credit Losses The Bank has established an allowance methodology for each of its portfolio segments: advances and other extensions of credit to members/borrowers, collectively referred to as "extensions of credit to members"; government-guaranteed/insured mortgage loans held for portfolio; and conventional mortgage loans held for portfolio. Advances and Other Extensions of Credit to Members. In accordance with federal statutes, including the FHLB Act, the Bank lends to financial institutions within its five-state district that are involved in housing finance. The FHLB Act requires the Bank to obtain and maintain sufficient collateral for advances and other extensions of credit to protect against losses. The Bank makes advances and otherwise extends credit only against eligible collateral, as defined by regulation. Eligible collateral includes whole first mortgages on improved residential real property (not more than 90 days delinquent), or securities representing a whole interest in such mortgages; securities issued, insured, or guaranteed by the U.S. government or any of its agencies, including mortgage-backed and other debt securities issued or guaranteed by the Federal National Mortgage Association (“Fannie Mae”), the Federal Home Loan Mortgage Corporation (“Freddie Mac”), or the Government National Mortgage Association (“Ginnie Mae”); term deposits in the Bank; and other real estate-related collateral acceptable to the Bank, provided that such collateral has a readily ascertainable value and the Bank can perfect a security interest in such property. In the case of Community Financial Institutions (which for 2015 included all FDIC-insured institutions with average total assets as of December 31, 2014 , 2013 and 2012 of less than $1.123 billion ), the Bank may also accept as eligible collateral secured small business, small farm and small agribusiness loans, securities representing a whole interest in such loans, and secured loans for community development activities. To ensure the value of collateral pledged to the Bank is sufficient to secure its advances and other extensions of credit, the Bank applies various haircuts, or discounts, to the collateral to determine the value against which borrowers may borrow. As additional security, the Bank has a statutory lien on each borrower’s capital stock in the Bank. Each member/borrower of the Bank executes a security agreement pursuant to which such member/borrower grants a security interest in favor of the Bank in certain assets of such member/borrower. The agreements under which a member grants a security interest fall into one of two general structures. In the first structure, the member grants a security interest in all of its assets that are included in the eligible collateral categories, as described in the preceding paragraph, which the Bank refers to as a “blanket lien.” A member may request that its blanket lien be modified, such that the member grants in favor of the Bank a security interest limited to certain of the eligible collateral categories (i.e., whole first residential mortgages, securities, term deposits in the Bank and other real estate-related collateral). In the second structure, the member grants a security interest in specifically identified assets rather than in the broad categories of eligible collateral covered by the blanket lien and the Bank identifies such members as being on “specific collateral only status.” The basis upon which the Bank will lend to a member that has granted the Bank a blanket lien depends on numerous factors, including, among others, that member’s financial condition and general creditworthiness. Generally, and subject to certain limitations, a member that has granted the Bank a blanket lien may borrow up to a specified percentage of the value of eligible collateral categories, as determined from such member’s financial reports filed with its federal regulator, without specifically identifying each item of collateral or delivering the collateral to the Bank. Under certain circumstances, including, among others, a deterioration of a member’s financial condition or general creditworthiness, the amount a member may borrow is determined on the basis of only that portion of the collateral subject to the blanket lien that such member delivers to the Bank. Under these circumstances, the Bank places the member on “custody status.” In addition, members on blanket lien status may choose to deliver some or all of the collateral to the Bank. The members/borrowers that are granted specific collateral only status by the Bank are generally either insurance companies or members/borrowers with an investment grade credit rating from an NRSRO that have requested this type of structure. Insurance companies are permitted to borrow only against the eligible collateral that is delivered to the Bank or a third-party custodian approved by the Bank, and insurance companies generally grant a security interest only in collateral they have delivered. Members/borrowers with an investment grade credit rating from an NRSRO may grant a security interest in, and would only be permitted to borrow against, delivered eligible securities and specifically identified, eligible first-lien mortgage loans. Such loans must be delivered to the Bank or a third-party custodian approved by the Bank, or the Bank and such member/borrower must otherwise take actions that ensure the priority of the Bank’s security interest in such loans. Investment grade rated members/borrowers that choose this option are subject to fewer provisions that allow the Bank to demand additional collateral or exercise other remedies based on the Bank’s discretion; however, the collateral they pledge is generally subject to larger haircuts (depending on the credit rating of the member/borrower from time to time) than are applied to similar types of collateral pledged by members under a blanket lien arrangement. The Bank perfects its security interests in borrowers’ collateral in a number of ways. The Bank usually perfects its security interest in collateral by filing a Uniform Commercial Code financing statement against the borrower. In the case of certain borrowers, the Bank perfects its security interest by taking possession or control of the collateral, which may be in addition to the filing of a financing statement. In these cases, the Bank also generally takes assignments of most of the mortgages and deeds of trust that are designated as collateral. Instead of requiring delivery of the collateral to the Bank, the Bank may allow certain borrowers to deliver specific collateral to a third-party custodian approved by the Bank or otherwise take actions that ensure the priority of the Bank’s security interest in such collateral. With certain exceptions set forth below, Section 10(e) of the FHLB Act affords any security interest granted to the Bank by any member/borrower of the Bank, or any affiliate of any such member/borrower, priority over the claims and rights of any party, including any receiver, conservator, trustee, or similar party having rights of a lien creditor. However, the Bank’s security interest is not entitled to priority over the claims and rights of a party that (i) would be entitled to priority under otherwise applicable law and (ii) is an actual bona fide purchaser for value or is a secured party who has a perfected security interest in such collateral in accordance with applicable law (e.g., a prior perfected security interest under the Uniform Commercial Code or other applicable law). For example, in a case in which the Bank has perfected its security interest in collateral by filing a Uniform Commercial Code financing statement against the borrower, another secured party’s security interest in that same collateral that was perfected by possession and without prior knowledge of the Bank's lien may be entitled to priority over the Bank’s security interest that was perfected by filing a Uniform Commercial Code financing statement. From time to time, the Bank agrees to subordinate its security interest in certain assets or categories of assets granted by a member/borrower of the Bank to the security interest of another creditor (typically, a Federal Reserve Bank or another FHLBank). If the Bank agrees to subordinate its security interest in certain assets or categories of assets granted by a member/borrower of the Bank to the security interest of another creditor, the Bank will not extend credit against those assets or categories of assets. On at least a quarterly basis, the Bank evaluates all outstanding extensions of credit to members/borrowers for potential credit losses. These evaluations include a review of: (1) the amount, type and performance of collateral available to secure the outstanding obligations; (2) metrics that may be indicative of changes in the financial condition and general creditworthiness of the member/borrower; and (3) the payment status of the obligations. Any outstanding extensions of credit that exhibit a potential credit weakness that could jeopardize the full collection of the outstanding obligations would be classified as substandard, doubtful or loss. The Bank did not have any advances or other extensions of credit to members/borrowers that were classified as substandard, doubtful or loss at December 31, 2015 or 2014 . The Bank considers the amount, type and performance of collateral to be the primary indicator of credit quality with respect to its extensions of credit to members/borrowers. At December 31, 2015 and 2014 , the Bank had rights to collateral on a borrower-by-borrower basis with an estimated value in excess of each borrower’s outstanding extensions of credit. The Bank continues to evaluate and, as necessary, modify its credit extension and collateral policies based on market conditions. At December 31, 2015 and 2014 , the Bank did not have any advances that were past due, on nonaccrual status, or considered impaired. There have been no troubled debt restructurings related to advances. The Bank has never experienced a credit loss on an advance or any other extension of credit to a member/borrower and, based on its credit extension and collateral policies, management currently does not anticipate any credit losses on its extensions of credit to members/borrowers. Accordingly, the Bank has not provided any allowance for credit losses on advances, nor has it recorded any liabilities to reflect an allowance for credit losses related to its off-balance sheet credit exposures. Mortgage Loans — Government-guaranteed/Insured. The Bank’s government-guaranteed/insured fixed-rate mortgage loans are insured or guaranteed by the FHA or the DVA. Any losses from these loans are expected to be recovered from those entities. Any losses from these loans that are not recovered from those entities are absorbed by the servicers. Therefore, the Bank has not established an allowance for credit losses on government-guaranteed/insured mortgage loans. Mortgage Loans — Conventional Mortgage Loans. The allowance for losses on conventional mortgage loans is determined by an analysis that includes consideration of various data such as past performance, current performance, loan portfolio characteristics, collateral-related characteristics and prevailing economic conditions. The allowance for losses on conventional mortgage loans also factors in the credit enhancement under the MPF program. Any incurred losses that are expected to be recovered from the credit enhancements are not reserved as part of the Bank’s allowance for loan losses. The Bank considers the key credit quality indicator for conventional mortgage loans to be the payment status of each loan. The table below summarizes the recorded investment by payment status for mortgage loans at December 31, 2015 and 2014 (dollars in thousands). December 31, 2015 December 31, 2014 Conventional Loans Government- Guaranteed/ Insured Loans Total Conventional Loans Government- Guaranteed/ Insured Loans Total Mortgage loans: 30-59 days delinquent $ 920 $ 1,180 $ 2,100 $ 1,409 $ 2,276 $ 3,685 60-89 days delinquent 348 337 685 531 400 931 90 days or more delinquent 387 202 589 316 299 615 Total past due 1,655 1,719 3,374 2,256 2,975 5,231 Total current loans 23,844 28,340 52,184 31,866 34,846 66,712 Total mortgage loans $ 25,499 $ 30,059 $ 55,558 $ 34,122 $ 37,821 $ 71,943 Other delinquency statistics: In process of foreclosure (1) $ 329 $ 77 $ 406 $ 79 $ — $ 79 Serious delinquency rate (2) 1.5 % 0.7 % 1.1 % 0.9 % 0.8 % 0.9 % Past due 90 days or more and still accruing interest (3) $ — $ 202 $ 202 $ — $ 299 $ 299 Nonaccrual loans $ 387 $ — $ 387 $ 316 $ — $ 316 Troubled debt restructurings $ 118 $ — $ 118 $ 116 $ — $ 116 ________________________________________ (1) Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu has been made. (2) Loans that are 90 days or more past due or in the process of foreclosure expressed as a percentage of the loan portfolio. (3) Only government-guaranteed/insured mortgage loans continue to accrue interest after they become 90 days or more past due. At December 31, 2015 and 2014 , the Bank’s other assets included $49,000 and $193,000 , respectively, of real estate owned. Mortgage loans are considered impaired when, based upon current information and events, it is probable that the Bank will be unable to collect all principal and interest amounts due according to the contractual terms of the mortgage loan agreement. Each nonaccrual mortgage loan and each troubled debt restructuring is specifically reviewed for impairment. At December 31, 2015 and 2014 , the estimated value of the collateral securing each of these loans, plus the estimated amount that can be recovered through credit enhancements and mortgage insurance, if any, exceeded the outstanding loan amount. Therefore, no specific reserve was established for any of these mortgage loans. The remaining conventional mortgage loans were evaluated for impairment on a pool basis. Based upon the current and past performance of these loans, the underwriting standards in place at the time the loans were acquired, and current economic conditions, the Bank determined that an allowance for loan losses of $141,000 was adequate to reserve for credit losses in its conventional mortgage loan portfolio at December 31, 2015 . The following table presents the activity in the allowance for credit losses on conventional mortgage loans held for portfolio during the years ended December 31, 2015, 2014 and 2013 (in thousands): Year Ended December 31, 2015 2014 2013 Balance, beginning of year $ 143 $ 165 $ 183 Chargeoffs (2 ) (22 ) (18 ) Balance, end of year $ 141 $ 143 $ 165 The following table presents information regarding the balances of the Bank's conventional mortgage loans held for portfolio that were individually or collectively evaluated for impairment as well as information regarding the ending balance of the allowance for credit losses as of December 31, 2015 and 2014 (in thousands). December 31, 2015 2014 Ending balance of allowance for credit losses related to loans collectively evaluated for impairment $ 141 $ 143 Recorded investment Individually evaluated for impairment $ 407 $ 432 Collectively evaluated for impairment 25,092 33,690 $ 25,499 $ 34,122

Deposits

Deposits	12 Months Ended
	Dec. 31, 2015
Deposits [Abstract]
Deposits Liabilities Disclosures [Text Block]	Deposits The Bank offers demand and overnight deposits for members and qualifying non-members. In addition, the Bank offers short-term interest-bearing deposit programs to members and qualifying non-members. Interest-bearing deposits classified as demand and overnight pay interest based on a daily interest rate. Term deposits pay interest based on a fixed rate that is determined on the issuance date of the deposit. The weighted average interest rates paid on average outstanding deposits were 0.03 percent, 0.01 percent and 0.01 percent during 2015 , 2014 and 2013 , respectively. For additional information regarding other interest-bearing deposits, see Note 13. The following table details interest-bearing and non-interest bearing deposits as of December 31, 2015 and 2014 (in thousands): 2015 2014 Interest-bearing Demand and overnight $ 954,546 $ 698,136 Term 91,393 99,254 Non-interest bearing (other) 19 24 Total deposits $ 1,045,958 $ 797,414 The aggregate amount of time deposits with a denomination of $250,000 or more was $91,134,000 and $98,850,000 as of December 31, 2015 and 2014 , respectively.

Consolidated Obligations

Consolidated Obligations	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Consolidated Obligations Consolidated obligations are the joint and several obligations of the FHLBanks and consist of consolidated obligation bonds and discount notes. Consolidated obligations are backed only by the financial resources of the 11 FHLBanks. Consolidated obligations are not obligations of, nor are they guaranteed by, the U.S. government. The FHLBanks issue consolidated obligations through the Office of Finance as their agent. In connection with each debt issuance, one or more of the FHLBanks specifies the amount of debt it wants issued on its behalf; the Bank receives the proceeds of only the debt issued on its behalf and records on its statements of condition only that portion of the consolidated obligations for which it has received the proceeds. The Finance Agency and the U.S. Secretary of the Treasury have oversight over the issuance of FHLBank debt through the Office of Finance. Consolidated obligation bonds are issued primarily to raise intermediate- and long-term funds for the FHLBanks and are not subject to any statutory or regulatory limits on maturity. Consolidated obligation discount notes are issued to raise short-term funds and have maturities of one year or less. These notes are generally issued at a price that is less than their face amount and are redeemed at par value when they mature. For additional information regarding the FHLBanks’ joint and several liability on consolidated obligations, see Note 17. The par amounts of the FHLBanks’ outstanding consolidated obligations, including consolidated obligations held as investments by other FHLBanks, were approximately $905 billion and $847 billion at December 31, 2015 and 2014 , respectively. The Bank was the primary obligor on $38.6 billion and $35.2 billion (at par value), respectively, of these consolidated obligations. Regulations require each of the FHLBanks to maintain unpledged qualifying assets equal to its participation in the consolidated obligations outstanding. Qualifying assets are defined as cash; secured advances; obligations of or fully guaranteed by the U.S. government; obligations, participations, mortgages, or other instruments of or issued by Fannie Mae or Ginnie Mae; mortgages, obligations or other securities which are or have ever been sold by Freddie Mac under the FHLB Act; and such securities as fiduciary and trust funds may invest in under the laws of the state in which the FHLBank is located. Any assets subject to a lien or pledge for the benefit of holders of any issue of consolidated obligations are treated as if they were free from lien or pledge for purposes of compliance with these regulations. General Terms. Consolidated obligation bonds are issued with either fixed-rate coupon payment terms or variable-rate coupon payment terms that use a variety of indices for interest rate resets such as LIBOR or the federal funds rate. To meet the specific needs of certain investors in consolidated obligations, both fixed-rate bonds and variable-rate bonds may contain complex coupon payment terms and call options. When such consolidated obligations are issued, the Bank generally enters into interest rate exchange agreements containing offsetting features that effectively convert the terms of the bond to those of a simple variable-rate bond. The consolidated obligation bonds typically issued by the Bank, beyond having fixed-rate or simple variable-rate coupon payment terms, may also have the following broad terms regarding either principal repayment or coupon payment terms: Optional principal redemption bonds (callable bonds) may be redeemed in whole or in part at the Bank's discretion on predetermined call dates according to the terms of the bond offerings; Capped floating rate bonds pay interest at variable rates subject to an interest rate ceiling; Step-up bonds pay interest at increasing fixed rates for specified intervals over the life of the bond. These bonds generally contain provisions that enable the Bank to call the bonds at its option on predetermined call dates; Conversion bonds have coupons that convert from fixed to variable, or from variable to fixed, on predetermined dates; Step-down bonds pay interest at decreasing fixed rates for specified intervals over the life of the bond. These bonds generally contain provisions that enable the Bank to call the bonds at its option on predetermined call dates. Interest Rate Payment Terms. The following table summarizes the Bank’s consolidated obligation bonds outstanding by interest rate payment terms at December 31, 2015 and 2014 (in thousands, at par value). 2015 2014 Fixed-rate $ 11,759,035 $ 8,377,640 Variable-rate 3,625,000 4,471,000 Step-up 2,510,000 3,112,500 Step-down 150,000 150,000 Total par value $ 18,044,035 $ 16,111,140 At December 31, 2015 and 2014 , 90 percent and 86 percent , respectively, of the Bank’s fixed-rate consolidated obligation bonds were swapped to a variable rate. Redemption Terms. The following is a summary of the Bank’s consolidated obligation bonds outstanding at December 31, 2015 and 2014 , by contractual maturity (dollars in thousands): 2015 2014 Contractual Maturity Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate Due in one year or less $ 5,811,410 0.75 % $ 6,225,840 0.58 % Due after one year through two years 5,383,590 0.77 2,790,080 1.19 Due after two years through three years 3,313,585 1.54 1,537,000 0.95 Due after three years through four years 585,180 1.41 1,847,000 1.94 Due after four years through five years 1,275,000 1.56 1,172,500 1.49 Due after five years 1,675,270 2.00 2,538,720 2.06 Total par value 18,044,035 1.09 % 16,111,140 1.18 % Premiums 11,612 6,345 Discounts (2,708 ) (3,486 ) Hedging adjustments (26,980 ) (35,299 ) Total $ 18,025,959 $ 16,078,700 At December 31, 2015 and 2014 , the Bank’s consolidated obligation bonds outstanding included the following (in thousands, at par value): 2015 2014 Non-callable bonds $ 12,868,765 $ 8,504,920 Callable bonds 5,175,270 7,606,220 Total par value $ 18,044,035 $ 16,111,140 The following table summarizes the Bank’s consolidated obligation bonds outstanding at December 31, 2015 and 2014 , by the earlier of contractual maturity or next possible call date (in thousands, at par value): Contractual Maturity or Next Call Date 2015 2014 Due in one year or less $ 10,774,680 $ 13,772,060 Due after one year through two years 4,888,590 1,645,080 Due after two years through three years 2,005,585 152,000 Due after three years through four years 245,180 437,000 Due after four years through five years 130,000 25,000 Due after five years — 80,000 Total par value $ 18,044,035 $ 16,111,140 Discount Notes. At December 31, 2015 and 2014 , the Bank’s consolidated obligation discount notes, all of which are due within one year, were as follows (dollars in thousands): Book Value Par Value Weighted Average Implied Interest Rate December 31, 2015 $ 20,541,329 $ 20,544,821 0.18 % December 31, 2014 $ 19,131,832 $ 19,134,303 0.09 %

Affordable Housing Program

Affordable Housing Program	12 Months Ended
	Dec. 31, 2015
Affordable Housing Program [Abstract]
Affordable Housing Program [Text Block]	Affordable Housing Program Section 10(j) of the FHLB Act requires each FHLBank to establish an AHP. Each FHLBank provides subsidies in the form of direct grants and/or below market interest rate advances to members who use the funds to assist with the purchase, construction, or rehabilitation of housing for very low-, low-, and moderate-income households. The Bank provides subsidies under its AHP solely in the form of direct grants. Annually, each FHLBank must set aside for the AHP 10 percent of its current year’s income before charges for AHP (as adjusted for interest expense on mandatorily redeemable capital stock), subject to a collective minimum contribution for all 11 FHLBanks of $100 million . The exclusion of interest expense on mandatorily redeemable capital stock is required pursuant to a Finance Agency regulatory interpretation. If the result of the aggregate 10 percent calculation is less than $100 million for all 11 FHLBanks, then the FHLB Act requires the shortfall to be allocated among the FHLBanks based on the ratio of each FHLBank’s income before AHP to the sum of the income before AHP of all of the FHLBanks provided, however, that each FHLBank’s required annual AHP contribution is limited to its annual net earnings. There was no shortfall during the years ended December 31, 2015 , 2014 or 2013 . If a FHLBank determines that its required contributions are contributing to its financial instability, it may apply to the Finance Agency for a temporary suspension of its AHP contributions. No FHLBank applied for a suspension of its AHP contributions in 2015 , 2014 or 2013 . The Bank’s AHP assessment is derived by adding interest expense on mandatorily redeemable capital stock (see Note 14) to reported income before assessments; the result of this calculation is then multiplied by 10 percent . The Bank charges the amount set aside for AHP to income and recognizes it as a liability. The Bank relieves the AHP liability as members receive AHP grants. If the Bank experiences a loss during a calendar quarter but still has income for the calendar year, the Bank’s obligation to the AHP is based upon its year-to-date income. In years where the Bank’s income before assessments (as adjusted for interest expense on mandatorily redeemable capital stock) is zero or less, the amount of the AHP assessment is typically equal to zero, and the Bank would not typically be entitled to a credit that could be used to reduce required contributions in future years. The following table summarizes the changes in the Bank’s AHP liability during the years ended December 31, 2015, 2014 and 2013 (in thousands): 2015 2014 2013 Balance, beginning of year $ 25,998 $ 31,864 $ 29,620 AHP assessment 7,468 5,391 9,766 Grants funded, net of recaptured amounts (10,756 ) (11,257 ) (7,522 ) Balance, end of year $ 22,710 $ 25,998 $ 31,864

Assets and Liabilities Subject

Assets and Liabilities Subject to Offsetting	12 Months Ended
	Dec. 31, 2015
Assets and Liabilities Subject to Offsetting [Abstract]
Assets and Liabilities Subject to Offsetting [Text Block]	Assets and Liabilities Subject to Offsetting The Bank has derivatives and securities purchased under agreements to resell that are subject to enforceable master netting agreements or similar arrangements. For purposes of reporting derivative assets and derivative liabilities, the Bank offsets the fair value amounts recognized for derivative instruments (including the right to reclaim cash collateral and the obligation to return cash collateral) where a legally enforceable right of setoff exists. The Bank did not have any liabilities that were eligible to offset its securities purchased under agreements to resell (i.e., securities sold under agreements to repurchase) as of December 31, 2015 or 2014 . The Bank's derivative transactions are executed either bilaterally or, if required, cleared through a third-party central clearinghouse. The Bank has entered into master agreements with each of its bilateral derivative counterparties that provide for the netting of all transactions with each of these counterparties. Under its master agreements with its non-member bilateral derivative counterparties, collateral is delivered (or returned) daily when certain thresholds (ranging from $100,000 to $500,000 ) are met. The Bank offsets the fair value amounts recognized for bilaterally traded derivatives executed with the same counterparty, including any cash collateral remitted to or received from the counterparty. When entering into derivative transactions with its members, the Bank requires the member to post eligible collateral in an amount equal to the sum of the net market value of the member’s derivative transactions with the Bank (if the value is positive to the Bank) plus a percentage of the notional amount of any interest rate swaps, with market values determined on at least a monthly basis. Eligible collateral for derivative transactions with members consists of collateral that is eligible to secure advances and other obligations under the member's Advances and Security Agreement with the Bank. The Bank is not required to pledge collateral to its members to secure derivative positions. For cleared derivatives, all transactions with each clearing member of each clearinghouse are netted pursuant to legally enforceable setoff rights. Cleared derivatives are subject to initial and variation margin requirements established by the clearinghouse and its clearing members. Collateral associated with cleared derivatives (i.e., initial and variation margin) is delivered (or returned) daily and is not subject to any maximum unsecured thresholds. The Bank offsets the fair value amounts recognized for cleared derivatives transacted with each clearing member of each clearinghouse, including cash collateral pledged or received. The following table presents derivative instruments and securities purchased under agreements to resell with the legal right of offset, including the related collateral received from or pledged to counterparties as of December 31, 2015 and 2014 (in thousands). Gross Amounts of Recognized Financial Instruments Gross Amounts Offset in the Statement of Condition Net Amounts Presented in the Statement of Condition Collateral Not Offset in the Statement of Condition (1) Net Unsecured Amount December 31, 2015 Assets Derivatives Bilateral derivatives $ 25,809 $ (8,110 ) $ 17,699 $ (13,214 ) (2) $ 4,485 Cleared derivatives 25,962 (20,581 ) 5,381 — 5,381 Total derivatives 51,771 (28,691 ) 23,080 (13,214 ) 9,866 Securities purchased under agreements to resell 1,000,000 — 1,000,000 (1,000,000 ) — Total assets $ 1,051,771 $ (28,691 ) $ 1,023,080 $ (1,013,214 ) $ 9,866 Liabilities Derivatives Bilateral derivatives $ 300,494 $ (293,530 ) $ 6,964 $ — $ 6,964 Cleared derivatives 257,480 (257,480 ) — — (3) — Total liabilities $ 557,974 $ (551,010 ) $ 6,964 $ — $ 6,964 December 31, 2014 Assets Derivatives Bilateral derivatives $ 31,666 $ (21,212 ) $ 10,454 $ (9,746 ) (2) $ 708 Cleared derivatives 6,574 (6,574 ) — — — Total derivatives 38,240 (27,786 ) 10,454 (9,746 ) 708 Securities purchased under agreements to resell 350,000 — 350,000 (350,000 ) — Total assets $ 388,240 $ (27,786 ) $ 360,454 $ (359,746 ) $ 708 Liabilities Derivatives Bilateral derivatives $ 629,920 $ (611,348 ) $ 18,572 $ — $ 18,572 Cleared derivatives 58,653 (55,704 ) 2,949 (2,949 ) (4) — Total liabilities $ 688,573 $ (667,052 ) $ 21,521 $ (2,949 ) $ 18,572 _____________________________ (1) Any overcollateralization at an individual clearinghouse/clearing member or bilateral counterparty level is not included in the determination of the net unsecured amount. (2) Consists of collateral pledged by member counterparties. (3) The Bank had pledged securities with an aggregate fair value of $300,184,000 at December 31, 2015 to further secure its cleared derivatives, which is a result of the initial margin requirements imposed upon the Bank. (4) Consists of securities pledged by the Bank. In addition to the amount needed to secure the counterparties' exposure to the Bank, the Bank had pledged additional securities with an aggregate fair value of $33,036,000 at December 31, 2014 to secure its cleared derivatives, which is a result of the initial margin requirements imposed upon the Bank.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivatives and Hedging Activities Hedging Activities. As a financial intermediary, the Bank is exposed to interest rate risk. This risk arises from a variety of financial instruments that the Bank enters into on a regular basis in the normal course of its business. The Bank enters into interest rate swap, swaption, cap and forward rate agreements (collectively, interest rate exchange agreements) to manage its exposure to changes in interest rates. The Bank may use these instruments to adjust the effective maturity, repricing frequency, or option characteristics of financial instruments to achieve risk management objectives. In addition, the Bank may use these instruments to hedge the variable cash flows associated with forecasted transactions. The Bank has not entered into any credit default swaps or foreign exchange-related derivatives and, as of December 31, 2015 , it was not a party to any forward rate agreements. The Bank uses interest rate exchange agreements in three ways: (1) by designating the agreement as a fair value hedge of a specific financial instrument or firm commitment; (2) by designating the agreement as a cash flow hedge of a forecasted transaction; or (3) by designating the agreement as a hedge of some defined risk in the course of its balance sheet management (referred to as an “economic hedge”). For example, the Bank uses interest rate exchange agreements in its overall interest rate risk management activities to adjust the interest rate sensitivity of consolidated obligations to approximate more closely the interest rate sensitivity of its assets (both advances and investments), and/or to adjust the interest rate sensitivity of advances or investments to approximate more closely the interest rate sensitivity of its liabilities. In addition to using interest rate exchange agreements to manage mismatches between the coupon features of its assets and liabilities, the Bank also uses interest rate exchange agreements to manage embedded options in assets and liabilities, to preserve the market value of existing assets and liabilities, to hedge the duration risk of prepayable instruments, to hedge the variable cash flows associated with forecasted transactions, to offset interest rate exchange agreements entered into with members (the Bank serves as an intermediary in these transactions), and to reduce funding costs. The Bank, consistent with Finance Agency regulations, enters into interest rate exchange agreements only to reduce potential market risk exposures inherent in otherwise unhedged assets and liabilities or anticipated transactions, or to act as an intermediary between its members and the Bank’s non-member derivative counterparties. The Bank is not a derivatives dealer and it does not trade derivatives for short-term profit. At inception, the Bank formally documents the relationships between derivatives designated as hedging instruments and their hedged items, its risk management objectives and strategies for undertaking the hedge transactions, and its method for assessing the effectiveness of the hedging relationships. For fair value hedges, this process includes linking the derivatives to: (1) specific assets and liabilities on the statements of condition or (2) firm commitments. For cash flow hedges, this process includes linking the derivatives to forecasted transactions. The Bank also formally assesses (both at the inception of the hedging relationship and on a monthly basis thereafter) whether the derivatives that are used in hedging transactions have been effective in offsetting changes in the fair value of hedged items or the cash flows associated with forecasted transactions and whether those derivatives may be expected to remain effective in future periods. The Bank uses regression analyses to assess the effectiveness of its hedges. Investments — The Bank has invested in agency and non-agency MBS. The interest rate and prepayment risk associated with these investment securities is managed through consolidated obligations and/or derivatives. The Bank may manage prepayment and duration risk presented by some investment securities with either callable or non-callable consolidated obligations or interest rate exchange agreements, including caps and interest rate swaps. A substantial portion of the Bank’s held-to-maturity securities are variable-rate MBS that include caps that would limit the variable-rate coupons if short-term interest rates rise dramatically. To hedge a portion of the potential cap risk embedded in these securities, the Bank has entered into interest rate cap agreements. These derivatives are treated as economic hedges. Substantially all of the Bank's available-for-sale securities are fixed-rate agency and other highly rated debentures and agency commercial MBS. To hedge the interest rate risk associated with these fixed-rate investment securities, the Bank has entered into fixed-for-floating interest rate exchange agreements, which are designated as fair value hedges. Advances — The Bank issues both fixed-rate and variable-rate advances. When appropriate, the Bank uses interest rate exchange agreements to adjust the interest rate sensitivity of its fixed-rate advances to approximate more closely the interest rate sensitivity of its liabilities. With issuances of putable advances, the Bank purchases from the member a put option that enables the Bank to terminate a fixed-rate advance on specified future dates. This embedded option is clearly and closely related to the host advance contract. The Bank typically hedges a putable advance by entering into a cancelable interest rate exchange agreement where the Bank pays a fixed-rate coupon and receives a variable-rate coupon, and sells an option to cancel the swap to the swap counterparty. This type of hedge is treated as a fair value hedge. The swap counterparty can cancel the interest rate exchange agreement on the call date and the Bank can cancel the putable advance and offer, subject to certain conditions, replacement funding at prevailing market rates. A small portion of the Bank’s variable-rate advances are subject to interest rate caps that would limit the variable-rate coupons if short-term interest rates rise above a predetermined level. To hedge the cap risk embedded in these advances, the Bank generally enters into interest rate cap agreements. This type of hedge is treated as a fair value hedge. The Bank may hedge a firm commitment for a forward-starting advance through the use of an interest rate swap. In this case, the swap will function as the hedging instrument for both the firm commitment and the subsequent advance. The carrying value of the firm commitment will be included in the basis of the advance at the time the commitment is terminated and the advance is issued. The basis adjustment will then be amortized into interest income over the life of the advance. The Bank enters into optional advance commitments with its members. In an optional advance commitment, the Bank sells an option to the member that provides the member with the right to enter into an advance at a specified fixed rate and term on a specified future date, provided the member has satisfied all of the customary requirements for such advance. Optional advance commitments involving Community Investment Program and Economic Development Program advances with a commitment period of three months or less are currently provided at no cost to members. The Bank may hedge an optional advance commitment through the use of an interest rate swaption. In this case, the swaption will function as the hedging instrument for both the commitment and, if the option is exercised by the member, the subsequent advance. These swaptions are treated as economic hedges. Consolidated Obligations - While consolidated obligations are the joint and several obligations of the FHLBanks, each FHLBank is the primary obligor for the consolidated obligations it has issued or assumed from another FHLBank. The Bank generally enters into derivative contracts to hedge the interest rate risk associated with its specific debt issuances. To manage the interest rate risk of certain of its consolidated obligations, the Bank will match the cash outflow on a consolidated obligation with the cash inflow of an interest rate exchange agreement. With issuances of fixed-rate consolidated obligation bonds, the Bank typically enters into a matching interest rate exchange agreement in which the counterparty pays fixed cash flows to the Bank that are designed to mirror in timing and amount the cash outflows the Bank pays on the consolidated obligation. In this transaction, the Bank pays a variable cash flow that closely matches the interest payments it receives on short-term or variable-rate assets, typically one-month or three-month LIBOR. These transactions are treated as fair value hedges. On occasion, the Bank may enter into fixed-for-floating interest rate exchange agreements to hedge the interest rate risk associated with certain of its consolidated obligation discount notes. The derivatives associated with the Bank’s fair value discount note hedging are treated as economic hedges. The Bank may also use interest rate exchange agreements to convert variable-rate consolidated obligation bonds from one index rate (e.g., the daily effective federal funds rate) to another index rate (e.g., one-month or three-month LIBOR); these transactions are treated as economic hedges. The Bank has not issued consolidated obligations denominated in currencies other than U.S. dollars. Forecasted Issuances of Consolidated Obligations — The Bank uses derivatives to hedge the variability of cash flows over a specified period of time as a result of the forecasted issuances and maturities of short-term, fixed-rate instruments, such as three-month consolidated obligation discount notes. Although each short-term consolidated obligation discount note has a fixed rate of interest, a portfolio of rolling consolidated obligation discount notes effectively has a variable interest rate. The variable cash flows associated with these liabilities are converted to fixed-rate cash flows by entering into receive-variable, pay-fixed interest rate swaps. The maturity dates of the cash flow streams are closely matched to the interest rate reset dates of the derivatives. These derivatives are treated as cash flow hedges. Balance Sheet Management — From time to time, the Bank may enter into interest rate basis swaps to reduce its exposure to changing spreads between one-month and three-month LIBOR. In addition, to reduce its exposure to reset risk, the Bank may occasionally enter into forward rate agreements. These derivatives are treated as economic hedges. Intermediation — The Bank offers interest rate swaps, caps and floors to its members to assist them in meeting their hedging needs. In these transactions, the Bank acts as an intermediary for its members by entering into an interest rate exchange agreement with a member and then entering into an offsetting interest rate exchange agreement with one of the Bank’s approved derivative counterparties. All interest rate exchange agreements related to the Bank’s intermediary activities with its members are accounted for as economic hedges. Impact of Derivatives and Hedging Activities. The following table summarizes the notional balances and estimated fair values of the Bank’s outstanding derivatives at December 31, 2015 and 2014 (in thousands). December 31, 2015 December 31, 2014 Notional Amount of Derivatives Estimated Fair Value Notional Amount of Derivatives Estimated Fair Value Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments under ASC 815 Interest rate swaps Advances $ 4,800,307 $ 3,176 $ 126,161 $ 4,936,984 $ 4,641 $ 183,285 Available-for-sale securities 9,375,109 11,109 401,543 5,877,601 401 462,501 Consolidated obligation bonds 12,988,035 21,319 16,273 10,102,140 15,610 28,046 Consolidated obligation discount notes 100,000 — 1,508 — — — Interest rate swaptions related to advances 4,000 17 — — — — Interest rate caps related to advances — — — 25,000 — — Total derivatives designated as hedging instruments under ASC 815 27,267,451 35,621 545,485 20,941,725 20,652 673,832 Derivatives not designated as hedging instruments under ASC 815 Interest rate swaps Advances 1,500 2 — 1,500 4 — Available-for-sale securities 2,625 21 40 1,000 — 32 Trading securities 100,000 1,270 — — — — Intermediary transactions 1,925,960 13,480 11,810 950,000 14,864 13,413 Interest rate caps Held-to-maturity securities 1,650,000 738 — 2,900,000 1,424 — Intermediary transactions 80,000 639 639 80,000 1,296 1,296 Total derivatives not designated as hedging instruments under ASC 815 3,760,085 16,150 12,489 3,932,500 17,588 14,741 Total derivatives before collateral and netting adjustments $ 31,027,536 51,771 557,974 $ 24,874,225 38,240 688,573 Cash collateral and related accrued interest (1,617 ) (523,936 ) (251 ) (639,517 ) Netting adjustments (27,074 ) (27,074 ) (27,535 ) (27,535 ) Total collateral and netting adjustments (1) (28,691 ) (551,010 ) (27,786 ) (667,052 ) Net derivative balances reported in statements of condition $ 23,080 $ 6,964 $ 10,454 $ 21,521 ________________________________________ (1) Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties. The following table presents the components of net gains (losses) on derivatives and hedging activities as presented in the statements of income for the years ended December 31, 2015, 2014 and 2013 (in thousands). Gain (Loss) Recognized in Earnings for the Year Ended December 31, 2015 2014 2013 Derivatives and hedged items in ASC 815 fair value hedging relationships Interest rate swaps $ 1,508 $ (3,082 ) $ 4,999 Interest rate swaptions 4 — — Interest rate caps — (2 ) (6 ) Total net gain (loss) related to fair value hedge ineffectiveness 1,512 (3,084 ) 4,993 Derivatives not designated as hedging instruments under ASC 815 Net interest income (expense) on interest rate swaps (24 ) 1,362 3,633 Interest rate swaps 5,682 3,900 (3,529 ) Interest rate caps (687 ) (2,601 ) (616 ) Total net gain (loss) related to derivatives not designated as hedging instruments under ASC 815 4,971 2,661 (512 ) Net gains (losses) on derivatives and hedging activities reported in the statements of income $ 6,483 $ (423 ) $ 4,481 The following table presents, by type of hedged item, the gains (losses) on derivatives and the related hedged items in ASC 815 fair value hedging relationships and the impact of those derivatives on the Bank’s net interest income for the years ended December 31, 2015, 2014 and 2013 (in thousands). Hedged Item Gain (Loss) on Derivatives Gain (Loss) on Hedged Items Net Fair Value Hedge Ineffectiveness (1) Derivative Net Interest Income (Expense) (2) Year ended December 31, 2015 Advances $ 34,686 $ (34,378 ) $ 308 $ (90,567 ) Available-for-sale securities 4,683 (3,653 ) 1,030 (122,560 ) Consolidated obligation bonds 7,300 (7,126 ) 174 131,790 Total $ 46,669 $ (45,157 ) $ 1,512 $ (81,337 ) Year ended December 31, 2014 Advances $ 18,468 $ (19,293 ) $ (825 ) $ (105,885 ) Available-for-sale securities (61,063 ) 58,419 (2,644 ) (80,808 ) Consolidated obligation bonds 96,746 (96,361 ) 385 115,928 Total $ 54,151 $ (57,235 ) $ (3,084 ) $ (70,765 ) Year ended December 31, 2013 Advances $ 207,392 $ (207,228 ) $ 164 $ (134,615 ) Available-for-sale securities 188,915 (185,697 ) 3,218 (80,569 ) Consolidated obligation bonds (185,479 ) 187,090 1,611 118,656 Total $ 210,828 $ (205,835 ) $ 4,993 $ (96,528 ) ________________________________________ (1) Reported as net gains (losses) on derivatives and hedging activities in the statements of income. (2) The net interest income (expense) associated with derivatives in ASC 815 fair value hedging relationships is reported in the statements of income in the interest income/expense line item for the indicated hedged item. The following table presents, by type of hedged item in ASC 815 cash flow hedging relationships, the gains (losses) on derivatives recognized in other comprehensive income and the gains (losses) reclassified from AOCI into earnings for the year ended December 31, 2015 (in thousands). The Bank did not have any derivatives designated in cash flow hedging relationships during the years ended December 31, 2014 or 2013 . Derivatives in Cash Flow Hedging Relationships Amount of Losses Recognized in Other Comprehensive Income on Derivatives (Effective Portion) Amount of Losses Reclassified from AOCI into Interest Expense (Effective Portion) (1) Amount of Gains (Losses) Recognized in Net Gains (Losses) on Derivatives and Hedging Activities (Ineffective Portion) Interest rate swap related to anticipated issuances of consolidated obligation discount notes $ 1,424 $ 577 $ — _____________________________ (1) Represents net interest expense associated with the derivative. For the year ended December 31, 2015 , there were no amounts reclassified from AOCI into earnings as a result of the discontinuance of cash flow hedges because the original forecasted transactions occurred by the end of the originally specified time period or within a two-month period thereafter. At December 31, 2015 , $1,417,000 of deferred net losses on derivative instruments in AOCI are expected to be reclassified to earnings during the next 12 months. At December 31, 2015 , the maximum length of time over which the Bank is hedging its exposure to the variability in future cash flows for forecasted transactions is 9.75 years. Credit Risk Related to Derivatives. The Bank is subject to credit risk due to the risk of nonperformance by counterparties to its derivative agreements. The Bank manages derivative counterparty credit risk through the use of master netting agreements or other similar collateral exchange arrangements, credit analysis, and adherence to the requirements set forth in the Bank’s Enterprise Market Risk Management Policy, Enterprise Credit Risk Management Policy and Finance Agency regulations. The Bank has transacted some of its interest rate exchange agreements bilaterally with large financial institutions under master netting agreements (as of December 31, 2015 , the notional balance of outstanding transactions with non-member bilateral counterparties and member counterparties totaled $12.6 billion and $1.0 billion , respectively). Some of these institutions (or their affiliates) buy, sell, and distribute consolidated obligations. The remainder of the Bank's interest rate exchange agreements have been cleared through third-party central clearinghouses (as of December 31, 2015 , the notional balance of cleared transactions outstanding totaled $17.4 billion ). With cleared transactions, the Bank is exposed to credit risk in the event that the clearinghouse or the clearing member fails to meet its obligations to the Bank. The notional amount of the Bank's interest rate exchange agreements does not reflect its credit risk exposure, which is much less than the notional amount. The Bank's net credit risk exposure is based on the current estimated cost, on a present value basis, of replacing at current market rates all interest rate exchange agreements with individual counterparties, if those counterparties were to default, after taking into account the value of any cash and/or securities collateral held or remitted by the Bank. For counterparties with which the Bank is in a net gain position, the Bank has credit exposure when the collateral it is holding (if any) has a value less than the amount of the gain. For counterparties with which the Bank is in a net loss position, the Bank has credit exposure when it has delivered collateral with a value greater than the amount of the loss position. The net exposure on derivative agreements is presented in Note 12. Based on the netting provisions and collateral requirements associated with its derivative agreements and the creditworthiness of its derivative counterparties, Bank management does not currently anticipate any credit losses on its derivative agreements.

Capital

Capital	12 Months Ended
	Dec. 31, 2015
Capital [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Capital Under the Gramm-Leach-Bliley Act of 1999 (the “GLB Act”) and the Finance Agency’s capital regulations, each FHLBank may issue Class A stock or Class B stock, or both, to its members. The Bank’s Capital Plan provides that it will issue only Class B capital stock. The Class B stock has a par value of $ 100 per share and is purchased, redeemed, repurchased and, with the prior approval of the Bank, transferred only at its par value. As required by statute and regulation, members may request the Bank to redeem excess Class B stock, or withdraw from membership and request the Bank to redeem all outstanding capital stock, with five years’ written notice to the Bank. The regulations also allow the Bank, in its sole discretion, to repurchase members’ excess stock at any time without regard for the five-year notification period as long as the Bank continues to meet its regulatory capital requirements following any stock repurchases, as described below. Members are required to maintain an investment in Class B Stock equal to the sum of a membership investment requirement and an activity-based investment requirement. The membership investment requirement is currently 0.04 percent of each member’s total assets as of the previous calendar year-end, subject to a minimum of 1,000 and a maximum of 7,000,000 . Except as described below, the activity-based investment requirement is (and has been) 4.1 percent of outstanding advances. Members and institutions that acquire members must comply with the activity-based investment requirements for as long as the relevant advances remain outstanding. The Bank’s Board of Directors has the authority to adjust these requirements periodically within ranges established in the Capital Plan, as amended from time to time, to ensure that the Bank remains adequately capitalized. On December 3, 2014, the Bank's Board of Directors adopted several amendments to the Bank’s Capital Plan, subject to approval by the Finance Agency and certain notification requirements. The Finance Agency approved the amendments to the Bank’s Capital Plan on June 1, 2015. Among other things, the Bank’s Capital Plan was amended to allow for the creation of two sub-classes of the Bank’s Class B Stock (Class B-1 Stock and Class B-2 Stock). On August 31, 2015, the Bank gave notice to its shareholders that the amended Capital Plan would be implemented and the two sub-classes of capital stock would be created on October 1, 2015. On October 1, 2015, the Bank exchanged all shares of outstanding Class B Stock at the open of business on that date for an equal number of shares of capital stock consisting of shares of Class B-1 Stock and Class B-2 Stock allocated as described in the next sentence. For each shareholder, (i) a number of shares of existing Class B Stock in an amount sufficient to meet such shareholder’s activity-based investment requirement were exchanged for an equal number of shares of Class B-2 Stock and (ii) all other outstanding shares of existing Class B Stock held by such shareholder were exchanged for an equal number of shares of Class B-1 Stock. Immediately following these exchanges, all shares of previously outstanding Class B Stock were retired. The Capital Plan amendments did not change members' voting rights in any way. For the purpose of voting rights, all shares of Class B Stock, regardless of sub-class, are treated the same. From and after October 1, 2015, Class B-1 Stock is used to meet the membership investment requirement and Class B-2 Stock is used to meet the activity-based investment requirement. Subject to the limitations in the Capital Plan, the Bank converts shares of one sub-class of Class B Stock to the other sub-class of Class B Stock under the following circumstances: (i) shares of Class B-2 Stock held by a shareholder in excess of its activity-based investment requirement are converted into Class B-1 Stock, if necessary, to meet that shareholder’s membership investment requirement and (ii) shares of Class B-1 Stock held by a shareholder in excess of the amount required to meet its membership investment requirement are converted into Class B-2 Stock as needed in order to satisfy that shareholder’s activity-based investment requirement. The Bank also amended its Capital Plan to modify the permissible range for the advances-based component of the activity-based investment requirement. Effective October 1, 2015, the permissible range for the advances-based component of the activity-based investment requirement changed from a range of 3.0 percent to 5.0 percent of members’ advances outstanding to a range of 2.0 percent to 5.0 percent of members’ advances outstanding. The requirement remained at 4.1 percent of members' advances outstanding upon the implementation of the amended Capital Plan. The amendments did not alter the permissible ranges for the membership investment requirement or the Acquired Member Asset component of the activity-based investment requirement and no changes to the then existing requirements were made upon the implementation of the amended Capital Plan. Further, under the amended Capital Plan, the Bank’s Board of Directors may also establish one or more separate advances investment requirement percentages (each an "advance type specific percentage") within the range described above to be applied to a specific category of advances in lieu of the generally applicable advances-related investment requirement percentage in effect at the time. Such category of advances may be defined as a particular advances product offering, advances with particular maturities or other features, advances that represent an increase in member borrowing, or such other criteria as the Bank’s Board of Directors may determine. Any advance type specific percentage may be established for an indefinite period of time, or for a specific time period, at the discretion of the Bank’s Board of Directors. Pursuant to the amended Capital Plan, any changes to the activity-based investment requirement require at least 30 days advance notice to the Bank’s members. On September 21, 2015, the Bank announced a Board-authorized reduction in the activity-based stock investment requirement from 4.1 percent to 2.0 percent for certain advances that were funded during the period from October 21, 2015 through December 31, 2015. To be eligible for the reduced activity-based investment requirement, advances funded during this period had to have a minimum maturity of one year or greater, among other things. The standard activity-based stock investment requirement of 4.1 percent continued to apply to all other advances that were funded during the period from October 21, 2015 through December 31, 2015. All other minimum investment requirements also continued to apply. Excess stock is defined as the amount of stock held by a member (or former member) in excess of that institution’s minimum investment requirement (i.e., the amount of stock held in excess of its activity-based investment requirement and, in the case of a member, its membership investment requirement). From and after October 1, 2015, all excess stock is held as Class B-1 Stock at all times. At any time, shareholders may request the Bank to repurchase excess capital stock. Although the Bank is not obligated to repurchase excess stock prior to the expiration of a five-year redemption or withdrawal notification period, it will typically endeavor to honor such requests within a reasonable period of time (generally not exceeding 30 days) so long as the Bank will continue to meet its regulatory capital requirements following the repurchase. The Bank’s Member Products and Credit Policy provides that the Bank may periodically repurchase a portion of members’ excess capital stock. In 2015 , 2014 and 2013 , the Bank repurchased surplus stock on or about the last business day of the month following the end of each calendar quarter. Surplus stock was defined as the amount of Class B Stock in excess of 102.5 percent of the member’s minimum investment requirement for the repurchases that occurred between January 31, 2013 and August 7, 2015. For the repurchases that occurred during this period, a shareholder's surplus stock was not repurchased if the amount of that shareholder's surplus stock was 100,000 or less or if, subject to certain exceptions, the shareholder was on restricted collateral status. For the repurchase that occurred on November 6, 2015, surplus stock was defined as the amount of stock held by a shareholder in excess of 120 percent of the shareholder’s minimum investment requirement. For the repurchase that occurred on November 6, 2015, a shareholder's surplus stock was not repurchased if the amount of that shareholder's surplus stock was $1,000,000 or less or if, subject to certain exceptions, the shareholder was on restricted collateral status. During the years ended December 31, 2015, 2014 and 2013 , the Bank repurchased surplus stock totaling $574,896,000 , $901,117,000 , and $773,954,500 , respectively, none of which was classified as mandatorily redeemable capital stock at the time of repurchase. On February 25, 2016, the Bank repurchased surplus stock totaling $103,707,000 , none of which was classified as mandatorily redeemable capital stock at that date. For this repurchase, surplus stock was defined as the amount of stock held by a shareholder in excess of 125 percent of the shareholder’s minimum investment requirement. For the repurchase that occurred on February 25, 2016, a shareholder's surplus stock was not repurchased if the amount of that shareholder's surplus stock was $2,500,000 or less or if, subject to certain exceptions, the shareholder was on restricted collateral status. For each of the repurchases that occurred in 2015 and the repurchase that occurred on February 25, 2016, shareholders were given the opportunity to opt-out of the repurchase if they chose to do so. From time to time, the Bank may further modify the definition of surplus stock or the timing and/or frequency of surplus stock repurchases. The following table presents total excess stock at December 31, 2015 and 2014 (in thousands). 2015 2014 Excess stock Capital stock $ 356,394 $ 199,202 Mandatorily redeemable capital stock 2,613 4,120 Total $ 359,007 $ 203,322 Under the Finance Agency’s regulations, the Bank is subject to three capital requirements. First, the Bank must maintain at all times permanent capital (defined under the Finance Agency’s rules and regulations as retained earnings and all Class B stock regardless of its classification for financial reporting purposes) in an amount at least equal to its risk-based capital requirement, which is the sum of its credit risk capital requirement, its market risk capital requirement, and its operations risk capital requirement, calculated in accordance with the rules and regulations of the Finance Agency. The Finance Agency may require the Bank to maintain a greater amount of permanent capital than is required by the risk-based capital requirements as defined. Second, the Bank must, at all times, maintain total capital in an amount at least equal to 4.0 percent of its total assets (capital-to-assets ratio). For the Bank, total capital is defined by Finance Agency rules and regulations as the Bank’s permanent capital and the amount of any general allowance for losses (i.e., those reserves that are not held against specific assets). Finally, the Bank is required to maintain at all times a minimum leverage capital-to-assets ratio in an amount at least equal to 5.0 percent of its total assets. In applying this requirement to the Bank, leverage capital includes the Bank’s permanent capital multiplied by a factor of 1.5 plus the amount of any general allowance for losses. The Bank did not have any general reserves at December 31, 2015 or 2014 . Under the regulatory definitions, total capital and permanent capital exclude AOCI. Additionally, mandatorily redeemable capital stock is considered capital for purposes of determining the Bank’s compliance with its regulatory capital requirements. At all times during the three years ended December 31, 2015 , the Bank was in compliance with the aforementioned capital requirements. The following table summarizes the Bank’s compliance with the Finance Agency’s capital requirements as of December 31, 2015 and 2014 (dollars in thousands): December 31, 2015 December 31, 2014 Required Actual Required Actual Regulatory capital requirements: Risk-based capital $ 493,617 $ 2,311,264 $ 347,402 $ 1,927,573 Total capital $ 1,683,332 $ 2,311,264 $ 1,521,835 $ 1,927,573 Total capital-to-assets ratio 4.00 % 5.49 % 4.00 % 5.07 % Leverage capital $ 2,104,165 $ 3,466,896 $ 1,902,293 $ 2,891,360 Leverage capital-to-assets ratio 5.00 % 8.24 % 5.00 % 7.60 % On August 4, 2009, the Finance Agency adopted a final rule establishing capital classifications and critical capital levels for the FHLBanks. The rule defines critical capital levels for the FHLBanks and establishes criteria for each of the following capital classifications identified in the Safety and Soundness Act, as amended by the Housing and Economic Recovery Act of 2008: adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized. An adequately capitalized FHLBank meets all existing risk-based and minimum capital requirements. An undercapitalized FHLBank does not meet one or more of its risk-based or minimum capital requirements, but nonetheless has total capital equal to or greater than 75 percent of all capital requirements. A significantly undercapitalized FHLBank does not have total capital equal to or greater than 75 percent of all capital requirements, but the FHLBank does have total capital greater than 2 percent of its total assets. A critically undercapitalized FHLBank has total capital that is less than or equal to 2 percent of its total assets. The Bank has been classified as adequately capitalized since the rule became effective. In addition to restrictions on capital distributions by a FHLBank that does not meet all of its risk-based and minimum capital requirements, a FHLBank that is classified as undercapitalized, significantly undercapitalized or critically undercapitalized is required to take certain actions, such as submitting a capital restoration plan to the Director of the Finance Agency for approval. Additionally, with respect to a FHLBank that is less than adequately capitalized, the Director of the Finance Agency may take other actions that he or she determines will help ensure the safe and sound operation of the FHLBank and its compliance with its risk-based and minimum capital requirements in a reasonable period of time. The GLB Act made membership voluntary for all members. Members that withdraw from membership may not be readmitted to membership in any FHLBank for at least five years following the date that their membership was terminated and all of their shares of stock were redeemed or repurchased. Effective February 28, 2011, the Bank entered into a Joint Capital Enhancement Agreement (the “JCE Agreement”) with the other FHLBanks. Effective August 5, 2011, the FHLBanks amended the JCE Agreement, and the Finance Agency approved an amendment to the Bank's capital plan to incorporate its provisions on that same date. The amended JCE Agreement provides that the Bank (and each of the other FHLBanks) will, on a quarterly basis, allocate at least 20 percent of its net income to a restricted retained earnings account (“RRE Account”). Pursuant to the provisions of the amended JCE Agreement, the Bank is required to build its RRE Account to an amount equal to one percent of its total outstanding consolidated obligations, which for this purpose is based on the most recent quarter’s average carrying value of all outstanding consolidated obligations, excluding hedging adjustments. Amounts allocated to the Bank’s RRE Account are not available to pay dividends. The Bank’s Board of Directors may declare dividends at the same rate for all shares of Class B Stock, or at different rates for Class B-1 Stock and Class B-2 Stock, provided that in no event can the dividend rate on Class B-2 Stock be lower than the dividend rate on Class B-1 Stock. Dividend payments may be made in the form of cash, additional shares of either, or both, sub-classes of Class B Stock, or a combination thereof as determined by the Bank’s Board of Directors and can be paid only from unrestricted retained earnings or a portion of current earnings. The Bank’s Board of Directors may not declare or pay a dividend if the Bank is not in compliance with its minimum capital requirements or if the Bank would fail to meet its minimum capital requirements after paying such dividend. In addition, the Bank’s Board of Directors may not declare or pay a dividend based on projected or anticipated earnings; further, the Bank may not declare or pay any dividends in the form of capital stock if its excess stock is greater than 1 percent of its total assets or if, after the issuance of such shares, the Bank’s outstanding excess stock would be greater than 1 percent of its total assets. Mandatorily Redeemable Capital Stock. As discussed in Note 1, the Bank’s capital stock is classified as equity (capital) for financial reporting purposes until either a written redemption or withdrawal notice is received from a member or a membership withdrawal or termination is otherwise initiated, at which time the capital stock is reclassified to liabilities. The Finance Agency has confirmed that the accounting classification of certain shares of its capital stock as liabilities does not affect the definition of capital for purposes of determining the Bank’s compliance with its regulatory capital requirements. At December 31, 2015 , the Bank had $8,929,000 in outstanding capital stock subject to mandatory redemption held by 16 institutions. As of December 31, 2014 , the Bank had $5,059,000 in outstanding capital stock subject to mandatory redemption held by 18 institutions. These amounts are classified as liabilities in the statements of condition. During the years ended December 31, 2015, 2014 and 2013 , dividends on mandatorily redeemable capital stock in the amount of $16,000 , $15,000 and $23,000 , respectively, were recorded as interest expense in the statements of income. The Bank is not required to redeem or repurchase activity-based stock until the later of the expiration of a notice of redemption or withdrawal or the date the activity no longer remains outstanding. If activity-based stock becomes excess stock as a result of reduced activity, the Bank, in its discretion and subject to certain regulatory restrictions, may repurchase excess stock prior to the expiration of the notice of redemption or withdrawal. The Bank will generally repurchase such excess stock as long as it expects to continue to meet its minimum capital requirements following the repurchase. The following table summarizes the Bank’s mandatorily redeemable capital stock at December 31, 2015 by year of earliest mandatory redemption (in thousands). The earliest mandatory redemption reflects the earliest time at which the Bank is required to redeem the shareholder’s capital stock, and is based on the assumption that the activities associated with the activity-based stock have concluded by the time the notice of redemption or withdrawal expires. 2016 $ 625 2017 1,115 2018 557 2019 915 2020 5,717 Total $ 8,929 The following table summarizes the Bank’s mandatorily redeemable capital stock activity during 2015 , 2014 and 2013 (in thousands). Balance, January 1, 2013 $ 4,504 Capital stock that became subject to mandatory redemption during the year 26,325 Redemption/repurchase of mandatorily redeemable capital stock (27,845 ) Mandatorily redeemable capital stock issued during the year 18 Stock dividends classified as mandatorily redeemable 63 Balance, December 31, 2013 3,065 Capital stock that became subject to mandatory redemption during the year 3,130 Redemption/repurchase of mandatorily redeemable capital stock (1,160 ) Mandatorily redeemable capital stock issued during the year 5 Stock dividends classified as mandatorily redeemable 19 Balance, December 31, 2014 5,059 Capital stock that became subject to mandatory redemption during the year, net 7,044 Redemption/repurchase of mandatorily redeemable capital stock (3,198 ) Mandatorily redeemable capital stock issued during the year 2 Stock dividends classified as mandatorily redeemable 22 Balance, December 31, 2015 $ 8,929 A member may cancel a previously submitted redemption or withdrawal notice by providing a written cancellation notice to the Bank prior to the expiration of the five-year redemption/withdrawal notice period. A member that cancels a stock redemption or withdrawal notice more than 30 days after it is received by the Bank and prior to its expiration is subject to a cancellation fee equal to a percentage of the par value of the capital stock subject to the cancellation notice. The following table provides the number of institutions that held mandatorily redeemable capital stock and the number that submitted a withdrawal notice or otherwise initiated a termination of their membership and the number of terminations completed during 2015 , 2014 and 2013 : 2015 2014 2013 Number of institutions, beginning of year 18 16 13 Due to mergers and acquisitions 7 7 2 Due to withdrawals — — 2 Due to termination of membership by the Bank* — — 1 Mandatorily redeemable capital stock reclassified to equity — — (1 ) Terminations completed during the year (9 ) (5 ) (1 ) Number of institutions, end of year 16 18 16 ________________________________________ * The Bank terminated the membership of an institution that was closed by its primary regulator. The Bank did not receive any stock redemption notices in 2015 , 2014 or 2013 . Limitations on Redemption or Repurchase of Capital Stock. The GLB Act imposes the following restrictions on the redemption or repurchase of the Bank’s capital stock. • In no event may the Bank redeem or repurchase capital stock if the Bank is not in compliance with its minimum capital requirements or if the redemption or repurchase would cause the Bank to be out of compliance with its minimum capital requirements, or if the redemption or repurchase would cause the member to be out of compliance with its minimum investment requirement. In addition, the Bank’s Board of Directors may suspend redemption of capital stock if the Bank reasonably believes that continued redemption of capital stock would cause the Bank to fail to meet its minimum capital requirements in the future, would prevent the Bank from maintaining adequate capital against a potential risk that may not be adequately reflected in its minimum capital requirements, or would otherwise prevent the Bank from operating in a safe and sound manner. • In no event may the Bank redeem or repurchase capital stock without the prior written approval of the Finance Agency if the Finance Agency or the Bank’s Board of Directors has determined that the Bank has incurred, or is likely to incur, losses that result in, or are likely to result in, charges against the capital of the Bank. For this purpose, charges against the capital of the Bank means an other than temporary decline in the Bank’s total equity that causes the value of total equity to fall below the Bank’s aggregate capital stock amount. Such a determination may be made by the Finance Agency or the Board of Directors even if the Bank is in compliance with its minimum capital requirements. • The Bank may not repurchase any capital stock without the written consent of the Finance Agency during any period in which the Bank has suspended redemptions of capital stock. The Bank is required to notify the Finance Agency if it suspends redemptions of capital stock and set forth its plan for addressing the conditions that led to the suspension. The Finance Agency may require the Bank to reinstate redemptions of capital stock. • In no event may the Bank redeem or repurchase shares of capital stock if the principal and interest due on any consolidated obligations issued through the Office of Finance have not been paid in full or, under certain circumstances, if the Bank becomes a non-complying FHLBank under Finance Agency regulations as a result of its inability to comply with regulatory liquidity requirements or to satisfy its current obligations. • If at any time the Bank determines that the total amount of capital stock subject to outstanding stock redemption or withdrawal notices with expiration dates within the following 12 months exceeds the amount of capital stock the Bank could redeem and still comply with its minimum capital requirements, the Bank will determine whether to suspend redemption and repurchase activities altogether, to fulfill requests for redemption sequentially in the order in which they were received, to fulfill the requests on a pro rata basis, or to take other action deemed appropriate by the Bank.

Employee Retirement Plans

Employee Retirement Plans	12 Months Ended
	Dec. 31, 2015
Employee Retirement Plans [Abstract]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Employee Retirement Plans The Bank participates in the Pentegra Defined Benefit Plan for Financial Institutions (“Pentegra DB Plan”), a tax-qualified defined benefit pension plan. The Pentegra DB Plan covers substantially all officers and employees of the Bank who were hired prior to January 1, 2007, and any new employee of the Bank who was hired on or after January 1, 2007, provided that the employee had prior service with a financial services institution that participated in the Pentegra DB Plan, during which service the employee was covered by such plan. In addition, effective July 1, 2015, coverage was extended to include all of the Bank's non-highly compensated employees (as defined by Internal Revenue Service rules) who were hired on and after January 1, 2007 but before August 1, 2010. The Pentegra 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 ("ERISA") and the Internal Revenue Code. As a result, certain multiemployer plan disclosures, including the certified zone status, are not applicable to the Pentegra DB Plan. Under the Pentegra 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 only to employees of that employer. In addition, in the event a participating employer is unable to meet its contribution requirements, the required contributions for the other participating employers could increase proportionately. The Pentegra DB Plan operates on a fiscal year from July 1 through June 30. The Pentegra DB Plan files one Form 5500 on behalf of all employers who participate in the plan. The Employer Identification Number is 13-5645888 and the three-digit plan number is 333 . There are no collective bargaining agreements in place at the Bank. The Pentegra DB Plan's annual valuation process includes separate calculations of the plan's funded status as well as the funded status of each participating employer. Participating employers in an under-funded position are billed for their required contributions while those in an over-funded position can use their surplus to offset all or a portion of their contribution requirement. The funded status is defined as the market value of assets divided by the funding target (an amount equal to 100 percent of the present value of all benefit liabilities accrued at the valuation date) and is calculated as of the beginning of the Pentegra DB Plan year. As permitted by ERISA, the Pentegra DB Plan accepts contributions for a plan year up to eight and a half months after the end of that plan year and, as a result, the market value of assets at the valuation date (July 1) is increased by any subsequent contributions that are designated for the immediately preceding plan year ended June 30. The most recent Form 5500 available for the Pentegra DB Plan is for the year ended June 30, 2014 . For the plan years ended June 30, 2014 and 2013 , the Bank's contributions did not represent more than 5 percent of the total contributions to the plan. The following table presents the Bank's net pension cost and its funded status, as well as the funded status of the Pentegra DB Plan (dollars in thousands, including amounts presented in the footnotes to the table). 2015 2014 2013 Net pension cost charged to compensation and benefit expense for the year ended December 31 $ 2,187 $ 1,806 $ 1,725 Pentegra DB Plan funded status as of July 1 106.9 % (a) 111.4 % (b) 101.3 % Bank's funded status as of July 1 95.1 % 107.0 % 100.0 % ____________ (a) The Pentegra DB Plan's funded status as of July 1, 2015 is preliminary and may increase because the plan's participants were permitted to make contributions for the plan year ended June 30, 2015 through March 15, 2016 . Contributions made during the period from July 1, 2015 through March 15, 2016 and designated for the plan year ended June 30, 2015 will be included in the final valuation as of July 1, 2015 . The final funded status as of July 1, 2015 will not be available until the Form 5500 for the plan year July 1, 2015 through June 30, 2016 is filed (this Form 5500 is due to be filed no later than April 2017 ). (b) The Pentegra DB Plan's funded status as of July 1, 2014 is preliminary and may increase because the plan's participants were permitted to make contributions for the plan year ended June 30, 2014 through March 15, 2015 . Contributions made during the period from July 1, 2014 through March 15, 2015 and designated for the plan year ended June 30, 2014 will be included in the final valuation as of July 1, 2014 . The final funded status as of July 1, 2014 will not be available until the Form 5500 for the plan year July 1, 2014 through June 30, 2015 is filed (this Form 5500 is due to be filed no later than April 2016 ). The Bank also participates in the Pentegra Defined Contribution Plan for Financial Institutions (“Pentegra DC Plan”), a tax-qualified defined contribution plan. The Bank’s contributions to the Pentegra DC Plan are equal to a percentage of voluntary employee contributions, subject to certain limitations. During the years ended December 31, 2015, 2014 and 2013 , the Bank contributed $1,257,000 , $1,171,000 and $1,185,000 , respectively, to the Pentegra DC Plan. Additionally, the Bank maintains a non-qualified deferred compensation plan that is available to some employees, which is, in substance, an unfunded supplemental retirement plan. The Bank’s liability, which consists of the accumulated employee compensation deferrals, accrued earnings (or losses) on those deferrals and matching Bank contributions corresponding to the contribution percentages applicable to the defined contribution plan, was $2,550,000 and $2,266,000 at December 31, 2015 and 2014 , respectively. Compensation and benefits expense includes accrued earnings on deferred employee compensation and Bank contributions totaling $46,000 , $146,000 , and $283,000 for the years ended December 31, 2015, 2014 and 2013 , respectively. The Bank's non-qualified deferred compensation plan is also available to all of its directors. The Bank’s liability for directors' deferred compensation, which consists of the accumulated compensation deferrals (representing directors’ fees) and the accrued earnings (losses) on those deferrals, was $1,483,000 and $1,264,000 at December 31, 2015 and 2014 , respectively. The Bank maintains a Special Non-Qualified Deferred Compensation Plan (the “Plan”), a defined contribution plan that was established primarily to provide supplemental retirement benefits to those employees who were serving as the Bank’s executive officers at the time the Plan was established. Each participant’s benefit under the Plan consists of contributions that were made by the Bank on the participant’s behalf, plus an allocation of the investment gains or losses on the assets used to fund the Plan. Contributions to the Plan are determined solely at the discretion of the Bank’s Board of Directors; the Bank has no obligation or current intention to make future contributions to the Plan. The Bank’s accrued liability under this plan was $4,722,000 and $5,173,000 at December 31, 2015 and 2014 , respectively. During the years ended December 31, 2014 and 2013, the Bank contributed $25,000 and $740,000 , respectively, to the Plan. The Bank did not make any contributions to the Plan during the year ended December 31, 2015. The Bank sponsors a retirement benefits program that includes health care and life insurance benefits for eligible retirees. The health care portion of the program is contributory while the life insurance benefits, which are available to retirees with at least 20 years of service, are offered on a noncontributory basis. Prior to January 1, 2005, retirees were eligible to remain enrolled in the Bank’s health care benefits plan if age 50 or older with at least 10 years of service at the time of retirement. In December 2004, the Bank modified the eligibility requirements relating to retiree health care continuation benefits. Effective January 1, 2005, retirees are eligible to remain enrolled in the Bank’s health care benefits plan if age 55 or older with at least 15 years of service at the time of retirement. Employees who were age 50 or older with 10 years of service and those who had 20 years of service as of December 31, 2004 were not subject to the revised eligibility requirements. Additionally, then current retiree benefits were unaffected by these modifications. In October 2005, the Bank modified the participant contribution requirements relating to its retirement benefits program. Effective December 31, 2005, retirees who are age 55 or older with at least 15 years of service at the time of retirement can remain enrolled in the Bank’s health care benefits program by paying 100% of the expected plan cost. Previously, participant contributions were subsidized by the Bank; this subsidy was based upon the Bank’s COBRA premium rate and the employee’s age and length of service with the Bank. Then current retirees, employees who were hired prior to January 1, 1991 and those who, as of December 31, 2004, had at least 20 years of service or were age 50 or older with 10 years of service are not subject to these revised contribution requirements prior to age 65. Under the revised plan, at age 65, all plan participants are required to pay 100% of the expected plan cost. The Bank does not have any plan assets set aside for the retirement benefits program. The Bank uses a December 31 measurement date for its retirement benefits program. A reconciliation of the accumulated postretirement benefit obligation (“APBO”) and funding status of the retirement benefits program for the years ended December 31, 2015 and 2014 is as follows (in thousands): Year Ended December 31, 2015 2014 Change in APBO APBO at beginning of year $ 1,410 $ 1,376 Service cost 19 18 Interest cost 46 61 Actuarial loss (gain) (222 ) 2 Participant contributions 162 160 Benefits paid (371 ) (207 ) APBO at end of year 1,044 1,410 Change in plan assets Fair value of plan assets at beginning of year — — Benefits paid by the Bank 209 47 Participant contributions 162 160 Benefits paid (371 ) (207 ) Fair value of plan assets at end of year — — Funded status recognized in other liabilities at end of year $ (1,044 ) $ (1,410 ) Amounts recognized in AOCI at December 31, 2015 and 2014 consist of the following (in thousands): December 31, 2015 2014 Net actuarial gain $ 1,648 $ 1,514 Prior service cost (170 ) (178 ) $ 1,478 $ 1,336 The amounts in AOCI include $20,000 of prior service cost and $98,000 of net actuarial gains that are expected to be recognized as components of net periodic benefit cost in 2016 . The actuarial assumptions used in the measurement of the Bank’s benefit obligation included a gross health care cost trend rate of 6.7 percent for 2016 . For 2015 , 2014 and 2013 , gross health care cost trend rates of 7.8 percent, 8.0 percent and 8.1 percent, respectively, were used. The gross health care cost trend rate is assumed to decline by 0.04 percent per year to a final rate of 4.4 percent in 2071 and thereafter. To compute the APBO at December 31, 2015 and 2014 , weighted average discount rates of 3.08 percent and 3.44 percent were used. Weighted average discount rates of 3.44 percent, 4.64 percent and 3.81 percent were used to compute the net periodic benefit cost for 2015 , 2014 and 2013 , respectively. Components of net periodic benefit cost (credit) for the years ended December 31, 2015, 2014 and 2013 were as follows (in thousands): Year Ended December 31, 2015 2014 2013 Service cost $ 19 $ 18 $ 21 Interest cost 46 61 59 Amortization of prior service cost (credit) 8 2 (17 ) Amortization of net actuarial gain (88 ) (91 ) (77 ) Net periodic benefit credit $ (15 ) $ (10 ) $ (14 ) Under U.S. GAAP, the Bank is required to recognize the overfunded or underfunded status of its retirement benefits program as an asset or liability in its statement of condition and to recognize changes in that funded status in the year in which the changes occur through other comprehensive income. Changes in benefit obligations recognized in other comprehensive income during the years ended December 31, 2015, 2014 and 2013 were as follows (in thousands): Year Ended December 31, 2015 2014 2013 Amortization of prior service cost (credit) included in net periodic benefit cost $ 8 $ 2 $ (17 ) Prior service cost — — (211 ) Actuarial gain (loss) 222 (2 ) 1,067 Amortization of net actuarial gain included in net periodic benefit cost (88 ) (91 ) (77 ) Total changes in benefit obligations recognized in other comprehensive income $ 142 $ (91 ) $ 762 A 1 percent increase in the health care cost trend rate would have increased the APBO at December 31, 2015 by $23,000 and the aggregate of the service and interest cost components of the net periodic benefit cost for the year ended December 31, 2015 by $2,000 . Alternatively, a 1 percent decrease in the health care cost trend rate would have reduced the APBO at December 31, 2015 by $43,000 and the aggregate of the service and interest cost components of the net periodic benefit cost for the year ended December 31, 2015 by $2,000 . The following net postretirement benefit payments, which reflect expected future service, as appropriate, are expected to be paid (in thousands): Year Ended December 31, Expected Benefits Payments, Net of Participant Contributions 2016 $ 147 2017 157 2018 145 2019 148 2020 123 2021-2025 461 $ 1,181

Estimated Fair Values

Estimated Fair Values	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Estimated Fair Values Fair value is defined under U.S. GAAP as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability. U.S. GAAP establishes a fair value hierarchy and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. U.S. GAAP also requires an entity to disclose the level within the fair value hierarchy in which each measurement is classified. The fair value hierarchy prioritizes the inputs used to measure fair value into three broad levels: Level 1 Inputs — Quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. Level 2 Inputs — Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. If the asset or liability has a specified (contractual) term, a Level 2 input must be observable for substantially the full term of the asset or liability. Level 2 inputs include the following: (1) quoted prices for similar assets or liabilities in active markets; (2) quoted prices for identical or similar assets or liabilities in markets that are not active or in which little information is released publicly; (3) 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 (4) inputs that are derived principally from or corroborated by observable market data (e.g., implied spreads). Level 3 Inputs — Unobservable inputs for the asset or liability that are supported by little or no market activity. None of the Bank’s assets or liabilities that are recorded at fair value on a recurring basis were measured using significant Level 3 inputs. For financial instruments carried at fair value, the Bank reviews the fair value hierarchy classifications on a quarterly basis. Changes in the observability of the valuation inputs may result in a reclassification of certain assets or liabilities. Reclassifications, if any, would be reported as transfers as of the beginning of the quarter in which the changes occurred. For the years ended December 31, 2015 and 2014 , the Bank did not reclassify any fair value measurements. The following estimated fair value amounts have been determined by the Bank using available market information and the Bank’s best judgment of appropriate valuation methods. These estimates are based on pertinent information available to the Bank as of December 31, 2015 and 2014 . Although the Bank uses its best judgment in estimating the fair value of these financial instruments, there are inherent limitations in any estimation technique or valuation methodology. For example, because an active secondary market does not exist for many of the Bank’s financial instruments (e.g., advances, non-agency RMBS and mortgage loans held for portfolio), in certain cases their fair values are not subject to precise quantification or verification. Therefore, the estimated fair values presented below in the Fair Value Summary Tables may not be indicative of the amounts that would have been realized in market transactions at the reporting dates. Further, the fair values do not represent an estimate of the overall market value of the Bank as a going concern, which would take into account future business opportunities. The valuation techniques used to measure the fair values of the Bank’s financial instruments are described below. Cash and due from banks. The estimated fair value equals the carrying value. Interest-bearing deposit assets. Interest-bearing deposit assets earn interest at floating market rates; therefore, the estimated fair value of the deposits approximates their carrying value. Securities purchased under agreements to resell and federal funds sold. All federal funds sold and securities purchased under agreements to resell represent overnight balances. The estimated fair values approximate the carrying values. Trading, available-for-sale and held-to-maturity securities. To value its holdings of U.S. Treasury Bills and U.S. Treasury Notes classified as trading securities, all of its available-for-sale securities and its held-to-maturity MBS holdings and state housing agency debentures, the Bank obtains prices from three designated third-party pricing vendors when available. Prior to December 31, 2015, the Bank obtained prices from four designated third-party pricing vendors (the three vendors currently in use as well as one additional vendor). This change in valuation technique did not have a significant impact on the estimated fair values of the financial instruments referred to above as of December 31, 2015. The pricing vendors use various proprietary models to price these securities. 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 securities do not trade on a daily basis, the pricing vendors use available information as applicable such as benchmark curves, benchmarking of like securities, sector groupings and matrix pricing to determine the prices for individual securities. Each pricing vendor has an established challenge process in place for all security valuations, which facilitates resolution of potentially erroneous prices identified by the Bank. Recently, the Bank conducted reviews of the three pricing vendors to reconfirm its understanding of the vendors' pricing processes, methodologies and control procedures and was satisfied that those processes, methodologies and control procedures were adequate and appropriate. A “median” price is first established for each security using a formula that is based upon the number of prices received. If three prices are received, the middle price is the median price; if two prices are received, the average of the two prices is the median price; and if one price is received, it is the median price (and also the final price) subject to some type of validation similar to the evaluation of outliers described below. Prior to December 31, 2015, if four prices were received, the average of the middle two prices was the median price. All prices that are within a specified tolerance threshold of the median price are included in the “cluster” of prices that are averaged to compute a “default” price. All prices that are outside the threshold (“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 an outlier (or some other price identified in the analysis) is determined to be a better estimate of fair value, then the outlier (or the other price, as appropriate) is used as the final price rather than the default price. If, on the other hand, the analysis confirms that an outlier (or outliers) is (are) in fact not representative of fair value and the default price is the best estimate, then the default price is used as the final price. In all cases, the final price is used to determine the fair value of the security. If all prices received for a security are outside the tolerance threshold level of the median price, then there is no default price, and the final price is determined by an evaluation of all outlier prices as described above. As of December 31, 2015, three vendor prices were received for substantially all of the Bank's trading, available-for-sale and held-to-maturity securities referred to above and the final prices for substantially all of those securities were computed by averaging the three prices. As of December 31, 2014, four vendor prices were received for substantially all of the Bank's trading, available-for-sale and held-to-maturity securities referred to above and the final prices for substantially all of those securities were computed by averaging the four prices. Based on the Bank's understanding of the pricing methods employed by the third-party pricing vendors and the relative lack of dispersion among the vendor prices (or, in those instances in which there were outliers, the Bank's additional analyses), the Bank believes its final prices result in reasonable estimates of the fair values and that the fair value measurements are classified appropriately in the fair value hierarchy. The Bank estimates the fair values of its held-to-maturity government-guaranteed debentures using a pricing model and observable market data (i.e., the U.S. Government Agency Fair Value curve and, for debentures containing call features, swaption volatility). To value its mutual fund investments classified as trading securities, the Bank obtains quoted prices for identical securities. Advances. The Bank determines the estimated fair values of advances by calculating the present value of expected future cash flows from the advances using the replacement advance rates for advances with similar terms and, for advances containing options, swaption volatility. This amount is then reduced for accrued interest receivable. Each FHLBank prices advances at a spread to its cost of funds. Each FHLBank's cost of funds approximates the "CO curve," which is derived by adding to the U.S. Treasury curve indicative spreads obtained from market-observable sources. The indicative spreads are generally derived from dealer pricing indications, recent trades, secondary market activity and historical pricing relationships. Mortgage loans held for portfolio. The Bank estimates the fair values of mortgage loans held for portfolio based upon the prices for to-be-announced ("TBA") securities, which represent quoted market prices for forward settling agency MBS. The prices are adjusted for differences in coupon, cost to carry, vintage, remittance type and product type between the Bank's mortgage loans and the referenced TBA MBS. The prices of the referenced TBA MBS and the Bank's mortgage loans are highly dependent upon current mortgage rates and the market's expectations of future mortgage rates and prepayments. Accrued interest receivable and payable. The estimated fair value of accrued interest receivable and payable approximates the carrying value due to their short-term nature. Derivative assets/liabilities . The fair values of the Bank’s interest rate swap and swaption agreements are estimated using a pricing model with inputs that are observable in the market (e.g., the relevant interest rate curves (that is, the relevant LIBOR swap curve and, for purposes of discounting, the overnight index swap ("OIS") curve) and, for agreements containing options, swaption volatility). The fair values of the Bank’s interest rate caps are also estimated using a pricing model with inputs that are observable in the market (that is, cap volatility, the relevant LIBOR swap curve and, for purposes of discounting, the OIS curve). Prior to September 30, 2014, the fair values of the Bank’s interest rate basis swaps and interest rate caps were obtained from dealers (for each basis swap and cap, one dealer estimate was received). These non-binding fair value estimates were corroborated using the Bank's pricing model and observable market data. Effective September 30, 2014, the Bank began using the fair values obtained from its pricing model to value its interest rate basis swaps and interest rate caps. This change in valuation technique did not have a significant impact on the estimated fair values of the Bank's basis swaps or caps as of September 30, 2014. As of December 31, 2014, the Bank was no longer a party to any interest rate basis swaps. As the collateral and netting provisions of the Bank’s arrangements with its derivative counterparties significantly reduce the risk from nonperformance (see Note 12), the Bank does not consider its own nonperformance risk or the nonperformance risk associated with each of its counterparties to be a significant factor in the valuation of its derivative assets and liabilities. The Bank compares the fair values obtained from its pricing model to non-binding dealer estimates (in the case of bilateral derivatives) and clearinghouse valuations (in the case of cleared derivatives) and may also compare its fair values to those of similar instruments to ensure that the fair values are reasonable. The fair values of the Bank’s derivative assets and liabilities include accrued interest receivable/payable and cash collateral remitted to/received from counterparties; the estimated fair values of the accrued interest receivable/payable and cash collateral approximate their carrying values due to their short-term nature. The fair values of the Bank's bilateral derivatives are netted by counterparty pursuant to the provisions of the credit support annexes to the Bank’s master netting agreements with its non-member bilateral derivative counterparties. The Bank's cleared derivative transactions with each clearing member of each clearinghouse are netted pursuant to the Bank's arrangements with those parties. In each case, if the netted amounts are positive, they are classified as an asset and, if negative, as a liability. Deposit liabilities. The Bank determines the estimated fair values of its deposit liabilities with fixed rates and more than three months to maturity by calculating the present value of expected future cash flows from the deposits and reducing this amount for accrued interest payable. The discount rates used in these calculations are based on replacement funding rates for liabilities with similar terms. The estimated fair value approximates the carrying value for deposits with variable rates and fixed rates with three months or less to their maturity or repricing date. Consolidated obligations. The Bank estimates the fair values of consolidated obligations by calculating the present value of expected future cash flows using discount rates that are based on replacement funding rates for liabilities with similar terms and reducing this amount for accrued interest payable. The inputs to the valuation are the CO curve and, for consolidated obligations containing options, swaption volatility. Mandatorily redeemable capital stock. The fair value of capital stock subject to mandatory redemption is generally equal to its par value ($100 per share), as adjusted for any estimated dividend earned but unpaid at the time of reclassification from equity to liabilities. The Bank’s capital stock cannot, by statute or implementing regulation, be purchased, redeemed, repurchased or transferred at any amount other than its par value. Commitments. The estimated fair value of the Bank’s commitments to extend credit, including advances and letters of credit, was not material at December 31, 2015 or 2014 . In May 2015, the Bank replaced its third-party pricing/risk model with a new third-party pricing/risk model. Among other things, the third-party pricing/risk model is used to estimate the fair values of the Bank's interest rate exchange agreements, advances, consolidated obligations, term deposits and held-to-maturity debentures. In addition, this model is used to calculate the periodic changes in the fair values of hedged items (e.g., certain advances, available-for-sale securities and consolidated obligations) that are attributable to changes in LIBOR, the designated benchmark interest rate ("the benchmark fair values") and, beginning in September 2015, the periodic changes in the fair values of hypothetical derivatives associated with cash flow hedges. The implementation of the new model did not have a significant impact on the estimated fair values and, where applicable, the benchmark fair values of the financial instruments referred to above. On the date the new model was implemented, there was an increase of approximately $3,100,000 in the computed amount of the Bank's net hedge ineffectiveness gains (including both fair value and economic hedges) relating to the Bank's entire derivatives portfolio. The derivatives portfolio approximated $30.4 billion (notional balance) at that time. The following table presents the carrying values and estimated fair values of the Bank’s financial instruments at December 31, 2015 (in thousands), as well as the level within the fair value hierarchy in which the measurements are classified. Financial assets and liabilities are classified in their entirety based on the lowest level input that is significant to the fair value estimate. FAIR VALUE SUMMARY TABLE Estimated Fair Value Financial Instruments Carrying Value Total Level 1 Level 2 Level 3 Netting Adjustment (4) Assets: Cash and due from banks $ 837,202 $ 837,202 $ 837,202 $ — $ — $ — Interest-bearing deposits 260 260 — 260 — — Security purchased under agreement to resell 1,000,000 1,000,000 — 1,000,000 — — Federal funds sold 2,171,000 2,171,000 — 2,171,000 — — Trading securities (1) 211,056 211,056 8,857 202,199 — — Available-for-sale securities (1) 9,713,191 9,713,191 — 9,713,191 — — Held-to-maturity securities 3,228,011 3,262,283 — 3,127,584 (2) 134,699 (3) — Advances 24,746,802 24,795,949 — 24,795,949 — — Mortgage loans held for portfolio, net 55,117 60,756 — 60,756 — — Accrued interest receivable 69,676 69,676 — 69,676 — — Derivative assets (1) 23,080 23,080 — 51,771 — (28,691 ) Liabilities: Deposits 1,045,958 1,045,956 — 1,045,956 — — Consolidated obligations Discount notes 20,541,329 20,539,576 — 20,539,576 — — Bonds 18,025,959 17,994,494 — 17,994,494 — — Mandatorily redeemable capital stock 8,929 8,929 8,929 — — — Accrued interest payable 38,972 38,972 — 38,972 — — Derivative liabilities (1) 6,964 6,964 — 557,974 — (551,010 ) ___________________________ (1) Financial instruments measured at fair value on a recurring basis as of December 31, 2015 . (2) Consists of the Bank's holdings of U.S. government-guaranteed debentures, state housing agency obligations, U.S. government-guaranteed RMBS, GSE RMBS and GSE commercial MBS. (3) Consists of the Bank's holdings of non-agency RMBS. (4) Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties. The following table presents the carrying values and estimated fair values of the Bank’s financial instruments at December 31, 2014 (in thousands), as well as the level within the fair value hierarchy in which the measurements are classified. Financial assets and liabilities are classified in their entirety based on the lowest level input that is significant to the fair value estimate. FAIR VALUE SUMMARY TABLE Estimated Fair Value Financial Instruments Carrying Value Total Level 1 Level 2 Level 3 Netting Adjustment (4) Assets: Cash and due from banks $ 1,507,708 $ 1,507,708 $ 1,507,708 $ — $ — $ — Interest-bearing deposits 266 266 — 266 — — Securities purchased under agreements to resell 350,000 350,000 — 350,000 — — Federal funds sold 5,613,000 5,613,000 — 5,613,000 — — Trading securities (1) 408,563 408,563 8,769 399,794 — — Available-for-sale securities (1) 6,388,502 6,388,502 — 6,388,502 — — Held-to-maturity securities 4,662,013 4,727,130 — 4,566,726 (2) 160,404 (3) — Advances 18,942,400 19,060,638 — 19,060,638 — — Mortgage loans held for portfolio, net 71,411 79,331 — 79,331 — — Accrued interest receivable 65,168 65,168 — 65,168 — — Derivative assets (1) 10,454 10,454 — 38,240 — (27,786 ) Liabilities: Deposits 797,414 797,408 — 797,408 — — Consolidated obligations Discount notes 19,131,832 19,131,732 — 19,131,732 — — Bonds 16,078,700 16,110,291 — 16,110,291 — — Mandatorily redeemable capital stock 5,059 5,059 5,059 — — — Accrued interest payable 39,726 39,726 — 39,726 — — Derivative liabilities (1) 21,521 21,521 — 688,573 — (667,052 ) ___________________________ (1) Financial instruments measured at fair value on a recurring basis as of December 31, 2014 . (2) Consists of the Bank's holdings of U.S. government-guaranteed debentures, U.S. government-guaranteed RMBS, GSE RMBS and GSE commercial MBS. (3) Consists of the Bank's holdings of non-agency RMBS. (4) Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties. During the year ended December 31, 2015 , the Bank recorded total OTTI losses on one of its non-agency RMBS classified as held-to-maturity (see Note 5). Based on the lack of significant market activity for non-agency RMBS, the nonrecurring fair value measurement for this impaired security was classified as a Level 3 measurement in the fair value hierarchy. Three third-party vendor prices were received for this security as of December 31, 2015 and the average of the three prices was used to determine the final fair value measurement at that date.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Joint and several liability. As described in Note 10, the Bank is jointly and severally liable with the other 10 FHLBanks for the payment of principal and interest on all of the consolidated obligations issued by the FHLBanks. At December 31, 2015 and 2014 , the par amounts of the other 10 FHLBanks’ outstanding consolidated obligations totaled $867 billion and $812 billion , respectively. The Finance Agency, in its discretion, may require any FHLBank to make principal or interest payments due on any consolidated obligation, regardless of whether there has been a default by a FHLBank having primary liability. To the extent that a FHLBank makes any consolidated obligation payment on behalf of another FHLBank, the paying FHLBank is entitled to reimbursement from the FHLBank with primary liability. However, if the Finance Agency determines that the primary obligor is unable to satisfy its obligations, then the Finance Agency may allocate the outstanding liability among the remaining FHLBanks on a pro rata basis in proportion to each FHLBank’s participation in all consolidated obligations outstanding, or on any other basis that the Finance Agency may determine. No FHLBank has ever failed to make any payment on a consolidated obligation for which it was the primary obligor; as a result, the regulatory provisions for directing other FHLBanks to make payments on behalf of another FHLBank or allocating the liability among other FHLBanks have never been invoked. The joint and several obligations are mandated by Finance Agency regulations and are not the result of arms-length transactions among the FHLBanks. As described above, the FHLBanks have no control over the amount of the guaranty or the determination of how each FHLBank would perform under the joint and several liability. If the Bank expected that it would be required to pay any amounts on behalf of its co-obligors under its joint and several liability, the Bank would charge to income the amount of the expected payment. Based upon the creditworthiness of the other FHLBanks, the Bank currently believes that the likelihood that it would have to pay any amounts beyond those for which it is primarily liable is remote. Other commitments and contingencies. At December 31, 2015 and 2014 , the Bank had commitments to make additional advances totaling approximately $36,892,000 and $14,065,000 , respectively. At December 31, 2015 , $29,292,000 of the outstanding commitments to make additional advances expire in 2016 and the remainder expire in 2017, 2018 or 2019. The Bank issues standby letters of credit for a fee on behalf of its members. Standby letters of credit serve as performance guarantees. If the Bank is required to make payment for a beneficiary’s draw on the letter of credit, the amount funded is converted into a collateralized advance to the member. Letters of credit are fully collateralized in the same manner as advances (see Note 6). Outstanding standby letters of credit totaled $7,180,763,000 and $4,330,557,000 at December 31, 2015 and 2014 , respectively. At December 31, 2015 , outstanding letters of credit had original terms of up to 10 years with a final expiration in 2020 . Unearned fees on standby letters of credit are recorded in other liabilities and totaled $3,685,000 and $3,746,000 at December 31, 2015 and 2014 , respectively. Based on management’s credit analyses and collateral requirements, the Bank does not deem it necessary to have any provision for credit losses on these letters of credit (see Note 8). At December 31, 2015 and 2014 , the Bank had commitments to issue $90,000,000 and $60,000,000 , respectively, of consolidated obligation bonds, all of which were hedged with interest rate swaps. In addition, at both December 31, 2015 and 2014 , the Bank had commitments to issue $750,000,000 of consolidated obligation discount notes, none of which were hedged. The Bank has transacted interest rate exchange agreements with large financial institutions and third-party clearinghouses that are subject to collateral exchange arrangements. As of December 31, 2015 and 2014 , the Bank had pledged cash collateral of $523,871,000 and $639,452,000 , respectively, to those parties that had credit risk exposure to the Bank related to interest rate exchange agreements. The pledged cash collateral (i.e., interest-bearing deposit asset) is netted against derivative assets and liabilities in the statements of condition. In addition, as of December 31, 2015 and 2014 , the Bank had pledged securities with carrying values (and fair values) of $300,184,000 and $35,985,000 , respectively, to parties that had credit risk exposure to the Bank related to interest rate exchange agreements. The pledged securities may be rehypothecated and are not netted against derivative assets and liabilities in the statement of condition. During the years ended December 31, 2015, 2014 and 2013 , the Bank charged to operating expenses net rental costs of approximately $405,000 , $370,000 , and $377,000 , respectively. Future minimum rentals at December 31, 2015 , were as follows (in thousands): Year Premises Equipment Total 2016 $ 255 $ 46 $ 301 2017 265 45 310 2018 131 30 161 2019 34 — 34 2020 3 — 3 Total $ 688 $ 121 $ 809 Lease agreements for Bank premises generally provide for increases in the base rentals resulting from increases in property taxes and maintenance expenses. These increases are not expected to have a material effect on the Bank. The Bank has entered into certain lease agreements to rent space to outside parties in its building. Future minimum rentals under these operating leases at December 31, 2015 were as follows (in thousands): Year Total 2016 $ 1,217 2017 1,185 2018 1,212 2019 1,233 2020 380 Total $ 5,227 In the ordinary course of its business, the Bank is subject to the risk that litigation may arise. Currently, the Bank is not a party to any material pending legal proceedings. For a discussion of other commitments and contingencies, see Notes 11, 12 and 15.

Transactions with Shareholders

Transactions with Shareholders	12 Months Ended
	Dec. 31, 2015
Transactions with Shareholders [Abstract]
Transactions with Stockholders [Text Block]	Transactions with Shareholders As a cooperative, the Bank’s capital stock is owned by its members, by former members that retain the stock as provided in the Bank’s capital plan or by non-member institutions that have acquired members and must retain the stock to support advances or other activities with the Bank. No shareholder owns more than 10% of the voting interests of the Bank due to statutory limits on members’ voting rights. As of December 31, 2015 , 9 of the Bank’s 16 directors were member directors. By law, member directors must be officers or directors of a member of the Bank. Substantially all of the Bank’s advances are made to its shareholders (while eligible to borrow from the Bank, housing associates are not required or allowed to hold capital stock). In addition, the majority of its mortgage loans held for portfolio were either funded by the Bank through, or purchased from, certain of its shareholders. The Bank maintains demand deposit accounts for shareholders primarily as an investment alternative for their excess cash and to facilitate settlement activities that are directly related to advances. As an additional service to members, the Bank also offers term deposit accounts. Further, the Bank offers interest rate swaps, caps and floors to its members. Periodically, the Bank may sell (or purchase) federal funds to (or from) shareholders and/or their affiliates. These transactions are executed on terms that are the same as those with other eligible third-party market participants, except that the Bank’s underwriting guidelines specify a lower minimum threshold for the amount of capital that members must have to be an eligible federal funds counterparty than non-members. The Bank has never held any direct equity investments in its shareholders or their affiliates. Affiliates of two of the Bank’s derivative counterparties (Citigroup and Wells Fargo) acquired member institutions on March 31, 2005 and October 1, 2006, respectively. Since the acquisitions were completed, the Bank has continued to enter into interest rate exchange agreements with Citigroup and Wells Fargo in the normal course of business and under the same terms and conditions as before. Effective October 1, 2006, Citigroup terminated the Ninth District charter of the affiliate that acquired the member institution and, as a result, an affiliate of Citigroup became a non-member shareholder of the Bank. The Bank did not purchase any debt or equity securities issued by any of its shareholders or their affiliates during the years ended December 31, 2015 , 2014 or 2013 . All transactions with shareholders are entered into in the ordinary course of business. The Bank provides the same pricing for advances and other services to all similarly situated members regardless of asset or transaction size, charter type, or geographic location. The Bank provides, in the ordinary course of its business, products and services to members whose officers or directors may serve as directors of the Bank (“Directors’ Financial Institutions”). Finance Agency regulations require that transactions with Directors’ Financial Institutions be made on the same terms as those with any other member. As of December 31, 2015 and 2014 , advances outstanding to Directors’ Financial Institutions aggregated $1,408,060,000 and $1,235,101,000 , respectively, representing 5.7 percent and 6.6 percent, respectively, of the Bank’s total outstanding advances as of those dates. The Bank did not acquire any mortgage loans from (or through) Directors’ Financial Institutions during the years ended December 31, 2015 , 2014 or 2013 . As of December 31, 2015 and 2014 , capital stock outstanding to Directors’ Financial Institutions aggregated $68,951,000 and $60,031,000 , respectively, representing 4.5 percent and 4.9 percent of the Bank’s outstanding capital stock, respectively. For purposes of this determination, the Bank’s outstanding capital stock includes those shares that are classified as mandatorily redeemable.

Transactions with Other FHLBank

Transactions with Other FHLBanks	12 Months Ended
	Dec. 31, 2015
Transactions with Other FHLBanks [Abstract]
Transactions with Other FHLBanks [Text Block]	Transactions with Other FHLBanks Occasionally, the Bank loans (or borrows) short-term federal funds to (from) other FHLBanks. During the years ended December 31, 2015 , 2014 and 2013 , interest income on loans to other FHLBanks totaled $4,214 , $3,504 and $2,031 , respectively; these amounts are reported as interest income from federal funds sold in the statements of income. The following table summarizes the Bank’s loans to other FHLBanks during the years ended December 31, 2015, 2014 and 2013 (in thousands). Year Ended December 31, 2015 2014 2013 Balance, January 1, $ — $ — $ — Loans made to: FHLBank of San Francisco 915,000 1,365,000 475,000 FHLBank of Des Moines 200,000 60,000 — FHLBank of Boston 200,000 — — FHLBank of Atlanta — 60,000 200,000 FHLBank of Topeka 55,000 — — FHLBank of Indianapolis — — 377,000 Collections from: FHLBank of San Francisco (915,000 ) (1,365,000 ) (475,000 ) FHLBank of Des Moines (200,000 ) (60,000 ) — FHLBank of Boston (200,000 ) — — FHLBank of Atlanta — (60,000 ) (200,000 ) FHLBank of Topeka (55,000 ) — — FHLBank of Indianapolis — — (377,000 ) Balance, December 31, $ — $ — $ — During the years ended December 31, 2015 , 2014 and 2013 , interest expense on borrowings from other FHLBanks totaled $4,860 , $1,958 and $931 , respectively. The following table summarizes the Bank’s borrowings from other FHLBanks during the years ended December 31, 2015, 2014 and 2013 (in thousands). Year Ended December 31, 2015 2014 2013 Balance, January 1, $ — $ — $ — Borrowings from: FHLBank of Boston 570,000 — — FHLBank of San Francisco 530,000 565,000 500,000 FHLBank of Topeka 360,000 40,000 — FHLBank of Atlanta 250,000 20,000 — FHLBank of Chicago 150,000 90,000 — FHLBank of Indianapolis — 90,000 — Repayments to: FHLBank of Boston (570,000 ) — — FHLBank of San Francisco (530,000 ) (565,000 ) (500,000 ) FHLBank of Topeka (360,000 ) (40,000 ) — FHLBank of Atlanta (250,000 ) (20,000 ) — FHLBank of Chicago (150,000 ) (90,000 ) — FHLBank of Indianapolis — (90,000 ) — Balance, December 31, $ — $ — $ — The Bank has, from time to time, assumed the outstanding debt of another FHLBank rather than issue new debt. In connection with these transactions, the Bank becomes the primary obligor for the transferred debt. The Bank did not assume any debt from other FHLBanks during the years ended December 31, 2015 , 2014 or 2013 . When they occur, the Bank accounts for these transfers in the same manner as it accounts for new debt issuances (see Note 1). Occasionally, the Bank transfers debt that it no longer needs to other FHLBanks. In connection with these transactions, the assuming FHLBanks become the primary obligors for the transferred debt. The Bank did not transfer any debt to other FHLBanks during the years ended December 31, 2015 , 2014 or 2013 .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Abstract]
Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Income (Loss) The following table presents the changes in the components of AOCI for the years ended December 31, 2015, 2014 and 2013 (in thousands). Net Unrealized Gains (Losses) on Available-for-Sale Securities (1) Net Unrealized Loss on Cash Flow Hedge Non-Credit Portion of Other-than-Temporary Impairment Losses on Held-to-Maturity Securities Postretirement Benefits Total AOCI Year ended December 31, 2015 Balance at January 1, 2015 $ 22,412 $ — $ (27,349 ) $ 1,336 $ (3,601 ) Reclassifications from AOCI to net income Realized gains on sales of available-for-sale securities included in net income (3,922 ) — — — (3,922 ) Losses on cash flow hedge included in interest expense — 577 — — 577 Reclassification adjustment for amortization of prior service costs and net actuarial gains recognized in compensation and benefits expense — — — (80 ) (80 ) Other amounts of other comprehensive income (loss) Net unrealized losses on available-for-sale securities (100,768 ) — — (100,768 ) Unrealized loss on cash flow hedge — (1,424 ) — — (1,424 ) Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities — — (254 ) — (254 ) Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities — — 6,227 — 6,227 Actuarial gain — — — 222 222 Total other comprehensive income (loss) (104,690 ) (847 ) 5,973 142 (99,422 ) Balance at December 31, 2015 $ (82,278 ) $ (847 ) $ (21,376 ) $ 1,478 $ (103,023 ) Net Unrealized Gains (Losses) on Available-for-Sale Securities (1) Net Unrealized Loss on Cash Flow Hedge Non-Credit Portion of Other-than-Temporary Impairment Losses on Held-to-Maturity Securities Postretirement Benefits Total AOCI Year ended December 31, 2014 Balance at January 1, 2014 $ (868 ) $ — $ (33,200 ) $ 1,427 $ (32,641 ) Reclassifications from AOCI to net income Reclassification adjustment for amortization of prior service costs and net actuarial gains recognized in compensation and benefits expense — — — (89 ) (89 ) Other amounts of other comprehensive income (loss) Net unrealized gains on available-for-sale securities 23,280 — — — 23,280 Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities — — (1,349 ) — (1,349 ) Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities — — 7,200 — 7,200 Actuarial loss — — — (2 ) (2 ) Total other comprehensive income (loss) 23,280 — 5,851 (91 ) 29,040 Balance at December 31, 2014 $ 22,412 $ — $ (27,349 ) $ 1,336 $ (3,601 ) Year ended December 31, 2013 Balance at January 1, 2013 $ 22,527 $ — $ (41,437 ) $ 665 $ (18,245 ) Reclassifications from AOCI to net income Reclassification adjustment for amortization of prior service credits and net actuarial gains recognized in compensation and benefits expense — — — (94 ) (94 ) Other amounts of other comprehensive income (loss) Net unrealized losses on available-for-sale securities (23,395 ) — — — (23,395 ) Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities — — 8,237 — 8,237 Actuarial gain — — — 1,067 1,067 Prior service cost — — — (211 ) (211 ) Total other comprehensive income (loss) (23,395 ) — 8,237 762 (14,396 ) Balance at December 31, 2013 $ (868 ) $ — $ (33,200 ) $ 1,427 $ (32,641 ) (1) Net unrealized gains (losses) on available-for-sale securities are net of unrealized gains and losses relating to hedged interest rate risk included in net income.

Other Operating Expenses

Other Operating Expenses	12 Months Ended
	Dec. 31, 2015
Other Operating Expenses [Abstract]
Other Operating Expense Disclosure [Text Block]	Other Operating Expenses The following table presents the significant components of other operating expenses for the years ended December 31, 2015, 2014 and 2013 (in thousands). Year Ended December 31, 2015 2014 2013 Occupancy expense $ 2,396 $ 2,607 $ 2,905 Legal fees 1,214 5,440 1,278 Professional fees 3,245 3,984 3,054 Independent contractors 2,634 977 3 Database fees 3,125 3,181 3,259 Software costs 4,691 5,069 5,727 Other 10,166 9,150 9,746 Total other operating expenses $ 27,471 $ 30,408 $ 25,972

Summary of Significant Accoun30

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Basis of Presentation [Abstract]
Use of Estimates, Policy [Policy Text Block]	Use of Estimates and Assumptions. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make assumptions and estimates. These assumptions and estimates may affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of income and expenses. Significant estimates include the valuations of the Bank’s investment securities, as well as its derivative instruments and any associated hedged items. Actual results could differ from these estimates.
Interest Bearing Deposits, Securities Purchased Under Agreements To Resell And Federal Funds Sold [Policy Text Block]	Federal Funds Sold, Securities Purchased Under Agreements to Resell and Interest-Bearing Deposits. These investments are carried at cost.
Investment, Policy [Policy Text Block]	Investment Securities. The Bank records investment securities on trade date. The Bank carries investment securities for which it has both the ability and intent to hold to maturity (held-to-maturity securities) at cost, adjusted for the amortization of premiums and accretion of discounts using the level-yield method. The carrying amount of held-to-maturity securities is further adjusted for any other-than-temporary impairment charges, as described below. The Bank classifies certain investment securities that it may sell before maturity as available-for-sale and carries them at fair value. For available-for-sale securities that have been hedged (with fixed-for-floating interest rate swaps) and qualify as fair value hedges, the Bank records the portion of the change in value related 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 records the remainder of the change in value of the securities in other comprehensive income as “net unrealized gains (losses) on available-for-sale securities.” The Bank classifies certain other investments as trading and carries them at fair value. The Bank records changes in the fair value of these investments in other income (loss) in the statements of income. Although the securities are classified as trading, the Bank does not engage in active or speculative trading practices. The Bank computes the amortization and accretion of premiums and discounts on mortgage-backed securities ("MBS") for which prepayments are probable and reasonably estimable using the level-yield method over the estimated lives of the securities. This method requires a retrospective adjustment of the effective yield each time the Bank changes the estimated life as if the new estimate had been known since the original acquisition date of the securities. The Bank computes the amortization and accretion of premiums and discounts on other investments using the level-yield method to the contractual maturity of the securities. The Bank computes gains and losses on sales of investment securities using the specific identification method and includes these gains and losses in other income (loss) in the statements of income. The Bank treats securities purchased under agreements to resell as collateralized financings. The Bank evaluates outstanding available-for-sale and held-to-maturity securities for other-than-temporary impairment on at least a quarterly basis. An investment security is impaired if the fair value of the investment is less than its amortized cost. Amortized cost includes adjustments (if any) made to the cost basis of an investment for accretion, amortization, the credit portion of previous other-than-temporary impairments and hedging. The Bank considers the impairment of a debt security to be other than temporary if the Bank (i) intends to sell the security, (ii) more likely than not will be required to sell the security before recovering its amortized cost basis, or (iii) does not expect to recover the security’s entire amortized cost basis (even if the Bank does not intend to sell the security). Further, an impairment is considered to be other than temporary if the Bank’s best estimate of the present value of cash flows expected to be collected from the debt security is less than the amortized cost basis of the security (any such shortfall is referred to as a “credit loss”). If an other-than-temporary impairment (“OTTI”) occurs because the Bank intends to sell an impaired debt security, or more likely than not will be required to sell the security before recovery of its amortized cost basis, the impairment is recognized currently in earnings in an amount equal to the entire difference between fair value and amortized cost. In instances in which a determination is made that a credit loss exists but the Bank does not intend to sell the debt security and it is not more likely than not that the Bank will be required to sell the debt security before the anticipated recovery of its remaining amortized cost basis, the other-than-temporary impairment (i.e., the difference between the security’s then-current carrying amount and its estimated fair value) is separated into (i) the amount of the total impairment related to the credit loss (i.e., the credit component) and (ii) the amount of the total impairment related to all other factors (i.e., the non-credit component). The credit component is recognized in earnings and the non-credit component is recognized in other comprehensive income. The total other-than-temporary impairment is presented in the statement of income with an offset for the amount of the total other-than-temporary impairment that is recognized in other comprehensive income. The non-credit component of any OTTI losses recognized in other comprehensive income for debt securities classified as held-to-maturity is accreted over the remaining life of the debt security (in a prospective manner based on the amount and timing of future estimated cash flows) as an increase in the carrying value of the security unless and until the security is sold, the security matures, or there is an additional other-than-temporary impairment that is recognized in earnings. In instances in which an additional other-than-temporary impairment is recognized in earnings, the amount of the credit loss is reclassified from accumulated other comprehensive income (loss) ("AOCI") to earnings. Further, if an additional other-than-temporary impairment is recognized in earnings and the held-to-maturity security’s then-current carrying amount exceeds its fair value, an additional non-credit impairment is concurrently recognized in other comprehensive income. Conversely, if an additional other-than-temporary impairment is recognized in earnings and the held-to-maturity security’s then-current carrying value is less than its fair value, the carrying value of the security is not increased. In periods subsequent to the recognition of an OTTI loss, the other-than-temporarily impaired debt security is accounted for as if it had been purchased on the measurement date of the other-than-temporary impairment at an amount equal to the previous amortized cost basis less the other-than-temporary impairment recognized in earnings. The difference between the new amortized cost basis and the cash flows expected to be collected is accreted as interest income over the remaining life of the security in a prospective manner based on the amount and timing of future estimated cash flows. In instances when there is a significant increase in a security's expected cash flows, the amount to be accreted is adjusted prospectively.
Federal Home Loan Bank Advances Policy [Policy Text Block]	Advances. The Bank reports advances at their principal amount outstanding, net of unearned commitment fees and deferred prepayment fees, if any, as discussed below. The Bank credits interest on advances to income as earned.
Finance, Loan and Lease Receivables, Held-for-investment, Policy [Policy Text Block]	Mortgage Loans Held for Portfolio. Through the Mortgage Partnership Finance ® (“MPF” ® ) program offered by the FHLBank of Chicago, the Bank invested in government-guaranteed/insured mortgage loans (i.e., those insured or guaranteed by the Federal Housing Administration (“FHA”) or the Department of Veterans Affairs (“DVA”)) and conventional residential mortgage loans during the period from 1998 to mid-2003. These mortgage loans were originated by certain of its member institutions that participated in the MPF program ("Participating Financial Institutions" or “PFIs”). Under its then existing arrangement with the FHLBank of Chicago, the Bank retained title to the mortgage loans, subject to any participation interest in such loans that was sold to the FHLBank of Chicago; the interest in the loans retained by the Bank ranged from 1 percent to 49 percent. Additionally, during the period from 1998 to 2000, the Bank also acquired from the FHLBank of Chicago a percentage interest (ranging up to 75 percent) in certain MPF loans originated by PFIs of other FHLBanks. The Bank manages the liquidity, interest rate and prepayment risk of these loans, while the PFIs retain the servicing activities. The Bank and the PFIs share in the credit risk of the loans with the Bank assuming the first loss obligation limited by the First Loss Account (“FLA”), and the PFIs assuming credit losses in excess of the FLA, up to the amount of the credit enhancement obligation as specified in the master agreement (“Second Loss Credit Enhancement”). The Bank assumes all losses in excess of the Second Loss Credit Enhancement.
Loans and Leases Receivable, Origination Fees, Discounts or Premiums, and Direct Costs to Acquire Loans Policy [Policy Text Block]	The Bank classifies mortgage loans held for portfolio as held for investment and, accordingly, reports them at their principal amount outstanding net of deferred premiums and discounts. The Bank credits interest on mortgage loans to income as earned. The Bank amortizes premiums and accretes discounts to interest income using the contractual method. The contractual method uses the cash flows required by the loan contracts, as adjusted for any actual prepayments, to apply the interest method. Future prepayments of principal are not anticipated under this method. The Bank has the ability and intent to hold these mortgage loans until maturity.
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 of the Bank’s identified portfolio segments, if necessary, to provide for probable losses inherent in its financing receivables portfolio and other off-balance sheet credit exposures as of the balance sheet date. To the extent necessary, an allowance for credit losses for off-balance sheet credit exposures is recorded as a liability. See Note 8 — Allowance for Credit Losses for information regarding the determination of the allowance for credit losses. A portfolio segment is defined as the level at which an entity develops and documents a systematic method for determining its allowance for credit losses. The Bank has developed and documented a systematic methodology for determining an allowance for credit losses for the following portfolio segments: (1) advances and other extensions of credit to members, collectively referred to as “extensions of credit to members;” (2) government-guaranteed/insured mortgage loans held for portfolio; and (3) conventional mortgage loans held for portfolio. Classes of financing receivables are generally a disaggregation of a portfolio segment and are determined on the basis of their initial measurement attribute, the risk characteristics of the financing receivable and an entity’s method for monitoring and assessing credit risk. Because the credit risk arising from the Bank’s financing receivables is assessed and measured at the portfolio segment level, the Bank does not have separate classes of financing receivables within each of its portfolio segments.
Loans and Leases Receivable, Nonaccrual Loan and Lease Status, Policy [Policy Text Block]	The Bank places a conventional mortgage loan on nonaccrual status when the collection of the contractual principal or interest is 90 days or more past due. When a mortgage loan is placed on nonaccrual status, accrued but uncollected interest is reversed against interest income. The Bank records cash payments received on nonaccrual loans first as interest income until it recovers all interest, and then as a reduction of principal. A loan on nonaccrual status is restored to accrual status when none of its contractual principal and interest is due and unpaid, and the Bank expects repayment of the remaining contractual interest and principal. Government-guaranteed/insured loans are not placed on nonaccrual status. A loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect all amounts due according to the contractual terms of the loan agreement. Collateral-dependent loans that are on nonaccrual status are measured for impairment based on the fair value of the underlying property less estimated selling costs. Loans are considered collateral-dependent if repayment is expected to be provided solely by the sale of the underlying property; that is, there is no other available and reliable source of repayment. A collateral-dependent loan is impaired if the fair value of the underlying collateral is insufficient to recover the unpaid principal balance on the loan. Interest income on impaired loans is recognized in the same manner as it is for nonaccrual loans noted above. The Bank evaluates whether to record a charge-off on a conventional mortgage loan when the loan becomes 180 days or more past due or upon the occurrence of a confirming event, whichever occurs first. Confirming events include, but are not limited to, the occurrence of foreclosure or notification of a claim against any of the credit enhancements. A charge-off is recorded if the recorded investment in the loan will not be recovered.
Finance, Loan and Lease Receivables, Held for Investments, Foreclosed Assets Policy [Policy Text Block]	Real Estate Owned. Real estate owned includes assets that have been received in satisfaction of debt or as a result of actual or in-substance foreclosures. Real estate owned is initially recorded at fair value less estimated costs to sell (and subsequently carried at the lower of cost or fair value less estimated costs to sell) and is included in other assets in the statements of condition. If the fair value of the real estate owned less estimated costs to sell is less than the recorded investment in the mortgage loan at the date of transfer, the Bank recognizes a charge-off to the allowance for loan losses. Subsequent realized gains and realized or unrealized losses are included in other income (loss) in the statements of income.
Property, Plant and Equipment, Policy [Policy Text Block]	Premises and Equipment. The Bank records premises and equipment at cost less accumulated depreciation and amortization. At December 31, 2015 and 2014 , the Bank’s accumulated depreciation and amortization relating to premises and equipment was $33,416,000 and $34,991,000 , respectively. The Bank computes depreciation using the straight-line method over the estimated useful lives of assets ranging from 3 to 39 years. It amortizes leasehold improvements on the straight-line basis over the shorter of the estimated useful life of the improvement or the remaining term of the lease. The Bank capitalizes improvements and major renewals but expenses ordinary maintenance and repairs when incurred. Depreciation and amortization expense was $2,176,000 , $2,050,000 and $2,449,000 during the years ended December 31, 2015, 2014 and 2013 , respectively. The Bank includes gains and losses on disposal of premises and equipment, if any, in other income (loss) under the caption “other, net.”
Internal Use Software, Policy [Policy Text Block]	Computer Software. The cost of purchased computer software and certain costs incurred in developing computer software for internal use are capitalized and amortized over future periods. As of December 31, 2015 and 2014 , the Bank had $2,081,000 and $1,287,000 , respectively, in unamortized computer software costs included in other assets. Amortization of computer software costs charged to expense was $1,744,000 , $1,513,000 and $2,171,000 for the years ended December 31, 2015, 2014 and 2013 , respectively.
Derivatives, Policy [Policy Text Block]	Derivatives and Hedging Activities. The Bank accounts for derivatives and hedging activities in accordance with the guidance in Topic 815 of the Financial Accounting Standards Board’s ("FASB") Accounting Standards Codification entitled “Derivatives and Hedging” (“ASC 815”). All derivatives are recognized on the statements of condition at their fair values, including accrued interest receivable and payable. For purposes of reporting derivative assets and derivative liabilities, the Bank offsets the fair value amounts recognized for derivative instruments (including the right to reclaim cash collateral and the obligation to return cash collateral) where a legally enforceable right of setoff exists. Changes in the fair value of a derivative that is effective as — and 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 gains or losses on firm commitments), are recorded in current period earnings. 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.” Net interest income/expense associated with derivatives that qualify for fair value hedge accounting under ASC 815 is recorded as a component of net interest income. If fair value hedging relationships meet certain criteria specified in ASC 815, they are eligible for hedge accounting and the offsetting changes in fair value of the hedged items may be recorded in earnings. The application of hedge accounting generally requires the Bank to evaluate the effectiveness of the fair value hedging relationships on an ongoing basis and to calculate the changes in fair value of the derivatives and related hedged items independently. This is commonly known as the “long-haul” method of accounting. Transactions that meet more stringent criteria qualify for the “shortcut” method of hedge accounting in which an assumption can be made that the change in fair value of a hedged item exactly offsets the change in value of the related derivative. The Bank considers hedges of committed advances to be eligible for the shortcut method of accounting as long as the settlement of the committed advance occurs within the shortest period possible for that type of instrument based on market settlement conventions, the fair value of the swap is zero at the inception of the hedging relationship, and the transaction meets all of the other criteria for shortcut accounting specified in ASC 815. The Bank has defined the market settlement convention to be five business days or less for advances. Changes in the fair value of a derivative that is designated and qualifies as a cash flow hedge, to the extent that the hedge is effective, are recorded in AOCI until earnings are affected by the variability of the cash flows of the hedged transaction. Any ineffective portion of a cash flow hedge (which represents the amount by which the change in the fair value of the derivative differs from the change in fair value of a hypothetical derivative having terms that match identically the critical terms of the hedged forecasted transaction) is recognized in other income (loss) as “net gains (losses) on derivatives and hedging activities.” An economic hedge is defined as a derivative hedging specific or non-specific assets or liabilities that does not qualify or was not designated for hedge accounting under ASC 815, but is an acceptable hedging strategy under the Bank’s Enterprise Market Risk Management Policy. These hedging strategies also comply with Finance Agency regulatory requirements prohibiting speculative derivative transactions. An economic hedge by definition introduces the potential for earnings variability as changes in the fair value of a derivative designated as an economic hedge are recorded in current period earnings with no offsetting fair value adjustment to an asset or liability. Both the net interest income/expense and the fair value changes associated with derivatives in economic hedging relationships are recorded in other income (loss) as “net gains (losses) on derivatives and hedging activities.” The Bank records the changes in fair value of all derivatives (and, in the case of fair value hedges, the hedged items) beginning on the trade date. Cash flows associated with derivatives are reported as cash flows from operating activities in the statements of cash flows, unless the derivatives contain an other-than-insignificant financing element, in which case the cash flows are reported as cash flows from financing activities. The Bank may issue debt, make advances, or purchase financial instruments in which a derivative instrument is “embedded” and the financial instrument that embodies the embedded derivative instrument is not remeasured at fair value with changes in fair value reported in earnings as they occur. Upon execution of these transactions, the Bank assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the financial instrument (i.e., the host contract) and whether a separate, non-embedded instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that (1) the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract and (2) a separate, stand-alone instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract, carried at fair value, and designated as either (1) a hedging instrument in a fair value hedge or (2) a stand-alone derivative instrument pursuant to an economic hedge. However, if the entire contract were to be measured at fair value, with changes in fair value reported in current earnings, or if the Bank could not reliably identify and measure the embedded derivative for purposes of separating that derivative from its host contract, the entire contract would be carried on the statement of condition at fair value and no portion of the contract would be separately accounted for as a derivative. The Bank discontinues hedge accounting prospectively when: (1) management determines that the derivative is no longer effective in offsetting changes in the fair value or cash flows of a hedged item; (2) the derivative and/or the hedged item expires or is sold, terminated, or exercised; (3) it is no longer probable that a forecasted transaction will occur within the originally specified time frame; (4) a hedged firm commitment no longer meets the definition of a firm commitment; or (5) management determines that designating the derivative as a hedging instrument in accordance with ASC 815 is no longer appropriate. In all cases in which hedge accounting is discontinued and the derivative remains outstanding, the Bank will carry the derivative at its fair value on the statement of condition, recognizing any additional changes in the fair value of the derivative in current period earnings. When fair value hedge accounting for a specific derivative is discontinued due to the Bank’s determination that such derivative no longer qualifies for hedge accounting treatment or because the derivative is terminated, the Bank will cease to adjust the hedged asset or liability for changes in fair value and amortize the cumulative basis adjustment on the formerly hedged item into earnings over its remaining term using the level-yield method. When hedge accounting is discontinued because the hedged item no longer meets the definition of a firm commitment, the Bank continues to carry the derivative on the statement of condition at its fair value, removing from the statement of condition any asset or liability that was recorded to recognize the firm commitment and recording it as a gain or loss in current period earnings. When cash flow hedge accounting for a specific derivative is discontinued due to the Bank's determination that such derivative no longer qualifies for hedge accounting treatment or because the derivative is terminated, the Bank will reclassify the cumulative fair value gains or losses recorded in AOCI as of the discontinuance date from AOCI into earnings when earnings are affected by the original forecasted transaction, except in cases where the cash flow hedge is discontinued because the forecasted transaction is no longer probable (i.e., the forecasted transaction will not occur in the originally expected period or within an additional two-month period of time thereafter). In such cases, any fair value gains or losses recorded in AOCI as of the determination date are immediately reclassified to earnings as a component of "gains (losses) on derivatives and hedging activities." Similarly, if the Bank expects at any time that continued reporting of a net loss in AOCI would lead to recognizing a net loss on the combination of the hedging instrument and hedged transaction in one or more future periods, the amount that is not expected to be recovered is immediately reclassified to earnings as a component of "gains (losses) on derivatives and hedging activities."
Derivatives, Offsetting Fair Value Amounts, Policy [Policy Text Block]	For purposes of reporting derivative assets and derivative liabilities, the Bank offsets the fair value amounts recognized for derivative instruments (including the right to reclaim cash collateral and the obligation to return cash collateral) where a legally enforceable right of setoff exists.
Derivatives, Embedded Derivatives [Policy Text Block]	The Bank may issue debt, make advances, or purchase financial instruments in which a derivative instrument is “embedded” and the financial instrument that embodies the embedded derivative instrument is not remeasured at fair value with changes in fair value reported in earnings as they occur. Upon execution of these transactions, the Bank assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the financial instrument (i.e., the host contract) and whether a separate, non-embedded instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that (1) the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract and (2) a separate, stand-alone instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract, carried at fair value, and designated as either (1) a hedging instrument in a fair value hedge or (2) a stand-alone derivative instrument pursuant to an economic hedge. However, if the entire contract were to be measured at fair value, with changes in fair value reported in current earnings, or if the Bank could not reliably identify and measure the embedded derivative for purposes of separating that derivative from its host contract, the entire contract would be carried on the statement of condition at fair value and no portion of the contract would be separately accounted for as a derivative.
Derivatives, Hedge Discontinuances [Policy Text Block]	The Bank discontinues hedge accounting prospectively when: (1) management determines that the derivative is no longer effective in offsetting changes in the fair value or cash flows of a hedged item; (2) the derivative and/or the hedged item expires or is sold, terminated, or exercised; (3) it is no longer probable that a forecasted transaction will occur within the originally specified time frame; (4) a hedged firm commitment no longer meets the definition of a firm commitment; or (5) management determines that designating the derivative as a hedging instrument in accordance with ASC 815 is no longer appropriate. In all cases in which hedge accounting is discontinued and the derivative remains outstanding, the Bank will carry the derivative at its fair value on the statement of condition, recognizing any additional changes in the fair value of the derivative in current period earnings. When fair value hedge accounting for a specific derivative is discontinued due to the Bank’s determination that such derivative no longer qualifies for hedge accounting treatment or because the derivative is terminated, the Bank will cease to adjust the hedged asset or liability for changes in fair value and amortize the cumulative basis adjustment on the formerly hedged item into earnings over its remaining term using the level-yield method. When hedge accounting is discontinued because the hedged item no longer meets the definition of a firm commitment, the Bank continues to carry the derivative on the statement of condition at its fair value, removing from the statement of condition any asset or liability that was recorded to recognize the firm commitment and recording it as a gain or loss in current period earnings. When cash flow hedge accounting for a specific derivative is discontinued due to the Bank's determination that such derivative no longer qualifies for hedge accounting treatment or because the derivative is terminated, the Bank will reclassify the cumulative fair value gains or losses recorded in AOCI as of the discontinuance date from AOCI into earnings when earnings are affected by the original forecasted transaction, except in cases where the cash flow hedge is discontinued because the forecasted transaction is no longer probable (i.e., the forecasted transaction will not occur in the originally expected period or within an additional two-month period of time thereafter). In such cases, any fair value gains or losses recorded in AOCI as of the determination date are immediately reclassified to earnings as a component of "gains (losses) on derivatives and hedging activities." Similarly, if the Bank expects at any time that continued reporting of a net loss in AOCI would lead to recognizing a net loss on the combination of the hedging instrument and hedged transaction in one or more future periods, the amount that is not expected to be recovered is immediately reclassified to earnings as a component of "gains (losses) on derivatives and hedging activities."
Shares Subject to Mandatory Redemption, Changes in Redemption Value, Policy [Policy Text Block]	Mandatorily Redeemable Capital Stock. The Bank reclassifies shares of capital stock from the capital section to the liability section of its statement of condition at the point in time when a member submits a written redemption notice, gives notice of its intent to withdraw from membership, or becomes a non-member by merger or acquisition, charter termination, or involuntary termination from membership, as the shares of capital stock then meet the definition of a mandatorily redeemable financial instrument. Shares of capital stock meeting this definition are reclassified to liabilities at fair value. Following reclassification of the stock, any dividends paid or accrued on such shares are recorded as interest expense in the statement of income. Repurchase or redemption of these mandatorily redeemable financial instruments is reported as a cash outflow in the financing activities section of the statement of cash flows. If a member cancels a written redemption or withdrawal notice, the Bank reclassifies the shares subject to the cancellation notice from liabilities back to equity. Following this reclassification to equity, dividends on the capital stock are once again recorded as a reduction of retained earnings. Although mandatorily redeemable capital stock is excluded from capital for financial reporting purposes, it is considered capital for regulatory purposes. See Note 14 for more information, including restrictions on stock redemption.
Federal Home Loan Bank Assessments, Policy [Policy Text Block]	Affordable Housing Program. The FHLB Act requires each FHLBank to establish and fund an Affordable Housing Program (“AHP”) (see Note 11). The Bank charges the required funding for AHP to earnings and establishes a liability. The Bank makes AHP funds available to members in the form of direct grants to assist in the purchase, construction, or rehabilitation of housing for very low-, low-, and moderate-income households.
Prepayment fees on Federal Home Loan Bank Advances, Policy [Policy Text Block]	Prepayment Fees. The Bank charges a prepayment fee when members/borrowers prepay certain advances before their original maturities. The Bank records prepayment fees received from members/borrowers net of hedging adjustments included in the book basis of the prepaid advance, if any, as interest income on advances in the statements of income either immediately (as prepayment fees on advances) or over time (as interest income on advances), as further described below. In cases in which the Bank funds a new advance concurrent with or within a short period of time before or after the prepayment of an existing advance, the Bank evaluates whether the new advance meets the accounting criteria to qualify as a modification of an existing advance. If the new advance qualifies as a modification of the existing advance, the net prepayment fee on the prepaid advance is deferred, recorded in the basis of the modified advance, and amortized into interest income over the life of the modified advance using the level-yield method. This amortization is recorded in interest income on advances. If the Bank determines that the advance should be treated as a new advance, or in instances where no new advance is funded, it records the net fees as “prepayment fees on advances” in the interest income section of the statements of income.
Loans and Leases Receivable, Commitment Fee Policy	Commitment Fees. The Bank defers commitment fees for advances and amortizes them to interest income using the level-yield method over the life of the advance. The Bank records commitment fees for letters of credit as a deferred credit when it receives the fees and amortizes them over the term of the letter of credit using the straight-line method.
Debt, Policy [Policy Text Block]	Concessions on Consolidated Obligations. The Bank defers and amortizes, using the level-yield method, the amounts paid to securities dealers in connection with the sale of consolidated obligation bonds over the term to maturity of the related bonds. The Office of Finance prorates the amount of the concession to the Bank based upon the percentage of the debt issued that is assumed by the Bank. Unamortized concessions were $1,266,000 and $2,179,000 at December 31, 2015 and 2014 , respectively, and are included in other assets on the statements of condition. As discussed in Note 2, the unamortized concessions will be reclassified as a reduction in the balance of consolidated obligation bonds effective January 1, 2016. Amortization of such concessions is included in consolidated obligation bond interest expense and totaled $2,544,000 , $2,111,000 and $1,732,000 during the years ended December 31, 2015, 2014 and 2013 , respectively. The Bank charges to expense as incurred the concessions applicable to the sale of consolidated obligation discount notes because of the short maturities of these notes. Concessions related to the sale of discount notes totaling $1,274,000 , $870,000 and $209,000 are included in interest expense on consolidated obligation discount notes in the statements of income for the years ended December 31, 2015, 2014 and 2013 , respectively. Discounts and Premiums on Consolidated Obligations. The Bank expenses the discounts on consolidated obligation discount notes using the level-yield method over the term to maturity of the related notes. It accretes the discounts and amortizes the premiums on consolidated obligation bonds to expense using the level-yield method over the term to maturity of the bonds.
Regulator and Office of Finance, Costs Assessed on Federal Home Loan Bank, Policy [Policy Text Block]	Finance Agency and Office of Finance Expenses. The Bank is assessed its proportionate share of the costs of operating the Finance Agency and the Office of Finance. The assessment for the FHLBanks’ portion of the Finance Agency’s operating and capital expenditures is allocated among the FHLBanks based on the ratio between each FHLBank’s minimum required regulatory capital and the aggregate minimum required regulatory capital of all FHLBanks determined as of June 30 of each year. The expenses of the Office of Finance are shared on a pro rata basis with two-thirds based on each FHLBank’s total consolidated obligations outstanding (as of the current month-end) and one-third divided equally among all of the FHLBanks. These costs are included in the other expense section of the statements of income.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Estimated Fair Values. Some of the Bank’s financial instruments (e.g., advances) lack an available trading market characterized by transactions between a willing buyer and a willing seller engaging in an exchange transaction. Therefore, the Bank uses internal models employing assumptions regarding interest rates, volatilities, prepayments, and other factors to perform present-value calculations when disclosing estimated fair values for these financial instruments. The Bank assumes that book value approximates fair value for certain financial instruments with three months or less to repricing or maturity. For a discussion of the Bank's valuation techniques and the estimated fair values of its financial instruments, see Note 16.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash Flows. In the statements of cash flows, the Bank considers cash and due from banks as cash and cash equivalents.

Trading Securities (Tables)

Trading Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Trading Securities [Abstract]
Trading Securities [Table Text Block]	Major Security Types. Trading securities as of December 31, 2015 and 2014 were as follows (in thousands): December 31, 2015 December 31, 2014 U.S. Treasury Notes $ 202,199 $ — U.S. Treasury Bills — 399,794 Other 8,857 8,769 Total $ 211,056 $ 408,563

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	Available-for-sale securities as of December 31, 2015 were as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 498,185 $ 1,315 $ 1,748 $ 497,752 GSE obligations 5,328,125 12,597 1,775 5,338,947 Other 372,532 10 1,002 371,540 6,198,842 13,922 4,525 6,208,239 GSE commercial MBS 3,596,627 766 92,441 3,504,952 Total $ 9,795,469 $ 14,688 $ 96,966 $ 9,713,191 Included in the table above are GSE commercial MBS that were purchased but which had not yet settled as of December 31, 2015 . The amount due of $164,889,000 is included in other liabilities on the statement of condition at that date. Available-for-sale securities as of December 31, 2014 were as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 49,666 $ 308 $ — $ 49,974 GSE obligations 4,890,484 31,066 — 4,921,550 Other 411,145 701 535 411,311 5,351,295 32,075 535 5,382,835 GSE commercial MBS 1,014,795 322 9,450 1,005,667 Total $ 6,366,090 $ 32,397 $ 9,985 $ 6,388,502
Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Schedule of Unrealized Loss on Investments [Table Text Block]	The following table summarizes (in thousands, except number of positions) the available-for-sale securities with unrealized losses as of December 31, 2015 . The unrealized losses are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Debentures U.S. government-guaranteed obligations 7 $ 229,793 $ 1,748 — $ — $ — 7 $ 229,793 $ 1,748 GSE obligations 28 802,283 1,775 — — — 28 802,283 1,775 Other 22 279,138 522 8 48,567 480 30 327,705 1,002 GSE commercial MBS 80 2,401,148 63,602 29 849,297 28,839 109 3,250,445 92,441 Total 137 $ 3,712,362 $ 67,647 37 $ 897,864 $ 29,319 174 $ 4,610,226 $ 96,966 The following table summarizes (in thousands, except number of positions) the available-for-sale securities with unrealized losses as of December 31, 2014 . The unrealized losses are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Debentures Other 18 $ 163,153 $ 535 — $ — $ — 18 $ 163,153 $ 535 GSE commercial MBS 29 863,159 9,450 — — — 29 863,159 9,450 Total 47 $ 1,026,312 $ 9,985 — $ — $ — 47 $ 1,026,312 $ 9,985
Investments Classified by Contractual Maturity Date [Table Text Block]	The amortized cost and estimated fair value of available-for-sale securities by contractual maturity at December 31, 2015 and 2014 are presented below (in thousands). December 31, 2015 December 31, 2014 Maturity Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Debentures Due in one year or less $ 133,117 $ 133,077 $ 87,379 $ 87,418 Due after one year through five years 3,637,966 3,643,909 4,224,231 4,245,122 Due after five years through ten years 2,313,112 2,316,854 1,039,685 1,050,295 Due after ten years 114,647 114,399 — — 6,198,842 6,208,239 5,351,295 5,382,835 GSE commercial MBS 3,596,627 3,504,952 1,014,795 1,005,667 Total $ 9,795,469 $ 9,713,191 $ 6,366,090 $ 6,388,502
Schedule of Interest Rate Payment Terms For Investments [Table Text Block]	The following table provides interest rate payment terms for investment securities classified as available-for-sale at December 31, 2015 and 2014 (in thousands): December 31, 2015 December 31, 2014 Amortized cost of available-for-sale securities other than MBS Fixed-rate $ 6,123,842 $ 5,276,295 Variable-rate 75,000 75,000 6,198,842 5,351,295 Amortized cost of fixed-rate multi-family MBS 3,596,627 1,014,795 Total $ 9,795,469 $ 6,366,090

Held-to-Maturity Securities (Ta

Held-to-Maturity Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities [Table Text Block]	Held-to-maturity securities as of December 31, 2015 were as follows (in thousands): Amortized Cost OTTI Recorded in AOCI Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 21,546 $ — $ 21,546 $ 15 $ 151 $ 21,410 State housing agency obligations 110,000 — 110,000 — — 110,000 131,546 — 131,546 15 151 131,410 Mortgage-backed securities U.S. government-guaranteed residential MBS 4,040 — 4,040 11 — 4,051 GSE residential MBS 2,909,065 — 2,909,065 22,457 766 2,930,756 Non-agency residential MBS 142,920 21,376 121,544 16,118 2,963 134,699 GSE commercial MBS 61,816 — 61,816 — 449 61,367 3,117,841 21,376 3,096,465 38,586 4,178 3,130,873 Total $ 3,249,387 $ 21,376 $ 3,228,011 $ 38,601 $ 4,329 $ 3,262,283 Held-to-maturity securities as of December 31, 2014 were as follows (in thousands): Amortized Cost OTTI Recorded in AOCI Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Estimated Fair Value Debentures U.S. government-guaranteed obligations $ 27,119 $ — $ 27,119 $ 143 $ — $ 27,262 Mortgage-backed securities U.S. government-guaranteed residential MBS 6,642 — 6,642 34 — 6,676 GSE residential MBS 4,424,542 — 4,424,542 46,767 398 4,470,911 Non-agency residential MBS 169,240 27,349 141,891 21,982 3,469 160,404 GSE commercial MBS 61,819 — 61,819 58 — 61,877 4,662,243 27,349 4,634,894 68,841 3,867 4,699,868 Total $ 4,689,362 $ 27,349 $ 4,662,013 $ 68,984 $ 3,867 $ 4,727,130
Categories of Investments, Marketable Securities, Held-to-maturity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Schedule of Unrealized Loss on Investments [Table Text Block]	The following table summarizes (in thousands, except number of positions) the held-to-maturity securities with unrealized losses as of December 31, 2015 . The unrealized losses include other-than-temporary impairments recorded in AOCI and gross unrecognized holding losses (or, in the case of the Bank's holdings of non-agency residential MBS, gross unrecognized holding gains) and are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Debentures U.S. government-guaranteed obligations 2 $ 12,683 $ 151 — $ — $ — 2 $ 12,683 $ 151 Mortgage-backed securities GSE residential MBS 19 503,000 697 1 44,782 69 20 547,782 766 Non-agency residential MBS — — — 24 107,302 9,060 24 107,302 9,060 GSE commercial MBS — — — 3 61,366 449 3 61,366 449 Total 21 $ 515,683 $ 848 28 $ 213,450 $ 9,578 49 $ 729,133 $ 10,426 The following table summarizes (in thousands, except number of positions) the held-to-maturity securities with unrealized losses as of December 31, 2014 . The unrealized losses include other-than-temporary impairments recorded in AOCI and gross unrecognized holding losses (or, in the case of the Bank's holdings of non-agency residential MBS, gross unrecognized holding gains) and are aggregated by major security type and length of time that individual securities have been in a continuous loss position. Less than 12 Months 12 Months or More Total Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Number of Positions Estimated Fair Value Gross Unrealized Losses Mortgage-backed securities GSE residential MBS 1 $ 10,798 $ 5 17 $ 485,626 $ 393 18 $ 496,424 $ 398 Non-agency residential MBS 1 6,874 223 24 131,265 9,917 25 138,139 10,140 Total 2 $ 17,672 $ 228 41 $ 616,891 $ 10,310 43 $ 634,563 $ 10,538
Schedule of Significant Inputs In Measuring Other Than Temporary Impairments Recognized In Earnings [Table Text Block]	For the security for which an other-than-temporary impairment was determined to have occurred as of the end of each calendar quarter in 2015 , the following table presents a summary of the significant inputs used to measure the amount of the credit loss recognized in earnings for the fourth quarter (dollars in thousands): Significant Inputs (2) Year of Securitization Collateral Type (1) Unpaid Principal Balance as of December 31, 2015 Projected Prepayment Rate Projected Default Rate Projected Loss Severity Current Credit Enhancement as of December 31, 2015 (3) 2005 Alt-A/Option ARM $ 10,762 7.7 % 18.6 % 32.2 % 32.0 % ________________________________________ (1) Although the other-than-temporarily impaired security was not labeled as Alt-A at the time of issuance, based upon its current collateral and performance characteristics, it was analyzed using Alt-A assumptions. (2) The prepayment rate reflects the weighted average of projected future voluntary prepayments. The default rate reflects the total balance of loans projected to default as a percentage of the current unpaid principal balance of the underlying loan pool. The loss severity reflects the total projected loan losses as a percentage of the total balance of loans that are projected to default. (3) The current credit enhancement percentage reflects the ability of subordinated classes of securities to absorb principal losses and interest shortfalls before the senior class held by the Bank is impacted (i.e., the losses, expressed as a percentage of the outstanding principal balances, that could be incurred in the underlying loan pool before the security held by the Bank would be impacted, assuming that all of those losses occurred on the measurement date). Depending upon the timing and amount of losses in the underlying loan pool, it is possible that the senior class held by the Bank could bear losses in scenarios where the cumulative loan losses do not exceed the current credit enhancement percentage.
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block]	The following table presents a rollforward for the years ended December 31, 2015, 2014 and 2013 of the amount related to credit losses on the Bank’s non-agency RMBS holdings for which a portion of an other-than-temporary impairment was recognized in other comprehensive income (loss) (in thousands). Year Ended December 31, 2015 2014 2013 Balance of credit losses, beginning of year $ 12,512 $ 12,901 $ 13,039 Credit losses on securities for which an other-than-temporary impairment was not previously recognized — 37 — Credit losses on securities for which an other-than-temporary impairment was previously recognized 33 — — Increases in cash flows expected to be collected (accreted as interest income over the remaining lives of the applicable securities) (849 ) (426 ) (138 ) Balance of credit losses, end of year 11,696 12,512 12,901 Cumulative principal shortfalls on securities held at end of year (1,668 ) (1,210 ) (684 ) Cumulative amortization of the time value of credit losses at end of year 350 293 233 Credit losses included in the amortized cost bases of other-than-temporarily impaired securities at end of year $ 10,378 $ 11,595 $ 12,450
Investments Classified by Contractual Maturity Date [Table Text Block]	The amortized cost, carrying value and estimated fair value of held-to-maturity securities by contractual maturity at December 31, 2015 and 2014 are presented below (in thousands). The expected maturities of some debentures could differ from the contractual maturities presented because issuers may have the right to call such debentures prior to their final stated maturities. December 31, 2015 December 31, 2014 Maturity Amortized Cost Carrying Value Estimated Fair Value Amortized Cost Carrying Value Estimated Fair Value Debentures Due after one year through five years $ 8,712 $ 8,712 $ 8,727 $ 12,544 $ 12,544 $ 12,649 Due after five years through ten years 12,834 12,834 12,683 14,575 14,575 14,613 Due after ten years 110,000 110,000 110,000 — — — 131,546 131,546 131,410 27,119 27,119 27,262 Mortgage-backed securities 3,117,841 3,096,465 3,130,873 4,662,243 4,634,894 4,699,868 Total $ 3,249,387 $ 3,228,011 $ 3,262,283 $ 4,689,362 $ 4,662,013 $ 4,727,130
Schedule of Interest Rate Payment Terms For Investments [Table Text Block]	The following table provides interest rate payment terms for investment securities classified as held-to-maturity at December 31, 2015 and 2014 (in thousands): 2015 2014 Amortized cost of variable-rate held-to-maturity securities other than MBS $ 131,546 $ 27,119 Amortized cost of held-to-maturity MBS Fixed-rate pass-through securities 228 276 Collateralized mortgage obligations Fixed-rate 453 624 Variable-rate 3,055,344 4,599,524 Variable-rate multi-family MBS 61,816 61,819 3,117,841 4,662,243 Total $ 3,249,387 $ 4,689,362

Advances (Tables)

Advances (Tables)	12 Months Ended
	Dec. 31, 2015
Advances [Abstract]
Federal Home Loan Bank, Advances [Table Text Block]	At December 31, 2015 and 2014 , the Bank had advances outstanding at interest rates ranging from 0.21 percent to 8.27 percent and 0.05 percent to 8.48 percent , respectively, as summarized below (dollars in thousands). 2015 2014 Contractual Maturity Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate Overdrawn demand deposit accounts $ — — % $ 79,477 4.04 % Due in one year or less 12,431,831 0.44 11,908,892 0.31 Due after one year through two years 5,886,049 0.77 1,085,057 1.46 Due after two years through three years 1,375,560 2.11 1,590,017 2.39 Due after three years through four years 613,243 2.01 1,085,640 2.40 Due after four years through five years 1,129,859 1.53 417,243 2.22 Due after five years 1,732,577 1.44 901,184 2.99 Amortizing advances 1,480,532 3.15 1,727,505 3.45 Total par value 24,649,651 0.93 % 18,795,015 1.14 % Premiums 22 — Deferred prepayment fees (16,113 ) (17,903 ) Commitment fees (131 ) (139 ) Hedging adjustments 113,373 165,427 Total $ 24,746,802 $ 18,942,400
Schedule of Advances Classified by Contractual Maturity Date or Next Call Date [Table Text Block]	The following table summarizes advances outstanding at December 31, 2015 and 2014 , by the earlier of contractual maturity or next call date, or the first date on which prepayable advances can be repaid without a prepayment fee (in thousands): Contractual Maturity or Next Call Date December 31, 2015 December 31, 2014 Overdrawn demand deposit accounts $ — $ 79,477 Due in one year or less 18,135,949 11,993,262 Due after one year through two years 1,727,927 1,053,687 Due after two years through three years 1,375,559 1,590,017 Due after three years through four years 605,243 1,085,640 Due after four years through five years 613,459 414,243 Due after five years 710,982 851,184 Amortizing advances 1,480,532 1,727,505 Total par value $ 24,649,651 $ 18,795,015
Schedule of Advances Classified by Contractual Maturity Date or Next Put Date [Table Text Block]	The following table summarizes advances at December 31, 2015 and 2014 , by the earlier of contractual maturity or next possible put date (in thousands): Contractual Maturity or Next Put Date 2015 2014 Overdrawn demand deposit accounts $ — $ 79,477 Due in one year or less 13,523,902 13,258,963 Due after one year through two years 5,489,429 1,062,557 Due after two years through three years 715,109 990,896 Due after three years through four years 578,243 397,190 Due after four years through five years 1,129,859 377,243 Due after five years 1,732,577 901,184 Amortizing advances 1,480,532 1,727,505 Total par value $ 24,649,651 $ 18,795,015
Schedule of Federal Home Loan Bank Advances by Interest Rate Payment Terms [Table Text Block]	The following table provides interest rate payment terms for advances outstanding at December 31, 2015 and 2014 (in thousands): 2015 2014 Fixed-rate Due in one year or less $ 12,236,879 $ 11,573,066 Due after one year 6,463,464 6,694,902 Total fixed-rate 18,700,343 18,267,968 Variable-rate Due in one year or less 208,590 426,477 Due after one year 5,740,718 100,570 Total variable-rate 5,949,308 527,047 Total par value $ 24,649,651 $ 18,795,015

Mortgage Loans Held for Portf35

Mortgage Loans Held for Portfolio (Tables)	12 Months Ended
	Dec. 31, 2015
Mortgage Loans Held for Portfolio [Abstract]
Mortgage Loans Held For Portfolio [Table Text Block]	The following table presents information as of December 31, 2015 and 2014 for mortgage loans held for portfolio (in thousands): 2015 2014 Fixed-rate medium-term* single-family mortgages $ 4,570 $ 9,332 Fixed-rate long-term single-family mortgages 50,404 61,838 Premiums 352 473 Discounts (68 ) (89 ) Total mortgage loans held for portfolio $ 55,258 $ 71,554 ________________________________________ *Medium-term is defined as an original term of 15 years or less.

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2015
Allowance for Credit Losses [Abstract]
Past Due Financing Receivables [Table Text Block]	The table below summarizes the recorded investment by payment status for mortgage loans at December 31, 2015 and 2014 (dollars in thousands). December 31, 2015 December 31, 2014 Conventional Loans Government- Guaranteed/ Insured Loans Total Conventional Loans Government- Guaranteed/ Insured Loans Total Mortgage loans: 30-59 days delinquent $ 920 $ 1,180 $ 2,100 $ 1,409 $ 2,276 $ 3,685 60-89 days delinquent 348 337 685 531 400 931 90 days or more delinquent 387 202 589 316 299 615 Total past due 1,655 1,719 3,374 2,256 2,975 5,231 Total current loans 23,844 28,340 52,184 31,866 34,846 66,712 Total mortgage loans $ 25,499 $ 30,059 $ 55,558 $ 34,122 $ 37,821 $ 71,943 Other delinquency statistics: In process of foreclosure (1) $ 329 $ 77 $ 406 $ 79 $ — $ 79 Serious delinquency rate (2) 1.5 % 0.7 % 1.1 % 0.9 % 0.8 % 0.9 % Past due 90 days or more and still accruing interest (3) $ — $ 202 $ 202 $ — $ 299 $ 299 Nonaccrual loans $ 387 $ — $ 387 $ 316 $ — $ 316 Troubled debt restructurings $ 118 $ — $ 118 $ 116 $ — $ 116 ________________________________________ (1) Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu has been made. (2) Loans that are 90 days or more past due or in the process of foreclosure expressed as a percentage of the loan portfolio. (3) Only government-guaranteed/insured mortgage loans continue to accrue interest after they become 90 days or more past due.
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The following table presents the activity in the allowance for credit losses on conventional mortgage loans held for portfolio during the years ended December 31, 2015, 2014 and 2013 (in thousands): Year Ended December 31, 2015 2014 2013 Balance, beginning of year $ 143 $ 165 $ 183 Chargeoffs (2 ) (22 ) (18 ) Balance, end of year $ 141 $ 143 $ 165
Allowance for Credit Losses and Recorded Investment by Impairment Methodology [Table Text Block]	The following table presents information regarding the balances of the Bank's conventional mortgage loans held for portfolio that were individually or collectively evaluated for impairment as well as information regarding the ending balance of the allowance for credit losses as of December 31, 2015 and 2014 (in thousands). December 31, 2015 2014 Ending balance of allowance for credit losses related to loans collectively evaluated for impairment $ 141 $ 143 Recorded investment Individually evaluated for impairment $ 407 $ 432 Collectively evaluated for impairment 25,092 33,690 $ 25,499 $ 34,122

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2015
Deposits [Abstract]
Schedule of Deposit Liabilities by Component [Table Text Block]	The following table details interest-bearing and non-interest bearing deposits as of December 31, 2015 and 2014 (in thousands): 2015 2014 Interest-bearing Demand and overnight $ 954,546 $ 698,136 Term 91,393 99,254 Non-interest bearing (other) 19 24 Total deposits $ 1,045,958 $ 797,414

Consolidated Obligations (Table

Consolidated Obligations (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Consolidated Obligation Bonds By Interest Rate Payment Terms [Table Text Block]	The following table summarizes the Bank’s consolidated obligation bonds outstanding by interest rate payment terms at December 31, 2015 and 2014 (in thousands, at par value). 2015 2014 Fixed-rate $ 11,759,035 $ 8,377,640 Variable-rate 3,625,000 4,471,000 Step-up 2,510,000 3,112,500 Step-down 150,000 150,000 Total par value $ 18,044,035 $ 16,111,140
Schedule of Maturities of Long-term Debt [Table Text Block]	The following is a summary of the Bank’s consolidated obligation bonds outstanding at December 31, 2015 and 2014 , by contractual maturity (dollars in thousands): 2015 2014 Contractual Maturity Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate Due in one year or less $ 5,811,410 0.75 % $ 6,225,840 0.58 % Due after one year through two years 5,383,590 0.77 2,790,080 1.19 Due after two years through three years 3,313,585 1.54 1,537,000 0.95 Due after three years through four years 585,180 1.41 1,847,000 1.94 Due after four years through five years 1,275,000 1.56 1,172,500 1.49 Due after five years 1,675,270 2.00 2,538,720 2.06 Total par value 18,044,035 1.09 % 16,111,140 1.18 % Premiums 11,612 6,345 Discounts (2,708 ) (3,486 ) Hedging adjustments (26,980 ) (35,299 ) Total $ 18,025,959 $ 16,078,700
Schedule of Consolidated Obligation Bonds by Call Feature [Table Text Block]	At December 31, 2015 and 2014 , the Bank’s consolidated obligation bonds outstanding included the following (in thousands, at par value): 2015 2014 Non-callable bonds $ 12,868,765 $ 8,504,920 Callable bonds 5,175,270 7,606,220 Total par value $ 18,044,035 $ 16,111,140
Schedule of Maturities of Consolidated Obligation Bonds by Contractual or Next Call Date [Table Text Block]	The following table summarizes the Bank’s consolidated obligation bonds outstanding at December 31, 2015 and 2014 , by the earlier of contractual maturity or next possible call date (in thousands, at par value): Contractual Maturity or Next Call Date 2015 2014 Due in one year or less $ 10,774,680 $ 13,772,060 Due after one year through two years 4,888,590 1,645,080 Due after two years through three years 2,005,585 152,000 Due after three years through four years 245,180 437,000 Due after four years through five years 130,000 25,000 Due after five years — 80,000 Total par value $ 18,044,035 $ 16,111,140
Schedule of Short-term Debt [Table Text Block]	At December 31, 2015 and 2014 , the Bank’s consolidated obligation discount notes, all of which are due within one year, were as follows (dollars in thousands): Book Value Par Value Weighted Average Implied Interest Rate December 31, 2015 $ 20,541,329 $ 20,544,821 0.18 % December 31, 2014 $ 19,131,832 $ 19,134,303 0.09 %

Affordable Housing Program (Tab

Affordable Housing Program (Tables)	12 Months Ended
	Dec. 31, 2015
Affordable Housing Program [Abstract]
Schedule of Activity in Affordable Housing Program Obligation [Table Text Block]	The following table summarizes the changes in the Bank’s AHP liability during the years ended December 31, 2015, 2014 and 2013 (in thousands): 2015 2014 2013 Balance, beginning of year $ 25,998 $ 31,864 $ 29,620 AHP assessment 7,468 5,391 9,766 Grants funded, net of recaptured amounts (10,756 ) (11,257 ) (7,522 ) Balance, end of year $ 22,710 $ 25,998 $ 31,864

Assets and Liabilities Subjec40

Assets and Liabilities Subject to Offsetting (Tables)	12 Months Ended
	Dec. 31, 2015
Assets and Liabilities Subject to Offsetting [Abstract]
Offsetting Assets and Liabilities [Table Text Block]	The following table presents derivative instruments and securities purchased under agreements to resell with the legal right of offset, including the related collateral received from or pledged to counterparties as of December 31, 2015 and 2014 (in thousands). Gross Amounts of Recognized Financial Instruments Gross Amounts Offset in the Statement of Condition Net Amounts Presented in the Statement of Condition Collateral Not Offset in the Statement of Condition (1) Net Unsecured Amount December 31, 2015 Assets Derivatives Bilateral derivatives $ 25,809 $ (8,110 ) $ 17,699 $ (13,214 ) (2) $ 4,485 Cleared derivatives 25,962 (20,581 ) 5,381 — 5,381 Total derivatives 51,771 (28,691 ) 23,080 (13,214 ) 9,866 Securities purchased under agreements to resell 1,000,000 — 1,000,000 (1,000,000 ) — Total assets $ 1,051,771 $ (28,691 ) $ 1,023,080 $ (1,013,214 ) $ 9,866 Liabilities Derivatives Bilateral derivatives $ 300,494 $ (293,530 ) $ 6,964 $ — $ 6,964 Cleared derivatives 257,480 (257,480 ) — — (3) — Total liabilities $ 557,974 $ (551,010 ) $ 6,964 $ — $ 6,964 December 31, 2014 Assets Derivatives Bilateral derivatives $ 31,666 $ (21,212 ) $ 10,454 $ (9,746 ) (2) $ 708 Cleared derivatives 6,574 (6,574 ) — — — Total derivatives 38,240 (27,786 ) 10,454 (9,746 ) 708 Securities purchased under agreements to resell 350,000 — 350,000 (350,000 ) — Total assets $ 388,240 $ (27,786 ) $ 360,454 $ (359,746 ) $ 708 Liabilities Derivatives Bilateral derivatives $ 629,920 $ (611,348 ) $ 18,572 $ — $ 18,572 Cleared derivatives 58,653 (55,704 ) 2,949 (2,949 ) (4) — Total liabilities $ 688,573 $ (667,052 ) $ 21,521 $ (2,949 ) $ 18,572 _____________________________ (1) Any overcollateralization at an individual clearinghouse/clearing member or bilateral counterparty level is not included in the determination of the net unsecured amount. (2) Consists of collateral pledged by member counterparties. (3) The Bank had pledged securities with an aggregate fair value of $300,184,000 at December 31, 2015 to further secure its cleared derivatives, which is a result of the initial margin requirements imposed upon the Bank. (4) Consists of securities pledged by the Bank. In addition to the amount needed to secure the counterparties' exposure to the Bank, the Bank had pledged additional securities with an aggregate fair value of $33,036,000 at December 31, 2014 to secure its cleared derivatives, which is a result of the initial margin requirements imposed upon the Bank.

Derivatives and Hedging Activ41

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table summarizes the notional balances and estimated fair values of the Bank’s outstanding derivatives at December 31, 2015 and 2014 (in thousands). December 31, 2015 December 31, 2014 Notional Amount of Derivatives Estimated Fair Value Notional Amount of Derivatives Estimated Fair Value Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments under ASC 815 Interest rate swaps Advances $ 4,800,307 $ 3,176 $ 126,161 $ 4,936,984 $ 4,641 $ 183,285 Available-for-sale securities 9,375,109 11,109 401,543 5,877,601 401 462,501 Consolidated obligation bonds 12,988,035 21,319 16,273 10,102,140 15,610 28,046 Consolidated obligation discount notes 100,000 — 1,508 — — — Interest rate swaptions related to advances 4,000 17 — — — — Interest rate caps related to advances — — — 25,000 — — Total derivatives designated as hedging instruments under ASC 815 27,267,451 35,621 545,485 20,941,725 20,652 673,832 Derivatives not designated as hedging instruments under ASC 815 Interest rate swaps Advances 1,500 2 — 1,500 4 — Available-for-sale securities 2,625 21 40 1,000 — 32 Trading securities 100,000 1,270 — — — — Intermediary transactions 1,925,960 13,480 11,810 950,000 14,864 13,413 Interest rate caps Held-to-maturity securities 1,650,000 738 — 2,900,000 1,424 — Intermediary transactions 80,000 639 639 80,000 1,296 1,296 Total derivatives not designated as hedging instruments under ASC 815 3,760,085 16,150 12,489 3,932,500 17,588 14,741 Total derivatives before collateral and netting adjustments $ 31,027,536 51,771 557,974 $ 24,874,225 38,240 688,573 Cash collateral and related accrued interest (1,617 ) (523,936 ) (251 ) (639,517 ) Netting adjustments (27,074 ) (27,074 ) (27,535 ) (27,535 ) Total collateral and netting adjustments (1) (28,691 ) (551,010 ) (27,786 ) (667,052 ) Net derivative balances reported in statements of condition $ 23,080 $ 6,964 $ 10,454 $ 21,521 ________________________________________ (1) Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	The following table presents the components of net gains (losses) on derivatives and hedging activities as presented in the statements of income for the years ended December 31, 2015, 2014 and 2013 (in thousands). Gain (Loss) Recognized in Earnings for the Year Ended December 31, 2015 2014 2013 Derivatives and hedged items in ASC 815 fair value hedging relationships Interest rate swaps $ 1,508 $ (3,082 ) $ 4,999 Interest rate swaptions 4 — — Interest rate caps — (2 ) (6 ) Total net gain (loss) related to fair value hedge ineffectiveness 1,512 (3,084 ) 4,993 Derivatives not designated as hedging instruments under ASC 815 Net interest income (expense) on interest rate swaps (24 ) 1,362 3,633 Interest rate swaps 5,682 3,900 (3,529 ) Interest rate caps (687 ) (2,601 ) (616 ) Total net gain (loss) related to derivatives not designated as hedging instruments under ASC 815 4,971 2,661 (512 ) Net gains (losses) on derivatives and hedging activities reported in the statements of income $ 6,483 $ (423 ) $ 4,481
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents, by type of hedged item, the gains (losses) on derivatives and the related hedged items in ASC 815 fair value hedging relationships and the impact of those derivatives on the Bank’s net interest income for the years ended December 31, 2015, 2014 and 2013 (in thousands). Hedged Item Gain (Loss) on Derivatives Gain (Loss) on Hedged Items Net Fair Value Hedge Ineffectiveness (1) Derivative Net Interest Income (Expense) (2) Year ended December 31, 2015 Advances $ 34,686 $ (34,378 ) $ 308 $ (90,567 ) Available-for-sale securities 4,683 (3,653 ) 1,030 (122,560 ) Consolidated obligation bonds 7,300 (7,126 ) 174 131,790 Total $ 46,669 $ (45,157 ) $ 1,512 $ (81,337 ) Year ended December 31, 2014 Advances $ 18,468 $ (19,293 ) $ (825 ) $ (105,885 ) Available-for-sale securities (61,063 ) 58,419 (2,644 ) (80,808 ) Consolidated obligation bonds 96,746 (96,361 ) 385 115,928 Total $ 54,151 $ (57,235 ) $ (3,084 ) $ (70,765 ) Year ended December 31, 2013 Advances $ 207,392 $ (207,228 ) $ 164 $ (134,615 ) Available-for-sale securities 188,915 (185,697 ) 3,218 (80,569 ) Consolidated obligation bonds (185,479 ) 187,090 1,611 118,656 Total $ 210,828 $ (205,835 ) $ 4,993 $ (96,528 ) ________________________________________ (1) Reported as net gains (losses) on derivatives and hedging activities in the statements of income. (2) The net interest income (expense) associated with derivatives in ASC 815 fair value hedging relationships is reported in the statements of income in the interest income/expense line item for the indicated hedged item.
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table presents, by type of hedged item in ASC 815 cash flow hedging relationships, the gains (losses) on derivatives recognized in other comprehensive income and the gains (losses) reclassified from AOCI into earnings for the year ended December 31, 2015 (in thousands). The Bank did not have any derivatives designated in cash flow hedging relationships during the years ended December 31, 2014 or 2013 . Derivatives in Cash Flow Hedging Relationships Amount of Losses Recognized in Other Comprehensive Income on Derivatives (Effective Portion) Amount of Losses Reclassified from AOCI into Interest Expense (Effective Portion) (1) Amount of Gains (Losses) Recognized in Net Gains (Losses) on Derivatives and Hedging Activities (Ineffective Portion) Interest rate swap related to anticipated issuances of consolidated obligation discount notes $ 1,424 $ 577 $ — _____________________________ (1) Represents net interest expense associated with the derivative.

Capital (Tables)

Capital (Tables)	12 Months Ended
	Dec. 31, 2015
Capital [Abstract]
Schedule of Excess Stock [Table Text Block]	The following table presents total excess stock at December 31, 2015 and 2014 (in thousands). 2015 2014 Excess stock Capital stock $ 356,394 $ 199,202 Mandatorily redeemable capital stock 2,613 4,120 Total $ 359,007 $ 203,322
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	The following table summarizes the Bank’s compliance with the Finance Agency’s capital requirements as of December 31, 2015 and 2014 (dollars in thousands): December 31, 2015 December 31, 2014 Required Actual Required Actual Regulatory capital requirements: Risk-based capital $ 493,617 $ 2,311,264 $ 347,402 $ 1,927,573 Total capital $ 1,683,332 $ 2,311,264 $ 1,521,835 $ 1,927,573 Total capital-to-assets ratio 4.00 % 5.49 % 4.00 % 5.07 % Leverage capital $ 2,104,165 $ 3,466,896 $ 1,902,293 $ 2,891,360 Leverage capital-to-assets ratio 5.00 % 8.24 % 5.00 % 7.60 %
Schedule of Mandatorily Redeemable Capital Stock by Maturity Date [Table Text Block]	The following table summarizes the Bank’s mandatorily redeemable capital stock at December 31, 2015 by year of earliest mandatory redemption (in thousands). The earliest mandatory redemption reflects the earliest time at which the Bank is required to redeem the shareholder’s capital stock, and is based on the assumption that the activities associated with the activity-based stock have concluded by the time the notice of redemption or withdrawal expires. 2016 $ 625 2017 1,115 2018 557 2019 915 2020 5,717 Total $ 8,929
Schedule of Mandatorily Redeemable Capital Stock [Table Text Block]	The following table summarizes the Bank’s mandatorily redeemable capital stock activity during 2015 , 2014 and 2013 (in thousands). Balance, January 1, 2013 $ 4,504 Capital stock that became subject to mandatory redemption during the year 26,325 Redemption/repurchase of mandatorily redeemable capital stock (27,845 ) Mandatorily redeemable capital stock issued during the year 18 Stock dividends classified as mandatorily redeemable 63 Balance, December 31, 2013 3,065 Capital stock that became subject to mandatory redemption during the year 3,130 Redemption/repurchase of mandatorily redeemable capital stock (1,160 ) Mandatorily redeemable capital stock issued during the year 5 Stock dividends classified as mandatorily redeemable 19 Balance, December 31, 2014 5,059 Capital stock that became subject to mandatory redemption during the year, net 7,044 Redemption/repurchase of mandatorily redeemable capital stock (3,198 ) Mandatorily redeemable capital stock issued during the year 2 Stock dividends classified as mandatorily redeemable 22 Balance, December 31, 2015 $ 8,929
Schedule of Withdrawals and Terminations in Membership [Table Text Block]	The following table provides the number of institutions that held mandatorily redeemable capital stock and the number that submitted a withdrawal notice or otherwise initiated a termination of their membership and the number of terminations completed during 2015 , 2014 and 2013 : 2015 2014 2013 Number of institutions, beginning of year 18 16 13 Due to mergers and acquisitions 7 7 2 Due to withdrawals — — 2 Due to termination of membership by the Bank* — — 1 Mandatorily redeemable capital stock reclassified to equity — — (1 ) Terminations completed during the year (9 ) (5 ) (1 ) Number of institutions, end of year 16 18 16 ________________________________________ * The Bank terminated the membership of an institution that was closed by its primary regulator.

Employee Retirement Plans (Tabl

Employee Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Employee Retirement Plans [Abstract]
Schedule of Multiemployer Plans [Table Text Block]	The following table presents the Bank's net pension cost and its funded status, as well as the funded status of the Pentegra DB Plan (dollars in thousands, including amounts presented in the footnotes to the table). 2015 2014 2013 Net pension cost charged to compensation and benefit expense for the year ended December 31 $ 2,187 $ 1,806 $ 1,725 Pentegra DB Plan funded status as of July 1 106.9 % (a) 111.4 % (b) 101.3 % Bank's funded status as of July 1 95.1 % 107.0 % 100.0 % ____________ (a) The Pentegra DB Plan's funded status as of July 1, 2015 is preliminary and may increase because the plan's participants were permitted to make contributions for the plan year ended June 30, 2015 through March 15, 2016 . Contributions made during the period from July 1, 2015 through March 15, 2016 and designated for the plan year ended June 30, 2015 will be included in the final valuation as of July 1, 2015 . The final funded status as of July 1, 2015 will not be available until the Form 5500 for the plan year July 1, 2015 through June 30, 2016 is filed (this Form 5500 is due to be filed no later than April 2017 ). (b) The Pentegra DB Plan's funded status as of July 1, 2014 is preliminary and may increase because the plan's participants were permitted to make contributions for the plan year ended June 30, 2014 through March 15, 2015 . Contributions made during the period from July 1, 2014 through March 15, 2015 and designated for the plan year ended June 30, 2014 will be included in the final valuation as of July 1, 2014 . The final funded status as of July 1, 2014 will not be available until the Form 5500 for the plan year July 1, 2014 through June 30, 2015 is filed (this Form 5500 is due to be filed no later than April 2016 ).
Schedule of Changes in Projected Benefit Obligations [Table Text Block]	The Bank uses a December 31 measurement date for its retirement benefits program. A reconciliation of the accumulated postretirement benefit obligation (“APBO”) and funding status of the retirement benefits program for the years ended December 31, 2015 and 2014 is as follows (in thousands): Year Ended December 31, 2015 2014 Change in APBO APBO at beginning of year $ 1,410 $ 1,376 Service cost 19 18 Interest cost 46 61 Actuarial loss (gain) (222 ) 2 Participant contributions 162 160 Benefits paid (371 ) (207 ) APBO at end of year 1,044 1,410 Change in plan assets Fair value of plan assets at beginning of year — — Benefits paid by the Bank 209 47 Participant contributions 162 160 Benefits paid (371 ) (207 ) Fair value of plan assets at end of year — — Funded status recognized in other liabilities at end of year $ (1,044 ) $ (1,410 )
Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block]	Amounts recognized in AOCI at December 31, 2015 and 2014 consist of the following (in thousands): December 31, 2015 2014 Net actuarial gain $ 1,648 $ 1,514 Prior service cost (170 ) (178 ) $ 1,478 $ 1,336
Schedule of Net Benefit Costs [Table Text Block]	Components of net periodic benefit cost (credit) for the years ended December 31, 2015, 2014 and 2013 were as follows (in thousands): Year Ended December 31, 2015 2014 2013 Service cost $ 19 $ 18 $ 21 Interest cost 46 61 59 Amortization of prior service cost (credit) 8 2 (17 ) Amortization of net actuarial gain (88 ) (91 ) (77 ) Net periodic benefit credit $ (15 ) $ (10 ) $ (14 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	Changes in benefit obligations recognized in other comprehensive income during the years ended December 31, 2015, 2014 and 2013 were as follows (in thousands): Year Ended December 31, 2015 2014 2013 Amortization of prior service cost (credit) included in net periodic benefit cost $ 8 $ 2 $ (17 ) Prior service cost — — (211 ) Actuarial gain (loss) 222 (2 ) 1,067 Amortization of net actuarial gain included in net periodic benefit cost (88 ) (91 ) (77 ) Total changes in benefit obligations recognized in other comprehensive income $ 142 $ (91 ) $ 762
Schedule of Expected Benefit Payments [Table Text Block]	The following net postretirement benefit payments, which reflect expected future service, as appropriate, are expected to be paid (in thousands): Year Ended December 31, Expected Benefits Payments, Net of Participant Contributions 2016 $ 147 2017 157 2018 145 2019 148 2020 123 2021-2025 461 $ 1,181

Estimated Fair Values (Tables)

Estimated Fair Values (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying values and estimated fair values of the Bank’s financial instruments at December 31, 2015 (in thousands), as well as the level within the fair value hierarchy in which the measurements are classified. Financial assets and liabilities are classified in their entirety based on the lowest level input that is significant to the fair value estimate. FAIR VALUE SUMMARY TABLE Estimated Fair Value Financial Instruments Carrying Value Total Level 1 Level 2 Level 3 Netting Adjustment (4) Assets: Cash and due from banks $ 837,202 $ 837,202 $ 837,202 $ — $ — $ — Interest-bearing deposits 260 260 — 260 — — Security purchased under agreement to resell 1,000,000 1,000,000 — 1,000,000 — — Federal funds sold 2,171,000 2,171,000 — 2,171,000 — — Trading securities (1) 211,056 211,056 8,857 202,199 — — Available-for-sale securities (1) 9,713,191 9,713,191 — 9,713,191 — — Held-to-maturity securities 3,228,011 3,262,283 — 3,127,584 (2) 134,699 (3) — Advances 24,746,802 24,795,949 — 24,795,949 — — Mortgage loans held for portfolio, net 55,117 60,756 — 60,756 — — Accrued interest receivable 69,676 69,676 — 69,676 — — Derivative assets (1) 23,080 23,080 — 51,771 — (28,691 ) Liabilities: Deposits 1,045,958 1,045,956 — 1,045,956 — — Consolidated obligations Discount notes 20,541,329 20,539,576 — 20,539,576 — — Bonds 18,025,959 17,994,494 — 17,994,494 — — Mandatorily redeemable capital stock 8,929 8,929 8,929 — — — Accrued interest payable 38,972 38,972 — 38,972 — — Derivative liabilities (1) 6,964 6,964 — 557,974 — (551,010 ) ___________________________ (1) Financial instruments measured at fair value on a recurring basis as of December 31, 2015 . (2) Consists of the Bank's holdings of U.S. government-guaranteed debentures, state housing agency obligations, U.S. government-guaranteed RMBS, GSE RMBS and GSE commercial MBS. (3) Consists of the Bank's holdings of non-agency RMBS. (4) Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties. The following table presents the carrying values and estimated fair values of the Bank’s financial instruments at December 31, 2014 (in thousands), as well as the level within the fair value hierarchy in which the measurements are classified. Financial assets and liabilities are classified in their entirety based on the lowest level input that is significant to the fair value estimate. FAIR VALUE SUMMARY TABLE Estimated Fair Value Financial Instruments Carrying Value Total Level 1 Level 2 Level 3 Netting Adjustment (4) Assets: Cash and due from banks $ 1,507,708 $ 1,507,708 $ 1,507,708 $ — $ — $ — Interest-bearing deposits 266 266 — 266 — — Securities purchased under agreements to resell 350,000 350,000 — 350,000 — — Federal funds sold 5,613,000 5,613,000 — 5,613,000 — — Trading securities (1) 408,563 408,563 8,769 399,794 — — Available-for-sale securities (1) 6,388,502 6,388,502 — 6,388,502 — — Held-to-maturity securities 4,662,013 4,727,130 — 4,566,726 (2) 160,404 (3) — Advances 18,942,400 19,060,638 — 19,060,638 — — Mortgage loans held for portfolio, net 71,411 79,331 — 79,331 — — Accrued interest receivable 65,168 65,168 — 65,168 — — Derivative assets (1) 10,454 10,454 — 38,240 — (27,786 ) Liabilities: Deposits 797,414 797,408 — 797,408 — — Consolidated obligations Discount notes 19,131,832 19,131,732 — 19,131,732 — — Bonds 16,078,700 16,110,291 — 16,110,291 — — Mandatorily redeemable capital stock 5,059 5,059 5,059 — — — Accrued interest payable 39,726 39,726 — 39,726 — — Derivative liabilities (1) 21,521 21,521 — 688,573 — (667,052 ) ___________________________ (1) Financial instruments measured at fair value on a recurring basis as of December 31, 2014 . (2) Consists of the Bank's holdings of U.S. government-guaranteed debentures, U.S. government-guaranteed RMBS, GSE RMBS and GSE commercial MBS. (3) Consists of the Bank's holdings of non-agency RMBS. (4) Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	During the years ended December 31, 2015, 2014 and 2013 , the Bank charged to operating expenses net rental costs of approximately $405,000 , $370,000 , and $377,000 , respectively. Future minimum rentals at December 31, 2015 , were as follows (in thousands): Year Premises Equipment Total 2016 $ 255 $ 46 $ 301 2017 265 45 310 2018 131 30 161 2019 34 — 34 2020 3 — 3 Total $ 688 $ 121 $ 809
Operating Leases of Lessor Disclosure [Text Block]	The Bank has entered into certain lease agreements to rent space to outside parties in its building. Future minimum rentals under these operating leases at December 31, 2015 were as follows (in thousands): Year Total 2016 $ 1,217 2017 1,185 2018 1,212 2019 1,233 2020 380 Total $ 5,227

Transactions with Other FHLBa46

Transactions with Other FHLBanks (Tables)	12 Months Ended
	Dec. 31, 2015
Transactions with Other FHLBanks [Abstract]
Schedule of Loans to Other Federal Home Loan Banks [Table Text Block]	The following table summarizes the Bank’s loans to other FHLBanks during the years ended December 31, 2015, 2014 and 2013 (in thousands). Year Ended December 31, 2015 2014 2013 Balance, January 1, $ — $ — $ — Loans made to: FHLBank of San Francisco 915,000 1,365,000 475,000 FHLBank of Des Moines 200,000 60,000 — FHLBank of Boston 200,000 — — FHLBank of Atlanta — 60,000 200,000 FHLBank of Topeka 55,000 — — FHLBank of Indianapolis — — 377,000 Collections from: FHLBank of San Francisco (915,000 ) (1,365,000 ) (475,000 ) FHLBank of Des Moines (200,000 ) (60,000 ) — FHLBank of Boston (200,000 ) — — FHLBank of Atlanta — (60,000 ) (200,000 ) FHLBank of Topeka (55,000 ) — — FHLBank of Indianapolis — — (377,000 ) Balance, December 31, $ — $ — $ —
Schedule of Loans from Other Federal Home Loan Banks [Table Text Block]	The following table summarizes the Bank’s borrowings from other FHLBanks during the years ended December 31, 2015, 2014 and 2013 (in thousands). Year Ended December 31, 2015 2014 2013 Balance, January 1, $ — $ — $ — Borrowings from: FHLBank of Boston 570,000 — — FHLBank of San Francisco 530,000 565,000 500,000 FHLBank of Topeka 360,000 40,000 — FHLBank of Atlanta 250,000 20,000 — FHLBank of Chicago 150,000 90,000 — FHLBank of Indianapolis — 90,000 — Repayments to: FHLBank of Boston (570,000 ) — — FHLBank of San Francisco (530,000 ) (565,000 ) (500,000 ) FHLBank of Topeka (360,000 ) (40,000 ) — FHLBank of Atlanta (250,000 ) (20,000 ) — FHLBank of Chicago (150,000 ) (90,000 ) — FHLBank of Indianapolis — (90,000 ) — Balance, December 31, $ — $ — $ —

Accumulated Other Comprehensi47

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2015
Schedule of Accumulated Other Comprehensive Income (Loss) [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table presents the changes in the components of AOCI for the years ended December 31, 2015, 2014 and 2013 (in thousands). Net Unrealized Gains (Losses) on Available-for-Sale Securities (1) Net Unrealized Loss on Cash Flow Hedge Non-Credit Portion of Other-than-Temporary Impairment Losses on Held-to-Maturity Securities Postretirement Benefits Total AOCI Year ended December 31, 2015 Balance at January 1, 2015 $ 22,412 $ — $ (27,349 ) $ 1,336 $ (3,601 ) Reclassifications from AOCI to net income Realized gains on sales of available-for-sale securities included in net income (3,922 ) — — — (3,922 ) Losses on cash flow hedge included in interest expense — 577 — — 577 Reclassification adjustment for amortization of prior service costs and net actuarial gains recognized in compensation and benefits expense — — — (80 ) (80 ) Other amounts of other comprehensive income (loss) Net unrealized losses on available-for-sale securities (100,768 ) — — (100,768 ) Unrealized loss on cash flow hedge — (1,424 ) — — (1,424 ) Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities — — (254 ) — (254 ) Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities — — 6,227 — 6,227 Actuarial gain — — — 222 222 Total other comprehensive income (loss) (104,690 ) (847 ) 5,973 142 (99,422 ) Balance at December 31, 2015 $ (82,278 ) $ (847 ) $ (21,376 ) $ 1,478 $ (103,023 ) Net Unrealized Gains (Losses) on Available-for-Sale Securities (1) Net Unrealized Loss on Cash Flow Hedge Non-Credit Portion of Other-than-Temporary Impairment Losses on Held-to-Maturity Securities Postretirement Benefits Total AOCI Year ended December 31, 2014 Balance at January 1, 2014 $ (868 ) $ — $ (33,200 ) $ 1,427 $ (32,641 ) Reclassifications from AOCI to net income Reclassification adjustment for amortization of prior service costs and net actuarial gains recognized in compensation and benefits expense — — — (89 ) (89 ) Other amounts of other comprehensive income (loss) Net unrealized gains on available-for-sale securities 23,280 — — — 23,280 Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities — — (1,349 ) — (1,349 ) Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities — — 7,200 — 7,200 Actuarial loss — — — (2 ) (2 ) Total other comprehensive income (loss) 23,280 — 5,851 (91 ) 29,040 Balance at December 31, 2014 $ 22,412 $ — $ (27,349 ) $ 1,336 $ (3,601 ) Year ended December 31, 2013 Balance at January 1, 2013 $ 22,527 $ — $ (41,437 ) $ 665 $ (18,245 ) Reclassifications from AOCI to net income Reclassification adjustment for amortization of prior service credits and net actuarial gains recognized in compensation and benefits expense — — — (94 ) (94 ) Other amounts of other comprehensive income (loss) Net unrealized losses on available-for-sale securities (23,395 ) — — — (23,395 ) Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities — — 8,237 — 8,237 Actuarial gain — — — 1,067 1,067 Prior service cost — — — (211 ) (211 ) Total other comprehensive income (loss) (23,395 ) — 8,237 762 (14,396 ) Balance at December 31, 2013 $ (868 ) $ — $ (33,200 ) $ 1,427 $ (32,641 ) (1) Net unrealized gains (losses) on available-for-sale securities are net of unrealized gains and losses relating to hedged interest rate risk included in net income.

Other Operating Expenses (Table

Other Operating Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Other Operating Expenses [Abstract]
Schedule of Other Operating Cost and Expense, by Component [Table Text Block]	The following table presents the significant components of other operating expenses for the years ended December 31, 2015, 2014 and 2013 (in thousands). Year Ended December 31, 2015 2014 2013 Occupancy expense $ 2,396 $ 2,607 $ 2,905 Legal fees 1,214 5,440 1,278 Professional fees 3,245 3,984 3,054 Independent contractors 2,634 977 3 Database fees 3,125 3,181 3,259 Software costs 4,691 5,069 5,727 Other 10,166 9,150 9,746 Total other operating expenses $ 27,471 $ 30,408 $ 25,972

Summary of Significant Accoun49

Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Capitalized Computer Software, Net	$ 2,081,000	$ 1,287,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	33,416,000	34,991,000
Depreciation	2,176,000	2,050,000	$ 2,449,000
Capitalized Computer Software, Amortization	$ 1,744,000	$ 1,513,000	$ 2,171,000
Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3
Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	39

Summary of Significant Accoun50

Summary of Significant Accounting Policies Concessions (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Concession [Abstract]
Unamortized Debt Issuance Expense	$ 1,266,000	$ 2,179,000
Concessions on consolidated obligations	2,544,000	2,111,000	$ 1,732,000
Discount Notes [Member]
Short-term Debt [Line Items]
Debt Related Commitment Fees and Debt Issuance Costs	$ 1,274,000	$ 870,000	$ 209,000

Trading Securities (Details)

Trading Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities	$ 211,056	$ 408,563
Trading Securities, Change in Unrealized Holding Gain (Loss)	(1,983)	418	$ 1,249
US Treasury Notes Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities	202,199	0
US Treasury Bill Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities	0	399,794
Other Debt Obligations [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities	8,857	8,769
Other Than Mortgage Backed Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities	$ 211,056	$ 408,563

Available-for-Sale Securities52

Available-for-Sale Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)position	Dec. 31, 2014USD ($)position
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Amortized Cost of Sold Available-for-sale Securities	$ 955,869
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	959,791
Available-for-sale Securities, Gross Realized Gains	3,922
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	9,795,469	$ 6,366,090
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	14,688	32,397
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	96,966	9,985
Available-for-sale Securities, Debt Securities	$ 9,713,191	$ 6,388,502
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position	137	47
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 3,712,362	$ 1,026,312
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss	$ 67,647	$ 9,985
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position	37	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	$ 897,864	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 29,319	$ 0
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position	174	47
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 4,610,226	$ 1,026,312
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	96,966	9,985
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	498,185	49,666
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	1,315	308
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	1,748	0
Available-for-sale Securities, Debt Securities	$ 497,752	49,974
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 229,793
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss	$ 1,748
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 229,793
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,748
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	5,328,125	4,890,484
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	12,597	31,066
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	1,775	0
Available-for-sale Securities, Debt Securities	$ 5,338,947	4,921,550
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position	28
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 802,283
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss	$ 1,775
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position	28
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 802,283
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,775
Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	372,532	411,145
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	10	701
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	1,002	535
Available-for-sale Securities, Debt Securities	$ 371,540	$ 411,311
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position	22	18
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 279,138	$ 163,153
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss	$ 522	$ 535
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position	8	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	$ 48,567	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 480	$ 0
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position	30	18
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 327,705	$ 163,153
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,002	535
Other Than Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	6,198,842	5,351,295
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	13,922	32,075
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	4,525	535
Available-for-sale Securities, Debt Securities	6,208,239	5,382,835
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis	133,117	87,379
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis	3,637,966	4,224,231
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis	2,313,112	1,039,685
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis	114,647	0
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	133,077	87,418
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	3,643,909	4,245,122
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	2,316,854	1,050,295
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	114,399	0
Other Than Mortgage Backed Securities [Member] | Fixed-rate [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	6,123,842	5,276,295
Other Than Mortgage Backed Securities [Member] | Variable Interest Rate [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	75,000	75,000
Multifamily [Member] | Mortgage Backed Securities [Member] | Fixed-rate [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	3,596,627	1,014,795
Multifamily [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	3,596,627	1,014,795
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	766	322
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	92,441	9,450
Available-for-sale Securities, Debt Securities	3,504,952	$ 1,005,667
Payables to Broker-Dealers and Clearing Organizations	$ 164,889
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position	80	29
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 2,401,148	$ 863,159
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss	$ 63,602	$ 9,450
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position	29	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	$ 849,297	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 28,839	$ 0
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position	109	29
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 3,250,445	$ 863,159
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 92,441	$ 9,450

Held-to-Maturity Securities (De

Held-to-Maturity Securities (Details) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2015USD ($)position	Dec. 31, 2015USD ($)position	Dec. 31, 2014USD ($)position	Dec. 31, 2013USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses		$ 5	$ 33	$ 0	$ 0
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		3,249,387	3,249,387	4,689,362
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		21,376	21,376	27,349
Held-to-maturity securities	[1]	3,228,011	3,228,011	4,662,013
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		38,601	38,601	68,984
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		4,329	4,329	3,867
Held-to-maturity Securities, Fair Value		$ 3,262,283	$ 3,262,283	$ 4,727,130
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position		21	21	2
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 515,683	$ 515,683	$ 17,672
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ 848	$ 848	$ 228
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position		28	28	41
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		$ 213,450	$ 213,450	$ 616,891
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 9,578	$ 9,578	$ 10,310
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position		49	49	43
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		$ 729,133	$ 729,133	$ 634,563
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		10,426	10,426	10,538
US Government Agencies Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		21,546	21,546	27,119
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		0	0	0
Held-to-maturity securities		21,546	21,546	27,119
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		15	15	143
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		151	151	0
Held-to-maturity Securities, Fair Value		$ 21,410	$ 21,410	27,262
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position		2	2
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 12,683	$ 12,683
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ 151	$ 151
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position		0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		$ 0	$ 0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 0	$ 0
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position		2	2
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		$ 12,683	$ 12,683
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		151	151
US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		110,000	110,000
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		0	0
Held-to-maturity securities		110,000	110,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		0	0
Held-to-maturity Securities, Fair Value		110,000	110,000
Residential, Mortgage Backed Securities, Other Us Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		4,040	4,040	6,642
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		0	0	0
Held-to-maturity securities		4,040	4,040	6,642
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		11	11	34
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		0	0	0
Held-to-maturity Securities, Fair Value		4,051	4,051	6,676
Other Than Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		131,546	131,546	27,119
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		0	0
Held-to-maturity securities		131,546	131,546	27,119
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		15	15
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		151	151
Held-to-maturity Securities, Fair Value		131,410	131,410	27,262
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost		8,712	8,712	12,544
Held-to-maturity Securities, Debt Maturities, After One Through Five Years, Net Carrying Amount		8,712	8,712	12,544
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value		8,727	8,727	12,649
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost		12,834	12,834	14,575
Held-to-maturity Securities, Debt Maturities, After Five Through Ten Years, Net Carrying Amount		12,834	12,834	14,575
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value		12,683	12,683	14,613
Held-to-maturity Securities, Debt Maturities, Rolling After Year Ten, Amortized Cost		110,000	110,000	0
Held-to-maturity Securities, Debt Maturities, After Ten Years, Net Carrying Amount		110,000	110,000	0
Held-to-maturity Securities, Debt Maturities, Rolling After Ten Years, Fair Value		110,000	110,000	0
US Treasury and Government [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		1,366	1,366
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		3,117,841	3,117,841	4,662,243
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		21,376	21,376	27,349
Held-to-maturity securities		3,096,465	3,096,465	4,634,894
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		38,586	38,586	68,841
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		4,178	4,178	3,867
Held-to-maturity Securities, Fair Value		3,130,873	3,130,873	4,699,868
Held-to-maturity Securities, Premium (Discounts), Net		(13,139)	(13,139)	(26,510)
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		142,920	142,920	169,240
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		21,376	21,376	27,349
Held-to-maturity securities		121,544	121,544	141,891
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		16,118	16,118	21,982
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		2,963	2,963	3,469
Held-to-maturity Securities, Fair Value		$ 134,699	$ 134,699	$ 160,404
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position		0	0	1
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0	$ 0	$ 6,874
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ 0	$ 0	$ 223
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position		24	24	24
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		$ 107,302	$ 107,302	$ 131,265
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 9,060	$ 9,060	$ 9,917
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position		24	24	25
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		$ 107,302	$ 107,302	$ 138,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		9,060	9,060	10,140
Single Family [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		2,909,065	2,909,065	4,424,542
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		0	0	0
Held-to-maturity securities		2,909,065	2,909,065	4,424,542
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		22,457	22,457	46,767
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		766	766	398
Held-to-maturity Securities, Fair Value		$ 2,930,756	$ 2,930,756	$ 4,470,911
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position		19	19	1
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 503,000	$ 503,000	$ 10,798
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ 697	$ 697	$ 5
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position		1	1	17
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		$ 44,782	$ 44,782	$ 485,626
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 69	$ 69	$ 393
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position		20	20	18
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		$ 547,782	$ 547,782	$ 496,424
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		766	766	398
Multifamily [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		61,816	61,816	61,819
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Held-to-maturity, Debt Securities		0	0	0
Held-to-maturity securities		61,816	61,816	61,819
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		0	0	58
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		449	449	0
Held-to-maturity Securities, Fair Value		$ 61,367	$ 61,367	$ 61,877
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions | position		0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0	$ 0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ 0	$ 0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions | position		3	3
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		$ 61,366	$ 61,366
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 449	$ 449
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | position		3	3
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		$ 61,366	$ 61,366
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 449	$ 449
[1]	(a) Fair values: $3,262,283 and $4,727,130 at December 31, 2015 and 2014, respectively.

Held-to-Maturity Securities (Ot

Held-to-Maturity Securities (Other-Than-Temporary Impairment Analysis) (Details) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2015USD ($)position	Dec. 31, 2015USD ($)position	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Held-to-maturity, Qualitative Disclosure, Non Agency RMBS Number of Positions | position		27	27
Held-to-maturity, Qualitative Disclosure, Non Agency RMBS Number of Positions, Identified as OTTI This Period | position			1
Held-to-maturity, Qualitative Disclosure, Non Agency RMBS Number of Securities, Previously Identified as OTTI not Further Impaired This Period | position			14
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities [Abstract]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			$ 33	$ 37	$ 0
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent			254	1,349	0
Other than Temporary Impairment Losses, Investments			287	1,386	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held			12,512	12,901	13,039
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment			0	37	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses		$ 5	33	0	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Cash Flows			(849)	(426)	(138)
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held		11,696	11,696	12,512	12,901
Cumulative Other Than Temporary Impairment Principal Shortfalls		(1,668)	(1,668)	(1,210)	(684)
Cumulative Amortization of the Time Value of Credit Losses		350	350	293	233
OTTI Credit Losses in the Amortized Cost of Held-to-maturity Securities		$ 10,378	$ 10,378	$ 11,595	$ 12,450
Minimum [Member]
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures [Abstract]
Projected House Price Decline Rate Over the Next 12 Months		3.00%	3.00%
Maximum [Member]
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures [Abstract]
Projected House Price Recovery Rate Over the Next 12 Months		8.00%	8.00%
Majority of Markets [Member] | Minimum [Member]
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures [Abstract]
Projected House Price Recovery Rate Over the Next 12 Months		2.00%	2.00%
Projected House Price Annual Appreciation Rate at Long-Term Equilibrium Level		2.00%	2.00%
Majority of Markets [Member] | Maximum [Member]
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures [Abstract]
Projected House Price Recovery Rate Over the Next 12 Months		5.00%	5.00%
Projected House Price Annual Appreciation Rate at Long-Term Equilibrium Level		5.00%	5.00%
Alt A Fixed Rate [Member] | Private Label Residential Mortgage Backed Securities, Security Fifteen [Member]
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities [Abstract]
Other Than Temporarily Impaired Securities, Unpaid Principal Balance	[1]	$ 10,762	$ 10,762
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Prepayment Speed Weighted Average	[2]	7.70%	7.70%
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Default Rate	[2]		18.60%
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Loss Severity Weighted Average	[2]	32.20%	32.20%
Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held Assumption For Measurement Credit Enhancements	[3]	32.00%	32.00%
[1]	Although the other-than-temporarily impaired security was not labeled as Alt-A at the time of issuance, based upon its current collateral and performance characteristics, it was analyzed using Alt-A assumptions.
[2]	repayment rate reflects the weighted average of projected future voluntary prepayments. The default rate reflects the total balance of loans projected to default as a percentage of the current unpaid principal balance of the underlying loan pool. The loss severity reflects the total projected loan losses as a percentage of the total balance of loans that are projected to default.
[3]	urrent credit enhancement percentage reflects the ability of subordinated classes of securities to absorb principal losses and interest shortfalls before the senior class held by the Bank is impacted (i.e., the losses, expressed as a percentage of the outstanding principal balances, that could be incurred in the underlying loan pool before the security held by the Bank would be impacted, assuming that all of those losses occurred on the measurement date). Depending upon the timing and amount of losses in the underlying loan pool, it is possible that the senior class held by the Bank could bear losses in scenarios where the cumulative loan losses do not exceed the current credit enhancement percentage.

Held-to-Maturity Securities (In

Held-to-Maturity Securities (Interest Rate Payment Terms) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	$ 3,249,387	$ 4,689,362
Other Than Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	131,546	27,119
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	3,117,841	4,662,243
Fixed Interest Rate [Member] | Mortgage Passthrough Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	228	276
Fixed Interest Rate [Member] | Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	453	624
Variable Interest Rate [Member] | Other Than Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	131,546	27,119
Variable Interest Rate [Member] | Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	3,055,344	4,599,524
Multifamily [Member] | Variable Interest Rate [Member] | Commercial Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	$ 61,816	$ 61,819

Held-to-Maturity Securities Sal

Held-to-Maturity Securities Sales of Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Proceeds and Gains (Losses) from Sale of HTM [Abstract]
Amortized Cost of Sold Held-to-maturity Securities	$ 806,809
Proceeds from sales of held-to-maturity securities	821,323	$ 0	$ 0
Realized gains on sales of held-to-maturity securities	$ 14,514	$ 0	$ 0

Advances (Details)

Advances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Advances [Line Items]
Deposit Liabilities Reclassified as Loans Receivable	$ 0	$ 79,477
Weighted Average Interest Rate on Overdrawn Demand Deposit	0.00%	4.04%
Federal Home Loan Bank, Advances, Maturities Summary, in Next Rolling Twelve Months	$ 12,431,831	$ 11,908,892
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Maturing in Next Twelve Rolling Months	0.44%	0.31%
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Two	$ 5,886,049	$ 1,085,057
Federal Home Loan Bank Advances, Weighted Average Interest Rate, Maturing in Rolling Year Two	0.77%	1.46%
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Three	$ 1,375,560	$ 1,590,017
Federal Home Loan Bank Advances, Weighted Average Interest Rate, Maturing in Rolling Year Three	2.11%	2.39%
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Four	$ 613,243	$ 1,085,640
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Maturing in Rolling Year Four	2.01%	2.40%
Federal Home Loan Bank, Advances, Maturities Summary, in Rolling Year Five	$ 1,129,859	$ 417,243
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Maturing in Rolling Year Five	1.53%	2.22%
Federal Home Loan Bank, Advances, Maturities Summary, after Rolling Year Five	$ 1,732,577	$ 901,184
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Maturing after Rolling Year Five	1.44%	2.99%
Federal Home Loan Bank Advances, Maturities, Amortizing Advances	$ 1,480,532	$ 1,727,505
Federal Home Loan Bank Advances, Weighted Average Interest Rate of Amortizing Advances	3.15%	3.45%
Federal Home Loan Bank Advances Par Value	$ 24,649,651	$ 18,795,015
Federal Home Loan Bank, Advances, Weighted Average Interest Rate	0.93%	1.14%
Federal Home Loan Bank, Advances, Premium	$ 22	$ 0
Deferred Prepayment Fees	(16,113)	(17,903)
Federal Home Loan Bank, Advances, Commitment Fees	(131)	(139)
Hedging adjustments	113,373	165,427
Federal Home Loan Bank Advances	24,746,802	18,942,400
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, in Next Rolling Twelve Months	18,135,949	11,993,262
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, in Rolling Year Two	1,727,927	1,053,687
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, in Rolling Year Three	1,375,559	1,590,017
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, in Rolling Year Four	605,243	1,085,640
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, in Rolling Year Five	613,459	414,243
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, after Rolling Year Five	710,982	851,184
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, in Next Rolling Twelve Months	13,523,902	13,258,963
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, in Rolling Year Two	5,489,429	1,062,557
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, in Rolling Year Three	715,109	990,896
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, in Rolling Year Four	578,243	397,190
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, in Rolling Year Five	1,129,859	377,243
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, after Rolling Year Five	1,732,577	901,184
Federal Home Loan Bank, Advances, Fixed Rate, under One Year	12,236,879	11,573,066
Federal Home Loan Bank, Advances, Fixed Rate, after One Year	6,463,464	6,694,902
Federal Home Loan Bank, Advances, Fixed Rate	18,700,343	18,267,968
Federal Home Loan Bank, Advances, Floating Rate, under One Year	208,590	426,477
Federal Home Loan Bank, Advances, Floating Rate, after One Year	5,740,718	100,570
Federal Home Loan Bank, Advances, Floating Rate	$ 5,949,308	$ 527,047
Percent Of Fixed Rate Advances Swapped To Adjustable Rate	26.00%	27.00%
Gross Prepayment Fees on Advances Received	$ 27,724	$ 26,035	$ 92,037
Deferred Prepayment Fees on Advances During Period	$ 6,398	$ 5,835	$ 1,449
Minimum [Member]
Advances [Line Items]
Federal Home Loan Bank, Advances, Interest Rate	0.21%	0.05%
Maximum [Member]
Advances [Line Items]
Federal Home Loan Bank, Advances, Interest Rate	8.27%	8.48%
Federal Home Loan Bank, Advances, Callable Option [Member]
Advances [Line Items]
Federal Home Loan Bank Advances Par Value	$ 5,895,751	$ 487,699
Federal Home Loan Bank, Advances, Putable Option [Member]
Advances [Line Items]
Federal Home Loan Bank Advances Par Value	$ 1,097,071	$ 1,454,071

Mortgage Loans Held for Portf58

Mortgage Loans Held for Portfolio (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Mortgage Loans on Real Estate [Line Items]
Loans and Leases Receivable, Unamortized Premiums		$ 352	$ 473
Loans and Leases Receivable, Unamortized Discounts		(68)	(89)
Loans and Leases Receivable, Gross, Consumer, Mortgage		55,258	71,554
Credit Enhancement Fees		21	26	$ 36
Performance Based Credit Enhancement Fee Recaptured		18	24	$ 31
Loans Receivable With Fixed Rates Of Interest Medium Term [Member]
Mortgage Loans on Real Estate [Line Items]
Loans and Leases Receivable, Unpaid Principal Balance	[1]	4,570	9,332
Loans Receivable With Fixed Rates Of Interest Long Term [Member]
Mortgage Loans on Real Estate [Line Items]
Loans and Leases Receivable, Unpaid Principal Balance		50,404	61,838
Government Mortgage Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Loans and Leases Receivable, Unpaid Principal Balance		29,741	37,404
Conventional Mortgage Loan [Member]
Mortgage Loans on Real Estate [Line Items]
Loans and Leases Receivable, Unpaid Principal Balance		$ 25,233	$ 33,766
Maximum [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage Loans On Real Estate, Original Contractual Terms Medium-Term Loan		15
[1]	*Medium-term is defined as an original term of 15 years or less.

Allowance for Credit Losses (De

Allowance for Credit Losses (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		$ 3,374	$ 5,231
Total current loans		52,184	66,712
Financing Receivable, Gross		55,558	71,943
Mortgage Loans in Process of Foreclosure, Amount	[1]	$ 406	$ 79
Serious delinquency rate	[1]	1.10%	0.90%
Past due 90 days or more and still accruing interest	[1]	$ 202	$ 299
Non-accrual loans		387	316
Troubled debt restructurings		118	116
Real Estate Acquired Through Foreclosure		49	193
Financing Receivable Allowance For Credit Losses Roll Forward
Loans and Leases Receivable, Allowance, Beginning Balance		143
Loans and Leases Receivable, Allowance, Ending Balance		141	143
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		2,100	3,685
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		685	931
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		589	615
Conventional Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		1,655	2,256
Total current loans		23,844	31,866
Financing Receivable, Gross		25,499	34,122
Mortgage Loans in Process of Foreclosure, Amount	[1]	$ 329	$ 79
Serious delinquency rate	[1]	1.50%	0.90%
Past due 90 days or more and still accruing interest	[1]	$ 0	$ 0
Non-accrual loans		387	316
Troubled debt restructurings		118	116
Financing Receivable Allowance For Credit Losses Roll Forward
Loans and Leases Receivable, Allowance, Beginning Balance		143	165	$ 183
Charge-offs		(2)	(22)	(18)
Loans and Leases Receivable, Allowance, Ending Balance		141	143	$ 165
Allowance for Credit Losses and Recorded Investment by Impairment Methodology [Abstract]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment		141	143
Financing Receivable, Individually Evaluated for Impairment		407	432
Financing Receivable, Collectively Evaluated for Impairment		25,092	33,690
Conventional Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		920	1,409
Conventional Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		348	531
Conventional Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		387	316
US Government Agency Insured Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		1,719	2,975
Total current loans		28,340	34,846
Financing Receivable, Gross		30,059	37,821
Mortgage Loans in Process of Foreclosure, Amount	[1]	$ 77	$ 0
Serious delinquency rate	[1]	0.70%	0.80%
Past due 90 days or more and still accruing interest	[1]	$ 202	$ 299
Non-accrual loans		0	0
Troubled debt restructurings		0	0
US Government Agency Insured Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		1,180	2,276
US Government Agency Insured Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		337	400
US Government Agency Insured Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Total past due		$ 202	$ 299
[1]	Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu has been made.

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deposits [Abstract]
Weighted Average Rate Interest Bearing Deposits	0.03%	0.01%	0.01%
Interest Bearing Deposit Demand And Overnight	$ 954,546	$ 698,136
Interest Bearing Deposits Term	91,393	99,254
Non-interest bearing	19	24
Total deposits	1,045,958	797,414
Time Deposits, $250,000 Or More, Domestic	$ 91,134	$ 98,850

Consolidated Obligations (Detai

Consolidated Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Short-term and Long-term Debt [Line Items]
Discount notes	$ 20,541,329	$ 19,131,832
Percent of Fixed Rate Long Term Debt Swapped to An Adjustable Rate	90.00%	86.00%
Bonds	$ 18,025,959	$ 16,078,700
Federal Home Loan Bank, Consolidated Obligations	38,567,288	35,210,532
Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	18,044,035	16,111,140
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	$ 5,811,410	$ 6,225,840
Debt, Maturities, Repayments of Principal in Next Twelve Months, Weighted Average Interest Rate	0.75%	0.58%
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	$ 5,383,590	$ 2,790,080
Long-term Debt, Maturities, Repayments of Principal in Year Two, Weighted Average Interest Rate	0.77%	1.19%
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Three	$ 3,313,585	$ 1,537,000
Long-term Debt, Maturities, Repayments of Principal in Year Three, Weighted Average Interest Rate	1.54%	0.95%
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Four	$ 585,180	$ 1,847,000
Long-term Debt, Maturities, Repayments of Principal in Year Four, Weighted Average Interest Rate	1.41%	1.94%
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Five	$ 1,275,000	$ 1,172,500
Long-term Debt, Maturities, Repayments of Principal in Year Five, Weighted Average Interest Rate	1.56%	1.49%
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	$ 1,675,270	$ 2,538,720
Long-term Debt, Maturities, Repayments of Principal After Year Five, Weighted Average Interest Rate	2.00%	2.06%
Long-term Debt, Weighted Average Interest Rate	1.09%	1.18%
Debt Instrument, Unamortized Premium	$ 11,612	$ 6,345
Debt Instrument, Unamortized Discount	(2,708)	(3,486)
Debt Valuation Adjustment for Hedging Activities	(26,980)	(35,299)
Bonds	18,025,959	16,078,700
Non Callable [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	12,868,765	8,504,920
Callable [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	5,175,270	7,606,220
Earlier of Contractual Maturity or Next Call Date [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	10,774,680	13,772,060
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	4,888,590	1,645,080
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Three	2,005,585	152,000
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Four	245,180	437,000
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Five	130,000	25,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	0	80,000
Discount Notes [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt Instrument, Face Amount	$ 20,544,821	$ 19,134,303
Short-term Debt, Weighted Average Interest Rate	0.18%	0.09%
FHLBanks [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	$ 905,000,000	$ 847,000,000
FHL Bank of Dallas [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	38,600,000	35,200,000
Fixed Interest Rate [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	11,759,035	8,377,640
Variable Rate [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	3,625,000	4,471,000
Step Up [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	2,510,000	3,112,500
Step Down [Member] | Unsecured Debt [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Debt, Gross	$ 150,000	$ 150,000

Affordable Housing Program (Det

Affordable Housing Program (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Affordable Housing Program [Abstract]
Affordable Housing Program Contribution Requirement Percentage	10.00%
Number Of Federal Home Loan Banks	11
Affordable Housing Program Contribution Requirement Amount	$ 100,000
Affordable Housing Program [Roll Forward]
AHP, Beginning of period	25,998	$ 31,864	$ 29,620
AHP assessment	7,468	5,391	9,766
Grants funded, net of recaptured amounts	(10,756)	(11,257)	(7,522)
AHP, End of period	$ 22,710	$ 25,998	$ 31,864

Assets and Liabilities Subjec63

Assets and Liabilities Subject to Offsetting (Details) - USD ($) $ in Thousands		Dec. 31, 2015		Dec. 31, 2014
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 51,771		$ 38,240
Derivative Asset, Fair Value, Amount Offset Against Collateral	[1]	(28,691)	[2],[3]	(27,786)	[4],[5]
Derivative assets		23,080		10,454
Derivative, Collateral, Obligation to Return Securities	[6]	(13,214)		(9,746)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		9,866		708
Securities Purchased under Agreements to Resell, Gross		1,000,000		350,000
Securities Purchased under Agreements to Resell, Amount Offset Against Collateral		0		0
Securities purchased under agreements to resell		1,000,000		350,000
Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities	[6]	(1,000,000)		(350,000)
Securities Purchased under Agreements to Resell, Amount Not Offset Against Collateral		0		0
Offsetting Assets, Gross		1,051,771		388,240
Assets, Amount Offset Against Collateral		(28,691)		(27,786)
Offsetting Assets, Total		1,023,080		360,454
Offsetting Assets, Collateral Not Offset in the Statement of Condition	[6]	(1,013,214)		(359,746)
Offsetting Assets, Amount Not Offset Against Collateral		9,866		708
Derivative Liability, Fair Value, Gross Liability		557,974		688,573
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	(551,010)	[2],[3]	(667,052)	[4],[5]
Derivative liabilities		6,964		21,521
Derivative, Collateral, Right to Reclaim Securities That Can Be Sold or Repledged	[6]	0		(2,949)
DerivativeLiabilitiesAdditionalNetExposureCollateralPledgedtoCounterpartiesInExcessOfNetLiability		(300,184)		(33,036)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		6,964		18,572
Over the Counter [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset		25,809		31,666
Derivative Asset, Fair Value, Amount Offset Against Collateral		(8,110)		(21,212)
Derivative assets		17,699		10,454
Derivative, Collateral, Obligation to Return Securities	[6],[7]	(13,214)		(9,746)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		4,485		708
Derivative Liability, Fair Value, Gross Liability		300,494		629,920
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset		(293,530)		(611,348)
Derivative liabilities		6,964		18,572
Derivative, Collateral, Right to Reclaim Securities That Can Be Sold or Repledged	[6]	0		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		6,964		18,572
Exchange Cleared [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset		25,962		6,574
Derivative Asset, Fair Value, Amount Offset Against Collateral		(20,581)		(6,574)
Derivative assets		5,381		0
Derivative, Collateral, Obligation to Return Securities	[6]	0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		5,381		0
Derivative Liability, Fair Value, Gross Liability		257,480		58,653
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset		(257,480)		(55,704)
Derivative liabilities		0		2,949
Derivative, Collateral, Right to Reclaim Securities That Can Be Sold or Repledged	[6]	0	[8]	(2,949)	[9]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		0		$ 0
Minimum [Member] | Non-member Counterparty [Member]
Offsetting Assets and Liabilities [Line Items]
Collateral Thresholds		100
Maximum [Member] | Non-member Counterparty [Member]
Offsetting Assets and Liabilities [Line Items]
Collateral Thresholds		$ 500
[1]	Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[2]	Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[3]	Financial instruments measured at fair value on a recurring basis as of December 31, 2015.
[4]	Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[5]	Financial instruments measured at fair value on a recurring basis as of December 31, 2014.
[6]	Any overcollateralization at an individual clearinghouse/clearing member or bilateral counterparty level is not included in the determination of the net unsecured amount.
[7]	Consists of collateral pledged by member counterparties.
[8]	The Bank had pledged securities with an aggregate fair value of $300,184,000 at December 31, 2015 to further secure its cleared derivatives, which is a result of the initial margin requirements imposed upon the Bank.
[9]	Consists of securities pledged by the Bank. In addition to the amount needed to secure the counterparties' exposure to the Bank, the Bank had pledged additional securities with an aggregate fair value of $33,036,000 at December 31, 2014 to secure its cleared derivatives, which is a result of the initial margin requirements imposed upon the Bank

Derivatives and Hedging Activ64

Derivatives and Hedging Activities (Derivatives in Statement of Condition) (Details) - USD ($) $ in Thousands		Dec. 31, 2015		May. 27, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		$ 51,771			$ 38,240
Derivative Instruments in Hedges, Liabilities, at Fair Value		557,974			688,573
Derivative, Notional Amount		31,027,536		$ 30,400,000	24,874,225
Derivative Asset, Fair Value, Amount Offset Against Collateral		(1,617)			(251)
Derivative Liability, Fair Value, Amount Offset Against Collateral		(523,936)			(639,517)
Derivative Asset, Fair Value, Gross Liability		(27,074)			(27,535)
Derivative Liability, Fair Value, Gross Asset		(27,074)			(27,535)
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(28,691)	[2],[3]		(27,786)	[4],[5]
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	(551,010)	[2],[3]		(667,052)	[4],[5]
Derivative assets		23,080			10,454
Derivative liabilities		6,964			21,521
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		35,621			20,652
Derivative Instruments in Hedges, Liabilities, at Fair Value		545,485			673,832
Derivative, Notional Amount		27,267,451			20,941,725
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Advances [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		3,176			4,641
Derivative Instruments in Hedges, Liabilities, at Fair Value		126,161			183,285
Derivative, Notional Amount		4,800,307			4,936,984
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		11,109			401
Derivative Instruments in Hedges, Liabilities, at Fair Value		401,543			462,501
Derivative, Notional Amount		9,375,109			5,877,601
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Consolidated Obligation Bonds [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		21,319			15,610
Derivative Instruments in Hedges, Liabilities, at Fair Value		16,273			28,046
Derivative, Notional Amount		12,988,035			10,102,140
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Consolidated Obligation Discount Notes [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		0			0
Derivative Instruments in Hedges, Liabilities, at Fair Value		1,508			0
Derivative, Notional Amount		100,000			0
Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member] | Advances [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		17			0
Derivative Instruments in Hedges, Liabilities, at Fair Value		0			0
Derivative, Notional Amount		4,000			0
Designated as Hedging Instrument [Member] | Interest Rate Cap [Member] | Advances [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		0			0
Derivative Instruments in Hedges, Liabilities, at Fair Value		0			0
Derivative, Notional Amount		0			25,000
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		16,150			17,588
Derivative Instruments in Hedges, Liabilities, at Fair Value		12,489			14,741
Derivative, Notional Amount		3,760,085			3,932,500
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Advances [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		2			4
Derivative Instruments in Hedges, Liabilities, at Fair Value		0			0
Derivative, Notional Amount		1,500			1,500
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		21			0
Derivative Instruments in Hedges, Liabilities, at Fair Value		40			32
Derivative, Notional Amount		2,625			1,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Trading Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		1,270			0
Derivative Instruments in Hedges, Liabilities, at Fair Value		0			0
Derivative, Notional Amount		100,000			0
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Intermediary Transactions [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		13,480			14,864
Derivative Instruments in Hedges, Liabilities, at Fair Value		11,810			13,413
Derivative, Notional Amount		1,925,960			950,000
Not Designated as Hedging Instrument [Member] | Interest Rate Cap [Member] | Intermediary Transactions [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		639			1,296
Derivative Instruments in Hedges, Liabilities, at Fair Value		639			1,296
Derivative, Notional Amount		80,000			80,000
Not Designated as Hedging Instrument [Member] | Interest Rate Cap [Member] | Held-to-maturity Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value		738			1,424
Derivative Instruments in Hedges, Liabilities, at Fair Value		0			0
Derivative, Notional Amount		$ 1,650,000			$ 2,900,000
[1]	Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[2]	Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[3]	Financial instruments measured at fair value on a recurring basis as of December 31, 2015.
[4]	Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[5]	Financial instruments measured at fair value on a recurring basis as of December 31, 2014.

Derivatives and Hedging Activ65

Derivatives and Hedging Activities (Derivatives in Statement of Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	[1]	$ 1,512	$ (3,084)	$ 4,993
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		4,971	2,661	(512)
Gain (Loss) on Derivative Instruments, Net, Pretax		6,483	(423)	4,481
Advances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	[1]	308	(825)	164
Available-for-sale Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	[1]	1,030	(2,644)	3,218
Consolidated Obligation Bonds [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	[1]	174	385	1,611
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)		1,508	(3,082)	4,999
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		5,682	3,900	(3,529)
Interest Rate Swaption [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)		4	0	0
Interest Rate Cap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)		0	(2)	(6)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(687)	(2,601)	(616)
Net Interest Income on Interest Rate Swaps [Member] | Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ (24)	$ 1,362	$ 3,633
[1]	Reported as net gains (losses) on derivatives and hedging activities in the statements of income.

Derivatives and Hedging Activ66

Derivatives and Hedging Activities (Derivatives in Statement of Income and Impact on Interest) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		$ 46,669	$ 54,151	$ 210,828
Gain (Loss) on Hedged Items		(45,157)	(57,235)	(205,835)
Net Fair Value Hedge Ineffectiveness	[1]	1,512	(3,084)	4,993
Derivatives Net Interest Income (Expense)	[2]	(81,337)	(70,765)	(96,528)
Advances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		34,686	18,468	207,392
Gain (Loss) on Hedged Items		(34,378)	(19,293)	(207,228)
Net Fair Value Hedge Ineffectiveness	[1]	308	(825)	164
Derivatives Net Interest Income (Expense)	[2]	(90,567)	(105,885)	(134,615)
Available-for-sale Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		4,683	(61,063)	188,915
Gain (Loss) on Hedged Items		(3,653)	58,419	(185,697)
Net Fair Value Hedge Ineffectiveness	[1]	1,030	(2,644)	3,218
Derivatives Net Interest Income (Expense)	[2]	(122,560)	(80,808)	(80,569)
Consolidated Obligation Bonds [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives		7,300	96,746	(185,479)
Gain (Loss) on Hedged Items		(7,126)	(96,361)	187,090
Net Fair Value Hedge Ineffectiveness	[1]	174	385	1,611
Derivatives Net Interest Income (Expense)	[2]	$ 131,790	$ 115,928	$ 118,656
[1]	Reported as net gains (losses) on derivatives and hedging activities in the statements of income.
[2]	The net interest income (expense) associated with derivatives in ASC 815 fair value hedging relationships is reported in the statements of income in the interest income/expense line item for the indicated hedged item.

Derivatives and Hedging Activ67

Derivatives and Hedging Activities (Narrative) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015	May. 27, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		$ 1,417,000
Maximum Length of Time Hedged in Cash Flow Hedge		9 years 9 months
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		$ 1,424,000
Derivative, Notional Amount		31,027,536,000	$ 30,400,000,000	$ 24,874,225,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]	577,000
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net		0
Exchange Cleared [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		17,400,000,000
Over the Counter [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		12,600,000,000
Member Counterparties [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		$ 1,000,000,000
[1]	Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.

Capital (Details)

Capital (Details)		12 Months Ended
		Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Feb. 25, 2016USD ($)	Nov. 06, 2015USD ($)	Oct. 01, 2015	Sep. 30, 2015	Aug. 07, 2015USD ($)	Apr. 30, 2015USD ($)	Jan. 30, 2015USD ($)
Capital Narrative [Abstract]
Common Stock, Par or Stated Value Per Share | $ / shares		$ 100
Membership Investment Requirement, Percent of Members Total Assets as of Previous Calendar Year		0.04%
Membership Investment Requirement, Minimum Dollar Amount		$ 1,000
Membership Investment Requirement, Maximum Dollar Amount		$ 7,000,000
Activity Based Investment Requirement, Percent of Outstanding Advances		4.10%
Number Of Subclasses Of Capital Stock		2
Surplus Stock Threshold Percentage					125.00%	120.00%			102.50%	102.50%	102.50%
Minimum Stock Surplus Required For Repurchase					$ 2,500,000	$ 1,000,000			$ 100,000	$ 100,000	$ 100,000
Repurchased Surplus Stock During The Period		$ 574,896,000	$ 901,117,000	$ 773,954,500
Repurchased Surplus Stock During Period, Mandatorily Redeemable Capital Stock Portion		$ 0	0	0
Number of Finance Agency Regulatory Capital Requirements		3
Multiplier for Determining Permanent Capital in Leverage Capital Calculation		1.5
Interest Expense, Capital Securities		$ 16,000	15,000	23,000
Joint Capital Enhancement Agreement Percentage		20.00%
Percent of Average Balance of Outstanding Consolidated Obligations Prescribed per the Joint Capital Enhancement Agreement For Each Previous Quarter		1.00%
Excess Stock [Abstract]
Excess Capital Stock		$ 356,394,000	199,202,000
Excess Capital Mandatorily Redeemable Capital Stock Portion		2,613,000	4,120,000
Excess Capital Stock And Excess Mandatorily Redeemable Capital Stock		359,007,000	203,322,000
Regulatory Capital Requirements [Abstract]
Federal Home Loan Bank, Risk-Based Capital, Required		493,617,000	347,402,000
Federal Home Loan Bank, Risk-Based Capital, Actual		2,311,264,000	1,927,573,000
Federal Home Loan Bank, Regulatory Capital, Required		1,683,332,000	1,521,835,000
Federal Home Loan Bank, Regulatory Capital, Actual		$ 2,311,264,000	$ 1,927,573,000
Regulatory Capital Ratio, Required		4.00%	4.00%
Federal Home Loan Bank, Regulatory Capital Ratio, Actual		5.49%	5.07%
Federal Home Loan Bank, Leverage Capital, Required		$ 2,104,165,000	$ 1,902,293,000
Federal Home Loan Bank, Leverage Capital, Actual		$ 3,466,896,000	$ 2,891,360,000
Leverage Ratio, Required		5.00%	5.00%
Leverage Ratio, Actual		8.24%	7.60%
Mandatorily Redeemable Capital Stock by Maturity Date [Abstract]
Financial Instruments Subject to Mandatory Redemption, Redeemable within One year		$ 625,000
Financial Instruments Subject to Mandatory Redemption, Redeemable in Year Two		1,115,000
Financial Instruments Subject to Mandatory Redemption, Redeemable in Year Three		557,000
Financial Instruments Subject to Mandatory Redemption, Redeemable in Year Four		915,000
Financial Instruments Subject to Mandatory Redemption, Redeemable in Year Five		5,717,000
Mandatorily Redeemable Capital Stock [Roll Forward]
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount, Beginning Balance		5,059,000	$ 3,065,000	4,504,000
Net Shares Reclassified to Mandatorily Redeemable Capital Stock, Value		7,044,000	3,130,000	26,325,000
Repayments of Mandatory Redeemable Capital Securities		(3,198,000)	(1,160,000)	(27,845,000)
Proceeds from Issuance of Mandatory Redeemable Capital Securities		2,000	5,000	18,000
Dividends Common Stock Mandatorily Redeemable Capital Stock		22,000	19,000	63,000
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount, Ending Balance		$ 8,929,000	$ 5,059,000	$ 3,065,000
Number of Stockholders Holding Mandatorily Redeemable Capital Stock [Roll Forward]
Number of Stockholders Holding Mandatorily Redeemable Capital Stock, Beginning Balance		18	16	13
Federal Home Loan, Bank Non Member Due to Merger		7	7	2
Federal Home Loan, Bank Voluntary Termination or Notices Received and Pending		0	0	2
Federal Home Loan, Bank Involuntary Termination	[1]	0	0	1
Federal Home Loan Bank, NonMembers Reclassified to Members		0	0	(1)
Federal Home Loan Bank, Number of Completed Membership Terminations		(9)	(5)	(1)
Number of Stockholders Holding Mandatorily Redeemable Capital Stock, Ending Balance		16	18	16
Subsequent Event [Member]
Capital Narrative [Abstract]
Repurchased Surplus Stock, Total					$ 103,707,000
Minimum [Member]
Capital Narrative [Abstract]
Activity Based Investment Requirement, Percent of Outstanding Advances							2.00%	3.00%
Maximum [Member]
Capital Narrative [Abstract]
Activity Based Investment Requirement, Percent of Outstanding Advances							5.00%	5.00%
[1]	The Bank terminated the membership of an institution that was closed by its primary regulator.

Pentegra Defined Benefit Plan (

Pentegra Defined Benefit Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 01, 2015		Jul. 01, 2014		Jul. 01, 2013
Defined Benefit Plan Disclosure [Line Items]
Entity Tax Identification Number	135,645,888
Pentegra Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plan, Period Contributions	$ 2,187	$ 1,806	$ 1,725
Pentegra Defined Benefit Plan Funded Status as of July 1				106.90%	[1]	111.40%	[2]	101.30%
FHLBank's funded status as of July 1				95.10%		107.00%		100.00%
[1]	The Pentegra DB Plan's funded status as of July 1, 2015 is preliminary and may increase because the plan's participants were permitted to make contributions for the plan year ended June 30, 2015 through March 15, 2016. Contributions made during the period from July 1, 2015 through March 15, 2016 and designated for the plan year ended June 30, 2015 will be included in the final valuation as of July 1, 2015. The final funded status as of July 1, 2015 will not be available until the Form 5500 for the plan year July 1, 2015 through June 30, 2016 is filed (this Form 5500 is due to be filed no later than April 2017).
[2]	The Pentegra DB Plan's funded status as of July 1, 2014 is preliminary and may increase because the plan's participants were permitted to make contributions for the plan year ended June 30, 2014 through March 15, 2015. Contributions made during the period from July 1, 2014 through March 15, 2015 and designated for the plan year ended June 30, 2014 will be included in the final valuation as of July 1, 2014. The final funded status as of July 1, 2014 will not be available until the Form 5500 for the plan year July 1, 2014 through June 30, 2015 is filed (this Form 5500 is due to be filed no later than April 2016).

Employee Retirement Plans Narra

Employee Retirement Plans Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Entity Tax Identification Number	135,645,888
Pentegra Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plan Number	333
Pentegra Defined Contribution Plan [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Cost Recognized	$ 1,257,000	$ 1,171,000	$ 1,185,000
Non-qualified Deferred Compensation Plan [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Deferred Compensation Arrangement with Individual, Recorded Liability	2,550,000	2,266,000
Deferred Compensation Arrangement with Individual, Compensation Expense	46,000	146,000	283,000
Directors' non-qualified deferred compensation plan [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Deferred Compensation Arrangement with Individual, Recorded Liability	1,483,000	1,264,000
Special Non-Qualified Deferred Compensation Plan [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Deferred Compensation Arrangement with Individual, Recorded Liability	4,722,000	5,173,000
Deferred Compensation Arrangement with Individual, Employer Contribution		$ 25,000	$ 740,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Future Amortization of Net Prior Service Cost (Credit)	20,000
Defined Benefit Plan, Future Amortization of Net Gains (Losses)	$ 98,000
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year	6.70%	7.80%	8.00%	8.10%
Defined Benefit Plan, Description of Direction and Pattern of Change for Assumed Health Care Cost Trend Rate	decline by 0.04 percent
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.40%
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2,071
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.08%	3.44%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.44%	4.64%	3.81%
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	$ 23,000
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	2,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	(43,000)
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	$ (2,000)

Employee Retirement Plans Recon

Employee Retirement Plans Reconciliation of the APBO (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Actuarial loss (gain)	$ (222)	$ 2	$ (1,067)
Prior service cost	0	0	211
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance	1,410	1,376
Defined Benefit Plan, Service Cost	19	18	21
Defined Benefit Plan, Interest Cost	46	61	59
Actuarial loss (gain)	(222)	2
Defined Benefit Plan, Contributions by Plan Participants	162	160
Defined Benefit Plan, Benefits Paid	(371)	(207)
Defined Benefit Plan, Benefit Obligation, Ending Balance	1,044	1,410	1,376
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance	0	0
Defined Benefit Plan, Other Changes	209	47
Defined Benefit Plan, Contributions by Plan Participants	162	160
Defined Benefit Plan, Benefits Paid	(371)	(207)
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	0	0	$ 0
Defined Benefit Plan, Funded Status of Plan	$ (1,044)	$ (1,410)

Employee Retirement Plans Amoun

Employee Retirement Plans Amounts recognized in AOCI (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	$ 1,648	$ 1,514
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	(170)	(178)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	$ 1,478	$ 1,336

Employee Retirement Plans Compo

Employee Retirement Plans Components of net periodic benefit cost (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 19	$ 18	$ 21
Defined Benefit Plan, Interest Cost	46	61	59
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	8	2	(17)
Defined Benefit Plan, Amortization of Gains (Losses)	(88)	(91)	(77)
Defined Benefit Plan, Net Periodic Benefit Credit	$ (15)	$ (10)	$ (14)

Employee Retirement Plans Chang

Employee Retirement Plans Changes in benefit obligations in OCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit) included in net periodic benefit cost	$ 8	$ 2	$ (17)
Prior service cost	0	0	(211)
Defined Benefit Plan, Actuarial Gain (Loss)	222	(2)	1,067
Amortization of net actuarial gain included in net periodic benefit cost	(88)	(91)	(77)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	142	(91)	$ 762
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actuarial Gain (Loss)	$ 222	$ (2)

Employee Retirement Plans Expec

Employee Retirement Plans Expected net postretirement benefit payments (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] $ in Thousands	Dec. 31, 2015USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	$ 147
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	157
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	145
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	148
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	123
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	461
Defined Benefit Plan Expected Future Benefit Payments	$ 1,181

Estimated Fair Values (Carrying

Estimated Fair Values (Carrying Value and Fair Value of Financial Instruments) (Details) - USD ($)		Dec. 31, 2015		May. 27, 2015	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Changes in Fair Value Due to Pricing System				$ 3,100,000
Derivative, Notional Amount		$ 31,027,536,000		$ 30,400,000,000	$ 24,874,225,000
Assets
Cash and due from banks		837,202,000			1,507,708,000
Trading securities		211,056,000			408,563,000
Available-for-sale Securities, Debt Securities		9,713,191,000			6,388,502,000
Held-to-maturity securities	[1]	3,228,011,000			4,662,013,000
Held-to-maturity securities, Fair Value		3,262,283,000			4,727,130,000
Accrued interest receivable		69,676,000			65,168,000
Derivative assets		23,080,000			10,454,000
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[2]	(28,691,000)	[3],[4]		(27,786,000)	[5],[6]
Consolidated obligations
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount		8,929,000			5,059,000		$ 3,065,000	$ 4,504,000
Accrued interest payable		38,972,000			39,726,000
Derivative liabilities		6,964,000			21,521,000
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[2]	(551,010,000)	[3],[4]		(667,052,000)	[5],[6]
Carrying Value [Member]
Assets
Cash and due from banks		837,202,000			1,507,708,000
Interest-bearing deposits		260,000			266,000
Securities purchased under agreements to resell		1,000,000,000			350,000,000
Federal funds sold		2,171,000,000			5,613,000,000
Trading securities		211,056,000	[4]		408,563,000	[6]
Available-for-sale Securities, Debt Securities		9,713,191,000	[4]		6,388,502,000	[6]
Held-to-maturity securities		3,228,011,000			4,662,013,000
Advances		24,746,802,000			18,942,400,000
Mortgage loans held for portfolio, net		55,117,000			71,411,000
Accrued interest receivable		69,676,000			65,168,000
Derivative assets		23,080,000	[4]		10,454,000	[6]
Liabilities
Deposits		1,045,958,000			797,414,000
Consolidated obligations
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount		8,929,000			5,059,000
Accrued interest payable		38,972,000			39,726,000
Derivative liabilities		6,964,000	[4]		21,521,000	[6]
Estimated Fair Value [Member]
Assets
Cash and due from banks		837,202,000			1,507,708,000
Interest-bearing deposits		260,000			266,000
Securities purchased under agreements to resell		1,000,000,000			350,000,000
Federal funds sold		2,171,000,000			5,613,000,000
Trading securities		211,056,000	[4]		408,563,000	[6]
Available-for-sale Securities, Debt Securities		9,713,191,000	[4]		6,388,502,000	[6]
Held-to-maturity securities, Fair Value		3,262,283,000			4,727,130,000
Advances		24,795,949,000			19,060,638,000
Mortgage loans held for portfolio, net		60,756,000			79,331,000
Accrued interest receivable		69,676,000			65,168,000
Derivative assets		23,080,000	[4]		10,454,000	[6]
Liabilities
Deposits		1,045,956,000			797,408,000
Consolidated obligations
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount		8,929,000			5,059,000
Accrued interest payable		38,972,000			39,726,000
Derivative liabilities		6,964,000	[4]		21,521,000	[6]
Fair Value, Inputs, Level 1 [Member]
Assets
Cash and due from banks		837,202,000			1,507,708,000
Interest-bearing deposits		0			0
Securities purchased under agreements to resell		0			0
Federal funds sold		0			0
Trading securities		8,857,000	[4]		8,769,000	[6]
Available-for-sale Securities, Debt Securities		0	[4]		0	[6]
Held-to-maturity securities, Fair Value		0			0
Advances		0			0
Mortgage loans held for portfolio, net		0			0
Accrued interest receivable		0			0
Derivative assets		0	[4]		0	[6]
Liabilities
Deposits		0			0
Consolidated obligations
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount		8,929,000			5,059,000
Accrued interest payable		0			0
Derivative liabilities		0	[4]		0	[6]
Fair Value, Inputs, Level 2 [Member]
Assets
Cash and due from banks		0			0
Interest-bearing deposits		260,000			266,000
Securities purchased under agreements to resell		1,000,000,000			350,000,000
Federal funds sold		2,171,000,000			5,613,000,000
Trading securities		202,199,000	[4]		399,794,000	[6]
Available-for-sale Securities, Debt Securities		9,713,191,000	[4]		6,388,502,000	[6]
Held-to-maturity securities, Fair Value		3,127,584,000	[7]		4,566,726,000	[8]
Advances		24,795,949,000			19,060,638,000
Mortgage loans held for portfolio, net		60,756,000			79,331,000
Accrued interest receivable		69,676,000			65,168,000
Derivative assets		51,771,000	[4]		38,240,000	[6]
Liabilities
Deposits		1,045,956,000			797,408,000
Consolidated obligations
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount		0			0
Accrued interest payable		38,972,000			39,726,000
Derivative liabilities		557,974,000	[4]		688,573,000	[6]
Fair Value, Inputs, Level 3 [Member]
Assets
Cash and due from banks		0			0
Interest-bearing deposits		0			0
Securities purchased under agreements to resell		0			0
Federal funds sold		0			0
Trading securities		0	[4]		0	[6]
Available-for-sale Securities, Debt Securities		0	[4]		0	[6]
Held-to-maturity securities, Fair Value		134,699,000	[9]		160,404,000	[10]
Advances		0			0
Mortgage loans held for portfolio, net		0			0
Accrued interest receivable		0			0
Derivative assets		0	[4]		0	[6]
Liabilities
Deposits		0			0
Consolidated obligations
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount		0			0
Accrued interest payable		0			0
Derivative liabilities		0	[4]		0	[6]
Consolidated Obligation Discount Notes [Member] | Carrying Value [Member]
Consolidated obligations
Discount notes, Fair Value		20,541,329,000			19,131,832,000
Consolidated Obligation Discount Notes [Member] | Estimated Fair Value [Member]
Consolidated obligations
Discount notes, Fair Value		20,539,576,000			19,131,732,000
Consolidated Obligation Discount Notes [Member] | Fair Value, Inputs, Level 1 [Member]
Consolidated obligations
Discount notes, Fair Value		0			0
Consolidated Obligation Discount Notes [Member] | Fair Value, Inputs, Level 2 [Member]
Consolidated obligations
Discount notes, Fair Value		20,539,576,000			19,131,732,000
Consolidated Obligation Discount Notes [Member] | Fair Value, Inputs, Level 3 [Member]
Consolidated obligations
Discount notes, Fair Value		0			0
Consolidated Obligation Bonds [Member] | Carrying Value [Member]
Consolidated obligations
Bonds, Fair Value		18,025,959,000			16,078,700,000
Consolidated Obligation Bonds [Member] | Estimated Fair Value [Member]
Consolidated obligations
Bonds, Fair Value		17,994,494,000			16,110,291,000
Consolidated Obligation Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Consolidated obligations
Bonds, Fair Value		0			0
Consolidated Obligation Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Consolidated obligations
Bonds, Fair Value		17,994,494,000			16,110,291,000
Consolidated Obligation Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Consolidated obligations
Bonds, Fair Value		$ 0			$ 0
[1]	(a) Fair values: $3,262,283 and $4,727,130 at December 31, 2015 and 2014, respectively.
[2]	Amounts represent the effect of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[3]	Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[4]	Financial instruments measured at fair value on a recurring basis as of December 31, 2015.
[5]	Amounts represent the impact of legally enforceable master netting agreements or other legally enforceable arrangements between the Bank and its derivative counterparties that allow the Bank to offset positive and negative positions as well as the cash collateral held or placed with those same counterparties.
[6]	Financial instruments measured at fair value on a recurring basis as of December 31, 2014.
[7]	Consists of the Bank's holdings of U.S. government-guaranteed debentures, state housing agency obligations, U.S. government-guaranteed RMBS, GSE RMBS and GSE commercial MBS.
[8]	Consists of the Bank's holdings of U.S. government-guaranteed debentures, U.S. government-guaranteed RMBS, GSE RMBS and GSE commercial MBS.
[9]	Consists of the Bank's holdings of non-agency RMBS.
[10]	Consists of the Bank's holdings of non-agency RMBS.

Estimated Fair Values (Narrativ

Estimated Fair Values (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015position
Fair Value Disclosures [Abstract]
Held-to-maturity, Qualitative Disclosure, Non Agency RMBS Number of Positions, Identified as OTTI This Period	1

Commitments and Contingencies78

Commitments and Contingencies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies [Line Items]
Current Fiscal Year End Date	--12-31
Derivative, Collateral, Right to Reclaim Cash	$ 523,871,000	$ 639,452,000
Derivative, Collateral, Right to Receive Securities	300,184,000	35,985,000
Operating Leases, Rent Expense, Net	405,000	370,000	$ 377,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	301,000
Operating Leases, Future Minimum Payments, Due in Two Years	310,000
Operating Leases, Future Minimum Payments, Due in Three Years	161,000
Operating Leases, Future Minimum Payments, Due in Four Years	34,000
Operating Leases, Future Minimum Payments, Due in Five Years	3,000
Operating Leases, Future Minimum Payments Due	809,000
Operating Leases, Future Minimum Payments Receivable, Current	1,217,000
Operating Leases, Future Minimum Payments Receivable, in Two Years	1,185,000
Operating Leases, Future Minimum Payments Receivable, in Three Years	1,212,000
Operating Leases, Future Minimum Payments Receivable, in Four Years	1,233,000
Operating Leases, Future Minimum Payments, Due in Five Years	380,000
Operating Leases Future Minimum Payments Receivable Due	5,227,000
Other FHLBanks [Member]
Commitments and Contingencies [Line Items]
Debt, Gross	867,000,000,000	812,000,000,000
Loan Origination Commitments [Member]
Commitments and Contingencies [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	36,892,000	14,065,000
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Expiring Within One Year	$ 29,292,000
Standby Letters of Credit [Member]
Commitments and Contingencies [Line Items]
Standby Letters of Credit, Final Expiration Year	2,020
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 7,180,763,000	4,330,557,000
Unearned Fees on Standby Letters of Credit	3,685,000	3,746,000
Consolidated Obligation Bonds [Member]
Commitments and Contingencies [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	90,000,000	60,000,000
Consolidated Obligation Discount Notes [Member]
Commitments and Contingencies [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	750,000,000	$ 750,000,000
Building and Building Improvements [Member]
Commitments and Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	255,000
Operating Leases, Future Minimum Payments, Due in Two Years	265,000
Operating Leases, Future Minimum Payments, Due in Three Years	131,000
Operating Leases, Future Minimum Payments, Due in Four Years	34,000
Operating Leases, Future Minimum Payments, Due in Five Years	3,000
Operating Leases, Future Minimum Payments Due	688,000
Furniture and Equipment, Rental Expense, Operating Lease [Member]
Commitments and Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	46,000
Operating Leases, Future Minimum Payments, Due in Two Years	45,000
Operating Leases, Future Minimum Payments, Due in Three Years	30,000
Operating Leases, Future Minimum Payments, Due in Four Years	0
Operating Leases, Future Minimum Payments, Due in Five Years	0
Operating Leases, Future Minimum Payments Due	$ 121,000
Maximum [Member]
Commitments and Contingencies [Line Items]
Maximum Original Term of Standby Letters of Credit	10 years

Transactions with Shareholders

Transactions with Shareholders (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Transactions with Shareholders [Line Items]
Advances by Federal Home Loan Bank	$ 24,746,802,000	$ 18,942,400,000
Directors' Financial Institutions [Member]
Transactions with Shareholders [Line Items]
Advances by Federal Home Loan Bank	$ 1,408,060,000	$ 1,235,101,000
Federal Home Loan Bank Advances At Par Value As Percentage of Total Advances Outstanding	5.70%	6.60%
Common Stock, Value, Outstanding	$ 68,951,000	$ 60,031,000
Capital Stock, Percent	4.50%	4.90%

Transactions with Other FHLBa80

Transactions with Other FHLBanks (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Other Transactions [Line Items]
Interest Income, Loans to Other Federal Home Loan Banks	$ 4,214	$ 3,504	$ 2,031
Loans Made to Other FHLBanks [Roll Forward]
Loans to other FHLBanks, Beginning of period	0	0	0
Loans to other FHLBanks, End of period	0	0	0
Interest Expense, Loans from Other Federal Home Loan Banks	4,860	1,958	931
Borrowings From Other FHLBanks [Roll Forward]
Loans from other FHLBanks, Beginning of period	0	0	0
Loans from other FHLBanks, End of period	0	0	0
Federal Home Loan Bank of Boston [Member]
Loans Made to Other FHLBanks [Roll Forward]
Loans made to other FHLBanks	200,000,000	0	0
Collections from other FHLBanks	(200,000,000)	0	0
Borrowings From Other FHLBanks [Roll Forward]
Borrowings from other FHLBanks	570,000,000	0	0
Repayments to other FHLBanks	(570,000,000)	0	0
FHLBank of San Francisco [Member]
Loans Made to Other FHLBanks [Roll Forward]
Loans made to other FHLBanks	915,000,000	1,365,000,000	475,000,000
Collections from other FHLBanks	(915,000,000)	(1,365,000,000)	(475,000,000)
Borrowings From Other FHLBanks [Roll Forward]
Borrowings from other FHLBanks	530,000,000	565,000,000	500,000,000
Repayments to other FHLBanks	(530,000,000)	(565,000,000)	(500,000,000)
FHLBank of Des Moines [Member]
Loans Made to Other FHLBanks [Roll Forward]
Loans made to other FHLBanks	200,000,000	60,000,000	0
Collections from other FHLBanks	(200,000,000)	(60,000,000)	0
FHLBank of Atlanta [Member]
Loans Made to Other FHLBanks [Roll Forward]
Loans made to other FHLBanks	0	60,000,000	200,000,000
Collections from other FHLBanks	0	(60,000,000)	(200,000,000)
Borrowings From Other FHLBanks [Roll Forward]
Borrowings from other FHLBanks	250,000,000	20,000,000	0
Repayments to other FHLBanks	(250,000,000)	(20,000,000)	0
FHLBank of Topeka [Member]
Loans Made to Other FHLBanks [Roll Forward]
Loans made to other FHLBanks	55,000,000	0	0
Collections from other FHLBanks	(55,000,000)	0	0
Borrowings From Other FHLBanks [Roll Forward]
Borrowings from other FHLBanks	360,000,000	40,000,000	0
Repayments to other FHLBanks	(360,000,000)	(40,000,000)	0
Federal Home Loan Bank of Chicago [Member]
Borrowings From Other FHLBanks [Roll Forward]
Borrowings from other FHLBanks	150,000,000	90,000,000	0
Repayments to other FHLBanks	(150,000,000)	(90,000,000)	0
FHLBank of Indianapolis [Member]
Loans Made to Other FHLBanks [Roll Forward]
Loans made to other FHLBanks	0	0	377,000,000
Collections from other FHLBanks	0	0	(377,000,000)
Borrowings From Other FHLBanks [Roll Forward]
Borrowings from other FHLBanks	0	90,000,000	0
Repayments to other FHLBanks	$ 0	$ (90,000,000)	$ 0

Accumulated Other Comprehensi81

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (Loss), start of period		$ (3,601)
Reclassifications from accumulated other comprehensive income (loss) to net income
Reclassification adjustment for realized gains on sales of available-for-sale securities included in net income		3,922	$ 0	$ 0
Reclassification adjustment for losses on cash flow hedge included in net income		(577)	0	0
Other amounts of other comprehensive income (loss)
Net unrealized gains (losses) on available-for-sale securities		(100,768)	23,280	(23,395)
Unrealized loss on cash flow hedge		(1,424)	0	0
Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities		(254)	(1,349)	0
Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities		6,227	7,200	8,237
Defined Benefit Plan, Actuarial Gain (Loss)		222	(2)	1,067
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax		0	0	211
Total other comprehensive income (loss)		(99,422)	29,040	(14,396)
Accumulated Other Comprehensive Income (loss), end of period		(103,023)	(3,601)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (Loss), start of period	[1]	22,412	(868)	22,527
Reclassifications from accumulated other comprehensive income (loss) to net income
Reclassification adjustment for realized gains on sales of available-for-sale securities included in net income	[1]	(3,922)
Other amounts of other comprehensive income (loss)
Net unrealized gains (losses) on available-for-sale securities	[1]	(100,768)	23,280	(23,395)
Total other comprehensive income (loss)	[1]	(104,690)	23,280	(23,395)
Accumulated Other Comprehensive Income (loss), end of period	[1]	(82,278)	22,412	(868)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (Loss), start of period		0	0	0
Reclassifications from accumulated other comprehensive income (loss) to net income
Reclassification adjustment for losses on cash flow hedge included in net income		577
Other amounts of other comprehensive income (loss)
Unrealized loss on cash flow hedge		(1,424)
Total other comprehensive income (loss)		(847)	0	0
Accumulated Other Comprehensive Income (loss), end of period		(847)	0	0
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (Loss), start of period		1,336	1,427	665
Reclassifications from accumulated other comprehensive income (loss) to net income
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax		(80)	(89)	(94)
Other amounts of other comprehensive income (loss)
Defined Benefit Plan, Actuarial Gain (Loss)		222	(2)	1,067
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax				(211)
Total other comprehensive income (loss)		142	(91)	762
Accumulated Other Comprehensive Income (loss), end of period		1,478	1,336	1,427
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (Loss), start of period		(3,601)	(32,641)	(18,245)
Reclassifications from accumulated other comprehensive income (loss) to net income
Reclassification adjustment for realized gains on sales of available-for-sale securities included in net income		(3,922)
Reclassification adjustment for losses on cash flow hedge included in net income		577
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax		(80)	(89)	(94)
Other amounts of other comprehensive income (loss)
Net unrealized gains (losses) on available-for-sale securities		(100,768)	23,280	(23,395)
Unrealized loss on cash flow hedge		(1,424)
Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities		(254)	(1,349)
Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities		6,227	7,200	8,237
Defined Benefit Plan, Actuarial Gain (Loss)		222	(2)	1,067
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax				(211)
Total other comprehensive income (loss)		(99,422)	29,040	(14,396)
Accumulated Other Comprehensive Income (loss), end of period		(103,023)	(3,601)	(32,641)
Held-to-maturity Securities [Member] | Accumulated Other-than-Temporary Impairment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (Loss), start of period		(27,349)	(33,200)	(41,437)
Other amounts of other comprehensive income (loss)
Non-credit portion of other-than-temporary impairment losses on held-to-maturity securities		(254)	(1,349)
Accretion of non-credit portion of other-than-temporary impairment losses to the carrying value of held-to-maturity securities		6,227	7,200	8,237
Total other comprehensive income (loss)		5,973	5,851	8,237
Accumulated Other Comprehensive Income (loss), end of period		$ (21,376)	$ (27,349)	$ (33,200)
[1]	Net unrealized gains (losses) on available-for-sale securities are net of unrealized gains and losses relating to hedged interest rate risk included in net income.

Other Operating Expenses (Detai

Other Operating Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Operating Expenses [Abstract]
Occupancy expense	$ 2,396	$ 2,607	$ 2,905
Legal fees	1,214	5,440	1,278
Professional fees	3,245	3,984	3,054
Independent contractors	2,634	977	3
Database fees	3,125	3,181	3,259
Software costs	4,691	5,069	5,727
Other	10,166	9,150	9,746
Total other operating expenses	$ 27,471	$ 30,408	$ 25,972