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

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	Federal Home Loan Bank of Chicago
Entity Central Index Key	1,331,451
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		19,936,024
Common Stock, Value, Outstanding			$ 1,828,755,701
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 ($) shares in Millions, $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 42	$ 351
Interest bearing deposits	775	650
Federal Funds sold	7,561	4,075
Securities purchased under agreements to resell	5,000	2,300
Investment securities -
Trading	233	1,045
pledged	67	97
Available-for-sale	12,957	14,918
Held-to-maturity,	4,157	5,072
fair value	4,538	5,516
Investment securities	17,347	21,035
Advances	48,085	45,067
carried at fair value	776	672
MPF Loans held in portfolio, net of	5,193	4,967
allowance for credit losses	(2)	(3)
Derivative assets	3	6
Other assets,	349	241
carried at fair value	118	44
Assets	84,355	78,692
Deposits -
Noninterest bearing	51	53
Interest bearing,	473	443
from other FHLBs	32	16
Deposits	524	496
Consolidated obligations, net -
Discount notes,	41,191	35,949
carried at fair value	749	6,368
Bonds	37,121	36,903
carried at fair value	5,260	5,443
Consolidated obligations, net	78,312	72,852
Derivative liabilities	20	43
Affordable Housing Program assessment payable	88	86
Mandatorily redeemable capital stock	311	301
Other liabilities	248	219
Liabilities	79,503	73,997
Commitments and contingencies - see notes to the financial statements
Capital
Class B1 activity stock,	$ 1,241	$ 1,160
million shares issued and outstanding	12	12
Class B2 membership stock,	$ 202	$ 551
million shares issued and outstanding	2	6
Capital stock - putable,	$ 1,443	$ 1,711
par value	$ 100	$ 100
Retained earnings - unrestricted	$ 2,845	$ 2,631
Retained earnings - restricted	452	389
Retained earnings	3,297	3,020
Accumulated other comprehensive income (loss) (AOCI)	112	(36)
Capital	4,852	4,695
Liabilities and capital	$ 84,355	$ 78,692

Statements of Income

Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Interest income	$ 1,558	$ 1,259	$ 1,252
Interest expense	1,075	803	744
Net interest income	483	456	508
Provision for (reversal of) credit losses	0	1	5
Net interest income after provision for (reversal of) credit losses	483	455	503
Noninterest income -
Derivatives and hedging activities	8	1	(16)
Instruments held under fair value option	(2)	5	8
Litigation settlement awards	2	38	13
MPF fees,	28	27	17
from other FHLBs	20	17	11
Other, net	8	5	1
Noninterest income	44	76	23
Noninterest expense -
Compensation and benefits	100	94	81
Operating expenses	62	60	51
Other	12	13	6
Noninterest expense	174	167	138
Income before assessments	353	364	388
Affordable Housing Program assessment	36	37	39
Net income	$ 317	$ 327	$ 349

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 317	$ 327	$ 349
Other comprehensive income (loss) -
Net unrealized gain (loss) available-for-sale securities	(52)	(199)	(402)
Noncredit OTTI held-to-maturity securities	34	40	47
Net unrealized gain (loss) cash flow hedges	165	151	117
Postretirement plans	1	0	(7)
Other comprehensive income (loss)	148	(8)	(245)
Comprehensive income	$ 465	$ 319	$ 104

Statements of Stockholders' Equ

Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Capital Stock - Putable - B1 Activity	Capital Stock - Putable - B2 Membership	Capital Stock	Retained Earnings, Unrestricted	Retained Earnings, Restricted	Retained Earnings, Total	AOCI
Shares, beginning at Dec. 31, 2014		8	11	19
Balance, beginning at Dec. 31, 2014	$ 4,525	$ 827	$ 1,075	$ 1,902	$ 2,152	$ 254	$ 2,406	$ 217
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	104				280	69	349	(245)
Issuance of capital stock (shares)		4	0	4
Issuance of capital stock	374	$ 357	$ 17	$ 374
Repurchases of capital stock (shares)		(1)	(3)	(4)
Repurchase of capital stock	(324)	$ (95)	$ (229)	$ (324)
Capital stock reclassified to mandatorily redeemable capital stock (liabilities) (shares)		0	0	0
Capital stock reclassified to mandatorily redeemable capital stock (liabilities)	(2)	$ 0	$ (2)	$ (2)
Transfers between classes of capital stock (shares)		2	(2)
Transfers between classes of capital stock		$ 224	$ (224)
Cash dividends - class B1	(20)				(20)		(20)
Cash dividends - class B2	(5)				(5)		(5)
Common Stock Dividend - Annualized Rate		2.31%	0.50%
Total change in period (shares)		5	(5)	0
Total change in period	127	$ 486	$ (438)	$ 48	255	69	324	(245)
Shares, ending at Dec. 31, 2015		13	6	19
Balance, ending at Dec. 31, 2015	4,652	$ 1,313	$ 637	$ 1,950	2,407	323	2,730	(28)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	319				261	66	327	(8)
Issuance of capital stock (shares)		14	1	15
Issuance of capital stock	1,309	$ 1,293	$ 16	$ 1,309
Repurchases of capital stock (shares)		(7)	(6)	(13)
Repurchase of capital stock	(1,248)	$ (672)	$ (576)	$ (1,248)
Capital stock reclassified to mandatorily redeemable capital stock (liabilities) (shares)		(3)	0	(3)
Capital stock reclassified to mandatorily redeemable capital stock (liabilities)	(300)	$ (295)	$ (5)	$ (300)
Transfers between classes of capital stock (shares)		(5)	5
Transfers between classes of capital stock		$ (479)	$ 479
Cash dividends - class B1	(33)				(33)		(33)
Cash dividends - class B2	(4)				(4)		(4)
Common Stock Dividend - Annualized Rate		2.75%	0.60%
Total change in period (shares)		(1)	0	(1)
Total change in period	43	$ (153)	$ (86)	$ (239)	224	66	290	(8)
Shares, ending at Dec. 31, 2016		12	6	18
Balance, ending at Dec. 31, 2016	4,695	$ 1,160	$ 551	$ 1,711	2,631	389	3,020	(36)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	465				254	63	317	148
Issuance of capital stock (shares)		27	0	27
Issuance of capital stock	2,830	$ 2,813	$ 17	$ 2,830
Repurchases of capital stock (shares)		0	(31)	(31)
Repurchase of capital stock	(3,093)	$ (35)	$ (3,058)	$ (3,093)
Capital stock reclassified to mandatorily redeemable capital stock (liabilities) (shares)		0	0	0
Capital stock reclassified to mandatorily redeemable capital stock (liabilities)	(5)	$ (2)	$ (3)	$ (5)
Transfers between classes of capital stock (shares)		(27)	27
Transfers between classes of capital stock		$ (2,695)	$ 2,695
Cash dividends - class B1	(37)				(37)		(37)
Cash dividends - class B2	(3)				(3)		(3)
Common Stock Dividend - Annualized Rate		3.19%	1.10%
Total change in period (shares)		0	(4)	(4)
Total change in period	157	$ 81	$ (349)	$ (268)	214	63	277	148
Shares, ending at Dec. 31, 2017		12	2	14
Balance, ending at Dec. 31, 2017	$ 4,852	$ 1,241	$ 202	$ 1,443	$ 2,845	$ 452	$ 3,297	$ 112

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating
Net income		$ 317	$ 327	$ 349
Adjustments to reconcile net income for noncash operating activities -
Amortization and accretion		41	19	2
Change in net fair value on derivatives and hedging activities		311	192	326
Other		(2)	(10)	11
Changes in operating assets or liabilities -
Purchases of mortgage loans to be securitized		(687)	(446)	(151)
Proceeds from sales of securitized mortgage loans		613	457	97
Other operating assets		(64)	(40)	(59)
Other operating liabilities		11	(17)	(5)
Net cash provided by (used in) operating activities		540	482	570
Investing
Net change interest bearing deposits		(125)	0	(90)
Net change Federal Funds sold		(3,486)	(2,373)	(177)
Net change securities purchased under agreements to resell		(2,700)	(925)	2,025
Trading securities -
Sales		801	2,158	300
Proceeds from maturities and paydowns		208	111	812
Purchases		(200)	(2,156)	(2,106)
Available-for-sale securities -
Proceeds from maturities and paydowns		1,798	2,243	2,027
Purchases		(5)	(2)	(14)
Held-to-maturity securities -
Short-term held-to-maturity securities, net	[1]	(10)	37	112
Proceeds from maturities and paydowns		1,043	979	1,154
Purchases		(31)	(41)	(24)
Advances -
Principal collected		747,813	704,656	342,573
Issued		(750,868)	(713,017)	(346,874)
MPF Loans held in portfolio -
Principal collected		1,003	1,164	1,424
Purchases		(1,236)	(1,306)	(204)
Other investing activities		21	33	31
Net cash provided by (used in) investing activities		(5,974)	(8,439)	969
Financing
Net change deposits		28	(43)	(125)
Discount notes -
Net proceeds from issuance		1,408,075	682,913	277,115
Payments for maturing and retiring		(1,402,859)	(688,540)	(266,620)
Consolidated obligation bonds -
Net proceeds from issuance		19,567	36,752	10,283
Payments for maturing and retiring		(19,358)	(22,297)	(21,962)
Net proceeds (payments) on bond transfers with other FHLBs		0	0	(35)
Payments for retiring of subordinated debt		0	(944)	0
Capital stock -
Proceeds from issuance		2,830	1,309	374
Repurchases		(3,093)	(1,248)	(324)
Cash dividends paid		(40)	(37)	(25)
Other financing activities		(25)	(56)	(63)
Net cash provided by (used in) financing activities		5,125	7,809	(1,382)
Net increase (decrease) in cash and due from banks		(309)	(148)	157
Cash and due from banks at beginning of period		351	499	342
Cash and due from banks at end of period		42	351	499
Supplemental
Interest paid		897	644	740
Affordable Housing Program assessments paid		34	40	40
Capital stock reclassified to mandatorily redeemable capital stock		5	300	2
Transfer of MPF Loans held for sale (in other assets) to securitized mortgage loans (in trading securities)		526	422	83
Transfer of MPF Loans held in portfolio to other assets		$ 16	$ 23	$ 30
[1]	Short-term held-to-maturity securities, net, consists of investment securities with a maturity of less than 90 days when purchased.

Background and Basis of Present

Background and Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Background and Basis of Presentation The Federal Home Loan Bank of Chicago is a federally chartered corporation and one of 11 Federal Home Loan Banks (the FHLBs) that, with the Office of Finance, comprise the Federal Home Loan Bank System (the System). The FHLBs are government-sponsored enterprises (GSE) of the United States of America and were organized under the Federal Home Loan Bank Act of 1932, as amended (FHLB Act), in order to improve the availability of funds to support home ownership. We are supervised and regulated by the Federal Housing Finance Agency (FHFA), an independent federal agency in the executive branch of the United States (U.S.) government. Each FHLB is a member-owned cooperative with members from a specifically defined geographic district. Our defined geographic district is Illinois and Wisconsin. All federally-insured depository institutions, insurance companies engaged in residential housing finance, credit unions and community development financial institutions located in our district are eligible to apply for membership with us. All our members are required to purchase our capital stock as a condition of membership. Our capital stock is not publicly traded and subject to certain statutory and regulatory limits, and is issued, repurchased or redeemed at a par value of $100 per share. As a cooperative, we do business with our members, and former members (under limited circumstances). Specifically, we provide credit principally in the form of secured loans called advances. We also provide liquidity for home mortgage loans to members approved as Participating Financial Institutions (PFIs) through the Mortgage Partnership Finance ® (MPF ® ) Program. Our accounting and financial reporting policies conform to generally accepted accounting principles in the United States of America (GAAP). Amounts in prior periods may be reclassified to conform to the current presentation and if material are disclosed in the following notes. Unless otherwise specified, references to we, us, our, and the Bank are to the Federal Home Loan Bank of Chicago. “Mortgage Partnership Finance”, “MPF”, “MPF Xtra”, and "Community First" are registered trademarks of the Federal Home Loan Bank of Chicago. Refer to the Glossary of Terms starting on page 122 for the definitions of certain terms used herein. Use of Estimates and Assumptions We are required to make estimates and assumptions when preparing our financial statements in accordance with GAAP. The most significant of these estimates and assumptions applies to fair value measurements and allowance for credit losses. Our actual results may differ from the results reported in our financial statements due to such estimates and assumptions. This includes the reported amounts of assets and liabilities, the reported amounts of income and expense, and the disclosure of contingent assets and liabilities. Basis of Presentation Gross versus Net Presentation - We present derivative assets and liabilities on a net basis in our statements of condition when our right to net amounts due to our counterparties and/or clearing agents is enforceable at law. We include accrued net interest settlements and cash collateral, including initial and variation margin, in the carrying amount of a derivative. Over-the-counter derivatives are netted by contract (e.g., master netting agreement), to discharge all or a portion of the amounts that would be owed to our counterparty by applying them against the amounts that our counterparty owes to us. Additionally, we clear certain derivatives transactions with clearinghouses classified as a Derivatives Clearing Organization (DCO), through Futures Commission Merchants (FCM), a clearing member of the DCO. If these netted amounts are positive, they are classified as a derivative asset and if negative, they are classified as a derivative liability. Effective in January of 2017, there was a change in our basis of presentation for our cleared derivative transactions. Prior to 2017, our accounting presented derivative assets and liabilities of our cleared derivative transactions on a net basis, inclusive of initial and variation margin, and accrued interest receivable/payable and cash collateral. Due to rule changes adopted by our DCOs, as of January of 2017, we characterize the treatment of variation margin payments as settlements rather than as collateral for our cleared derivatives. As result, we account for variation margin payments as settlements to our derivative assets and derivative liabilities. The amendments to the DCOs’ rules had no effect on how we present initial margin, which we include in the carrying amount of our derivative assets or derivative liabilities. See Note 2 - Summary of Significant Accounting Policies for further details. The net exposure for these financial instruments can change on a daily basis; therefore, there may be a delay between the time this exposure change is identified and additional collateral is requested, and the time when this collateral is received or pledged. Likewise, there may be a delay for excess collateral to be returned. For derivative instruments that meet the netting requirements, any excess cash collateral received or pledged is recognized as a derivative liability or asset. Derivatives that do not have the legal right of offset are presented on a gross basis in our statements of condition. Refer to Note 9 - Derivatives and Hedging Activities for further details. Our policy is to report securities purchased under agreements to resell and securities sold under agreements to repurchase, if any, and securities borrowing transactions, if any, on a gross basis. Consolidation of Variable Interest Entities

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Fair Value Fair value represents the exit price that we would receive to sell an asset or pay to transfer a liability in an orderly transaction with a market participant at the measurement date. Valuation Techniques and Significant Inputs We utilize the fair value hierarchy when selecting valuation techniques and significant inputs to measure the fair value of our assets and liabilities. Our valuation techniques may utilize market, cost, and/or income models to estimate fair values. Under the fair value hierarchy, valuation techniques and significant inputs are prioritized from the most objective, such as quoted market prices in external active markets, to the least objective, such as valuation approaches that utilize unobservable inputs. The fair value hierarchy requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Outlined below is an overview of Level 1, Level 2, and Level 3 of the fair value hierarchy. Refer to Note 16 - Fair Value for further details on our valuation techniques and significant inputs. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we can access at the measurement date. Level 2 inputs are inputs other than quoted prices included within 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 3 inputs are unobservable inputs used to measure fair value of an asset or liability to the extent that relevant observable inputs are not available; for example, situations in which there is little, if any, market activity for the asset or liability at the measurement date. For instruments carried at fair value, we review the fair value hierarchy classifications on a quarterly basis. Changes in the observability of the valuation attributes may result in a reclassification of certain financial assets or liabilities from one level to another. Such reclassifications are reported as transfers in/out at fair value as of the beginning of the quarter in which the changes occur. Fair Value Option We may elect the fair value option for financial instruments, such as advances, MPF Loans held for sale, consolidated obligation discount notes and bonds in cases where hedge accounting treatment may not be achieved due to the inability to meet the hedge effectiveness testing criterion. We carry these financial instruments at fair value in our statements of condition. Changes in their fair value are immediately recognized into our statements of income as noninterest income on instruments held under fair value option. We economically hedge these financial instruments with derivatives, which are carried at fair value in our statements of condition. Changes in their fair value also are immediately recognized into our statements of income; however, such changes in fair value are classified as noninterest income on derivatives and hedging activities. Interest income or expense recognized in our statements of income on these financial instruments is based solely on the contractual amount of interest due or unpaid, except for our discount notes, which have a zero coupon rate. For discount notes, we accrete the initial discount into interest expense over the life of the discount note into our statements of income. Any transaction fees or costs, such as concession fees on consolidated obligation bonds and discount notes, are immediately recognized into noninterest expense - other. See Note 16 - Fair Value to the financial statements for further details. Cash and Cash Equivalents We consider only cash and due from banks as cash and cash equivalents. We do not have any restricted cash. Interest Bearing Deposits, Federal Funds Sold and Securities Purchased Under Agreements to Resell We utilize these investments for short-term liquidity purposes and carry them on an amortized cost basis in our statements of condition. Collateral on Securities Purchased Under Agreements to Resell (resale agreements) • Collateral accepted from our counterparties is held in our name for safekeeping by third party custodians. • We do not sell or repledge any collateral we receive due to the short-term nature of our resale agreements. • The collateral's fair value less haircuts approximates the resale agreement's carrying amount in our statements of condition. • Our counterparty is required to make up any shortfall, which exists if the collateral's fair value decreases below the contractually required amount, by providing additional securities as collateral equal to the amount of the shortfall. If our counterparty does not provide such additional collateral, the resale agreement's carrying amount is reduced by the collateral shortfall amount. Investment Securities We record purchases and sales of investment securities (securities) on a trade date basis. We classify securities as either trading, held-to-maturity (HTM), or available-for-sale (AFS) based on the criteria outlined below. Classification is made at the time a security is acquired and then reassessed each subsequent reporting period. • Securities held solely for liquidity purposes are classified as trading. We are prohibited from holding trading securities for speculative purposes pursuant to FHFA regulations. • Securities held to provide additional earnings are classified as HTM. Classification as HTM requires that we have both the intent and ability to hold the security to maturity. • Securities not classified as either trading or HTM are classified as AFS; for example, securities held for asset-liability management purposes. Our accounting policies for trading, HTM and AFS securities are outlined below. • Trading securities are carried at fair value. Fair value changes related to trading securities are recognized in noninterest income on trading securities. Interest income on trading securities is based solely on the contractual amount of interest due, except for securities, if any, that have a zero coupon rate. For trading securities with a zero coupon rate, we accrete the initial discount into interest income over their life into our statements of income. Cash flows from trading securities, excluding cash flows from our securitized MPF Government MBS product, are presented on a gross basis and classified as investing activities in our statements of cash flows. Cash flows from our securitized MPF Government MBS product are classified as operating activities in our statements of cash flows. • HTM securities are carried on an amortized cost basis adjusted for any noncredit other-than-temporary impairment (OTTI) recognized in AOCI. Amortized cost basis represents the original cost of a security adjusted for accretion, amortization, collection of cash, previous other-than-temporary impairment (OTTI) recognized into earnings (less any cumulative effect adjustments), and any fair value hedge accounting adjustments. • AFS securities are carried at fair value. Changes in fair value on AFS securities are recognized into AOCI in our statements of condition except for AFS securities that are in a fair value hedge relationship. Changes in fair value on AFS securities and the derivative hedging AFS securities in a fair value hedging relationship are immediately recognized into noninterest income on derivatives and hedging activities. • We use the interest method to amortize/accrete premiums/discounts on HTM and AFS securities into interest income in our statements of income. HTM and AFS securities having a prepayment feature amortize/accrete premiums/discounts over their estimated lives based on anticipated prepayments. We recalculate their effective yield on an ongoing basis to reflect actual payments to date and anticipated future payments. HTM and AFS securities that do not have a prepayment feature amortize/accrete premiums/discounts over their contractual life. • Gains and losses on sales of securities are determined using the specific identification method and are included in noninterest income in our statements of income. Investment Securities - Other-than-Temporary Impairment (OTTI) We assess an HTM or AFS security for OTTI whenever its fair value is less than its amortized cost basis as of the reporting date. We write down an OTTI security to fair value if we decide to sell it or if we believe it is more likely than not that we will be required to sell it before recovery of its amortized cost basis. The entire amount of the fair value write-down is recognized as an OTTI credit loss in our statements of income. If a fair value write-down on an OTTI security is not required but a recovery of its entire amortized cost basis is not expected, then the OTTI security is written down to its fair value in our statements of condition. The offset to such a fair value write-down is allocated between an OTTI credit loss that is recognized in our statements of income and a noncredit related loss that is recognized in AOCI. Subsequent Accretion and Amortization We prospectively accrete the noncredit OTTI recognized in AOCI for HTM securities to the security's carrying amount over its remaining life. The accretion is based on the amount and timing of the security's future estimated cash flows. This accretion increases the security's carrying amount until we derecognize the security (e.g., at maturity) or until we recognize additional OTTI on that security into earnings. See Statements of Comprehensive Income on page F-6. We evaluate the yield of each impaired HTM or AFS security on a quarterly basis. We adjust the impaired security's yield for subsequent increases or decreases in its estimated cash flows, if any. The adjusted yield is then used to calculate the amount to be recognized into interest income over the remaining life of the impaired security. Advances We offer a wide range of fixed-and variable-rate advance products with different maturities, interest rates, payment characteristics and optionality. An advance is carried at its amortized cost basis, except when we elect the fair value option and carry it at fair value. Amortized cost basis represents the original amount funded to our member adjusted for any accretion, amortization, collection of cash, and fair value hedge accounting adjustments, if any. Fair value hedge adjustments include ongoing (open) and/or discontinued (closed) fair value hedges. Cash flow hedging adjustments related to ongoing (open) and/or discontinued (closed) cash flow hedges are classified in AOCI. We utilize the interest method to amortize/accrete any premiums/discounts and closed fair value and/or cash flow hedging adjustments. Prepayments We recognize prepayment fees, if any, and any related fair value and/or cash flow hedging adjustments into interest income in our statements of income when an advance is prepaid. Modifications versus Extinguishments We assess whether a modification or an extinguishment of an existing advance has occurred in cases where a new advance is issued concurrently or shortly after the prepayment of that existing advance (within 5 business days) by a member. An advance is considered extinguished if either of the conditions shown below are met: • The present value of the cash flow on the new advance is at least 10% different from the present value of the remaining cash flows on the original advance; or • A significant modification has occurred based on the specific facts and circumstances (and other relevant considerations) surrounding the modification. Any prepayment fees and any unamortized cumulative basis adjustment resulting from a fair value hedge of an extinguished advance would be immediately recognized into interest income in our statements of income. Amounts deferred in AOCI related to a cash flow hedge on the extinguished advance are immediately recognized into noninterest income on derivatives and hedging activities. If both of the above conditions are not met, a modification of the existing advance has occurred. Any prepayment fees and any unamortized cumulative basis adjustment resulting from a fair value hedge of the modified advance would continue to be amortized over its contractual life. MPF Loans See Note 7 - MPF Loans Held in Portfolio for further details pertaining to the MPF Program and MPF Loans. MPF Loans Held in Portfolio MPF Loans for which we have the intent and ability to hold until maturity are classified as MPF Loans held in portfolio. Such loans are carried on an amortized cost basis on our statements of condition. Amortized cost basis represents the initial fair value amount of the MPF delivery commitment as of the purchase or settlement date, agent fees (i.e., market risk premiums or discounts paid to or received from PFIs), if any, subsequently adjusted, if applicable, for accretion, amortization, collection of cash, charge-offs, and cumulative basis adjustments related to fair value hedges. We use the interest method to amortize yield adjustments into interest income in our statements of income over the contractual life of an MPF Loan held in portfolio. Yield adjustments may include agent fees, the fair value amount of the delivery commitment as of its settlement date, any origination fees or costs representing yield adjustments, closed fair value hedging adjustments, and credit enhancement fees. MPF Loans Held for Sale MPF Loans acquired by the Bank under the MPF Xtra, MPF Direct, and MPF Government MBS products are classified as MPF Loans held for sale (HFS). MPF Loans under the MPF Government MBS product are reclassified from Mortgage Loans HFS to trading securities upon their securitization qualifying for sales accounting treatment. If the securitization does not meet the conditions of sales accounting treatment, then we continue to classify these mortgage loans as MPF Loans HFS. We classify MPF Loans HFS in Other Assets rather than as a separate line item in our statements of condition on the basis of materiality. Cash flows from MPF Loans HFS are classified as operating activities in our statements of cash flows. We have elected the fair value option for MPF Loans HFS, and accordingly, carry these mortgage loans at fair value. The initial fair value of the MPF Loans HFS includes the fair value amount of the MPF Delivery Commitment as of the purchase or settlement date. The difference between the price paid to a PFI for a MPF Loan HFS and the price we receive from a third party for such loan is intended to include compensation for future operating expenses incurred to administer the loans. These amounts and other related transaction fees are recognized into Noninterest income - MPF fees in our statements of income as follows: • Amounts used to pay for third party transaction costs attributable to the sale and securitization of MPF Loans HFS are recognized immediately. • For MPF Loans HFS sold where servicing is retained by the PFI, the amounts are recognized on a straight-line basis over the life of the loan. • For MPF Loans HFS sold where servicing is released, the amounts are recognized immediately. MPF Fees from other FHLBs Other FHLBs pay us a membership fee to participate in the MPF Program and a fee for us to provide services related to their on balance sheet MPF Loans, which offsets a portion of expenses we incur to administer the program. We present these fees on a gross basis and classify them parenthetically in Noninterest income as MPF fees from other FHLBs. Allowance for Credit Losses Refer to Note 8 - Allowance for Credit Losses for further details. On-Balance Sheet Financial Instruments We determine an allowance for credit losses, if any, for each of our portfolio segments. A portfolio segment represents the level of disaggregation we utilize to develop and document a systematic method for determining an allowance for credit losses attributable to our financing receivables. An allowance for credit losses is a contra valuation account attributable to an on-balance sheet portfolio segment. We recognize a credit loss when it is probable a credit loss has been incurred and when the credit loss amount is reasonably estimable. Our assessment is based on all available information, which includes, but is not limited to, past events and current economic conditions existing at the reporting date. We recognize the change in our allowance for credit losses during the reporting period as a provision for (reversal of) credit losses in our statements of income. Off-Balance Sheet Financial Instruments We establish a separate liability for credit losses, if any, attributable to off-balance sheet financial instruments, such as standby letters of credit (also referred to herein as letters of credit), using the same approach described above for on-balance sheet financial instruments. We recognize the change in credit losses during the reporting period, if any, in other noninterest expense in our statements of income. Details about the allowance for credit losses methodology for each of our portfolio segments is discussed below. Member Credit Products (advances, letters of credit and other extensions of credit to borrowers) We consider our risk-based approach to determining collateral requirements, including risk-based collateral levels and collateral delivery triggers, and our credit extension policies as the primary tools for managing the credit quality on our member credit products. We assess and protect our rights to collateral on a member-by-member basis to determine if we are holding collateral with a value that is at least equal to the credit outstanding to that member. The collateral value required to secure each member’s credit products is calculated for securities, by multiplying the applicable percentage margin by the market value of each security and for loans, by multiplying the applicable percentage margin by the unpaid principal balance of pledged loans, along with any applicable percentage applied to adjust for ineligible loans found during a member's collateral review. We also factor in the repayment history of our members when assessing whether a credit risk loss has been incurred with respect to our member credit products. Conventional MPF Loans Held in Portfolio MPF Risk Sharing Structure Our allowance for credit losses methodology factors in the allocation of losses for conventional MPF products held in our portfolio as further described below. The credit risk analysis determines the degree to which layers of the MPF Risk Sharing Structure are available to recover losses on MPF Loans. PFIs deliver MPF Loans into pools designated by product specific Master Commitments (MCs). The credit risk analysis is performed at an individual MC level since credit loss recovery from a PFI is MC-specific - that is, credit losses on a loan may be absorbed by the PFI only by its risk layer of the MC related to that loan. We allocate losses on participation interests in MPF Loans amongst the participating MPF Banks pro-ratably based upon their respective percentage participation interest in the related MC. Credit losses are absorbed in the following order (the MPF Risk Sharing Structure): • Borrower's equity. • Primary mortgage insurance (PMI), if any. • The PFI. We will withhold a PFI's scheduled performance credit enhancement fee in order to reimburse ourselves for any losses allocated to the FLA (as further described below). • Us, or pro-rata with another MPF Bank in the case of a participation, up to the amount of the First Loss Account (FLA). The FLA functions as a tracking mechanism for our first layer of loss exposure before determining the point in which a PFI's credit enhancement obligation (CE Amount) would cover the next layer of losses. Our FLA exposure varies by MPF Loan product type - that is, MPF Original, MPF 35, MPF 100, MPF 125, and MPF Plus. • The PFI. The PFI's CE Amount, which may include proceeds from a provider of supplemental mortgage guaranty insurance (SMI). • Us, or pro-rata with another MPF Bank in the case of a participation. We and the participating MPF Bank, if applicable, will absorb any losses after the CE Amount has been exhausted. Review Process Our overall allowance for credit losses is determined by an analysis that includes consideration of various data observations such as past performance, current performance, loan portfolio characteristics, other collateral related characteristics, industry data, and prevailing economic conditions. The measurement of the allowance for credit losses consists of: (1) reviewing the change in the rates (i.e., migration or "roll rates") of delinquencies on residential mortgage loans for the entire portfolio; (2) reviewing the total severity rate and the credit loss severity rate; and (3) estimating credit losses in the remaining portfolio. Loss Severity The Total Severity Rate and the Credit Loss Severity Rate calculations, as defined further below, are based on analysis of MPF Loans that have experienced a credit loss in the previous 12 months. The analysis is done on a rolling 12 month basis. • Total Severity Rate: This severity rate is based on the total losses experienced and expenses incurred on conventional MPF Loans under the MPF Risk Sharing Structure. Specifically, this severity rate includes all credit losses related to contractual principal and interest due on impaired conventional MPF Loans, periodic expenses incurred through the life cycle of a conventional MPF Loan, such as real estate taxes and attorney fees incurred after it is transferred to real estate owned (REO), and REO sale gains or losses. • Credit Loss Severity Rate: The second severity rate only includes credit losses attributable to the contractual principal amounts due on impaired conventional MPF Loan portfolios that either were not collected or were not received on a timely basis. The Total Severity Rate includes total losses and expenses to prevent our allowance for credit losses from being understated. This ensures the portion of the MPF Risk Sharing Structure utilized to absorb noncredit losses is not being included when calculating the amount to be utilized to absorb credit losses. We may adjust these severity rates to reach the final Total Severity Rate and Credit Loss Severity Rate used in the allowance for credit losses methodology. Adjustments may include factors that exist in the current economic environment, such as the FHFA Purchase-Only House Price Index, as of the reporting date. We have not presented quantitative information pertaining to our total and credit loss severity rates due to the immateriality of our allowance for credit losses. Consideration of the MPF Risk Sharing Structure The entire population of conventional MPF Loans is analyzed using the MPF Risk Sharing Structure at the MC level using roll rates and the Total Severity Rate. The total losses resulting after factoring in the MPF Risk Sharing Structure are then calculated. The adjusted total losses are then split into credit losses and noncredit losses. A credit loss only consists of the loss resulting from the timing and amount of unpaid principal on an MPF Loan and does not include periodic expenses incurred during the time period in which an MPF Loan has become REO. Such periodic expenses are noncredit losses, and they are directly expensed through the statements of income as incurred. Estimating Credit Losses in the Remaining Portfolio We apply an imprecision factor to our homogeneous pools of conventional MPF Loans when estimating our allowance for credit losses. Our margin of imprecision represents a subjective management judgment based on facts and circumstances that exist as of the reporting date that is unallocated to any specific measurable economic or credit event and is intended to cover other inherent losses that may not be captured by our loan loss methodology. Government Loans Held in Portfolio The PFI provides insurance or a guaranty from governmental agencies, which includes ensuring compliance with all of their requirements. Servicers maintain the insurance or guaranty and obtain the benefit of the applicable insurance or guaranty with respect to defaulted Government Loans. Any losses incurred on Government Loans that are not recovered from the government insurer or guarantor are absorbed by the servicer. Accordingly, credit losses of our portfolio segment for Government Loans included in our MPF Loan held in portfolio for the reporting periods presented is based on our assessment of our servicers' ability to absorb losses not covered by the applicable government guarantee or insurance. Federal Funds Sold and Securities Purchased Under Agreements to Resell Federal Funds sold are only evaluated for purposes of an allowance for credit losses if payment is not made when due. In this regard, we may establish an allowance for credit losses for Federal Funds sold when repayment has not been made according to contractual terms. We may establish an allowance for credit losses for securities purchased under agreements to resell or resale agreements in cases where all payments due under the contractual terms have not been received and where we do not hold sufficient underlying collateral. For example, if the credit markets experience disruptions, it may increase the likelihood that one of our counterparties could experience liquidity or financial constraints that may cause them to become insolvent or otherwise default on their obligations to us. If the collateral's fair value amount has decreased below the resale agreement's carrying amount, we may suffer a credit loss that would be recognized as an allowance for credit loss with an offsetting amount recognized as a provision for credit losses in our statements of income. Charge-off Provisions We recognize a charge-off on a loan upon the occurrence of a confirming event, which include, but are not limited to, the events shown below. The charge-off amount equals the difference between the loan's amortized cost basis and its fair value, less costs to sell. We use an Automated Valuation Methodology (AVM) to determine the fair value of our impaired conventional MPF Loans held in portfolio, including troubled debt restructurings, and REO. • When a loan is 180 days or more past due and its fair value, less cost to sell, is less than the loan's amortized cost basis. • When a borrower is in bankruptcy, loans are written down to the fair value of the collateral, less costs to sell, within 60 days of receipt of the notification of filing from the bankruptcy court or within the delinquency time frames specified in the guidance, whichever is shorter. A loan is not written down if the loan is performing, the borrower continues making payments on the loan, and repayment in full is expected. • Fraudulent loans, not covered by any existing representations and warranties in the loan purchase agreement, are charged off within 90 days of discovery of the fraud, or within the delinquency time frames specified in the adverse classification guidance, whichever is shorter. Nonaccrual Conventional MPF Loans held in portfolio are placed on nonaccrual when they become "adversely classified" - that is, when a loan is classified as "Substandard", "Doubtful", or "Loss". An adverse classification means that such a loan is not considered well secured and is in the process of collection. Derivatives Refer to Note 9 - Derivatives and Hedging Activities for additional details. We carry all derivatives at fair value in our statements of condition. We designate derivatives either as fair value hedges, cash flow hedges, or economic hedges. We use fair value hedges to offset changes in the fair value or a benchmark interest rate (e.g., LIBOR) related to (1) a recognized asset or liability or (2) an unrecognized firm commitment. We use cash flow hedges to offset an exposure to variability in expected future cash flows associated with an existing recognized asset or liability or a forecasted transaction. We use economic hedges in cases where hedge accounting treatment is not permitted or achievable; for example, hedges of portfolio interest rate risk or financial instruments carried at fair value under the fair value option. Accounting for Variation Margin Payments - Effective in January of 2017 we began accounting for variation margin payments made to or received by the DCOs through our FCMs as settlements to our cleared derivative assets and derivative liabilities. See Note 1 - Background and Basis for Presentation for further details. This change in accounting did not have any effect on the accounting of our existing hedge relationships. Specifically, the change in accounting would not require us to discontinue existing hedge relationships or preclude us from using the short-cut method of hedge accounting provided no additional changes are made by the DCOs that would preclude the use of the short-cut method of hedge accounting. The International Swaps and Derivatives Association (ISDA) issued a confirmation letter confirming the SEC staff’s non-objection to the conclusions reached by ISDA related to the accounting implications of the DCO rule changes regarding the characterization of the variation margin payments as daily settlements and the continued application of existing hedge accounting relationships, including the use of the short-cut method of hedge accounting. Derivative Hedge Accounting - We apply hedge accounting to qualifying hedge relationships. A qualifying hedge relationship exists when a derivative hedging instrument is expected to effectively offset changes in fair values, cash flows, or underlying risk of the hedged item during the term of the hedge relationship. We prepare formal contemporaneous documentation at inception of the hedge relationship to support that the hedge relationship qualifies for hedge accounting treatment. Such documentation includes the items outlined below: • The nature of the risk being hedged. • The risk management objective and strategy. • The hedging relationship. • The hedged item or forecasted transaction. • The derivative hedging instrument. • The method used to retrospectively and prospectively assess the hedge effectiveness between the hedged item and hedging instrument. We use regression analysis to assess hedge effectiveness. We perform hedge effectiveness testing at hedge inception and on a daily basis thereafter. Subsequent to hedge inception, we use the same regression analysis approach for both prospective considerations and retrospective evaluations of assessing hedge effectiveness. • The method we will use to measure the amount of hedge ineffectiveness into earnings. • For cash flow hedges only, we document details that include, but are not limited to, the probability that the forecasted transaction will occur, the date or period when a forecasted transaction is expected to occur, and how we meet the sufficient specificity requirement in the event a hedge relationship is discontinued. For example, we use the first-in first out approach to determine the amounts to be reclassified from AOCI into earning should a hedging relationship related to the Bank's Rolling Discount Note (DN) Hedging Strategy be discontinued. We immediately recognize changes in fair values for both the derivative hedging instrument and the related hedged item beginning on the derivative hedging instrument's trade date. For fair value hedges, changes in fair value on the hedged item are recognized as a cumulative basis adjustment and are included in the amortized cost basis of the asset or liability being hedged. For cash flow hedges, we recognize changes in fair value on the hedged item in AOCI to the extent that the hedge is effective. A cash flow hedge's ineffective portion is immediately recognized as noninterest income on derivatives and hedging activities in our statements of income. Amounts recorded in AOCI are reclassified either to interest income or interest expense depending on the hedged item during the period in which the hedged transaction affects earnings. Discontinuance of Derivative Hedge Accounting - We discontinue hedge accounting treatment prospectively for an existing fair value or cash flow hedge if any one of the following occurs: • Any hedge criterion is no longer met. • The derivative expires or is sold, terminated, or exercised. • We remove the designation of the fair value or cash flow hedge. For discontinued asset and liability fair value hedges, we prospectively amortize the cumulative basis adjustment on the hedged item into interest income or interest expense, whichever

Recently Issued but Not Yet Ado

Recently Issued but Not Yet Adopted Accounting Standards	12 Months Ended
	Dec. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	Recently Issued but Not Yet Adopted Accounting Standards Targeted Improvements to Accounting for Hedging Activities In August of 2017, the FASB issued targeted improvements to existing derivatives and hedging guidance to facilitate financial reporting that more closely reflects an entity’s risk management activities. Adoption is required as of January 1, 2019; however, the targeted improvements may be adopted immediately in any interim period prior to that date. Outlined below are the significant changes to existing GAAP guidance that are relevant to us. Cash Flow Hedges: • Permits the hedging of the variability in cash flows in a financial instrument that has a contractually specified interest rate. • The entire change in fair value of the hedging instrument is recorded in accumulated other comprehensive income. As a result, hedge ineffectiveness will no longer be immediately recognized into earnings. Reclassification from AOCI into earnings will depend on whether a recognition event has occurred; for example, the hedge relationship is discontinued. • Enables application of the critical terms match method for a group of forecasted transactions in cases where both the derivative maturity and the forecasted transactions occur within the same 31-day period or fiscal month. Fair Value Hedges: • Changes in fair value of the hedged item may be based on the contractual coupon’s benchmark rate component determined at hedge inception. Existing GAAP only permits the change in fair value to be based on the full contractual coupon cash flows. • Provides flexibility to enter into partial-term fair value hedges. Specifically, permits assuming that the hedged item has a term that reflects only the designated cash flows being hedged. Existing GAAP does not permit this approach. • Permits us to hedge a closed portfolio of prepayable financial assets or one or more beneficial interests secured by a portfolio of prepayable financial instruments if we can designate as the hedged item a stated amount of the asset or assets that are not expected to be affected by prepayments, defaults, and other factors affecting the timing and amount of cash flows, provided the designation is made in conjunction with the partial-term hedging election. This designation is referred to as the last-of-layer-method. Under this designation, prepayment risk is not incorporated into the measurement of the hedged item. Cash Flow Hedges and Fair Value Hedges: • Requires both the effective and ineffective portion of a hedging relationship to be presented in either interest income or interest expense, whichever is appropriate. As a result, ineffectiveness related to hedging relationships would no longer be presented in derivatives and hedging activities. • Enables the initial prospective quantitative hedge effectiveness assessment to be performed after hedge designation but no later than the end of the reporting period in which the hedge designation was made. Hedge effectiveness testing should use data applicable as of the hedge inception date. • Enables applying the long-haul method of assessing hedge effectiveness in cases where the shortcut method was initially applied but subsequently becomes no longer appropriate. This is provided only if we documented at hedge inception which long-haul methodology we will use in the event the shortcut method is discontinued. • A change in the original risk being hedged that is beyond our control (e.g., discontinuance of LIBOR) does not necessarily require de-designating the hedge relationship. Specifically, as long as the hedge effectiveness test is still met based on the new risk being hedged (e.g., OIS index), then the hedge relationship and hedge accounting treatment may continue. Transition: • Upon adoption, a cumulative-effect adjustment relating to eliminating the separate measurement of ineffectiveness to AOCI with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year that we adopt these amendments to hedge accounting ineffectiveness into earnings. • Permits us to modify our measurement methodology for a hedged item without de-designation of the hedging relationship. The cumulative basis adjustment carried forward is adjusted to an amount that reflects what the cumulative basis adjustment would have been at the date of adoption had the modified measurement method been used in past reporting periods. The adjustment requires defining the benchmark rate component of the contractual coupon rate cash flows to be determined as of the hedge relationship’s original inception date. We also may elect to de-designate a portion of the hedged item and reclassify the basis adjustment attributable to the portion of the hedged item de-designated to the opening balance of retained earnings as of the initial application. • We are permitted to reclassify a debt security from held-to-maturity to available-for-sale if the debt security is eligible to be hedged under the last-of-the layer method. Any unrealized gain or loss at the date of the transfer should be recorded in accumulated other comprehensive income. As discussed above, the last-of-the-layer-method represents a hedge by us of a closed portfolio amount of prepayable financial assets for which the timing and amount of cash flows are not expected to be affected by prepayments, defaults, and other events. The amended accounting guidance is required only prospectively. We are in the process of determining the expected effect of this guidance on our financial condition, results of operations, and cash flows. Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March of 2017, the FASB amended existing GAAP to require the service cost component of our net periodic pension and postretirement benefit costs to be classified as compensation costs. The other components of our net periodic pension and postretirement benefit costs are required to be classified as Noninterest expense - Other operating expenses. We adopted the new guidance on January 1, 2018 on a prospective rather than the required retrospective basis due to the immaterial effect the new guidance had on our 2016 and 2017 statements of income. Our prior practice was to classify our total net periodic pension and postretirement costs as compensation costs. Classification of Certain Cash Receipts and Cash Payments in the Statement of Cash Flows In August of 2016, the FASB issued statement of cash flows classification guidance governing certain cash receipts and cash payments. The new guidance became effective on January 1, 2018. The new guidance did not have any effect on our financial condition, results of operations, and cash flows at the time of adoption. Transition provisions were not applicable to us since our existing practice was consistent with the new guidance applicable to us. In particular: • We classify cash payments related to prepaying or extinguishing our consolidated obligations as financing activities in our statements of cash flows. • We classify the cash payments attributable to interest expense paid at the maturity of our discount notes, which have a zero coupon rate, as operating activities in our statements of cash flows and in our supplemental disclosure of interest expense paid. Measurement of Credit Losses on Financial Instruments In June of 2016, the FASB amended existing GAAP guidance applicable to measuring credit losses on financial instruments. Specifically, the amendment replaces the “incurred loss” impairment methodology applied under current GAAP with an “expected credit losses” methodology. The expected credit losses methodology requires us to estimate all credit losses on financial instruments carried on an amortized cost basis and off-balance-sheet credit exposures over their contractual term. On balance sheet financial instruments include, but are not limited to, advances, MPF Loans held in portfolio, and Held-to-maturity (HTM) securities. Off-balance-sheet credit exposure refers to unfunded credit exposures, such as standby letters of credit. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the financial instrument’s reported amount. Accordingly, the amendment is expected to result in recognizing credit losses in the financial statements on a timelier basis by utilizing forward looking information. In addition, the accounting for securities is amended as follows: • Aligns the income statement recognition of credit losses for securities with the reporting period in which changes in collectability occur by recording credit losses (and subsequent reversals) through an allowance rather than a write-down as currently required under GAAP. • Requires recognition of a credit loss on available-for-sale (AFS) securities into the income statement if the present value of cash flows expected to be collected on the security is less than its amortized cost basis. Additionally, the allowance on AFS debt securities will be limited to the amount by which fair value is less than the amortized cost basis. • Expands upon the current credit quality disclosures by requiring further disaggregation of financial instruments by their year of origination. This disclosure is expected to help financial statement users better understand credit quality trends of asset portfolios. The new guidance takes effect January 1, 2020. Upon adoption, any difference in the credit loss amount attributable to both our on balance sheet and off-balance sheet financial instruments resulting from applying the expected credit loss methodology compared to our existing incurred loss methodology will be recognized as a cumulative-effect adjustment to our January 1, 2020 opening retained earnings balance. A prospective transition approach is required for debt securities. Accordingly, any OTTI write-downs on securities recognized prior to January 1, 2020 may not be reversed at the time of our adoption. Improvements in expected cash flows for these securities will continue to be accounted for as yield adjustments over their remaining life. Additionally, recoveries for these securities will be recorded in earnings only when received. We are in the process of reviewing the expected effect of this guidance on our financial condition, results of operations, and cash flows. Leases In February of 2016, the FASB issued new guidance pertaining to lease accounting that becomes effective January 1, 2019. The new guidance requires us to recognize operating leases and right-to-use assets with terms exceeding 12 months, if any, in our statements of condition. Our existing practice is to recognize operating leases off-balance sheet. The expense related to our lease payments and the interest expense on our lease obligations will continue to be included in a single line item in our statements of income. A modified retrospective transition approach is required to be applied to leases existing at, or entered into after, January 1, 2018. We do not expect the new guidance to have a significant effect on our financial condition, results of operations, and cash flows since our existing off-balance sheet operating leases are not material. Recognition and Measurement of Financial Assets and Financial Liabilities In January of 2016, the FASB issued new guidance governing the recognition and measurement of financial assets and financial liabilities. We adopted the new guidance on January 1, 2018. Under the new guidance, we will separately present financial assets and financial liabilities by measurement category, such as amortized cost, and by form, such as securities or loans, in the accompanying notes to the financial statements. The new guidance did not have a significant effect on our financial condition, results of operations, and cash flows for the reasons outlined below. • The fair value option will continue to be permitted under this guidance. • We measure the portion of instrument-specific credit risk attributable to the total change in fair value of our consolidated obligations carried at fair value under the fair value option based on our nonperformance risk, which includes our own credit risk and the credit risk associated with the joint and several liability of other FHLBs. As a result, we did not recognize any instrument-specific credit risk attributable to the total change in fair value of our consolidated obligations in other comprehensive income at the time of adoption. In the event that the instrument-specific credit risk attributable to the total change in fair value of our consolidated obligations were to become significant, that amount would be recognized in other comprehensive income. Revenue from Contracts with Customers

Interest Income and Interest Ex

Interest Income and Interest Expense	12 Months Ended
	Dec. 31, 2017
Interest Income (Expense), Net [Abstract]
Interest Income and Interest Expense Disclosure [Text Block]	Interest Income and Interest Expense The following table presents interest income and interest expense for the periods indicated: For the years ended December 31, 2017 2016 2015 Interest income - Trading $ 4 $ 10 $ 4 Available-for-sale interest income 428 440 471 Available-for-sale prepayment fees 27 45 60 Available-for-sale 455 485 531 Held-to-maturity interest income 195 222 255 Held-to-maturity prepayment fees 2 2 15 Held-to-maturity 197 224 270 Investment securities 656 719 805 Advances 560 290 181 MPF Loans held in portfolio 213 218 256 Federal Funds sold and securities purchased under agreements to resell 115 25 8 Other interest bearing assets 14 7 2 Interest income 1,558 1,259 1,252 Interest expense - Consolidated obligations - Discount notes 527 359 294 Bonds 533 411 396 Subordinated notes — 24 54 Other interest bearing liabilities 15 9 — Interest expense 1,075 803 744 Net interest income 483 456 508 Provision for (reversal of) credit losses — 1 5 Net interest income after provision for (reversal of) credit losses $ 483 $ 455 $ 503

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities [Text Block]	Investment Securities We classify securities as either trading, held-to-maturity (HTM), or available-for-sale (AFS). Our security disclosures within these classifications are disaggregated by major security types as shown below. Our major security types are based on the nature and risks of the security. • U.S. Government & other government related may consist of the sovereign debt of the United States; debt issued by government sponsored enterprises (GSE); and non-mortgage-backed securities of the Small Business Administration and Tennessee Valley Authority. • Federal Family Education Loan Program - asset backed securities (FFELP ABS). • GSE residential mortgage-backed securities (MBS) issued by Fannie Mae and Freddie Mac. • Government-guaranteed MBS. • Private-label residential MBS. • State or local housing agency obligations. Pledged Collateral We disclose the amount of investment securities pledged as collateral pertaining to our derivatives activity on our statements of condition. See Note 9 - Derivatives and Hedging Activities for further details. Trading Securities The following table presents the fair value of our trading securities. Our unrealized gains or losses on trading securities still held on our statement of condition as of the end of the reporting period were no t material. As of December 31, 2017 December 31, 2016 U.S. Government & other government related $ 202 $ 1,005 Residential MBS GSE 30 39 Government-guaranteed 1 1 Trading securities $ 233 $ 1,045 Amortized Cost Basis and Fair Value – Available-for-Sale Securities (AFS) Amortized Cost Basis Gross Unrealized Gains in AOCI Gross Unrealized (Losses) in AOCI Carrying Amount and Fair Value As of December 31, 2017 U.S. Government & other government related $ 256 $ 15 $ — $ 271 State or local housing agency 21 — — 21 FFELP ABS 3,987 234 (7 ) 4,214 Residential MBS: GSE 7,275 132 (1 ) 7,406 Government-guaranteed 971 24 — 995 Private-label 40 10 — 50 Available-for-sale securities $ 12,550 $ 415 $ (8 ) $ 12,957 As of December 31, 2016 U.S. Government & other government related $ 322 $ 15 $ (1 ) $ 336 State or local housing agency 19 — — 19 FFELP ABS 4,431 165 (24 ) 4,572 Residential MBS: GSE 8,291 266 (2 ) 8,555 Government-guaranteed 1,346 34 — 1,380 Private-label 50 6 — 56 Available-for-sale securities $ 14,459 $ 486 $ (27 ) $ 14,918 We had no sales of AFS securities for the periods presented. Amortized Cost Basis, Carrying Amount, and Fair Value - Held-to-Maturity Securities (HTM) Amortized Cost Basis Noncredit OTTI Recognized in AOCI Carrying Amount Gross Unrecognized Holding Gains Gross Unrecognized Holding (Losses) Fair Value As of December 31, 2017 U.S. Government & other government related $ 1,531 $ — $ 1,531 $ 29 $ (1 ) $ 1,559 State or local housing agency 9 — 9 — — 9 Residential MBS: GSE 1,513 — 1,513 62 — 1,575 Government-guaranteed 585 — 585 6 — 591 Private-label 662 (143 ) 519 285 — 804 Held-to-maturity securities $ 4,300 $ (143 ) $ 4,157 $ 382 $ (1 ) $ 4,538 As of December 31, 2016 U.S. Government & other government related $ 1,733 $ — $ 1,733 $ 42 $ (1 ) $ 1,774 State or local housing agency 13 — 13 — — 13 Residential MBS: GSE 1,856 — 1,856 100 — 1,956 Government-guaranteed 791 — 791 10 — 801 Private-label 856 (177 ) 679 294 (1 ) 972 Held-to-maturity securities $ 5,249 $ (177 ) $ 5,072 $ 446 $ (2 ) $ 5,516 We had no sales of HTM securities for the periods presented. Interest Rate Payment Terms The following table presents the interest rate payment terms of AFS and HTM securities at amortized cost basis for the reporting periods indicated. Available-for-Sale Held-to-Maturity As of December 31, 2017 2016 2017 2016 Non-MBS: Fixed-rate $ 275 $ 336 $ 1,531 $ 1,732 Variable-rate 3,989 4,436 9 14 Non-MBS 4,264 4,772 1,540 1,746 Residential MBS: Fixed-rate 7,653 8,955 1,614 2,034 Variable-rate 633 732 1,146 1,469 Residential MBS 8,286 9,687 2,760 3,503 Total $ 12,550 $ 14,459 $ 4,300 $ 5,249 Contractual Maturity The following table presents the aging of our investments for the current year, as well as the carrying amounts for the previous two years. It also discloses the yields by aging categories for the current year. 2017 2016 2015 As of December 31, Due in one year or less Due one through five years Due five through ten years Due after ten years Carrying Amount Carrying Amount Carrying Amount Trading securities- U.S. Government & other governmental related $ 202 $ — $ — $ — $ 202 $ 1,005 $ 1,108 Residential MBS: GSE — — — 30 30 39 50 Government guaranteed — — 1 — 1 1 2 Trading securities 202 — 1 30 233 1,045 1,160 Yield on trading securities 1.37 % — % 2.37 % 4.40 % 1.76 % 1.13 % 0.93 % AFS securities- U.S. Government & other governmental related — 26 50 195 271 336 422 State or local housing agency 2 4 9 6 21 19 18 FFELP ABS — — — 4,214 4,214 4,572 5,299 Residential MBS: GSE — 7,328 5 73 7,406 8,555 9,798 Government-guaranteed — — — 995 995 1,380 1,868 Private-label — — — 50 50 56 65 AFS securities 2 7,358 64 5,533 12,957 14,918 17,470 Yield on AFS securities 1.71 % 4.46 % 4.85 % 3.40 % 4.01 % 4.04 % 4.14 % HTM securities- U.S. Government & other governmental related 678 172 115 566 1,531 1,733 1,932 State or local housing agency — 6 3 — 9 13 16 Residential MBS: GSE 1 908 67 537 1,513 1,856 2,163 Government-guaranteed — 85 4 496 585 791 969 Private-label — — — 519 519 679 887 HTM securities 679 1,171 189 2,118 4,157 5,072 5,967 Yield on HTM securities 1.80 % 3.34 % 4.01 % 3.47 % 3.19 % 3.18 % 3.12 % Investment securities 883 8,529 254 7,681 17,347 21,035 24,597 Interest bearing deposits 775 775 650 650 Federal Funds sold 7,561 7,561 4,075 1,702 Securities purchased under agreements to resell 5,000 5,000 2,300 1,375 Investments $ 14,219 $ 8,529 $ 254 $ 7,681 $ 30,683 $ 28,060 $ 28,324 Aging of Unrealized Temporary Losses The following table presents unrealized temporary losses on our AFS and HTM portfolio for periods less than 12 months and for 12 months or more. We recognized no OTTI charges on these unrealized loss positions. Refer to the Other-Than-Temporary Impairment Analysis section below for further discussion. In the tables below, in cases where the gross unrealized losses for an investment category are less than $1 million, the losses are not reported. Less than 12 Months 12 Months or More Total Fair Value Gross Unrealized (Losses) Fair Value Gross Unrealized (Losses) Fair Value Gross Unrealized (Losses) Available-for-Sale Securities As of December 31, 2017 U.S. Government & other government related $ 3 $ — $ — $ — $ 3 $ — State or local housing agency 4 — — — 4 — FFELP ABS — — 644 (7 ) 644 (7 ) Residential MBS: GSE 51 — 801 (1 ) 852 (1 ) Private-label — — 7 — 7 — Available-for-sale securities $ 58 $ — $ 1,452 $ (8 ) $ 1,510 $ (8 ) As of December 31, 2016 U.S. Government & other government related $ — $ — $ 47 $ (1 ) $ 47 $ (1 ) State or local housing agency 7 — — — 7 — FFELP ABS — — 753 (24 ) 753 (24 ) Residential MBS: GSE — — 991 (2 ) 991 (2 ) Government-guaranteed — — 23 — 23 — Private-label — — 8 — 8 — Available-for-sale securities $ 7 $ — $ 1,822 $ (27 ) $ 1,829 $ (27 ) Held-to-Maturity Securities As of December 31, 2017 U.S. Government & other government related $ 594 $ — $ 24 $ (1 ) $ 618 $ (1 ) State or local housing agency 2 — — — 2 — Residential MBS: GSE — — 2 — 2 — Private-label — — 769 (143 ) 769 (143 ) Held-to-maturity securities $ 596 $ — $ 795 $ (144 ) $ 1,391 $ (144 ) As of December 31, 2016 U.S. Government & other government related $ 26 $ — $ 17 $ (1 ) $ 43 $ (1 ) State or local housing agency — — 1 — 1 — Residential MBS: GSE — — 4 — 4 — Government-guaranteed 117 — — — 117 — Private-label — — 934 (178 ) 934 (178 ) Held-to-maturity securities $ 143 $ — $ 956 $ (179 ) $ 1,099 $ (179 ) Other-Than-Temporary Impairment We recognized no OTTI charges on HTM or AFS securities for the year ending December 31, 2017 . This is because we do not intend to sell these securities and we believe it is more likely than not that we will not be required to sell them prior to recovering their amortized cost basis. We also recognized no OTTI charges for the years ending December 31, 2016 or December 31, 2015 . We assess a security for OTTI whenever its fair value is less than its amortized cost basis as of the reporting date. Our assessment entails generating cash flow projections to determine OTTI, if any, on our private-label MBS. Our initial cash flow projections are based on key modeling assumptions, significant inputs, and methodologies provided by an FHLB System OTTI Committee, which was formed by the FHLBs to achieve consistency among the FHLBs in their OTTI analyses for private-label MBS. We then determine the final cash flow projections after assessing the reasonableness of, and if necessary, modifying those assumptions, significant inputs, and methodologies used. We also perform present value calculations using appropriate historical cost bases and yields to crosscheck the reasonableness of the final cash flow projections. OTTI exists when a security's cash flow projection is not expected to result in the recovery of its entire amortized cost basis. As of December 31, 2017 , we had a short-term housing price forecast with projected changes ranging from -5.0% to +12.0% over the twelve month period beginning October 1, 2017 over all markets. For the vast majority of markets, the short-term forecast has changes ranging from +2.0% to +6.0% . Based on these inputs and assumptions, we had no OTTI charge for the year ended December 31, 2017 . Unpaid Principal Balance, Amortized Cost, Carrying Amount, and Fair Value - OTTI Private-Label MBS The following table presents private-label MBS that have incurred OTTI at some point in time since we acquired the security. Each private-label MBS presented below is classified as prime, subprime, or Alt-A. Such classification depends upon the nature of the majority of underlying mortgages collateralizing each private-label MBS based on the issuer's classification, or as published by a nationally recognized statistical rating organization (NRSRO), at the time of issuance of the MBS. As of December 31, 2017 Unpaid Principal Balance Amortized Cost Basis Noncredit OTTI in AOCI Gross Unrealized Gains Carrying Amount Fair Value Private-label residential MBS: OTTI AFS Securities- Alt-A $ 61 $ 40 $ — $ 9 $ 49 $ 49 OTTI HTM Securities- Prime $ 535 $ 430 $ (107 ) $ — $ 323 $ 479 Subprime 368 194 (36 ) — 158 285 OTTI HTM securities $ 903 $ 624 $ (143 ) $ — $ 481 $ 764 The following table presents the changes in the cumulative amount of OTTI credit losses previously recognized into earnings on investment securities for the reporting periods indicated. For the years ended December 31, 2017 2016 2015 Beginning Balance $ 520 $ 568 $ 620 Reductions: Securities sold, matured, or fully prepaid over the period (1 ) — — Increases in expected future cash flows recorded as credit-related accretion into interest income (42 ) (48 ) (52 ) Ending Balance $ 477 $ 520 $ 568 Ongoing Litigation On October 15, 2010, we instituted litigation relating to 64 private label MBS bonds we purchased. While we continue to pursue this litigation, we have recognized litigation settlement awards with respect to these matters as noted in our statements of income for the periods presented. As of December 31, 2017 , the remaining litigation covers three private-label MBS bonds in the aggregate principal amount of $38 million

Advances

Advances	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank, Advances [Text Block]	Advances We offer a wide range of fixed- and variable-rate advance products with different maturities, interest rates, payment characteristics and optionality. The following table presents our advances by terms of contractual maturity. Actual maturities may differ from contractual maturities because some borrowers have the right to call or prepay advances with or without penalties. As of December 31, 2017 Amount Weighted Average Interest Rate Due in one year or less $ 22,177 1.42 % One to two years 2,314 1.65 % Two to three years 1,698 1.91 % Three to four years 1,994 1.65 % Four to five years 3,168 1.78 % More than five years 16,669 1.54 % a Par value $ 48,020 1.52 % a The weighted average interest rate is relatively lower when compared to other categories due to a majority of advances in this category consisting of variable rate advances which reset periodically at current interest rates. See Note 2 - Summary of Significant Accounting Policies for information related to our accounting for advances. See Note 8 - Allowance for Credit Losses for information related to our credit risk on advances and allowance methodology for credit losses. The following table presents our advances by payment terms as of the dates indicated. As of December 31, 2017 December 31, 2016 Fixed-rate due in one year or less $ 9,544 $ 9,473 Fixed-rate due after one year 7,732 5,704 Total fixed-rate 17,276 15,177 Variable-rate due in one year or less 12,633 10,960 Variable-rate due after one year 18,111 18,828 Total variable-rate 30,744 29,788 Par value 48,020 44,965 Fair value hedging adjustments 69 98 Other adjustments (4 ) 4 Advances $ 48,085 $ 45,067 The following advance borrowers exceeded 10% of our advances outstanding: As of December 31, 2017 Par Value % of Total Outstanding One Mortgage Partners Corp. $ 11,000 a 22.9 % The Northern Trust Company 6,000 12.5 % BMO Harris Bank, NA 5,975 12.4 % a

MPF Loans Held in Portfolio

MPF Loans Held in Portfolio	12 Months Ended
	Dec. 31, 2017
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, by Loan Disclosure [Text Block]	MPF Loans Held in Portfolio We acquire MPF Loans from PFIs to hold in our portfolio and historically purchased participations in pools of eligible mortgage loans from other FHLBs (MPF Banks). MPF Loans that are held in portfolio are fixed-rate conventional and Government Loans secured by one-to-four family residential properties with maturities ranging from 5 years to 30 years or participations in pools of similar eligible mortgage loans from other MPF Banks. The following table presents information on MPF Loans held in portfolio by contractual maturity at the time of purchase. As of December 31, 2017 December 31, 2016 Medium term (15 years or less) $ 285 $ 417 Long term (greater than 15 years) 4,835 4,489 Unpaid principal balance 5,120 4,906 Net premiums, credit enhancement and deferred loan fees 55 38 Fair value hedging adjustments 20 26 MPF Loans held in portfolio, before allowance for credit losses 5,195 4,970 Allowance for credit losses on MPF Loans (2 ) (3 ) MPF Loans held in portfolio, net $ 5,193 $ 4,967 Conventional mortgage loans $ 4,133 $ 3,818 Government Loans 987 1,088 Unpaid principal balance $ 5,120 $ 4,906 The above table excludes MPF Loans acquired under the MPF Xtra, MPF Direct, and MPF Government MBS products. See Note 2 - Summary of Significant Accounting Policies for information related to the accounting treatment of these off balance sheet MPF Loan products. See Note 8 - Allowance for Credit Losses

Allowance for Credit Losses

Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Credit Losses [Text Block]	Allowance for Credit Losses See Note 2 - Summary of Significant Accounting Policies for further details regarding our allowance for credit losses methodology for each of our portfolio segments discussed below. • Member credit products (advances, letters of credit and other extensions of credit to borrowers); • Conventional MPF Loans held in portfolio; • Government Loans held in portfolio; and • Federal Funds sold and securities purchased under agreements to resell. Member Credit Products We have not recorded any allowance for credit losses for our member credit products portfolio segment based upon our credit analysis and the repayment history on member credit products. We had no member credit products that were past due, on nonaccrual status, involved in a troubled debt restructuring or otherwise considered impaired. We have not recorded a separate liability to reflect credit losses on our member credit products with off-balance sheet credit exposure. Conventional MPF Loans Held in Portfolio The following table presents the changes in the allowance for credit losses attributable to our portfolio segment for conventional MPF Loans held in portfolio. FHFA regulatory guidance that became effective January 1, 2015, resulted in the increased amount of losses charged to the allowance during 2015. For the years ended December 31, 2017 2016 2015 Balance, beginning of period $ 3 $ 3 $ 15 Losses charged to the allowance (1 ) (1 ) (17 ) Provision for (reversal of) credit losses — 1 5 Balance, end of period $ 2 $ 3 $ 3 The following table presents the recorded investment and the allowance for credit losses in conventional MPF Loans by impairment methodology. The recorded investment in a conventional MPF Loan includes its amortized cost basis and related accrued interest receivable, if any. The recorded investment in a conventional MPF Loan excludes our allowance for credit losses. As of December 31, 2017 December 31, 2016 Recorded investment in conventional MPF Loans - Individually evaluated for impairment $ 49 $ 74 Collectively evaluated for impairment 4,167 3,812 Recorded investment $ 4,216 $ 3,886 Allowance for credit losses on conventional MPF Loans - Collectively evaluated for impairment $ 2 $ 3 Government Loans Held in Portfolio Servicers are responsible for absorbing any losses incurred on Government Loans held in portfolio that are not recovered from the government insurer or guarantor. We did not establish an allowance for credit losses on our Government Loans held in portfolio for the reporting periods presented based on our assessment that our servicers have the ability to absorb such losses. Further, Government Loans were not placed on nonaccrual status or disclosed as troubled debt restructurings for the same reason. Credit Quality Indicators - MPF Loans Held in Portfolio The following table summarizes our recorded investment in MPF Loans by our key credit quality indicators, which include: • "Serious delinquency rate" consists of MPF Loans that are 90 days or more past due or in the process of foreclosure, as a percentage of the total recorded investment. MPF Loans that are both 90 days or more past due and in the process of foreclosure are only included once in our serious delinquency rate calculation. • "Past due 90 days or more still accruing interest" consists of MPF Loans that are either insured or guaranteed by the government or conventional mortgage loans that are well secured (by collateral that have a realizable value sufficient to discharge the debt or by the guarantee or insurance, such as primary mortgage insurance, of a financially responsible party) and in the process of collection. December 31, 2017 December 31, 2016 As of Conventional Government Total Conventional Government Total Past due 30-59 days $ 74 $ 48 $ 122 $ 83 $ 57 $ 140 Past due 60-89 days 21 16 37 26 17 43 Past due 90 days or more 48 21 69 69 23 92 Past due 143 85 228 178 97 275 Current 4,073 921 4,994 3,708 1,013 4,721 Recorded investment $ 4,216 $ 1,006 $ 5,222 $ 3,886 $ 1,110 $ 4,996 In process of foreclosure $ 21 $ 7 $ 28 $ 35 $ 7 $ 42 Serious delinquency rate 1.16 % 2.11 % 1.34 % 1.82 % 2.07 % 1.88 % Past due 90 days or more and still accruing interest $ 8 $ 21 $ 29 $ 8 $ 23 $ 31 On nonaccrual status $ 49 $ — $ 49 $ 74 $ — $ 74 Individually Evaluated Impaired Conventional MPF Loans The following table summarizes the recorded investment and unpaid principal balance of individually evaluated impaired conventional MPF Loans. Conventional MPF Loans are individually evaluated for impairment when they are adversely classified. There is no allowance for credit losses attributable to conventional MPF Loans that are individually evaluated for impairment, since the related allowance for credit losses have been charged off. As of December 31, 2017 December 31, 2016 Recorded investment without an allowance for credit losses $ 49 $ 74 Unpaid principal balance without an allowance for credit losses 53 80 We do not recognize interest income on impaired conventional MPF Loans. Term Federal Funds Sold and Term Securities Purchased Under Agreements to Resell We only held overnight Federal Funds sold and Securities Purchased Under Agreements to Resell as of December 31, 2017 , and December 31, 2016

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities [Text Block]	Derivatives and Hedging Activities Refer to Note 2 - Summary of Significant Accounting Policies for our accounting policies for derivatives. We transact most of our derivatives with large banks and major broker-dealers. Some of these banks and broker-dealers or their affiliates buy, sell, and distribute consolidated obligations. We are not a derivatives dealer and do not trade derivatives for speculative purposes. We enter into derivative transactions through either of the following: • A bilateral agreement with an individual counterparty for over-the-counter derivative transactions. • Clearinghouses classified as DCOs through FCMs, which are clearing members of the DCOs, for cleared derivative transactions. Managing Interest Rate Risk We use fair value hedges to offset changes in the fair value or a benchmark interest rate (e.g., LIBOR) related to (1) a recognized asset or liability or (2) an unrecognized firm commitment. We use cash flow hedges to offset an exposure to variability in expected future cash flows associated with an existing recognized asset or liability or a forecasted transaction. We use economic hedges in cases where hedge accounting treatment is not permitted or achievable; for example, hedges of portfolio interest rate risk or financial instruments carried at fair value under the fair value option. Managing Credit Risk on Derivative Agreements Over-the-counter (bilateral) Derivative Transactions : We are subject to credit risk due to the risk of nonperformance by counterparties to our derivative agreements. For bilateral derivative agreements, the degree of counterparty risk depends on the extent to which master netting arrangements, collateral requirements and other credit enhancements are included in such contracts to mitigate the risk. We manage counterparty credit risk through credit analysis, collateral requirements and adherence to the requirements set forth in our policies and FHFA regulations. We require collateral agreements on all over-the-counter derivatives. Additionally, collateral related to over-the-counter derivatives with member institutions includes collateral assigned to us, as evidenced by a written security agreement, and which may be held by the member institution for our benefit. Based on credit analyses and collateral requirements, we do not anticipate any credit losses on our over-the-counter derivative agreements. See Note 16 - Fair Value for discussion regarding our fair value methodology for over-the-counter derivative assets and liabilities, including an evaluation of the potential for the fair value of these instruments to be affected by counterparty credit risk. For nearly all of our bilateral derivative transactions executed prior to March 1, 2017, and for all transactions entered into after March 1, 2017, our bilateral derivative agreements are fully collateralized with a zero unsecured threshold in accordance with variation margin requirements issued by the U.S. federal bank regulatory agencies and the CFTC. For certain transactions executed prior to March 1, 2017, we may be required to post net additional collateral with our counterparties if there is deterioration in our credit rating . If our credit rating had been lowered from its current rating to the next lower rating by a major credit rating agency, such as Standard and Poor's, or Moody’s, the amount of collateral we would have been required to deliver would no t have been material at December 31, 2017 . Cleared Derivative Transactions : Cleared derivative transactions are subject to variation and initial margin requirements established by the DCO and its clearing members. As a result of rule changes adopted by our DCOs, variation margin payments are characterized as settlement of a derivative’s mark-to-market exposure and not as collateral against the derivative’s mark-to-market exposure. See Note 1 - Background and Basis of Presentation and Note 2 - Summary of Significant Accounting Policies for further discussion. We post our initial margin collateral payments and make variation margin settlement payments through our FCMs, on behalf of the DCO, which could expose us to institutional credit risk in the event that the FCMs or the DCO fail to meet their obligations. Clearing derivatives through a DCO mitigates counterparty credit risk exposure because the DCO is substituted for individual counterparties and variation margin settlement payments are made daily through the FCMs for changes in the value of cleared derivatives . The DCO determines initial margin requirements for cleared derivatives. In this regard, we pledged $67 million of investment securities at December 31, 2017 that can be sold or repledged, as part of our initial margin related to cleared derivative transactions. Additionally, an FCM may require additional initial margin to be posted based on credit considerations, including, but not limited to, if our credit rating is downgraded. We had no requirement to post additional initial margin by our FCMs at December 31, 2017 . The following table presents details on the notional amounts, and derivative assets and liabilities on our statements of condition. Effective in January of 2017, we began treating daily variation margin on our cleared derivatives as cash settlements instead of as cash collateral. December 31, 2017 December 31, 2016 As of Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives in hedge accounting relationships- Interest rate contracts $ 26,655 $ 57 $ 589 $ 25,999 $ 40 $ 898 Derivatives not in hedge accounting relationships- Interest rate contracts 20,506 270 157 29,313 432 260 Other 810 1 1 892 2 3 Derivatives not in hedge accounting relationships 21,316 271 158 30,205 434 263 Variation margin daily settlements on cleared derivatives (16 ) (168 ) Gross derivative amount before netting adjustments and cash collateral $ 47,971 312 579 $ 56,204 474 1,161 Netting adjustments and cash collateral (309 ) a (559 ) a (468 ) a (1,118 ) a Derivatives on statements of condition $ 3 $ 20 $ 6 $ 43 a Cash collateral received was $35 million and $40 million , and cash collateral posted was $284 million and $689 million at December 31, 2017 , and December 31, 2016 . The following table presents the noninterest income on derivatives and hedging activities as presented in the statements of income. The amounts attributable to fair value and cash flow hedges represent hedge ineffectiveness. For the years ending December 31, 2017 2016 2015 Fair value hedges - interest rate contracts $ (4 ) $ 7 $ (35 ) Cash flow hedges - interest rate contracts 3 5 3 Economic hedges - Interest rate contracts 4 (15 ) 15 Other 3 4 1 Economic hedges 7 (11 ) 16 Variation margin on daily settled cleared derivatives 2 — — Noninterest income on derivatives and hedging activities $ 8 $ 1 $ (16 ) The following table presents details regarding the offsetting of our derivative assets and liabilities on our statements of condition. Effective in January of 2017, we began treating daily variation margin on our cleared derivatives as cash settlements instead of as cash collateral . Derivative Assets Derivative Liabilities Bilateral Cleared Total Bilateral Cleared Total As of December 31, 2017 Derivatives with legal right of offset - Gross recognized amount $ 216 $ 95 $ 311 $ 476 $ 102 $ 578 Netting adjustments and cash collateral (214 ) (95 ) (309 ) (463 ) (96 ) (559 ) Derivatives with legal right of offset - net 2 — 2 13 6 19 Derivatives without legal right of offset 1 — 1 1 — 1 Derivatives on statements of condition 3 — 3 14 6 20 Less: Noncash collateral received and cannot be sold or repledged — — — 6 6 Noncash collateral pledged and cannot be sold or repledged (1 ) (1 ) Net amount $ 3 $ 1 $ 4 $ 14 $ — $ 14 As of December 31, 2016 Derivatives with legal right of offset - Gross recognized amount $ 339 $ 133 $ 472 $ 820 $ 339 $ 1,159 Netting adjustments and cash collateral (335 ) (133 ) (468 ) (788 ) (330 ) (1,118 ) Derivatives with legal right of offset - net 4 — 4 32 9 41 Derivatives without legal right of offset 2 — 2 2 — 2 Derivatives on statements of condition 6 — 6 34 9 43 Less: Noncash collateral received and cannot be sold or repledged — — — 9 9 Cash collateral for initial margin (1 ) (1 ) Noncash collateral pledged and cannot be sold or repledged (2 ) (2 ) Net amount $ 6 $ 3 $ 9 $ 34 $ — $ 34 At December 31, 2017 , we had $60 million of additional credit exposure on cleared derivatives due to pledging of noncash collateral to our DCOs, for initial margin, which exceeded our derivative liability position. We had $86 million of comparable exposure at December 31, 2016 . Fair Value Hedges The following table presents our fair value hedging results by the type of hedged item. We had no gain (loss) for hedges that no longer qualified as a fair value hedge. Additionally, the table indicates where fair value hedging results are classified in our statements of income. In this regard, the Amount Recorded in Net Interest Income column includes the following: • The amortization of closed fair value hedging adjustments, which are included in the interest income/expense line item of the respective hedged item type. • The effect of net interest settlements attributable to open derivative hedging instruments, which are recorded directly to the interest income/expense line item of the respective hedged item type. For the years ending December 31, Gain (Loss) on Hedging Instrument Gain (Loss) on Hedged Item Total Ineffectiveness Recognized in Derivatives and Hedging Activities Amount Recorded in Net Interest Income 2017 Available-for-sale securities $ 91 $ (100 ) $ (9 ) $ (90 ) Advances 31 (29 ) 2 (32 ) MPF Loans held in portfolio — — — (6 ) Consolidated obligation bonds 5 (2 ) 3 31 Total $ 127 $ (131 ) $ (4 ) $ (97 ) 2016 Available-for-sale securities $ 86 $ (85 ) $ 1 $ (122 ) Advances 66 (59 ) 7 (70 ) MPF Loans held in portfolio — — — (9 ) Consolidated obligation bonds (140 ) 139 (1 ) 62 Total $ 12 $ (5 ) $ 7 $ (139 ) 2015 Available-for-sale securities $ 43 $ (56 ) $ (13 ) $ (146 ) Advances 6 (5 ) 1 (84 ) MPF Loans held in portfolio — — — (13 ) Consolidated obligation bonds 46 (69 ) (23 ) 205 Total $ 95 $ (130 ) $ (35 ) $ (38 ) Cash Flow Hedges We reclassify amounts in AOCI into our statements of income in the same periods during which the hedged forecasted transaction affects our earnings. We had no discontinued hedges for the periods presented. The deferred net gains (losses) on derivative instruments in AOCI that are expected to be reclassified to earnings during the next twelve months were no t material as of December 31, 2017 . The maximum length of time over which we are hedging our exposure to the variability in future cash flows for forecasted transactions is 3 years . The following table presents our cash flow hedging results by type of hedged item. Additionally, the table indicates where cash flow hedging results are classified in our statements of income. In this regard, the Amount Recorded in Net Interest Income column includes the following: • The amortization of closed cash flow hedging adjustments, which are reclassified from AOCI into the interest income/expense line item of the respective hedged item type. • The effect of net interest settlements attributable to open derivative hedging instruments, which are recorded directly to the interest income/expense line item of the respective hedged item type. For the years ending December 31, Ineffectiveness Recorded in Derivatives and Hedging Activities Effective Portion Recorded in AOCI Amount Recorded in Net Interest Income 2017 Advances $ — $ — $ 10 Discount notes 3 173 (168 ) Bonds — — (3 ) Total $ 3 $ 173 $ (161 ) 2016 Advances $ — $ — $ 10 Discount notes 5 161 (195 ) Bonds — — (3 ) Total $ 5 $ 161 $ (188 ) 2015 Advances $ — $ — $ 10 Discount notes 3 125 (242 ) Bonds — — (3 ) Total $ 3 $ 125 $ (235 )

Consolidated Obligations

Consolidated Obligations	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Consolidated Obligations The FHLBs issue consolidated obligations through the Office of Finance as their agent. Consolidated obligations consist of discount notes and consolidated obligation bonds. Consolidated discount notes are issued to raise short-term funds, are issued at less than their face amount and redeemed at par value when they mature. The maturity of consolidated obligation bonds may range from less than one year to over 20 years , but they are not subject to any statutory or regulatory limits on maturity. The following table presents our consolidated obligation discount notes for which we are the primary obligor. All are due in one year or less. As of December 31, 2017 December 31, 2016 Carrying Amount $ 41,191 $ 35,949 Weighted Average Interest Rate 1.23 % 0.46 % The following table presents our consolidated obligation bonds, for which we are the primary obligor, including callable bonds that are redeemable in whole, or in part, at our discretion on predetermined call dates. As of December 31, 2017 Contractual Maturity Weighted Average Interest Rate By Maturity or Next Call Date Due in one year or less $ 16,616 1.25 % $ 27,347 One to two years 7,919 1.32 % 6,749 Two to three years 2,734 1.38 % 1,959 Three to four years 3,739 1.97 % 374 Four to five years 2,823 2.46 % 575 Thereafter 3,516 2.70 % 343 Total par value $ 37,347 1.58 % $ 37,347 The following table presents consolidated obligation bonds outstanding by call feature: As of December 31, 2017 December 31, 2016 Noncallable $ 23,644 $ 22,356 Callable 13,703 14,778 Par value 37,347 37,134 Fair value hedging adjustments (214 ) (229 ) Other adjustments (12 ) (2 ) Consolidated obligation bonds $ 37,121 $ 36,903 Consolidated obligations are issued with either fixed- or floating-rate payment terms that may use a variety of indices for interest rate resets including the London Interbank Offered Rate (LIBOR). Additionally, both fixed-rate bonds and floating-rate bonds may contain an embedded derivative, such as a call feature or complex coupon payment terms, if requested by investors. When such consolidated obligations are issued, we may concurrently enter into an interest rate swap containing offsetting features that effectively convert the terms of the bond to a variable-rate bond tied to an index or a fixed-rate bond. Consolidated obligation bonds, beyond having fixed-rate or floating-rate payment terms, may also have the following broad terms regarding either principal repayment or coupon payment terms: Step-Up Bonds and Step-Down Bonds - Bonds that pay interest at increasing or decreasing fixed rates for specified intervals over their life. These bonds are callable at our option on the step-up or step-down dates. The following table presents interest rate payment terms for consolidated obligation bonds for which we are primary obligor at the dates indicated: As of December 31, 2017 December 31, 2016 Fixed-rate $ 21,357 $ 22,389 Variable-rate 12,884 11,615 Step-up 2,730 2,650 Step-down 366 480 Other 10 — Par value $ 37,347 $ 37,134 The following table summarizes the consolidated obligations of the FHLBs and those for which we are the primary obligor. We did not accrue a liability for our joint and several liability related to the other FHLBs’ share of the consolidated obligations as of December 31, 2017 and December 31, 2016 . Refer to Note 17 - Commitments and Contingencies for further details. December 31, 2017 December 31, 2016 Par values as of Bonds Discount Notes Total Bonds Discount Notes Total FHLB System total consolidated obligations $ 642,211 $ 392,049 $ 1,034,260 $ 579,189 $ 410,122 $ 989,311 FHLB Chicago as primary obligor 37,347 41,235 78,582 37,134 35,969 73,103 As a percent of the FHLB System 6 % 11 % 8 % 6 % 9 % 7 %

Affordable Housing Program (Not

Affordable Housing Program (Notes)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Affordable Housing Program [Text Block]	Affordable Housing Program The Financial Institutions Reform, Recovery and Enforcement Act of 1989 (FIRREA) contains provisions for the establishment of an Affordable Housing Program (AHP) by each FHLB. We provide subsidies in the form of direct grants for members that use the funds for qualifying affordable housing projects. Annually, the FHLB System must set aside for their AHPs, in the aggregate, the greater of $100 million or 10% of the current year's income before assessments excluding any interest expense related to mandatorily redeemable capital stock (MRCS). The exclusion of interest expense related to MRCS is a regulatory calculation that was established by the FHFA. Interest expense related to MRCS for 2017 , 2016 , and 2015 , was $10 million , $6 million , and $0 million . We accrue AHP expense monthly based on our regulatory income and recognize an AHP liability. As subsidies are provided, the AHP liability is reduced. The following table summarizes the changes in the AHP payable for the periods indicated: For the years ended December 31, 2017 2016 2015 AHP balance at beginning of year $ 86 $ 89 $ 90 AHP expense accrual 36 37 39 Cash disbursements for AHP (34 ) (40 ) (40 ) AHP balance at end of year $ 88 $ 86 $ 89

Subordinated Notes

Subordinated Notes	12 Months Ended
	Dec. 31, 2017
Subordinated Debt [Abstract]
Subordinated Notes [Text Block]	Subordinated Notes Subordinated Notes Payoff As approved by the Finance Board (predecessor to the FHFA), we issued $1 billion of 10-year subordinated notes in 2006, and during 2013, we purchased $56 million of these notes in the open market. On June 13, 2016, our remaining $944 million

Capital and Mandatorily Redeema

Capital and Mandatorily Redeemable Capital Stock (MRCS)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Capital and Mandatorily Redeemable Capital Stock (MRCS) Under our Capital Plan our stock consists of two sub-classes of stock, Class B1 activity stock and Class B2 membership stock (together, Class B stock), both with a par value of $100 and redeemable on five years ' written notice, subject to certain conditions. Under the Capital Plan, each member is required to own capital stock in an amount equal to the greater of a membership stock requirement or an activity stock requirement. Class B1 activity stock is available to support a member's activity stock requirement. Class B2 membership stock is available to support a member's membership stock requirement and any activity stock requirement. Members that withdraw from membership must wait at least five years after their membership was terminated and all of their capital stock was redeemed or repurchased before being readmitted to membership in any FHLB. Under our Capital Plan, any dividend declared on Class B1 shares must be greater than or equal to the dividend declared on Class B2 shares for the same period. We have paid an enhanced dividend on Class B1 activity stock since the fourth quarter of 2013. Future dividend determination remains at our Board's sole discretion and subject to future operating results, our Retained Earnings and Dividend Policy and any other factors the Board determines to be relevant. Minimum Capital Requirements We are subject by regulation to the following three capital requirements: • Total regulatory capital ratio; • Leverage capital ratio; and • Risk-based capital. For purposes of calculating our compliance with these minimum capital requirements: • “Permanent capital” includes our retained earnings plus the amount paid in for our Class B stock, including Class B stock classified as mandatorily redeemable. • “Total capital” means the sum of (1) our permanent capital plus (2) any general allowance for losses. • “Total assets” are the total assets determined in accordance with GAAP. Permanent capital and total capital do not include accumulated other comprehensive income (loss). Total Regulatory Capital Ratio . We must maintain a minimum ratio of total capital to total assets of 4.00%. For safety and soundness reasons, this ratio may be increased by the FHFA with respect to an individual FHLB. Leverage Capital Ratio . We must also maintain a leverage ratio of total capital to total assets of at least 5.00%. For purposes of determining this leverage ratio, total capital is modified by multiplying our permanent capital by 1.5 and adding to this product all other components of total capital. This ratio also may be increased by the FHFA with respect to an individual FHLB. Risk-Based Capital . Under the risk-based capital requirement, we must maintain permanent capital in an amount at least equal to the sum of our: (i) credit risk capital requirement, (ii) market risk capital requirement, and (iii) operations risk capital requirement; all of which are calculated in accordance with the rules and regulations of the FHFA. The following table details our minimum capital requirements: December 31, 2017 December 31, 2016 As of Requirement Actual Requirement Actual Risk-based capital $ 1,075 $ 5,051 $ 1,088 $ 5,032 Total regulatory capital $ 3,374 $ 5,051 $ 3,148 $ 5,032 Total regulatory capital ratio 4.00 % 5.99 % 4.00 % 6.40 % Leverage capital $ 4,218 $ 7,577 $ 3,935 $ 7,549 Leverage capital ratio 5.00 % 8.98 % 5.00 % 9.59 % Total regulatory capital and leverage capital includes mandatorily redeemable capital stock (MRCS) but does not include AOCI. Under the FHFA regulation on capital classifications and critical capital levels for the FHLBs, we are adequately capitalized. Capital Concentration The following members had regulatory capital stock exceeding 10% of our total regulatory capital stock outstanding (which includes MRCS). As of December 31, 2017 Regulatory Capital Stock Outstanding % of Total Outstanding Amount of Which is Classified as a Liability (MRCS) BMO Harris Bank, N.A. $ 269 15.3 % $ — One Mortgage Partners Corp. 245 a 14.0 % 245 a One Mortgage Partners Corp. is a subsidiary of JPMorgan Chase Bank NA. Repurchase of Excess Capital Stock Beginning in 2017, we began repurchasing all excess Class B2 stock on a weekly basis at par value, i.e., at $100 per share . Members may continue to request repurchase of excess stock on any business day in addition to the weekly repurchase. All repurchases of excess stock, including automatic weekly repurchases, will continue until otherwise announced, but remain subject to our regulatory requirements, certain financial and capital thresholds, and prudent business practices. As of December 31, 2017 , our regulatory capital stock outstanding was $1.754 billion , a net decrease of $258 million from December 31, 2016 , due in part to the automatic weekly repurchases. Joint Capital Enhancement Agreement All of the FHLBs, including us, entered into a Joint Capital Enhancement Agreement, as later amended (JCE Agreement) and implemented in the FHLBs' capital plans. The intent of the JCE Agreement is to enhance the capital position of each FHLB by allocating that portion of each FHLB's earnings to a separate restricted retained earnings account at that FHLB. The JCE Agreement provides that each FHLB is required to contribute 20% of its net income each quarter to a restricted retained earnings account until the balance of that account equals at least 1% of that FHLB's average balance of outstanding consolidated obligations for the previous quarter. These restricted retained earnings will not be available to pay dividends. Mandatorily Redeemable Capital Stock (MRCS) In 2016, we transferred our captive insurance company members' capital stock from equity to MRCS in liabilities on our statement of condition. The transfer was triggered by the issuance of the FHFA rule on FHLB membership making captive insurance companies ineligible for FHLB membership, which rule became effective February, 2016. Under this rule, our three captive insurance company members will have their memberships terminated by February 2021. The transfer from equity to MRCS in liabilities was required because the rule creates an unconditional obligation requiring us to redeem our capital stock from our captive insurance company members after their membership terminates. In addition to our captive insurers, we have other members or former members who hold MRCS. The following table shows our MRCS redemption terms by year payable. As of December 31, 2017 Amount Due in one year or less $ 1 One to two years 2 Two to three years 1 Three to four years 5 Four to five years 4 After five years 298 MRCS $ 311

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Income (Loss) The following table summarizes the gains (losses) in AOCI for the reporting periods indicated. Net Unrealized - Noncredit OTTI - Net Unrealized - Cash Flow Hedges For the years ended December 31, Available-for-sale Securities Held-to-maturity Securities Post-retirement Plans AOCI 2017 Beginning balance $ 459 $ (177 ) $ (312 ) $ (6 ) $ (36 ) Change in the period recorded to the statements of condition, before reclassifications to statements of income (52 ) 34 173 1 156 Amounts reclassified in period to statements of income: Net interest income — — (5 ) — (5 ) Noninterest income on derivatives and hedging activities — — (3 ) — (3 ) Ending balance $ 407 $ (143 ) $ (147 ) $ (5 ) $ 112 2016 Beginning balance $ 658 $ (217 ) $ (463 ) $ (6 ) $ (28 ) Change in the period recorded to the statements of condition, before reclassifications to statements of income (199 ) 40 161 — 2 Amounts reclassified in period to statements of income: Net interest income — — (5 ) — (5 ) Noninterest income on derivatives and hedging activities — — (5 ) — (5 ) Ending balance $ 459 $ (177 ) $ (312 ) $ (6 ) $ (36 ) 2015 Beginning balance $ 1,060 $ (264 ) $ (580 ) $ 1 $ 217 Change in the period recorded to the statements of condition, before reclassifications to statements of income (402 ) 47 125 (7 ) (237 ) Amounts reclassified in period to statements of income: Net interest income — — (5 ) — (5 ) Noninterest income on derivatives and hedging activities — — (3 ) — (3 ) Ending balance $ 658 $ (217 ) $ (463 ) $ (6 ) $ (28 )

Employee retirement plans (Note

Employee retirement plans (Notes)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Employee Retirement Plans We participate in the Pentegra Defined Benefit (DB) Plan for Financial Institutions (the Pension Plan), a tax-qualified defined-benefit pension plan. The Pension Plan year runs from July 1 to June 30. Substantially all of our officers and employees participate in the Pension Plan. Our risks in participating in the Pension Plan are as follows: • The Pension Plan is a single plan under Internal Revenue Code Section 413(c) and, as a result, all of the assets stand behind all of the liabilities. Accordingly, contributions made by us may be used to provide benefits to participants of other participating employers. • If a participating employer withdraws from the Pension Plan, the unfunded obligations of the Pension Plan may be borne by the remaining participating employers, which would include us. • If we choose to withdraw from the Pension Plan, we may be required to pay the Pension Plan an amount based on the underfunded status of the Pension Plan, referred to as a withdrawal liability. Relevant information concerning the Pension Plan is outlined below: • The Pension Plan's Employer Identification Number is 135645888 and the Plan Number is 333 . • A single Form 5500 is filed on behalf of all employers who participate in the Pension Plan. A Form 5500 was not available for the Pension Plan year ended June 30, 2017 , as of the date of this Form 10-K filing. • Our contributions for the years presented were not more than 5% of the total contributions to the Pension Plan. • The Pension Plan is not a collective bargaining agreement. • We did not pay any surcharges to the Pension Plan. • There was no funding improvement plan or rehabilitation plan implemented, nor is any such plan pending. Contributions to the Pension Plan include both mandatory amounts required under federal law and discretionary contributions to improve the Plan's funded status. The Moving Ahead for Progress in the 21st Century Act (“MAP-21”), enacted in 2012, provided temporary relief for employers like the Bank who participate in plans for which funding contributions are determined under the Employee Retirement Income Security Act of 1974. Specifically, MAP-21 allows the Bank to use a 25-year average discount rate within an upper and lower range rather than the current discount rate when determining its minimum funding obligation. In effect, the discount rate under MAP-21 is higher than the current discount rate, which reduces the Bank’s minimum funding obligation and expense recognized into earnings. This is due to the inverse relationship between the discount rate and the pension liability and expense - that is, the higher the discount rate, the lower the liability and expense amount. This discount rate relief was extended in 2014 when the Highway and Transportation Funding Act (“HATFA”) was signed into law. The discount rate relief was extended again through the year 2020 (with graduated increases each year thereafter until expiring in 2023) when the Bipartisan Budget Act of 2015 (“BBA 2015”) was enacted in 2015. The following table provides details on our multiemployer Pension Plan. The funded status is calculated as the market value of plan assets divided by the funding target and reflects contributions received through the plan year ended June 30. Pension Plan 2017 2016 2015 Net pension cost (minimum required contribution) including administrative fees, charged to compensation and benefits expense for the years ended December 31, $ 7 $ 7 $ 3 Actual cash paid including administrative fees for calendar year ended December 31, 9 9 5 Prepaid pension contributions, in other assets, as of December 31, 19 17 15 Plan funded status as of the plan years ended June 30, 111 % 104 % 107 % Our portion of plan funded status as of the plan years ended June 30, 120 % 112 % 121 % In addition to the multiemployer Pension Plan we have a tax-qualified defined contribution 401(k) plan, an unfunded non-qualified deferred compensation plan, and a postretirement health and life insurance benefit plan. The financial amounts related to these plans were no

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Fair Value Fair value represents the exit price that we would receive to sell an asset or pay to transfer a liability in an orderly transaction with a market participant at the measurement date. Refer to Note 2 - Summary of Significant Accounting Policies for our fair value measurement policies. Valuation Techniques and Significant Inputs We believe our estimated fair value amounts are reasonable; however, as outlined below, there are inherent limitations in any valuation technique. • Our estimated fair value amounts are highly subjective in nature. We select assumptions and inputs from a market participant's perspective to use with any of our valuation techniques. Such assumptions and inputs include, but are not limited to, the amount and timing of future cash flows, prepayment speed, expected interest rate volatility, possible distributions of future interest rates used to value options, and the selection of discount rates that appropriately reflect market and credit risks. Significant judgment is required when selecting such assumptions and inputs. Using different assumptions and inputs could have a material effect on our estimated fair value amounts. Further, the estimated fair value amounts presented in our statements of condition and disclosed in our notes to financial statements are not necessarily indicative of the amounts that would be realized in current market transactions. • Our estimated fair value amounts are made as of the statement of condition date; and accordingly, such estimated fair value amounts are susceptible to material changes thereafter. Outlined below is a description of our valuation techniques and significant assumptions. Assets for which fair value approximates carrying amount. Due to the short-term nature and negligible credit risk, we use the carrying amount to estimate fair value of cash and due from banks, interest bearing deposits, Federal Funds sold, securities purchased under agreements to resell, and accrued interest receivable. Investment securities—non-MBS and MBS. We use one of the valuation approaches outlined below to determine fair value. • Prices received from third party pricing vendors provided we believe their pricing models are consistent with what other market participants would use; or • An income approach based on a market-observable interest rate curve adjusted for a spread. The significant inputs and assumptions utilized by third party pricing vendors in their proprietary pricing models are derived as outlined below for these securities. • Market observable sources (Level 1), which include, but are not limited to, benchmark yields, reported trades, broker/dealer quotes, issuer spreads, benchmark securities, bids, offers, and other market related data, for securities that are actively traded. • Available market observable inputs (Level 2) rather than quoted market prices when valuing securities primarily comprised of our portfolio of government, mortgage and asset-backed securities. • Available market information (Level 2), such as benchmark curves, benchmarking of like securities, sector groupings, and matrix pricing, for fixed income securities that do not trade on a daily basis. • Significant unobservable inputs (Level 3) for securities, such as private-label MBS. We annually review the multiple third party pricing vendors we utilize to measure the fair value of our agency and private-label MBS. Our annual review includes, but is not limited to, the following: • Confirming and further augmenting our understanding of the vendors' pricing processes, methodologies and control procedures. • Reviewing, if available, the vendors' independent auditors' reports to assess the vendors' internal controls over their valuation processes. • Assessing our third party vendors' proprietary pricing models for reasonableness, including the underlying inputs and assumptions utilized. This is achieved by sampling securities across different asset classes and utilizing deep dive analyses since we do not have direct access to their propriety pricing models. • Using our third party vendor's pricing challenge process, which is in place for all security valuations. The pricing challenge process facilitates identification and resolution of potentially erroneous prices. Private-label MBS and agency MBS. We determine our fair value measurement for private-label MBS and for agency MBS using the inputs received from our third party pricing vendors using a pricing process that is completed on at least a quarterly basis. Outlined below are the steps we follow to measure fair value for these securities. • We establish a median price for each security from the prices we receive from our third party pricing vendors. 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. We determine the final price of the security based on the cluster average and an evaluation of any outlier prices as outlined below. • If all prices fall within the tolerance threshold level of the median price, the final price is simply the cluster average. • 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. A revised price may be assigned to an MBS in situations where strong contrary evidence supports a price different than the price derived from the "default" price or the outlier price. In either case, justification of the price selected is documented and presented to our Risk Management Group for their review and approval. • If some prices fall within the tolerance threshold level and some prices are outside the tolerance threshold level of the median price, additional analysis is required. The price or prices falling outside of the tolerance threshold level of the median price would be evaluated by us and a determination made to exclude that price or prices in the final price. If the price or prices that fall outside the tolerance threshold level of the median price are evaluated to be a better estimate of the fair value, then the selected outlier price will be the final price instead of the average of prices that fit within the tolerance level threshold of the median price. Possible factors that may be used to determine the quality of the outlier price or prices include: ▪ Comparison to bonds with similar characteristics, such as collateral type, credit quality, deal structure, or expected weighted-average life or maturity; ▪ Comparing option-adjusted spread or projected yield to similar bonds; ▪ Consideration of expected weighted-average life or maturity; ▪ Consideration of expected default, loss, and credit support; ▪ Consideration of the remaining principal versus the original principal of a security; ▪ Recent data on transactions with the security or similar securities; and ▪ Implied yields calculated with our OTTI projected cash flows at quarter ends compared to industry benchmarks. Specifically, we calculated an implied yield for our private-label MBS using the estimated fair value derived from the process described above and the security's projected cash flows from our OTTI process and compared such yield to the market yield data for comparable securities according to dealers and other third party sources to the extent comparable market yield data was available. Significant variances were evaluated in conjunction with all of the other available pricing information to determine whether an adjustment to the fair value estimate was appropriate. As of December 31, 2017 , multiple vendor prices were received for substantially all of our MBS holdings. We computed the final prices by taking the median of the prices, excluding any outlier price deemed as unreasonable. We believe our final prices are representative of the exit price that we would receive to sell these securities in an orderly transaction with a market participant at the measurement date. Non-MBS securities - SBA, agency bonds and housing development bonds. We use one third party pricing vendor to measure the fair value of these securities. If available, we compare the prices received from that service to two other third party pricing vendors to determine if the price is reasonable. If no other third party prices are available we validate against internal models. FFELP ABS. We use the fair value provided by a third party pricing vendor or average of pricing services or our internal model price in cases where a fair value is not provided by any third party pricing vendor to measure the fair value of our FFELP ABS. We assess these fair value measurements for reasonableness as outlined below. • Our internal pricing model . We compare prices for comparable FFELP securities provided by third party pricing vendors. The internal model price also is compared to other third party pricing vendors to test for reasonableness. If only one pricing vendor is providing prices, our internal pricing model will be averaged with the vendor price. Private-label residential MBS. The significant unobservable inputs used by third party pricing vendors in the fair value measurement of our private-label residential MBS are prepayment rates, probability of default, and loss severity in the event of default. Significant increases (decreases) in any of those inputs in isolation may result in a significantly lower (higher) fair value measurement. A change in the assumption used for the probability of default is accompanied by a directionally similar change in the assumption used for the loss severity and a directionally opposite change in the assumption used for prepayment rates. The following table shows the range of values for our investment securities that are carried at fair value on our statements of condition using Level 3 significant inputs provided to us by multiple third party pricing vendors. Range of Values As of December 31, 2017 Fair Value Minimum Maximum Available-for-sale securities Private-label residential MBS $ 50 $ 48 $ 51 Advances. We determine the fair value of advances by calculating the present value of expected future cash flows. Accrued interest receivable is included in the expected future cash flows for advances carried at fair value under the fair value option, and accordingly, accrued interest receivable is classified in Advances in our statements of condition. In determining fair value we do not factor in prepayment risk in cases where an advance carries a prepayment fee since we are financially indifferent whether or not the borrower prepays. Accrued interest receivable is not included in the expected future cash flows on advances carried on an amortized cost basis, and accordingly, accrued interest receivable is classified in Other Assets in our statements of condition. The significant inputs used to determine fair value for advances carried under the fair value option in our statements of condition are shown below. • Consolidated Obligation Curve (CO Curve). The Office of Finance constructs this market-observable curve using the U.S. Treasury Curve as a base which is then adjusted by adding indicative spreads obtained largely from market observable sources. These market indications are derived from pricing indications from dealers, historical pricing relationships, market activity such as recent GSE trades, and other secondary market activity. The CO Curve best represents our cost of funds and is an integral factor with respect to pricing our advance products, and accordingly, we utilize it to measure an advance's fair value. • Volatility assumption. Market-based expectations of future interest rate volatility implied from current market prices for similar options. • Target spread assumption. The target spread relative to our cost of funds that we expect to earn for a given advance. MPF Loans held in portfolio. We measure the fair value of our entire mortgage loan portfolio based on to-be-announced (TBA) securities, which represent quoted market prices for new mortgage-backed securities issued by U.S. government-sponsored enterprises, and adjust that fair value amount for impaired MPF Loans held in portfolio. We use a third party Automated Valuation Methodology (AVM) model based on market inputs to determine the fair value of our impaired conventional MPF Loans held in portfolio, including troubled debt restructurings. The prices of the referenced mortgage-backed securities and the MPF Loans are highly dependent upon the underlying prepayment assumptions priced in the secondary market. Prices are then adjusted for differences in coupon, average loan rate, seasoning, settlements, purchase market spread, loan balance, and cash flow remittance between our MPF Loans and the referenced mortgage-backed securities. MPF Loans held for sale (included in Other Assets). We measure the fair value of our MPF Loans HFS portfolio based on TBA securities, which represent quoted market prices for new mortgage-backed securities issued by U.S. government-sponsored enterprises. Derivative assets/liabilities. Derivative instruments are primarily transacted in the institutional dealer market and priced with observable market assumptions at a mid-market valuation point. We estimate the fair value of a derivative that is not transacted in such an active market using standard valuation techniques, such as discounted cash-flow analysis and comparisons to similar instruments. We are subject to nonperformance risk in derivative transactions due to the potential default by our derivati ve counterparties or a DCO. To mitigate this risk, we have entered into master netting agreements and credit support agreements with our derivative counterparties for our bilaterally executed derivative contracts that provide for the delivery of collateral at specified levels at least weekly. We apply the “portfolio exception” for purposes of determining the nonperformance risk adjustment, if any, to the fair value of our derivative instruments. As a result, we measure the nonperformance risk adjustment on our derivative instruments by taking into consideration the effects of legally enforceable master netting agreements that allow us to settle positive and negative positions and offset cash collateral with the same counterparty on a net basis. For derivative transactions executed as a cleared derivative, the transactions are fully collateralized in cash and exchanged daily with the DCO. We also have established the enforceability of offsetting rights incorporated in the agreements for the cleared derivative transactions. Our net counterparty position equals the amount attributable to a particular credit exposure that we would receive to sell a net long position or that we would pay to transfer a net short position. Based on our risk management practices described above and our assessment of any change in our own credit spread, we concluded that the effect of the credit differential between us and our derivative counterparties and DCO was sufficiently mitigated to an immaterial level that no nonperformance risk adjustments were deemed necessary to the recorded fair value of our derivative assets/liabilities in our statements of condition. See Note 9 - Derivatives and Hedging Activities for further discussion of our credit risk management practices. In estimating a derivative's fair value, we use the carrying amount of a derivative's accrued net interest settlements and the carrying amount of any cash collateral remitted to or received from counterparties. We use the carrying amount as a proxy for fair value due to the short-term nature of the interest receivable/payable and cash collateral. A discounted cash flow analysis utilizes market-observable inputs (inputs that are actively quoted and can be validated to external sources). Inputs by class of derivative are shown below. Interest-rate related: • We use the OIS curve to determine the fair value of our derivative contracts. • Volatility assumption market-based expectations of future interest rate volatility implied from current market prices for similar options. • Prepayment assumption, if applicable. Mortgage delivery commitments and TBA mortgage-backed securities: • TBA price. Market-based prices of TBAs are determined by coupon class and expected term until settlement. Deposits. We determine the fair values of deposits 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 the costs of deposits with similar terms. Consolidated obligations. We estimate fair values based on the cost of raising comparable term debt using internal valuation models. Our internal valuation models use standard valuation techniques and estimate fair values based on the following significant inputs for those consolidated obligations carried at fair value: • CO Curve for fixed-rate, noncallable (bullet) consolidated obligations and a spread to the LIBOR swap curve for callable consolidated obligations based on price indications for callable consolidated obligations from the Office of Finance. • Volatility assumption. Market-based expectations of future interest rate volatility implied from current market prices for similar options. • Spread assumption. A spread adjustment to the LIBOR Curve used to value callable consolidated obligations carried at fair value. Fair Value Estimates The following tables are a summary of the fair value estimates and related levels in the fair value hierarchy. The carrying amounts are as recorded in the statements of condition. These tables do not represent an estimate of our overall market value as a going concern; as they do not take into account future business opportunities and future net profitability of assets and liabilities. We had no transfers between levels in the fair value hierarchy for the periods shown. Carrying Amount Fair Value Level 1 Level 2 Level 3 Netting As of December 31, 2017 Carried at amortized cost- Cash and due from banks $ 42 $ 42 $ 42 $ — $ — Interest bearing deposits 775 775 775 — — Federal Funds sold and securities purchased under agreements to resell 12,561 12,561 — 12,561 — Held-to-maturity securities 4,157 4,538 — 3,734 804 Advances 47,309 47,336 — 47,336 — MPF Loans held in portfolio, net 5,186 5,306 — 5,295 11 Other assets 228 228 — 228 — Carried at fair value on a recurring basis- U.S. Government & other government related non-MBS 202 202 — 202 — GSE residential MBS 30 30 — 30 — U.S. Governmental-guaranteed residential MBS 1 1 — 1 — Trading securities 233 233 — 233 — U.S. Government & other government related non-MBS 271 271 — 271 — State or local housing agency non-MBS 21 21 — 21 — FFELP ABS 4,214 4,214 — 4,214 — GSE residential MBS 7,406 7,406 — 7,406 — U.S. Government-guaranteed residential MBS 995 995 — 995 — Private-label residential MBS 50 50 — — 50 Available-for-sale securities 12,957 12,957 — 12,907 50 Advances 776 776 — 776 — Derivative assets 3 3 — 312 — $ (309 ) a Other assets 118 118 — 118 — Carried at fair value on a nonrecurring basis- MPF Loans held in portfolio, net 7 7 — — 7 Other assets 3 3 — — 3 Total assets 84,355 84,883 817 83,500 875 (309 ) Carried at amortized cost- Deposits (524 ) (524 ) — (524 ) — Consolidated obligation discount notes (40,442 ) (40,437 ) — (40,437 ) — Consolidated obligation bonds (31,861 ) (32,011 ) — (32,011 ) — Mandatorily redeemable capital stock (311 ) (311 ) (311 ) — — Other liabilities (336 ) (336 ) — (336 ) — Carried at fair value on a recurring basis- Consolidated obligation discount notes (749 ) (749 ) — (749 ) — Consolidated obligation bonds (5,260 ) (5,260 ) — (5,260 ) — Derivative liabilities (20 ) (20 ) — (579 ) — 559 a Total liabilities $ (79,503 ) $ (79,648 ) $ (311 ) $ (79,896 ) $ — $ 559 Carrying Amount Fair Value Level 1 Level 2 Level 3 Netting As of December 31, 2016 Carried at amortized cost- Cash and due from banks $ 351 $ 351 $ 351 $ — $ — Interest bearing deposits 650 650 650 — — Federal Funds sold and securities purchased under agreements to resell 6,375 6,375 — 6,375 — Held-to-maturity securities 5,072 5,516 — 4,544 972 Advances 44,395 44,393 — 44,393 — MPF Loans held in portfolio, net 4,941 5,136 — 5,136 — Other assets 188 188 — 188 — Carried at fair value on a recurring basis- U.S. Government & other government related non-MBS 1,005 1,005 — 1,005 — GSE residential MBS 39 39 — 39 — U.S. Governmental-guaranteed residential MBS 1 1 — 1 — Trading securities 1,045 1,045 — 1,045 — U.S. Government & other government related non-MBS 336 336 — 336 — State or local housing agency non-MBS 19 19 — 19 — FFELP ABS 4,572 4,572 — 4,572 — GSE residential MBS 8,555 8,555 — 8,555 — U.S. Government-guaranteed residential MBS 1,380 1,380 — 1,380 — Private-label residential MBS 56 56 — — 56 Available-for-sale securities 14,918 14,918 — 14,862 56 Advances 672 672 — 672 — Derivative assets 6 6 — 474 — $ (468 ) a Other assets 44 44 — 44 — Carried at fair value on a nonrecurring basis- MPF Loans held in portfolio, net 26 26 — — 26 Other assets 9 9 — — 9 Total assets 78,692 79,329 1,001 77,733 1,063 (468 ) Carried at amortized cost- Deposits (496 ) (496 ) — (496 ) — Consolidated obligation discount notes (29,581 ) (29,581 ) — (29,581 ) — Consolidated obligation bonds (31,460 ) (31,706 ) — (31,706 ) — Mandatorily redeemable capital stock (301 ) (301 ) (301 ) — — Other liabilities (305 ) (305 ) — (305 ) — Carried at fair value on a recurring basis- Consolidated obligation discount notes (6,368 ) (6,368 ) — (6,368 ) — Consolidated obligation bonds (5,443 ) (5,443 ) — (5,443 ) — Derivative liabilities (43 ) (43 ) — (1,161 ) — 1,118 a Total liabilities $ (73,997 ) $ (74,243 ) $ (301 ) $ (75,060 ) $ — $ 1,118 a The netting adjustment amount includes cash collateral (either received or paid by us) and related accrued interest in cases where we have a legal right of setoff, by contract (e.g., master netting agreement) or otherwise, to discharge all or a portion of the debt owed to our counterparty by applying against the debt an amount that our counterparty owes to us. See Note 9 - Derivatives and Hedging Activities . Level 3 Rollforward The following table presents a rollforward of assets and liabilities that are measured at fair value on the statements of condition using significant unobservable inputs (Level 3). Available-For-Sale Private-Label MBS Derivative Assets Interest-Rate Related Consolidated Obligation Bonds For the years ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 Balance at beginning of period $ 56 $ 65 $ 71 $ — $ 5 $ 13 $ — $ (55 ) $ (63 ) Gain (loss) included in earnings - Interest income 4 5 4 Derivatives and hedging activities — (5 ) (8 ) — 55 8 Gain (loss) included in OCI - Net unrealized on AFS securities 3 2 (1 ) Paydowns and settlements (13 ) (16 ) (9 ) — — — — — — Balance at end of period $ 50 $ 56 $ 65 $ — $ — $ 5 $ — $ — $ (55 ) Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end $ 3 $ 4 $ 4 $ — $ — $ — $ — $ — $ 8 Fair Value Option We may elect the fair value option for financial instruments, such as advances, MPF Loans held for sale, consolidated obligation discount notes and bonds, in cases where hedge accounting treatment may not be achieved due to the inability to meet the hedge effectiveness testing criterion. Refer to Note 2 - Summary of Significant Accounting Policies for further details. The following table presents the changes in fair value of financial assets and liabilities carried at fair value under the fair value option that were recognized in noninterest income - instruments held under the fair value option in our statements of income. For the years ended December 31, 2017 2016 2015 Advances $ (5 ) $ (7 ) $ (2 ) Mortgage loans held for sale (in other assets) (4 ) (4 ) (1 ) Discount notes — (2 ) 2 Bonds 7 18 9 Noninterest income - Instruments held under fair value option $ (2 ) $ 5 $ 8 The following table reflects the difference between the aggregate unpaid principal balance (UPB) outstanding and the aggregate fair value for our long term financial instruments for which the fair value option has been elected. None of the advances were 90 days or more past due and none were on nonaccrual status. December 31, 2017 December 31, 2016 As of Advances Consolidated Obligation Bonds Advances Consolidated Obligation Bonds Unpaid principal balance $ 786 $ 5,270 $ 677 $ 5,447 Fair value over (under) UPB (10 ) (10 ) (5 ) (4 ) Fair value 776 5,260 672 5,443

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies [Text Block]	Commitments and Contingencies The following table shows our commitments outstanding, which represent off-balance sheet obligations. December 31, 2017 December 31, 2016 As of Expire within one year Expire after one year Total Expire within one year Expire after one year Total Unsettled consolidated obligation bonds $ — $ — $ — $ 10 $ — $ 10 Member standby letters of credit 15,703 3,869 a 19,572 8,459 2,369 a 10,828 Housing authority standby bond purchase agreements — 337 337 25 281 306 Advance commitments 151 — 151 15 1 16 MPF delivery commitments 371 — 371 417 — 417 Other 14 — 14 24 — 24 Commitments $ 16,239 $ 4,206 $ 20,445 $ 8,950 $ 2,651 $ 11,601 a Contains $750 million and $486 million of member standby letters of credit at December 31, 2017 and December 31, 2016 , which were renewable annually. Commitments Member standby letters of credit. A member standby letter of credit is a financing arrangement between us and our member. We execute a letter of credit with a member for a fee and require that member to fully collateralize the letter of credit at the time of issuance. If we are required to make payment for a beneficiary's draw, the payment amount is converted into a collateralized advance to the member if not reimbursed by the member. We monitor the creditworthiness of our members that have letters of credit. See Note 8 - Allowance for Credit Losses for information related to our credit risk for member standby letters of credit. Housing authority standby bond purchase agreements. We enter into agreements with state housing authorities within our district to provide them liquidity for a fee. Specifically, if required under the terms of the agreement, we purchase and hold a state housing authority's bonds until their designated marketing agent can find a suitable investor or the state housing authority repurchases the bond. These standby bond purchase commitments have original expiration periods of up to 5 years , expiring no later than December 31, 2022 , although some may be renewable at our option. We purchased no bonds under these agreements during the periods presented above. Advance commitments. We enter into forward-starting advances, which lock in a predetermined interest rate for an advance that will be funded at a future date subject to certain conditions. MPF delivery commitments. Includes delivery commitments to purchase on- and off-balance sheet mortgage loans. Contingencies Joint and Several Liability on Behalf of Another FHLB. We have a contingent obligation for the payment of principal and interest on consolidated obligations of all the FHLBs resulting from our joint and several liability. We did not expect to pay any additional amounts under our joint and several liability as of December 31, 2017 and December 31, 2016 . Legal Proceedings.

Transactions with Related Parti

Transactions with Related Parties and Other FHLBs	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	Transactions with Related Parties and Other FHLBs We define related parties as either members whose officers or directors serve on our Board of Directors, or members that control more than 10% of our total voting interests. We did not have any members that controlled more than 10% of our total voting interests for the periods presented in these financial statements. In the normal course of business, we may extend credit to or enter into other transactions with a related party. All transactions are done at market terms that are no more favorable than the terms of comparable transactions with other members who are not considered related parties. Members The following table summarizes material balances we had with our members who are related parties as defined above (including their affiliates) as of the periods presented. As of December 31, 2017 December 31, 2016 Assets - Advances $ 165 $ 107 Liabilities - Deposits 13 8 Equity - Capital Stock 10 18 Other FHLBs From time to time, we may loan to, or borrow from, other FHLBs. All transactions are done at market terms that are no more favorable than the terms of comparable transactions with other counterparties. These transactions are overnight, maturing the following business day. These transactions with other FHLBs, if any, are identified on the face of our Financial Statements

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Fair Value Measurement, Policy [Policy Text Block]	Fair Value Fair value represents the exit price that we would receive to sell an asset or pay to transfer a liability in an orderly transaction with a market participant at the measurement date. Valuation Techniques and Significant Inputs We utilize the fair value hierarchy when selecting valuation techniques and significant inputs to measure the fair value of our assets and liabilities. Our valuation techniques may utilize market, cost, and/or income models to estimate fair values. Under the fair value hierarchy, valuation techniques and significant inputs are prioritized from the most objective, such as quoted market prices in external active markets, to the least objective, such as valuation approaches that utilize unobservable inputs. The fair value hierarchy requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Outlined below is an overview of Level 1, Level 2, and Level 3 of the fair value hierarchy. Refer to Note 16 - Fair Value for further details on our valuation techniques and significant inputs. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we can access at the measurement date. Level 2 inputs are inputs other than quoted prices included within 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 3 inputs are unobservable inputs used to measure fair value of an asset or liability to the extent that relevant observable inputs are not available; for example, situations in which there is little, if any, market activity for the asset or liability at the measurement date. For instruments carried at fair value, we review the fair value hierarchy classifications on a quarterly basis. Changes in the observability of the valuation attributes may result in a reclassification of certain financial assets or liabilities from one level to another. Such reclassifications are reported as transfers in/out at fair value as of the beginning of the quarter in which the changes occur. Fair Value Option We may elect the fair value option for financial instruments, such as advances, MPF Loans held for sale, consolidated obligation discount notes and bonds in cases where hedge accounting treatment may not be achieved due to the inability to meet the hedge effectiveness testing criterion. We carry these financial instruments at fair value in our statements of condition. Changes in their fair value are immediately recognized into our statements of income as noninterest income on instruments held under fair value option. We economically hedge these financial instruments with derivatives, which are carried at fair value in our statements of condition. Changes in their fair value also are immediately recognized into our statements of income; however, such changes in fair value are classified as noninterest income on derivatives and hedging activities. Interest income or expense recognized in our statements of income on these financial instruments is based solely on the contractual amount of interest due or unpaid, except for our discount notes, which have a zero coupon rate. For discount notes, we accrete the initial discount into interest expense over the life of the discount note into our statements of income. Any transaction fees or costs, such as concession fees on consolidated obligation bonds and discount notes, are immediately recognized into noninterest expense - other. See Note 16 - Fair Value to the financial statements for further details.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents
Interest Bearing Deposits, Federal Funds Sold, and Securities Purchased Under Agreements to Resell, Policy [Policy Text Block]	Interest Bearing Deposits, Federal Funds Sold and Securities Purchased Under Agreements to Resell We utilize these investments for short-term liquidity purposes and carry them on an amortized cost basis in our statements of condition. Collateral on Securities Purchased Under Agreements to Resell (resale agreements) • Collateral accepted from our counterparties is held in our name for safekeeping by third party custodians. • We do not sell or repledge any collateral we receive due to the short-term nature of our resale agreements. • The collateral's fair value less haircuts approximates the resale agreement's carrying amount in our statements of condition. • Our counterparty is required to make up any shortfall, which exists if the collateral's fair value decreases below the contractually required amount, by providing additional securities as collateral equal to the amount of the shortfall. If our counterparty does not provide such additional collateral, the resale agreement's carrying amount is reduced by the collateral shortfall amount.
Marketable Securities, Policy [Policy Text Block]	Investment Securities We record purchases and sales of investment securities (securities) on a trade date basis. We classify securities as either trading, held-to-maturity (HTM), or available-for-sale (AFS) based on the criteria outlined below. Classification is made at the time a security is acquired and then reassessed each subsequent reporting period. • Securities held solely for liquidity purposes are classified as trading. We are prohibited from holding trading securities for speculative purposes pursuant to FHFA regulations. • Securities held to provide additional earnings are classified as HTM. Classification as HTM requires that we have both the intent and ability to hold the security to maturity. • Securities not classified as either trading or HTM are classified as AFS; for example, securities held for asset-liability management purposes. Our accounting policies for trading, HTM and AFS securities are outlined below. • Trading securities are carried at fair value. Fair value changes related to trading securities are recognized in noninterest income on trading securities. Interest income on trading securities is based solely on the contractual amount of interest due, except for securities, if any, that have a zero coupon rate. For trading securities with a zero coupon rate, we accrete the initial discount into interest income over their life into our statements of income. Cash flows from trading securities, excluding cash flows from our securitized MPF Government MBS product, are presented on a gross basis and classified as investing activities in our statements of cash flows. Cash flows from our securitized MPF Government MBS product are classified as operating activities in our statements of cash flows. • HTM securities are carried on an amortized cost basis adjusted for any noncredit other-than-temporary impairment (OTTI) recognized in AOCI. Amortized cost basis represents the original cost of a security adjusted for accretion, amortization, collection of cash, previous other-than-temporary impairment (OTTI) recognized into earnings (less any cumulative effect adjustments), and any fair value hedge accounting adjustments. • AFS securities are carried at fair value. Changes in fair value on AFS securities are recognized into AOCI in our statements of condition except for AFS securities that are in a fair value hedge relationship. Changes in fair value on AFS securities and the derivative hedging AFS securities in a fair value hedging relationship are immediately recognized into noninterest income on derivatives and hedging activities. • We use the interest method to amortize/accrete premiums/discounts on HTM and AFS securities into interest income in our statements of income. HTM and AFS securities having a prepayment feature amortize/accrete premiums/discounts over their estimated lives based on anticipated prepayments. We recalculate their effective yield on an ongoing basis to reflect actual payments to date and anticipated future payments. HTM and AFS securities that do not have a prepayment feature amortize/accrete premiums/discounts over their contractual life. •
Investment, Policy [Policy Text Block]	Investment Securities - Other-than-Temporary Impairment (OTTI) We assess an HTM or AFS security for OTTI whenever its fair value is less than its amortized cost basis as of the reporting date. We write down an OTTI security to fair value if we decide to sell it or if we believe it is more likely than not that we will be required to sell it before recovery of its amortized cost basis. The entire amount of the fair value write-down is recognized as an OTTI credit loss in our statements of income. If a fair value write-down on an OTTI security is not required but a recovery of its entire amortized cost basis is not expected, then the OTTI security is written down to its fair value in our statements of condition. The offset to such a fair value write-down is allocated between an OTTI credit loss that is recognized in our statements of income and a noncredit related loss that is recognized in AOCI. Subsequent Accretion and Amortization We prospectively accrete the noncredit OTTI recognized in AOCI for HTM securities to the security's carrying amount over its remaining life. The accretion is based on the amount and timing of the security's future estimated cash flows. This accretion increases the security's carrying amount until we derecognize the security (e.g., at maturity) or until we recognize additional OTTI on that security into earnings. See Statements of Comprehensive Income on page F-6.
Finance, Loan and Lease Receivables, Held-for-investment, Policy [Policy Text Block]	Advances We offer a wide range of fixed-and variable-rate advance products with different maturities, interest rates, payment characteristics and optionality. An advance is carried at its amortized cost basis, except when we elect the fair value option and carry it at fair value. Amortized cost basis represents the original amount funded to our member adjusted for any accretion, amortization, collection of cash, and fair value hedge accounting adjustments, if any. Fair value hedge adjustments include ongoing (open) and/or discontinued (closed) fair value hedges. Cash flow hedging adjustments related to ongoing (open) and/or discontinued (closed) cash flow hedges are classified in AOCI. We utilize the interest method to amortize/accrete any premiums/discounts and closed fair value and/or cash flow hedging adjustments. Prepayments We recognize prepayment fees, if any, and any related fair value and/or cash flow hedging adjustments into interest income in our statements of income when an advance is prepaid. Modifications versus Extinguishments We assess whether a modification or an extinguishment of an existing advance has occurred in cases where a new advance is issued concurrently or shortly after the prepayment of that existing advance (within 5 business days) by a member. An advance is considered extinguished if either of the conditions shown below are met: • The present value of the cash flow on the new advance is at least 10% different from the present value of the remaining cash flows on the original advance; or • A significant modification has occurred based on the specific facts and circumstances (and other relevant considerations) surrounding the modification. Any prepayment fees and any unamortized cumulative basis adjustment resulting from a fair value hedge of an extinguished advance would be immediately recognized into interest income in our statements of income. Amounts deferred in AOCI related to a cash flow hedge on the extinguished advance are immediately recognized into noninterest income on derivatives and hedging activities.
Loans and Leases Receivable, Mortgage Banking Activities, Policy [Policy Text Block]	MPF Loans See Note 7 - MPF Loans Held in Portfolio for further details pertaining to the MPF Program and MPF Loans. MPF Loans Held in Portfolio MPF Loans for which we have the intent and ability to hold until maturity are classified as MPF Loans held in portfolio. Such loans are carried on an amortized cost basis on our statements of condition. Amortized cost basis represents the initial fair value amount of the MPF delivery commitment as of the purchase or settlement date, agent fees (i.e., market risk premiums or discounts paid to or received from PFIs), if any, subsequently adjusted, if applicable, for accretion, amortization, collection of cash, charge-offs, and cumulative basis adjustments related to fair value hedges. We use the interest method to amortize yield adjustments into interest income in our statements of income over the contractual life of an MPF Loan held in portfolio. Yield adjustments may include agent fees, the fair value amount of the delivery commitment as of its settlement date, any origination fees or costs representing yield adjustments, closed fair value hedging adjustments, and credit enhancement fees. MPF Loans Held for Sale MPF Loans acquired by the Bank under the MPF Xtra, MPF Direct, and MPF Government MBS products are classified as MPF Loans held for sale (HFS). MPF Loans under the MPF Government MBS product are reclassified from Mortgage Loans HFS to trading securities upon their securitization qualifying for sales accounting treatment. If the securitization does not meet the conditions of sales accounting treatment, then we continue to classify these mortgage loans as MPF Loans HFS. We classify MPF Loans HFS in Other Assets rather than as a separate line item in our statements of condition on the basis of materiality. Cash flows from MPF Loans HFS are classified as operating activities in our statements of cash flows. We have elected the fair value option for MPF Loans HFS, and accordingly, carry these mortgage loans at fair value. The initial fair value of the MPF Loans HFS includes the fair value amount of the MPF Delivery Commitment as of the purchase or settlement date. The difference between the price paid to a PFI for a MPF Loan HFS and the price we receive from a third party for such loan is intended to include compensation for future operating expenses incurred to administer the loans. These amounts and other related transaction fees are recognized into Noninterest income - MPF fees in our statements of income as follows: • Amounts used to pay for third party transaction costs attributable to the sale and securitization of MPF Loans HFS are recognized immediately. • For MPF Loans HFS sold where servicing is retained by the PFI, the amounts are recognized on a straight-line basis over the life of the loan. • For MPF Loans HFS sold where servicing is released, the amounts are recognized immediately.
Revenue Recognition, Services, Management Fees [Policy Text Block]	MPF Fees from other FHLBs
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for Credit Losses Refer to Note 8 - Allowance for Credit Losses for further details. On-Balance Sheet Financial Instruments We determine an allowance for credit losses, if any, for each of our portfolio segments. A portfolio segment represents the level of disaggregation we utilize to develop and document a systematic method for determining an allowance for credit losses attributable to our financing receivables. An allowance for credit losses is a contra valuation account attributable to an on-balance sheet portfolio segment. We recognize a credit loss when it is probable a credit loss has been incurred and when the credit loss amount is reasonably estimable. Our assessment is based on all available information, which includes, but is not limited to, past events and current economic conditions existing at the reporting date. We recognize the change in our allowance for credit losses during the reporting period as a provision for (reversal of) credit losses in our statements of income. Off-Balance Sheet Financial Instruments We establish a separate liability for credit losses, if any, attributable to off-balance sheet financial instruments, such as standby letters of credit (also referred to herein as letters of credit), using the same approach described above for on-balance sheet financial instruments. We recognize the change in credit losses during the reporting period, if any, in other noninterest expense in our statements of income. Details about the allowance for credit losses methodology for each of our portfolio segments is discussed below. Member Credit Products (advances, letters of credit and other extensions of credit to borrowers) We consider our risk-based approach to determining collateral requirements, including risk-based collateral levels and collateral delivery triggers, and our credit extension policies as the primary tools for managing the credit quality on our member credit products. We assess and protect our rights to collateral on a member-by-member basis to determine if we are holding collateral with a value that is at least equal to the credit outstanding to that member. The collateral value required to secure each member’s credit products is calculated for securities, by multiplying the applicable percentage margin by the market value of each security and for loans, by multiplying the applicable percentage margin by the unpaid principal balance of pledged loans, along with any applicable percentage applied to adjust for ineligible loans found during a member's collateral review. We also factor in the repayment history of our members when assessing whether a credit risk loss has been incurred with respect to our member credit products. Conventional MPF Loans Held in Portfolio MPF Risk Sharing Structure Our allowance for credit losses methodology factors in the allocation of losses for conventional MPF products held in our portfolio as further described below. The credit risk analysis determines the degree to which layers of the MPF Risk Sharing Structure are available to recover losses on MPF Loans. PFIs deliver MPF Loans into pools designated by product specific Master Commitments (MCs). The credit risk analysis is performed at an individual MC level since credit loss recovery from a PFI is MC-specific - that is, credit losses on a loan may be absorbed by the PFI only by its risk layer of the MC related to that loan. We allocate losses on participation interests in MPF Loans amongst the participating MPF Banks pro-ratably based upon their respective percentage participation interest in the related MC. Credit losses are absorbed in the following order (the MPF Risk Sharing Structure): • Borrower's equity. • Primary mortgage insurance (PMI), if any. • The PFI. We will withhold a PFI's scheduled performance credit enhancement fee in order to reimburse ourselves for any losses allocated to the FLA (as further described below). • Us, or pro-rata with another MPF Bank in the case of a participation, up to the amount of the First Loss Account (FLA). The FLA functions as a tracking mechanism for our first layer of loss exposure before determining the point in which a PFI's credit enhancement obligation (CE Amount) would cover the next layer of losses. Our FLA exposure varies by MPF Loan product type - that is, MPF Original, MPF 35, MPF 100, MPF 125, and MPF Plus. • The PFI. The PFI's CE Amount, which may include proceeds from a provider of supplemental mortgage guaranty insurance (SMI). • Us, or pro-rata with another MPF Bank in the case of a participation. We and the participating MPF Bank, if applicable, will absorb any losses after the CE Amount has been exhausted. Review Process Our overall allowance for credit losses is determined by an analysis that includes consideration of various data observations such as past performance, current performance, loan portfolio characteristics, other collateral related characteristics, industry data, and prevailing economic conditions. The measurement of the allowance for credit losses consists of: (1) reviewing the change in the rates (i.e., migration or "roll rates") of delinquencies on residential mortgage loans for the entire portfolio; (2) reviewing the total severity rate and the credit loss severity rate; and (3) estimating credit losses in the remaining portfolio. Loss Severity The Total Severity Rate and the Credit Loss Severity Rate calculations, as defined further below, are based on analysis of MPF Loans that have experienced a credit loss in the previous 12 months. The analysis is done on a rolling 12 month basis. • Total Severity Rate: This severity rate is based on the total losses experienced and expenses incurred on conventional MPF Loans under the MPF Risk Sharing Structure. Specifically, this severity rate includes all credit losses related to contractual principal and interest due on impaired conventional MPF Loans, periodic expenses incurred through the life cycle of a conventional MPF Loan, such as real estate taxes and attorney fees incurred after it is transferred to real estate owned (REO), and REO sale gains or losses. • Credit Loss Severity Rate: The second severity rate only includes credit losses attributable to the contractual principal amounts due on impaired conventional MPF Loan portfolios that either were not collected or were not received on a timely basis. The Total Severity Rate includes total losses and expenses to prevent our allowance for credit losses from being understated. This ensures the portion of the MPF Risk Sharing Structure utilized to absorb noncredit losses is not being included when calculating the amount to be utilized to absorb credit losses. We may adjust these severity rates to reach the final Total Severity Rate and Credit Loss Severity Rate used in the allowance for credit losses methodology. Adjustments may include factors that exist in the current economic environment, such as the FHFA Purchase-Only House Price Index, as of the reporting date. We have not presented quantitative information pertaining to our total and credit loss severity rates due to the immateriality of our allowance for credit losses. Consideration of the MPF Risk Sharing Structure The entire population of conventional MPF Loans is analyzed using the MPF Risk Sharing Structure at the MC level using roll rates and the Total Severity Rate. The total losses resulting after factoring in the MPF Risk Sharing Structure are then calculated. The adjusted total losses are then split into credit losses and noncredit losses. A credit loss only consists of the loss resulting from the timing and amount of unpaid principal on an MPF Loan and does not include periodic expenses incurred during the time period in which an MPF Loan has become REO. Such periodic expenses are noncredit losses, and they are directly expensed through the statements of income as incurred. Estimating Credit Losses in the Remaining Portfolio We apply an imprecision factor to our homogeneous pools of conventional MPF Loans when estimating our allowance for credit losses. Our margin of imprecision represents a subjective management judgment based on facts and circumstances that exist as of the reporting date that is unallocated to any specific measurable economic or credit event and is intended to cover other inherent losses that may not be captured by our loan loss methodology. Government Loans Held in Portfolio The PFI provides insurance or a guaranty from governmental agencies, which includes ensuring compliance with all of their requirements. Servicers maintain the insurance or guaranty and obtain the benefit of the applicable insurance or guaranty with respect to defaulted Government Loans. Any losses incurred on Government Loans that are not recovered from the government insurer or guarantor are absorbed by the servicer. Accordingly, credit losses of our portfolio segment for Government Loans included in our MPF Loan held in portfolio for the reporting periods presented is based on our assessment of our servicers' ability to absorb losses not covered by the applicable government guarantee or insurance. Federal Funds Sold and Securities Purchased Under Agreements to Resell Federal Funds sold are only evaluated for purposes of an allowance for credit losses if payment is not made when due. In this regard, we may establish an allowance for credit losses for Federal Funds sold when repayment has not been made according to contractual terms. We may establish an allowance for credit losses for securities purchased under agreements to resell or resale agreements in cases where all payments due under the contractual terms have not been received and where we do not hold sufficient underlying collateral. For example, if the credit markets experience disruptions, it may increase the likelihood that one of our counterparties could experience liquidity or financial constraints that may cause them to become insolvent or otherwise default on their obligations to us. If the collateral's fair value amount has decreased below the resale agreement's carrying amount, we may suffer a credit loss that would be recognized as an allowance for credit loss with an offsetting amount recognized as a provision for credit losses in our statements of income. Charge-off Provisions We recognize a charge-off on a loan upon the occurrence of a confirming event, which include, but are not limited to, the events shown below. The charge-off amount equals the difference between the loan's amortized cost basis and its fair value, less costs to sell. We use an Automated Valuation Methodology (AVM) to determine the fair value of our impaired conventional MPF Loans held in portfolio, including troubled debt restructurings, and REO. • When a loan is 180 days or more past due and its fair value, less cost to sell, is less than the loan's amortized cost basis. • When a borrower is in bankruptcy, loans are written down to the fair value of the collateral, less costs to sell, within 60 days of receipt of the notification of filing from the bankruptcy court or within the delinquency time frames specified in the guidance, whichever is shorter. A loan is not written down if the loan is performing, the borrower continues making payments on the loan, and repayment in full is expected. • Fraudulent loans, not covered by any existing representations and warranties in the loan purchase agreement, are charged off within 90 days of discovery of the fraud, or within the delinquency time frames specified in the adverse classification guidance, whichever is shorter. Nonaccrual Conventional MPF Loans held in portfolio are placed on nonaccrual when they become "adversely classified" - that is, when a loan is classified as "Substandard", "Doubtful", or "Loss". An adverse classification means that such a loan is not considered well secured and is in the process of collection.
Derivatives, Policy [Policy Text Block]	Derivatives Refer to Note 9 - Derivatives and Hedging Activities for additional details. We carry all derivatives at fair value in our statements of condition. We designate derivatives either as fair value hedges, cash flow hedges, or economic hedges. We use fair value hedges to offset changes in the fair value or a benchmark interest rate (e.g., LIBOR) related to (1) a recognized asset or liability or (2) an unrecognized firm commitment. We use cash flow hedges to offset an exposure to variability in expected future cash flows associated with an existing recognized asset or liability or a forecasted transaction. We use economic hedges in cases where hedge accounting treatment is not permitted or achievable; for example, hedges of portfolio interest rate risk or financial instruments carried at fair value under the fair value option. Accounting for Variation Margin Payments - Effective in January of 2017 we began accounting for variation margin payments made to or received by the DCOs through our FCMs as settlements to our cleared derivative assets and derivative liabilities. See Note 1 - Background and Basis for Presentation for further details. This change in accounting did not have any effect on the accounting of our existing hedge relationships. Specifically, the change in accounting would not require us to discontinue existing hedge relationships or preclude us from using the short-cut method of hedge accounting provided no additional changes are made by the DCOs that would preclude the use of the short-cut method of hedge accounting. The International Swaps and Derivatives Association (ISDA) issued a confirmation letter confirming the SEC staff’s non-objection to the conclusions reached by ISDA related to the accounting implications of the DCO rule changes regarding the characterization of the variation margin payments as daily settlements and the continued application of existing hedge accounting relationships, including the use of the short-cut method of hedge accounting. Derivative Hedge Accounting - We apply hedge accounting to qualifying hedge relationships. A qualifying hedge relationship exists when a derivative hedging instrument is expected to effectively offset changes in fair values, cash flows, or underlying risk of the hedged item during the term of the hedge relationship. We prepare formal contemporaneous documentation at inception of the hedge relationship to support that the hedge relationship qualifies for hedge accounting treatment. Such documentation includes the items outlined below: • The nature of the risk being hedged. • The risk management objective and strategy. • The hedging relationship. • The hedged item or forecasted transaction. • The derivative hedging instrument. • The method used to retrospectively and prospectively assess the hedge effectiveness between the hedged item and hedging instrument. We use regression analysis to assess hedge effectiveness. We perform hedge effectiveness testing at hedge inception and on a daily basis thereafter. Subsequent to hedge inception, we use the same regression analysis approach for both prospective considerations and retrospective evaluations of assessing hedge effectiveness. • The method we will use to measure the amount of hedge ineffectiveness into earnings. • For cash flow hedges only, we document details that include, but are not limited to, the probability that the forecasted transaction will occur, the date or period when a forecasted transaction is expected to occur, and how we meet the sufficient specificity requirement in the event a hedge relationship is discontinued. For example, we use the first-in first out approach to determine the amounts to be reclassified from AOCI into earning should a hedging relationship related to the Bank's Rolling Discount Note (DN) Hedging Strategy be discontinued. We immediately recognize changes in fair values for both the derivative hedging instrument and the related hedged item beginning on the derivative hedging instrument's trade date. For fair value hedges, changes in fair value on the hedged item are recognized as a cumulative basis adjustment and are included in the amortized cost basis of the asset or liability being hedged. For cash flow hedges, we recognize changes in fair value on the hedged item in AOCI to the extent that the hedge is effective. A cash flow hedge's ineffective portion is immediately recognized as noninterest income on derivatives and hedging activities in our statements of income. Amounts recorded in AOCI are reclassified either to interest income or interest expense depending on the hedged item during the period in which the hedged transaction affects earnings. Discontinuance of Derivative Hedge Accounting - We discontinue hedge accounting treatment prospectively for an existing fair value or cash flow hedge if any one of the following occurs: • Any hedge criterion is no longer met. • The derivative expires or is sold, terminated, or exercised. • We remove the designation of the fair value or cash flow hedge. For discontinued asset and liability fair value hedges, we prospectively amortize the cumulative basis adjustment on the hedged item into interest income or interest expense, whichever is appropriate, over the remaining life of the hedged item using the interest method. For discontinued cash flow hedges in which the Bank elects to discontinue the hedge strategy (e.g., the swap is terminated, sold or exercised) or the hedge effectiveness test fails, then the amount in net unrealized gain (loss) on cash flow hedges in AOCI is prospectively amortized into interest income or interest expense, whichever is applicable, over the remaining life of the hedged item using the interest method. In cases where all or a portion of the hedge relationship is discontinued as a result of a forecasted transaction that does not occur, then all or a portion of the amount in net unrealized gain (loss) on cash flow hedges in AOCI attributable to the discontinued cash flow hedge relationship(s) is immediately recognized to derivatives and hedging activities in our statements of income. If hedge accounting is discontinued and the derivative is not redesignated to another qualifying hedge relationship, we account for the derivative as an economic hedge. Economic Hedges - Derivatives used in economic hedges do not qualify for hedge accounting treatment. Changes in fair value on economic hedges are immediately recognized as noninterest income on derivatives and hedging activities in our statements of income. Purchased Options - Premiums paid to acquire options are included in the initial basis of the derivative and reported in derivative assets on the statements of condition. Accrual of Net Interest Settlements - Accrual of net interest settlements on a derivative qualifying as a fair value or cash flow hedge are recognized in the same line item in our statements of income as the interest income or interest expense of the underlying hedged item. Accrual of net interest settlements on economic hedges are recognized as noninterest income on derivatives and hedging activities in our statements of income. MPF Delivery Commitments - Commitments to purchase MPF Loans are carried at fair value as a derivative asset or derivative liability, with changes in fair value immediately recognized as noninterest income on derivatives and hedging activities in our statements of income. Advance Commitments - An unhedged advance commitment on an advance we intend to hold for investment purposes upon funding is accounted for as a firm commitment rather than a derivative. Firm commitments are accounted for off-balance sheet rather than carried at fair value. A hedged advance commitment (i.e., in a fair value hedge relationship) is carried at fair value with any changes in fair value immediately recognized in noninterest income on derivatives and hedging activities. Derivative Contracts with a Financing Element - We present cash flows from derivative contracts where an other-than-insignificant financing element is present at the derivative contract's inception as a financing activity. We define the term “other-than-insignificant” as an amount that is equal to or greater than 10% of the present value of an at-the-market derivative’s fully prepaid amount. Novation
Debt, Policy [Policy Text Block]	Consolidated Obligations Consolidated obligations consist of discount notes and consolidated obligation bonds. Consolidated obligations are the joint and several liability of the FHLBs. See Note 10 - Consolidated Obligations to the financial statements for further details. We carry consolidated obligations on an amortized cost basis, except when we elect the fair value option and carry the consolidated obligation at fair value. Amortized cost basis represents the amount funded to us adjusted for any premiums and discounts, concession fees, and cumulative basis adjustments, if any, related to ongoing (open) and/or discontinued (closed) fair value hedges (fair value hedging adjustments). Cumulative basis adjustments related to ongoing (open) and/or discontinued (closed) cash flow hedges (cash flow hedging adjustments) are classified in AOCI. We use the interest method to amortize/accrete premiums/discounts, concession fees, and hedging adjustments on consolidated obligations into interest expense in our statements of income. The amortization/accretion period for a callable consolidated obligation is over its estimated life. The amortization/accretion period for a consolidated obligation that is noncallable or that has a zero-coupon rate is over its contractual life. We immediately recognize any remaining premiums/discounts, concession fees, and any fair value hedging adjustments attributable to a consolidated obligation that is called into interest expense in our statements of income. Any remaining cash flow hedging adjustment in AOCI attributable to the consolidated obligation that was called is immediately recognized into noninterest income on derivatives and hedging activities in our statements of income. We derecognize a consolidated obligation only if it has been extinguished in the open market or transferred to another FHLB. We record a transfer of our consolidated obligations to another FHLB as an extinguishment of debt because we have been legally released from being the primary obligor. An extinguishment gain or loss is recognized in noninterest income on early extinguishment of debt, if any. The amount recognized equals the difference between the debt's reacquisition price and its net carrying amount, which includes the remaining premiums/discounts, concession fees, and cumulative fair value hedging adjustments, if any, attributable to the extinguished consolidated obligation. Any cash flow hedging adjustment remaining in AOCI attributable to the extinguished consolidated obligation is immediately recognized into noninterest income on derivatives and hedging activities in our statements of income.
Stockholders' Equity, Policy [Policy Text Block]	Capital and Mandatorily Redeemable Capital Stock (MRCS) Capital stock is issued and recorded at par. We record the repurchase of our capital stock from our members at par. The capital stock repurchased is retired. We recognize dividends on our capital stock on the date they are declared by our Board of Directors. Specifically, upon being declared, we recognize a reduction to our retained earnings with an offsetting entry to other liabilities (i.e., accrued dividends payable) in our statements of condition based on the number of shares outstanding of our Class B1 activity stock and its dividend rate and the number of shares outstanding of our Class B2 membership stock and its dividend rate. We reclassify capital stock from equity to mandatorily redeemable capital stock (MRCS), a liability on our statements of condition, once we become unconditionally obligated to redeem capital stock by transferring cash at a specified or determinable date (or dates) or upon an event certain to occur. Capital stock is reclassified to MRCS at fair value. The fair value of capital stock subject to mandatory redemption is its par value (as indicated by contemporaneous member purchases and sales at par value) plus any dividends related to the capital stock which are also reclassified as a liability, accrued at the expected dividend rate, and reported as a component of interest expense. Our stock can only be acquired and redeemed or repurchased at par value. It is not publicly traded and no market mechanism exists for the exchange of stock outside our cooperative structure. Refer to Note 13 - Capital and Mandatorily Redeemable Capital Stock (MRCS) for further details.
Guarantees, Indemnifications and Warranties Policies [Policy Text Block]	Joint and Several Liability We consider our joint and several liability for consolidated obligations as a related party guarantee. GAAP guidance pertaining to the initial recognition and measurement of guarantees does not apply to related party guarantees. As a result, we did not recognize an initial liability for our joint and several liability at fair value. We would accrue a liability if subsequently we expect to pay any additional amounts on behalf of other FHLBs under the joint and several liability.
Legal Costs, Policy [Policy Text Block]	Litigation Settlement Awards and related Litigation Settlement Legal Expense We recognize litigation settlement awards into other noninterest income on litigation settlement awards when realized. A litigation settlement award is considered realized when we receive cash or assets that are readily convertible to known amounts of cash or claims to cash. Prior to being recognized, we consider the potential litigation settlement awards to be gain contingencies. Legal expenses related to litigation settlement awards are contingent based fees for the attorneys representing the Bank. We incur and recognize these contingent based legal fees only if we receive a litigation settlement award. We classify litigation related legal fees in noninterest expense - other in our statements of income. Refer to Ongoing Litigation
Pension and Other Postretirement Plans, Policy [Policy Text Block]	Pentegra Defined Benefit (DB) Plan for Financial Institutions (the Pension Plan) We participate in the Pentegra Defined Benefit (DB) Plan for Financial Institutions (the Pension Plan), a tax-qualified defined-benefit pension plan. We account for the Pension Plan as a multiemployer plan since contributions made by us may be used to provide benefits to participants of other participating employers. We include administrative fees in the amount of pension cost recognized into our statements of income. A prepaid pension asset is recognized when our contributions are in excess of 100% of our minimum required contribution while a liability is recognized for contributions due and unpaid at the end of the reporting period. Certain multiemployer plan disclosures, such as the certified zone status, are not applicable to the Pension Plan. Refer to Note 15 - Employee Retirement Plans
Segment Reporting, Policy [Policy Text Block]	Segment Reporting

Interest Income and Interest 26

Interest Income and Interest Expense (Tables)	12 Months Ended
	Dec. 31, 2017
Interest Income (Expense), Net [Abstract]
Interest Income and Interest Expense [Table Text Block]	The following table presents interest income and interest expense for the periods indicated: For the years ended December 31, 2017 2016 2015 Interest income - Trading $ 4 $ 10 $ 4 Available-for-sale interest income 428 440 471 Available-for-sale prepayment fees 27 45 60 Available-for-sale 455 485 531 Held-to-maturity interest income 195 222 255 Held-to-maturity prepayment fees 2 2 15 Held-to-maturity 197 224 270 Investment securities 656 719 805 Advances 560 290 181 MPF Loans held in portfolio 213 218 256 Federal Funds sold and securities purchased under agreements to resell 115 25 8 Other interest bearing assets 14 7 2 Interest income 1,558 1,259 1,252 Interest expense - Consolidated obligations - Discount notes 527 359 294 Bonds 533 411 396 Subordinated notes — 24 54 Other interest bearing liabilities 15 9 — Interest expense 1,075 803 744 Net interest income 483 456 508 Provision for (reversal of) credit losses — 1 5 Net interest income after provision for (reversal of) credit losses $ 483 $ 455 $ 503

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Trading Securities by Major Security Type [Table Text Block]	Trading Securities The following table presents the fair value of our trading securities. Our unrealized gains or losses on trading securities still held on our statement of condition as of the end of the reporting period were no t material. As of December 31, 2017 December 31, 2016 U.S. Government & other government related $ 202 $ 1,005 Residential MBS GSE 30 39 Government-guaranteed 1 1 Trading securities $ 233 $ 1,045
Available-for-sale Securities by Major Security Type [Table Text Block]	Amortized Cost Basis and Fair Value – Available-for-Sale Securities (AFS) Amortized Cost Basis Gross Unrealized Gains in AOCI Gross Unrealized (Losses) in AOCI Carrying Amount and Fair Value As of December 31, 2017 U.S. Government & other government related $ 256 $ 15 $ — $ 271 State or local housing agency 21 — — 21 FFELP ABS 3,987 234 (7 ) 4,214 Residential MBS: GSE 7,275 132 (1 ) 7,406 Government-guaranteed 971 24 — 995 Private-label 40 10 — 50 Available-for-sale securities $ 12,550 $ 415 $ (8 ) $ 12,957 As of December 31, 2016 U.S. Government & other government related $ 322 $ 15 $ (1 ) $ 336 State or local housing agency 19 — — 19 FFELP ABS 4,431 165 (24 ) 4,572 Residential MBS: GSE 8,291 266 (2 ) 8,555 Government-guaranteed 1,346 34 — 1,380 Private-label 50 6 — 56 Available-for-sale securities $ 14,459 $ 486 $ (27 ) $ 14,918 We had no
Held-to-maturity Securities by Major Security Type [Table Text Block]	Amortized Cost Basis, Carrying Amount, and Fair Value - Held-to-Maturity Securities (HTM) Amortized Cost Basis Noncredit OTTI Recognized in AOCI Carrying Amount Gross Unrecognized Holding Gains Gross Unrecognized Holding (Losses) Fair Value As of December 31, 2017 U.S. Government & other government related $ 1,531 $ — $ 1,531 $ 29 $ (1 ) $ 1,559 State or local housing agency 9 — 9 — — 9 Residential MBS: GSE 1,513 — 1,513 62 — 1,575 Government-guaranteed 585 — 585 6 — 591 Private-label 662 (143 ) 519 285 — 804 Held-to-maturity securities $ 4,300 $ (143 ) $ 4,157 $ 382 $ (1 ) $ 4,538 As of December 31, 2016 U.S. Government & other government related $ 1,733 $ — $ 1,733 $ 42 $ (1 ) $ 1,774 State or local housing agency 13 — 13 — — 13 Residential MBS: GSE 1,856 — 1,856 100 — 1,956 Government-guaranteed 791 — 791 10 — 801 Private-label 856 (177 ) 679 294 (1 ) 972 Held-to-maturity securities $ 5,249 $ (177 ) $ 5,072 $ 446 $ (2 ) $ 5,516 We had no
Securities by Contractual Maturity [Table Text Block]	Interest Rate Payment Terms The following table presents the interest rate payment terms of AFS and HTM securities at amortized cost basis for the reporting periods indicated. Available-for-Sale Held-to-Maturity As of December 31, 2017 2016 2017 2016 Non-MBS: Fixed-rate $ 275 $ 336 $ 1,531 $ 1,732 Variable-rate 3,989 4,436 9 14 Non-MBS 4,264 4,772 1,540 1,746 Residential MBS: Fixed-rate 7,653 8,955 1,614 2,034 Variable-rate 633 732 1,146 1,469 Residential MBS 8,286 9,687 2,760 3,503 Total $ 12,550 $ 14,459 $ 4,300 $ 5,249 Contractual Maturity The following table presents the aging of our investments for the current year, as well as the carrying amounts for the previous two years. It also discloses the yields by aging categories for the current year. 2017 2016 2015 As of December 31, Due in one year or less Due one through five years Due five through ten years Due after ten years Carrying Amount Carrying Amount Carrying Amount Trading securities- U.S. Government & other governmental related $ 202 $ — $ — $ — $ 202 $ 1,005 $ 1,108 Residential MBS: GSE — — — 30 30 39 50 Government guaranteed — — 1 — 1 1 2 Trading securities 202 — 1 30 233 1,045 1,160 Yield on trading securities 1.37 % — % 2.37 % 4.40 % 1.76 % 1.13 % 0.93 % AFS securities- U.S. Government & other governmental related — 26 50 195 271 336 422 State or local housing agency 2 4 9 6 21 19 18 FFELP ABS — — — 4,214 4,214 4,572 5,299 Residential MBS: GSE — 7,328 5 73 7,406 8,555 9,798 Government-guaranteed — — — 995 995 1,380 1,868 Private-label — — — 50 50 56 65 AFS securities 2 7,358 64 5,533 12,957 14,918 17,470 Yield on AFS securities 1.71 % 4.46 % 4.85 % 3.40 % 4.01 % 4.04 % 4.14 % HTM securities- U.S. Government & other governmental related 678 172 115 566 1,531 1,733 1,932 State or local housing agency — 6 3 — 9 13 16 Residential MBS: GSE 1 908 67 537 1,513 1,856 2,163 Government-guaranteed — 85 4 496 585 791 969 Private-label — — — 519 519 679 887 HTM securities 679 1,171 189 2,118 4,157 5,072 5,967 Yield on HTM securities 1.80 % 3.34 % 4.01 % 3.47 % 3.19 % 3.18 % 3.12 % Investment securities 883 8,529 254 7,681 17,347 21,035 24,597 Interest bearing deposits 775 775 650 650 Federal Funds sold 7,561 7,561 4,075 1,702 Securities purchased under agreements to resell 5,000 5,000 2,300 1,375 Investments $ 14,219 $ 8,529 $ 254 $ 7,681 $ 30,683 $ 28,060 $ 28,324
Securities in a Continuous Unrealized Loss Position [Table Text Block]	The following table presents unrealized temporary losses on our AFS and HTM portfolio for periods less than 12 months and for 12 months or more. We recognized no OTTI charges on these unrealized loss positions. Refer to the Other-Than-Temporary Impairment Analysis section below for further discussion. In the tables below, in cases where the gross unrealized losses for an investment category are less than $1 million, the losses are not reported. Less than 12 Months 12 Months or More Total Fair Value Gross Unrealized (Losses) Fair Value Gross Unrealized (Losses) Fair Value Gross Unrealized (Losses) Available-for-Sale Securities As of December 31, 2017 U.S. Government & other government related $ 3 $ — $ — $ — $ 3 $ — State or local housing agency 4 — — — 4 — FFELP ABS — — 644 (7 ) 644 (7 ) Residential MBS: GSE 51 — 801 (1 ) 852 (1 ) Private-label — — 7 — 7 — Available-for-sale securities $ 58 $ — $ 1,452 $ (8 ) $ 1,510 $ (8 ) As of December 31, 2016 U.S. Government & other government related $ — $ — $ 47 $ (1 ) $ 47 $ (1 ) State or local housing agency 7 — — — 7 — FFELP ABS — — 753 (24 ) 753 (24 ) Residential MBS: GSE — — 991 (2 ) 991 (2 ) Government-guaranteed — — 23 — 23 — Private-label — — 8 — 8 — Available-for-sale securities $ 7 $ — $ 1,822 $ (27 ) $ 1,829 $ (27 ) Held-to-Maturity Securities As of December 31, 2017 U.S. Government & other government related $ 594 $ — $ 24 $ (1 ) $ 618 $ (1 ) State or local housing agency 2 — — — 2 — Residential MBS: GSE — — 2 — 2 — Private-label — — 769 (143 ) 769 (143 ) Held-to-maturity securities $ 596 $ — $ 795 $ (144 ) $ 1,391 $ (144 ) As of December 31, 2016 U.S. Government & other government related $ 26 $ — $ 17 $ (1 ) $ 43 $ (1 ) State or local housing agency — — 1 — 1 — Residential MBS: GSE — — 4 — 4 — Government-guaranteed 117 — — — 117 — Private-label — — 934 (178 ) 934 (178 ) Held-to-maturity securities $ 143 $ — $ 956 $ (179 ) $ 1,099 $ (179 )
Gain (Loss) on Investments [Table Text Block]	The following table presents private-label MBS that have incurred OTTI at some point in time since we acquired the security. Each private-label MBS presented below is classified as prime, subprime, or Alt-A. Such classification depends upon the nature of the majority of underlying mortgages collateralizing each private-label MBS based on the issuer's classification, or as published by a nationally recognized statistical rating organization (NRSRO), at the time of issuance of the MBS. As of December 31, 2017 Unpaid Principal Balance Amortized Cost Basis Noncredit OTTI in AOCI Gross Unrealized Gains Carrying Amount Fair Value Private-label residential MBS: OTTI AFS Securities- Alt-A $ 61 $ 40 $ — $ 9 $ 49 $ 49 OTTI HTM Securities- Prime $ 535 $ 430 $ (107 ) $ — $ 323 $ 479 Subprime 368 194 (36 ) — 158 285 OTTI HTM securities $ 903 $ 624 $ (143 ) $ — $ 481 $ 764
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block]	The following table presents the changes in the cumulative amount of OTTI credit losses previously recognized into earnings on investment securities for the reporting periods indicated. For the years ended December 31, 2017 2016 2015 Beginning Balance $ 520 $ 568 $ 620 Reductions: Securities sold, matured, or fully prepaid over the period (1 ) — — Increases in expected future cash flows recorded as credit-related accretion into interest income (42 ) (48 ) (52 ) Ending Balance $ 477 $ 520 $ 568

Advances (Tables)

Advances (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank, Advances [Table Text Block]	The following table presents our advances by terms of contractual maturity. Actual maturities may differ from contractual maturities because some borrowers have the right to call or prepay advances with or without penalties. As of December 31, 2017 Amount Weighted Average Interest Rate Due in one year or less $ 22,177 1.42 % One to two years 2,314 1.65 % Two to three years 1,698 1.91 % Three to four years 1,994 1.65 % Four to five years 3,168 1.78 % More than five years 16,669 1.54 % a Par value $ 48,020 1.52 % a The weighted average interest rate is relatively lower when compared to other categories due to a majority of advances in this category consisting of variable rate advances which reset periodically at current interest rates. See Note 2 - Summary of Significant Accounting Policies for information related to our accounting for advances. See Note 8 - Allowance for Credit Losses for information related to our credit risk on advances and allowance methodology for credit losses. The following table presents our advances by payment terms as of the dates indicated. As of December 31, 2017 December 31, 2016 Fixed-rate due in one year or less $ 9,544 $ 9,473 Fixed-rate due after one year 7,732 5,704 Total fixed-rate 17,276 15,177 Variable-rate due in one year or less 12,633 10,960 Variable-rate due after one year 18,111 18,828 Total variable-rate 30,744 29,788 Par value 48,020 44,965 Fair value hedging adjustments 69 98 Other adjustments (4 ) 4 Advances $ 48,085 $ 45,067
Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	The following advance borrowers exceeded 10% of our advances outstanding: As of December 31, 2017 Par Value % of Total Outstanding One Mortgage Partners Corp. $ 11,000 a 22.9 % The Northern Trust Company 6,000 12.5 % BMO Harris Bank, NA 5,975 12.4 % a

MPF Loans Held in Portfolio (Ta

MPF Loans Held in Portfolio (Tables)	12 Months Ended
	Dec. 31, 2017
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans Held for Portfolio [Table Text Block]	The following table presents information on MPF Loans held in portfolio by contractual maturity at the time of purchase. As of December 31, 2017 December 31, 2016 Medium term (15 years or less) $ 285 $ 417 Long term (greater than 15 years) 4,835 4,489 Unpaid principal balance 5,120 4,906 Net premiums, credit enhancement and deferred loan fees 55 38 Fair value hedging adjustments 20 26 MPF Loans held in portfolio, before allowance for credit losses 5,195 4,970 Allowance for credit losses on MPF Loans (2 ) (3 ) MPF Loans held in portfolio, net $ 5,193 $ 4,967 Conventional mortgage loans $ 4,133 $ 3,818 Government Loans 987 1,088 Unpaid principal balance $ 5,120 $ 4,906 The above table excludes MPF Loans acquired under the MPF Xtra, MPF Direct, and MPF Government MBS products. See Note 2 - Summary of Significant Accounting Policies

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The following table presents the changes in the allowance for credit losses attributable to our portfolio segment for conventional MPF Loans held in portfolio. FHFA regulatory guidance that became effective January 1, 2015, resulted in the increased amount of losses charged to the allowance during 2015. For the years ended December 31, 2017 2016 2015 Balance, beginning of period $ 3 $ 3 $ 15 Losses charged to the allowance (1 ) (1 ) (17 ) Provision for (reversal of) credit losses — 1 5 Balance, end of period $ 2 $ 3 $ 3 The following table presents the recorded investment and the allowance for credit losses in conventional MPF Loans by impairment methodology. The recorded investment in a conventional MPF Loan includes its amortized cost basis and related accrued interest receivable, if any. The recorded investment in a conventional MPF Loan excludes our allowance for credit losses. As of December 31, 2017 December 31, 2016 Recorded investment in conventional MPF Loans - Individually evaluated for impairment $ 49 $ 74 Collectively evaluated for impairment 4,167 3,812 Recorded investment $ 4,216 $ 3,886 Allowance for credit losses on conventional MPF Loans - Collectively evaluated for impairment $ 2 $ 3
Past Due Financing Receivables [Table Text Block]	The following table summarizes our recorded investment in MPF Loans by our key credit quality indicators, which include: • "Serious delinquency rate" consists of MPF Loans that are 90 days or more past due or in the process of foreclosure, as a percentage of the total recorded investment. MPF Loans that are both 90 days or more past due and in the process of foreclosure are only included once in our serious delinquency rate calculation. • "Past due 90 days or more still accruing interest" consists of MPF Loans that are either insured or guaranteed by the government or conventional mortgage loans that are well secured (by collateral that have a realizable value sufficient to discharge the debt or by the guarantee or insurance, such as primary mortgage insurance, of a financially responsible party) and in the process of collection. December 31, 2017 December 31, 2016 As of Conventional Government Total Conventional Government Total Past due 30-59 days $ 74 $ 48 $ 122 $ 83 $ 57 $ 140 Past due 60-89 days 21 16 37 26 17 43 Past due 90 days or more 48 21 69 69 23 92 Past due 143 85 228 178 97 275 Current 4,073 921 4,994 3,708 1,013 4,721 Recorded investment $ 4,216 $ 1,006 $ 5,222 $ 3,886 $ 1,110 $ 4,996 In process of foreclosure $ 21 $ 7 $ 28 $ 35 $ 7 $ 42 Serious delinquency rate 1.16 % 2.11 % 1.34 % 1.82 % 2.07 % 1.88 % Past due 90 days or more and still accruing interest $ 8 $ 21 $ 29 $ 8 $ 23 $ 31 On nonaccrual status $ 49 $ — $ 49 $ 74 $ — $ 74
Impaired Financing Receivables [Table Text Block]	The following table summarizes the recorded investment and unpaid principal balance of individually evaluated impaired conventional MPF Loans. Conventional MPF Loans are individually evaluated for impairment when they are adversely classified. There is no allowance for credit losses attributable to conventional MPF Loans that are individually evaluated for impairment, since the related allowance for credit losses have been charged off. As of December 31, 2017 December 31, 2016 Recorded investment without an allowance for credit losses $ 49 $ 74 Unpaid principal balance without an allowance for credit losses 53 80 We do not recognize interest income on impaired conventional MPF Loans.

Derivatives and Hedging Activ31

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments [Table Text Block]	The following table presents details on the notional amounts, and derivative assets and liabilities on our statements of condition. Effective in January of 2017, we began treating daily variation margin on our cleared derivatives as cash settlements instead of as cash collateral. December 31, 2017 December 31, 2016 As of Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives in hedge accounting relationships- Interest rate contracts $ 26,655 $ 57 $ 589 $ 25,999 $ 40 $ 898 Derivatives not in hedge accounting relationships- Interest rate contracts 20,506 270 157 29,313 432 260 Other 810 1 1 892 2 3 Derivatives not in hedge accounting relationships 21,316 271 158 30,205 434 263 Variation margin daily settlements on cleared derivatives (16 ) (168 ) Gross derivative amount before netting adjustments and cash collateral $ 47,971 312 579 $ 56,204 474 1,161 Netting adjustments and cash collateral (309 ) a (559 ) a (468 ) a (1,118 ) a Derivatives on statements of condition $ 3 $ 20 $ 6 $ 43 a Cash collateral received was $35 million and $40 million , and cash collateral posted was $284 million and $689 million at December 31, 2017 , and December 31, 2016
Derivatives And Hedging Activities as Presented in the Statements of Income [Table Text Block]	The following table presents the noninterest income on derivatives and hedging activities as presented in the statements of income. The amounts attributable to fair value and cash flow hedges represent hedge ineffectiveness. For the years ending December 31, 2017 2016 2015 Fair value hedges - interest rate contracts $ (4 ) $ 7 $ (35 ) Cash flow hedges - interest rate contracts 3 5 3 Economic hedges - Interest rate contracts 4 (15 ) 15 Other 3 4 1 Economic hedges 7 (11 ) 16 Variation margin on daily settled cleared derivatives 2 — — Noninterest income on derivatives and hedging activities $ 8 $ 1 $ (16 )
Offsetting Assets [Table Text Block]	The following table presents details regarding the offsetting of our derivative assets and liabilities on our statements of condition. Effective in January of 2017, we began treating daily variation margin on our cleared derivatives as cash settlements instead of as cash collateral . Derivative Assets Derivative Liabilities Bilateral Cleared Total Bilateral Cleared Total As of December 31, 2017 Derivatives with legal right of offset - Gross recognized amount $ 216 $ 95 $ 311 $ 476 $ 102 $ 578 Netting adjustments and cash collateral (214 ) (95 ) (309 ) (463 ) (96 ) (559 ) Derivatives with legal right of offset - net 2 — 2 13 6 19 Derivatives without legal right of offset 1 — 1 1 — 1 Derivatives on statements of condition 3 — 3 14 6 20 Less: Noncash collateral received and cannot be sold or repledged — — — 6 6 Noncash collateral pledged and cannot be sold or repledged (1 ) (1 ) Net amount $ 3 $ 1 $ 4 $ 14 $ — $ 14 As of December 31, 2016 Derivatives with legal right of offset - Gross recognized amount $ 339 $ 133 $ 472 $ 820 $ 339 $ 1,159 Netting adjustments and cash collateral (335 ) (133 ) (468 ) (788 ) (330 ) (1,118 ) Derivatives with legal right of offset - net 4 — 4 32 9 41 Derivatives without legal right of offset 2 — 2 2 — 2 Derivatives on statements of condition 6 — 6 34 9 43 Less: Noncash collateral received and cannot be sold or repledged — — — 9 9 Cash collateral for initial margin (1 ) (1 ) Noncash collateral pledged and cannot be sold or repledged (2 ) (2 ) Net amount $ 6 $ 3 $ 9 $ 34 $ — $ 34
Offsetting Liabilities [Table Text Block]	The following table presents details regarding the offsetting of our derivative assets and liabilities on our statements of condition. Effective in January of 2017, we began treating daily variation margin on our cleared derivatives as cash settlements instead of as cash collateral . Derivative Assets Derivative Liabilities Bilateral Cleared Total Bilateral Cleared Total As of December 31, 2017 Derivatives with legal right of offset - Gross recognized amount $ 216 $ 95 $ 311 $ 476 $ 102 $ 578 Netting adjustments and cash collateral (214 ) (95 ) (309 ) (463 ) (96 ) (559 ) Derivatives with legal right of offset - net 2 — 2 13 6 19 Derivatives without legal right of offset 1 — 1 1 — 1 Derivatives on statements of condition 3 — 3 14 6 20 Less: Noncash collateral received and cannot be sold or repledged — — — 6 6 Noncash collateral pledged and cannot be sold or repledged (1 ) (1 ) Net amount $ 3 $ 1 $ 4 $ 14 $ — $ 14 As of December 31, 2016 Derivatives with legal right of offset - Gross recognized amount $ 339 $ 133 $ 472 $ 820 $ 339 $ 1,159 Netting adjustments and cash collateral (335 ) (133 ) (468 ) (788 ) (330 ) (1,118 ) Derivatives with legal right of offset - net 4 — 4 32 9 41 Derivatives without legal right of offset 2 — 2 2 — 2 Derivatives on statements of condition 6 — 6 34 9 43 Less: Noncash collateral received and cannot be sold or repledged — — — 9 9 Cash collateral for initial margin (1 ) (1 ) Noncash collateral pledged and cannot be sold or repledged (2 ) (2 ) Net amount $ 6 $ 3 $ 9 $ 34 $ — $ 34 At December 31, 2017 , we had $60 million of additional credit exposure on cleared derivatives due to pledging of noncash collateral to our DCOs, for initial margin, which exceeded our derivative liability position. We had $86 million of comparable exposure at December 31, 2016
Fair Value Hedges [Table Text Block]	Fair Value Hedges The following table presents our fair value hedging results by the type of hedged item. We had no gain (loss) for hedges that no longer qualified as a fair value hedge. Additionally, the table indicates where fair value hedging results are classified in our statements of income. In this regard, the Amount Recorded in Net Interest Income column includes the following: • The amortization of closed fair value hedging adjustments, which are included in the interest income/expense line item of the respective hedged item type. • The effect of net interest settlements attributable to open derivative hedging instruments, which are recorded directly to the interest income/expense line item of the respective hedged item type. For the years ending December 31, Gain (Loss) on Hedging Instrument Gain (Loss) on Hedged Item Total Ineffectiveness Recognized in Derivatives and Hedging Activities Amount Recorded in Net Interest Income 2017 Available-for-sale securities $ 91 $ (100 ) $ (9 ) $ (90 ) Advances 31 (29 ) 2 (32 ) MPF Loans held in portfolio — — — (6 ) Consolidated obligation bonds 5 (2 ) 3 31 Total $ 127 $ (131 ) $ (4 ) $ (97 ) 2016 Available-for-sale securities $ 86 $ (85 ) $ 1 $ (122 ) Advances 66 (59 ) 7 (70 ) MPF Loans held in portfolio — — — (9 ) Consolidated obligation bonds (140 ) 139 (1 ) 62 Total $ 12 $ (5 ) $ 7 $ (139 ) 2015 Available-for-sale securities $ 43 $ (56 ) $ (13 ) $ (146 ) Advances 6 (5 ) 1 (84 ) MPF Loans held in portfolio — — — (13 ) Consolidated obligation bonds 46 (69 ) (23 ) 205 Total $ 95 $ (130 ) $ (35 ) $ (38 )
Cash Flow Hedges [Table Text Block]	Cash Flow Hedges We reclassify amounts in AOCI into our statements of income in the same periods during which the hedged forecasted transaction affects our earnings. We had no discontinued hedges for the periods presented. The deferred net gains (losses) on derivative instruments in AOCI that are expected to be reclassified to earnings during the next twelve months were no t material as of December 31, 2017 . The maximum length of time over which we are hedging our exposure to the variability in future cash flows for forecasted transactions is 3 years . The following table presents our cash flow hedging results by type of hedged item. Additionally, the table indicates where cash flow hedging results are classified in our statements of income. In this regard, the Amount Recorded in Net Interest Income column includes the following: • The amortization of closed cash flow hedging adjustments, which are reclassified from AOCI into the interest income/expense line item of the respective hedged item type. • The effect of net interest settlements attributable to open derivative hedging instruments, which are recorded directly to the interest income/expense line item of the respective hedged item type. For the years ending December 31, Ineffectiveness Recorded in Derivatives and Hedging Activities Effective Portion Recorded in AOCI Amount Recorded in Net Interest Income 2017 Advances $ — $ — $ 10 Discount notes 3 173 (168 ) Bonds — — (3 ) Total $ 3 $ 173 $ (161 ) 2016 Advances $ — $ — $ 10 Discount notes 5 161 (195 ) Bonds — — (3 ) Total $ 5 $ 161 $ (188 ) 2015 Advances $ — $ — $ 10 Discount notes 3 125 (242 ) Bonds — — (3 ) Total $ 3 $ 125 $ (235 )

Consolidated Obligations (Table

Consolidated Obligations (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Short-term Debt [Table Text Block]	The following table presents our consolidated obligation discount notes for which we are the primary obligor. All are due in one year or less. As of December 31, 2017 December 31, 2016 Carrying Amount $ 41,191 $ 35,949 Weighted Average Interest Rate 1.23 % 0.46 %
Schedule of Maturities of Long-term Debt [Table Text Block]	The following table presents our consolidated obligation bonds, for which we are the primary obligor, including callable bonds that are redeemable in whole, or in part, at our discretion on predetermined call dates. As of December 31, 2017 Contractual Maturity Weighted Average Interest Rate By Maturity or Next Call Date Due in one year or less $ 16,616 1.25 % $ 27,347 One to two years 7,919 1.32 % 6,749 Two to three years 2,734 1.38 % 1,959 Three to four years 3,739 1.97 % 374 Four to five years 2,823 2.46 % 575 Thereafter 3,516 2.70 % 343 Total par value $ 37,347 1.58 % $ 37,347
Schedule of Long-term Debt Instruments [Table Text Block]	The following table presents consolidated obligation bonds outstanding by call feature: As of December 31, 2017 December 31, 2016 Noncallable $ 23,644 $ 22,356 Callable 13,703 14,778 Par value 37,347 37,134 Fair value hedging adjustments (214 ) (229 ) Other adjustments (12 ) (2 ) Consolidated obligation bonds $ 37,121 $ 36,903 Consolidated obligations are issued with either fixed- or floating-rate payment terms that may use a variety of indices for interest rate resets including the London Interbank Offered Rate (LIBOR). Additionally, both fixed-rate bonds and floating-rate bonds may contain an embedded derivative, such as a call feature or complex coupon payment terms, if requested by investors. When such consolidated obligations are issued, we may concurrently enter into an interest rate swap containing offsetting features that effectively convert the terms of the bond to a variable-rate bond tied to an index or a fixed-rate bond. Consolidated obligation bonds, beyond having fixed-rate or floating-rate payment terms, may also have the following broad terms regarding either principal repayment or coupon payment terms: Step-Up Bonds and Step-Down Bonds - Bonds that pay interest at increasing or decreasing fixed rates for specified intervals over their life. These bonds are callable at our option on the step-up or step-down dates. The following table presents interest rate payment terms for consolidated obligation bonds for which we are primary obligor at the dates indicated: As of December 31, 2017 December 31, 2016 Fixed-rate $ 21,357 $ 22,389 Variable-rate 12,884 11,615 Step-up 2,730 2,650 Step-down 366 480 Other 10 — Par value $ 37,347 $ 37,134
Schedule of Guarantor Obligations [Table Text Block]	The following table summarizes the consolidated obligations of the FHLBs and those for which we are the primary obligor. We did not accrue a liability for our joint and several liability related to the other FHLBs’ share of the consolidated obligations as of December 31, 2017 and December 31, 2016 . Refer to Note 17 - Commitments and Contingencies for further details. December 31, 2017 December 31, 2016 Par values as of Bonds Discount Notes Total Bonds Discount Notes Total FHLB System total consolidated obligations $ 642,211 $ 392,049 $ 1,034,260 $ 579,189 $ 410,122 $ 989,311 FHLB Chicago as primary obligor 37,347 41,235 78,582 37,134 35,969 73,103 As a percent of the FHLB System 6 % 11 % 8 % 6 % 9 % 7 %

Affordable Housing Program (Tab

Affordable Housing Program (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Activity in Affordable Housing Program Obligation [Table Text Block]	The following table summarizes the changes in the AHP payable for the periods indicated: For the years ended December 31, 2017 2016 2015 AHP balance at beginning of year $ 86 $ 89 $ 90 AHP expense accrual 36 37 39 Cash disbursements for AHP (34 ) (40 ) (40 ) AHP balance at end of year $ 88 $ 86 $ 89

Capital and Mandatorily Redee34

Capital and Mandatorily Redeemable Capital Stock (MRCS) (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	The following table details our minimum capital requirements: December 31, 2017 December 31, 2016 As of Requirement Actual Requirement Actual Risk-based capital $ 1,075 $ 5,051 $ 1,088 $ 5,032 Total regulatory capital $ 3,374 $ 5,051 $ 3,148 $ 5,032 Total regulatory capital ratio 4.00 % 5.99 % 4.00 % 6.40 % Leverage capital $ 4,218 $ 7,577 $ 3,935 $ 7,549 Leverage capital ratio 5.00 % 8.98 % 5.00 % 9.59 % Total regulatory capital and leverage capital includes mandatorily redeemable capital stock (MRCS) but does not include AOCI. Under the FHFA regulation on capital classifications and critical capital levels for the FHLBs, we are adequately capitalized.
Mandatorily Redeemable Capital Stock [Table Text Block]	The following table shows our MRCS redemption terms by year payable. As of December 31, 2017 Amount Due in one year or less $ 1 One to two years 2 Two to three years 1 Three to four years 5 Four to five years 4 After five years 298 MRCS $ 311
Stockholders' Equity, Total [Member]
Concentration Risk [Line Items]
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	The following members had regulatory capital stock exceeding 10% of our total regulatory capital stock outstanding (which includes MRCS). As of December 31, 2017 Regulatory Capital Stock Outstanding % of Total Outstanding Amount of Which is Classified as a Liability (MRCS) BMO Harris Bank, N.A. $ 269 15.3 % $ — One Mortgage Partners Corp. 245 a 14.0 % 245 a One Mortgage Partners Corp. is a subsidiary of JPMorgan Chase Bank NA.

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table summarizes the gains (losses) in AOCI for the reporting periods indicated. Net Unrealized - Noncredit OTTI - Net Unrealized - Cash Flow Hedges For the years ended December 31, Available-for-sale Securities Held-to-maturity Securities Post-retirement Plans AOCI 2017 Beginning balance $ 459 $ (177 ) $ (312 ) $ (6 ) $ (36 ) Change in the period recorded to the statements of condition, before reclassifications to statements of income (52 ) 34 173 1 156 Amounts reclassified in period to statements of income: Net interest income — — (5 ) — (5 ) Noninterest income on derivatives and hedging activities — — (3 ) — (3 ) Ending balance $ 407 $ (143 ) $ (147 ) $ (5 ) $ 112 2016 Beginning balance $ 658 $ (217 ) $ (463 ) $ (6 ) $ (28 ) Change in the period recorded to the statements of condition, before reclassifications to statements of income (199 ) 40 161 — 2 Amounts reclassified in period to statements of income: Net interest income — — (5 ) — (5 ) Noninterest income on derivatives and hedging activities — — (5 ) — (5 ) Ending balance $ 459 $ (177 ) $ (312 ) $ (6 ) $ (36 ) 2015 Beginning balance $ 1,060 $ (264 ) $ (580 ) $ 1 $ 217 Change in the period recorded to the statements of condition, before reclassifications to statements of income (402 ) 47 125 (7 ) (237 ) Amounts reclassified in period to statements of income: Net interest income — — (5 ) — (5 ) Noninterest income on derivatives and hedging activities — — (3 ) — (3 ) Ending balance $ 658 $ (217 ) $ (463 ) $ (6 ) $ (28 )

Employee retirement plans (Tabl

Employee retirement plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Schedule of Multiemployer Plans [Table Text Block]	The following table provides details on our multiemployer Pension Plan. The funded status is calculated as the market value of plan assets divided by the funding target and reflects contributions received through the plan year ended June 30. Pension Plan 2017 2016 2015 Net pension cost (minimum required contribution) including administrative fees, charged to compensation and benefits expense for the years ended December 31, $ 7 $ 7 $ 3 Actual cash paid including administrative fees for calendar year ended December 31, 9 9 5 Prepaid pension contributions, in other assets, as of December 31, 19 17 15 Plan funded status as of the plan years ended June 30, 111 % 104 % 107 % Our portion of plan funded status as of the plan years ended June 30, 120 % 112 % 121 %

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Inputs, Assets, Quantitative Information [Table Text Block]	The following table shows the range of values for our investment securities that are carried at fair value on our statements of condition using Level 3 significant inputs provided to us by multiple third party pricing vendors. Range of Values As of December 31, 2017 Fair Value Minimum Maximum Available-for-sale securities Private-label residential MBS $ 50 $ 48 $ 51
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following tables are a summary of the fair value estimates and related levels in the fair value hierarchy. The carrying amounts are as recorded in the statements of condition. These tables do not represent an estimate of our overall market value as a going concern; as they do not take into account future business opportunities and future net profitability of assets and liabilities. We had no transfers between levels in the fair value hierarchy for the periods shown. Carrying Amount Fair Value Level 1 Level 2 Level 3 Netting As of December 31, 2017 Carried at amortized cost- Cash and due from banks $ 42 $ 42 $ 42 $ — $ — Interest bearing deposits 775 775 775 — — Federal Funds sold and securities purchased under agreements to resell 12,561 12,561 — 12,561 — Held-to-maturity securities 4,157 4,538 — 3,734 804 Advances 47,309 47,336 — 47,336 — MPF Loans held in portfolio, net 5,186 5,306 — 5,295 11 Other assets 228 228 — 228 — Carried at fair value on a recurring basis- U.S. Government & other government related non-MBS 202 202 — 202 — GSE residential MBS 30 30 — 30 — U.S. Governmental-guaranteed residential MBS 1 1 — 1 — Trading securities 233 233 — 233 — U.S. Government & other government related non-MBS 271 271 — 271 — State or local housing agency non-MBS 21 21 — 21 — FFELP ABS 4,214 4,214 — 4,214 — GSE residential MBS 7,406 7,406 — 7,406 — U.S. Government-guaranteed residential MBS 995 995 — 995 — Private-label residential MBS 50 50 — — 50 Available-for-sale securities 12,957 12,957 — 12,907 50 Advances 776 776 — 776 — Derivative assets 3 3 — 312 — $ (309 ) a Other assets 118 118 — 118 — Carried at fair value on a nonrecurring basis- MPF Loans held in portfolio, net 7 7 — — 7 Other assets 3 3 — — 3 Total assets 84,355 84,883 817 83,500 875 (309 ) Carried at amortized cost- Deposits (524 ) (524 ) — (524 ) — Consolidated obligation discount notes (40,442 ) (40,437 ) — (40,437 ) — Consolidated obligation bonds (31,861 ) (32,011 ) — (32,011 ) — Mandatorily redeemable capital stock (311 ) (311 ) (311 ) — — Other liabilities (336 ) (336 ) — (336 ) — Carried at fair value on a recurring basis- Consolidated obligation discount notes (749 ) (749 ) — (749 ) — Consolidated obligation bonds (5,260 ) (5,260 ) — (5,260 ) — Derivative liabilities (20 ) (20 ) — (579 ) — 559 a Total liabilities $ (79,503 ) $ (79,648 ) $ (311 ) $ (79,896 ) $ — $ 559 Carrying Amount Fair Value Level 1 Level 2 Level 3 Netting As of December 31, 2016 Carried at amortized cost- Cash and due from banks $ 351 $ 351 $ 351 $ — $ — Interest bearing deposits 650 650 650 — — Federal Funds sold and securities purchased under agreements to resell 6,375 6,375 — 6,375 — Held-to-maturity securities 5,072 5,516 — 4,544 972 Advances 44,395 44,393 — 44,393 — MPF Loans held in portfolio, net 4,941 5,136 — 5,136 — Other assets 188 188 — 188 — Carried at fair value on a recurring basis- U.S. Government & other government related non-MBS 1,005 1,005 — 1,005 — GSE residential MBS 39 39 — 39 — U.S. Governmental-guaranteed residential MBS 1 1 — 1 — Trading securities 1,045 1,045 — 1,045 — U.S. Government & other government related non-MBS 336 336 — 336 — State or local housing agency non-MBS 19 19 — 19 — FFELP ABS 4,572 4,572 — 4,572 — GSE residential MBS 8,555 8,555 — 8,555 — U.S. Government-guaranteed residential MBS 1,380 1,380 — 1,380 — Private-label residential MBS 56 56 — — 56 Available-for-sale securities 14,918 14,918 — 14,862 56 Advances 672 672 — 672 — Derivative assets 6 6 — 474 — $ (468 ) a Other assets 44 44 — 44 — Carried at fair value on a nonrecurring basis- MPF Loans held in portfolio, net 26 26 — — 26 Other assets 9 9 — — 9 Total assets 78,692 79,329 1,001 77,733 1,063 (468 ) Carried at amortized cost- Deposits (496 ) (496 ) — (496 ) — Consolidated obligation discount notes (29,581 ) (29,581 ) — (29,581 ) — Consolidated obligation bonds (31,460 ) (31,706 ) — (31,706 ) — Mandatorily redeemable capital stock (301 ) (301 ) (301 ) — — Other liabilities (305 ) (305 ) — (305 ) — Carried at fair value on a recurring basis- Consolidated obligation discount notes (6,368 ) (6,368 ) — (6,368 ) — Consolidated obligation bonds (5,443 ) (5,443 ) — (5,443 ) — Derivative liabilities (43 ) (43 ) — (1,161 ) — 1,118 a Total liabilities $ (73,997 ) $ (74,243 ) $ (301 ) $ (75,060 ) $ — $ 1,118 a The netting adjustment amount includes cash collateral (either received or paid by us) and related accrued interest in cases where we have a legal right of setoff, by contract (e.g., master netting agreement) or otherwise, to discharge all or a portion of the debt owed to our counterparty by applying against the debt an amount that our counterparty owes to us. See Note 9 - Derivatives and Hedging Activities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table presents a rollforward of assets and liabilities that are measured at fair value on the statements of condition using significant unobservable inputs (Level 3). Available-For-Sale Private-Label MBS Derivative Assets Interest-Rate Related Consolidated Obligation Bonds For the years ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 Balance at beginning of period $ 56 $ 65 $ 71 $ — $ 5 $ 13 $ — $ (55 ) $ (63 ) Gain (loss) included in earnings - Interest income 4 5 4 Derivatives and hedging activities — (5 ) (8 ) — 55 8 Gain (loss) included in OCI - Net unrealized on AFS securities 3 2 (1 ) Paydowns and settlements (13 ) (16 ) (9 ) — — — — — — Balance at end of period $ 50 $ 56 $ 65 $ — $ — $ 5 $ — $ — $ (55 ) Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end $ 3 $ 4 $ 4 $ — $ — $ — $ — $ — $ 8
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table presents a rollforward of assets and liabilities that are measured at fair value on the statements of condition using significant unobservable inputs (Level 3). Available-For-Sale Private-Label MBS Derivative Assets Interest-Rate Related Consolidated Obligation Bonds For the years ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 Balance at beginning of period $ 56 $ 65 $ 71 $ — $ 5 $ 13 $ — $ (55 ) $ (63 ) Gain (loss) included in earnings - Interest income 4 5 4 Derivatives and hedging activities — (5 ) (8 ) — 55 8 Gain (loss) included in OCI - Net unrealized on AFS securities 3 2 (1 ) Paydowns and settlements (13 ) (16 ) (9 ) — — — — — — Balance at end of period $ 50 $ 56 $ 65 $ — $ — $ 5 $ — $ — $ (55 ) Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end $ 3 $ 4 $ 4 $ — $ — $ — $ — $ — $ 8
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table presents a rollforward of assets and liabilities that are measured at fair value on the statements of condition using significant unobservable inputs (Level 3). Available-For-Sale Private-Label MBS Derivative Assets Interest-Rate Related Consolidated Obligation Bonds For the years ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 Balance at beginning of period $ 56 $ 65 $ 71 $ — $ 5 $ 13 $ — $ (55 ) $ (63 ) Gain (loss) included in earnings - Interest income 4 5 4 Derivatives and hedging activities — (5 ) (8 ) — 55 8 Gain (loss) included in OCI - Net unrealized on AFS securities 3 2 (1 ) Paydowns and settlements (13 ) (16 ) (9 ) — — — — — — Balance at end of period $ 50 $ 56 $ 65 $ — $ — $ 5 $ — $ — $ (55 ) Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end $ 3 $ 4 $ 4 $ — $ — $ — $ — $ — $ 8
Fair Value, Option, Quantitative Disclosures [Table Text Block]	The following table presents the changes in fair value of financial assets and liabilities carried at fair value under the fair value option that were recognized in noninterest income - instruments held under the fair value option in our statements of income. For the years ended December 31, 2017 2016 2015 Advances $ (5 ) $ (7 ) $ (2 ) Mortgage loans held for sale (in other assets) (4 ) (4 ) (1 ) Discount notes — (2 ) 2 Bonds 7 18 9 Noninterest income - Instruments held under fair value option $ (2 ) $ 5 $ 8 The following table reflects the difference between the aggregate unpaid principal balance (UPB) outstanding and the aggregate fair value for our long term financial instruments for which the fair value option has been elected. None of the advances were 90 days or more past due and none were on nonaccrual status. December 31, 2017 December 31, 2016 As of Advances Consolidated Obligation Bonds Advances Consolidated Obligation Bonds Unpaid principal balance $ 786 $ 5,270 $ 677 $ 5,447 Fair value over (under) UPB (10 ) (10 ) (5 ) (4 ) Fair value 776 5,260 672 5,443

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Off-Balance Sheet Commitments [Table Text Block]	The following table shows our commitments outstanding, which represent off-balance sheet obligations. December 31, 2017 December 31, 2016 As of Expire within one year Expire after one year Total Expire within one year Expire after one year Total Unsettled consolidated obligation bonds $ — $ — $ — $ 10 $ — $ 10 Member standby letters of credit 15,703 3,869 a 19,572 8,459 2,369 a 10,828 Housing authority standby bond purchase agreements — 337 337 25 281 306 Advance commitments 151 — 151 15 1 16 MPF delivery commitments 371 — 371 417 — 417 Other 14 — 14 24 — 24 Commitments $ 16,239 $ 4,206 $ 20,445 $ 8,950 $ 2,651 $ 11,601 a Contains $750 million and $486 million of member standby letters of credit at December 31, 2017 and December 31, 2016

Transactions with Related Par39

Transactions with Related Parties and Other FHLBs (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions, by Balance Sheet Grouping [Table Text Block]	The following table summarizes material balances we had with our members who are related parties as defined above (including their affiliates) as of the periods presented. As of December 31, 2017 December 31, 2016 Assets - Advances $ 165 $ 107 Liabilities - Deposits 13 8 Equity - Capital Stock 10 18

Interest Income and Interest 40

Interest Income and Interest Expense Interest Income and Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income -
Trading	$ 4	$ 10	$ 4
Available-for-sale interest income	428	440	471
Available-for-sale prepayment fees	27	45	60
Available-for-sale	455	485	531
Held-to-maturity interest income	195	222	255
Held-to-maturity prepayment fees	2	2	15
Held-to-maturity	197	224	270
Investment securities	656	719	805
Advances	560	290	181
MPF Loans held in portfolio	213	218	256
Federal Funds sold and securities purchased under agreements to resell	115	25	8
Other interest bearing assets	14	7	2
Interest income	1,558	1,259	1,252
Consolidated obligations -
Discount notes	527	359	294
Bonds	533	411	396
Subordinated notes	0	24	54
Other interest bearing liabilities	15	9	0
Interest expense	1,075	803	744
Net interest income	483	456	508
Provision for (reversal of) credit losses	0	1	5
Net interest income after provision for (reversal of) credit losses	$ 483	$ 455	$ 503

Investment Securities (Trading

Investment Securities (Trading securities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	$ 233	$ 1,045	$ 1,160
U.S. Government & other government related
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	202	1,005	1,108
Residential MBS | GSE
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	30	39	50
Residential MBS | Government-guaranteed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	$ 1	$ 1	$ 2

Investment Securities (Availabl

Investment Securities (Available-for-sale Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	$ 12,550	$ 14,459
Gross Unrealized Gains in AOCI	415	486
Gross Unrealized (Losses) in AOCI	(8)	(27)
Carrying Amount and Fair Value	12,957	14,918	$ 17,470
U.S. Government & other government related
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	256	322
Gross Unrealized Gains in AOCI	15	15
Gross Unrealized (Losses) in AOCI	0	(1)
Carrying Amount and Fair Value	271	336	422
State or local housing agency
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	21	19
Gross Unrealized Gains in AOCI	0	0
Gross Unrealized (Losses) in AOCI	0	0
Carrying Amount and Fair Value	21	19	18
FFELP ABS | FFELP ABS
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	3,987	4,431
Gross Unrealized Gains in AOCI	234	165
Gross Unrealized (Losses) in AOCI	(7)	(24)
Carrying Amount and Fair Value	4,214	4,572	5,299
Residential MBS
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	8,286	9,687
Residential MBS | GSE
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	7,275	8,291
Gross Unrealized Gains in AOCI	132	266
Gross Unrealized (Losses) in AOCI	(1)	(2)
Carrying Amount and Fair Value	7,406	8,555	9,798
Residential MBS | Government-guaranteed
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	971	1,346
Gross Unrealized Gains in AOCI	24	34
Gross Unrealized (Losses) in AOCI	0	0
Carrying Amount and Fair Value	995	1,380	1,868
Residential MBS | Private-label
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	40	50
Gross Unrealized Gains in AOCI	10	6
Gross Unrealized (Losses) in AOCI	0	0
Carrying Amount and Fair Value	$ 50	$ 56	$ 65

Investment Securities (Held-to-

Investment Securities (Held-to-Maturities Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	$ 4,300	$ 5,249
Noncredit OTTI Recognized in AOCI	(143)	(177)
HTM securities	4,157	5,072	$ 5,967
Gross Unrecognized Holding Gains	382	446
Gross Unrecognized Holding (Losses)	(1)	(2)
Held-to-maturity securities	4,538	5,516
U.S. Government & other government related
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	1,531	1,733
Noncredit OTTI Recognized in AOCI	0	0
HTM securities	1,531	1,733	1,932
Gross Unrecognized Holding Gains	29	42
Gross Unrecognized Holding (Losses)	(1)	(1)
Held-to-maturity securities	1,559	1,774
State or local housing agency
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	9	13
Noncredit OTTI Recognized in AOCI	0	0
HTM securities	9	13	16
Gross Unrecognized Holding Gains	0	0
Gross Unrecognized Holding (Losses)	0	0
Held-to-maturity securities	9	13
Residential MBS
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	2,760	3,503
Residential MBS | GSE
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	1,513	1,856
Noncredit OTTI Recognized in AOCI	0	0
HTM securities	1,513	1,856	2,163
Gross Unrecognized Holding Gains	62	100
Gross Unrecognized Holding (Losses)	0	0
Held-to-maturity securities	1,575	1,956
Residential MBS | Government-guaranteed
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	585	791
Noncredit OTTI Recognized in AOCI	0	0
HTM securities	585	791	969
Gross Unrecognized Holding Gains	6	10
Gross Unrecognized Holding (Losses)	0	0
Held-to-maturity securities	591	801
Residential MBS | Private-label
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost Basis	662	856
Noncredit OTTI Recognized in AOCI	(143)	(177)
HTM securities	519	679	$ 887
Gross Unrecognized Holding Gains	285	294
Gross Unrecognized Holding (Losses)	0	(1)
Held-to-maturity securities	$ 804	$ 972

Investment Securities Interest

Investment Securities Interest rate payment terms (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Investment Securities [Line Items]
Available-for-Sale	$ 12,550	$ 14,459
Held-to-Maturity	4,300	5,249
Non-MBS
Investment Securities [Line Items]
Available-for-Sale	4,264	4,772
Held-to-Maturity	1,540	1,746
Non-MBS | Fixed-rate
Investment Securities [Line Items]
Available-for-Sale	275	336
Held-to-Maturity	1,531	1,732
Non-MBS | Variable-rate
Investment Securities [Line Items]
Available-for-Sale	3,989	4,436
Held-to-Maturity	9	14
Residential MBS
Investment Securities [Line Items]
Available-for-Sale	8,286	9,687
Held-to-Maturity	2,760	3,503
Residential MBS | Fixed-rate
Investment Securities [Line Items]
Available-for-Sale	7,653	8,955
Held-to-Maturity	1,614	2,034
Residential MBS | Variable-rate
Investment Securities [Line Items]
Available-for-Sale	633	732
Held-to-Maturity	$ 1,146	$ 1,469

Investment Securities Contractu

Investment Securities Contractual Maturity Terms Trading Securities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	$ 202
Trading Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Trading Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	1
Trading Securities, Debt Maturities, Rolling After Year Ten, Fair Value	30
Trading securities	$ 233	$ 1,045	$ 1,160
Yield On Trading Securities, Debt Maturities, Next Rolling Twelve Months	1.37%
Yield On Trading Securities, Debt Maturities, Rolling Year Two Through Five	0.00%
Yield On Trading Securities, Debt Maturities, Rolling Year Six Through Ten	2.37%
Yield On Trading Securities, Debt Maturities, Rolling After Year Ten	4.40%
Yield On Trading Securities, Debt	1.76%	1.13%	0.93%
U.S. Government & other government related
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	$ 202
Trading Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Trading Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	0
Trading Securities, Debt Maturities, Rolling After Year Ten, Fair Value	0
Trading securities	202	$ 1,005	$ 1,108
Residential MBS | GSE
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	0
Trading Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Trading Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	0
Trading Securities, Debt Maturities, Rolling After Year Ten, Fair Value	30
Trading securities	30	39	50
Residential MBS | Government-guaranteed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	0
Trading Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Trading Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	1
Trading Securities, Debt Maturities, Rolling After Year Ten, Fair Value	0
Trading securities	$ 1	$ 1	$ 2

Investment Securities Contrac46

Investment Securities Contractual Maturity Terms Available For Sale Securities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	$ 2
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	7,358
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	64
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	5,533
AFS securities	$ 12,957	$ 14,918	$ 17,470
Yield On Available For Sale Securities, Debt Maturities, Next Rolling Twelve Months	1.71%
Yield On Available For Sale Securities, Debt Maturities, Rolling Year Two Through Five	4.46%
Yield On Available For Sale Securities, Debt Maturities, Rolling Year Six Through Ten	4.85%
Yield On Available For Sale Securities, Debt Maturities, Rolling After Year Ten	3.40%
Yield On Available For Sale Securities, Debt Securities	4.01%	4.04%	4.14%
U.S. Government & other government related
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	$ 0
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	26
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	50
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	195
AFS securities	271	$ 336	$ 422
State or local housing agency
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	2
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	4
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	9
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	6
AFS securities	21	19	18
FFELP ABS | FFELP ABS
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	4,214
AFS securities	4,214	4,572	5,299
Residential MBS | GSE
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	7,328
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	5
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	73
AFS securities	7,406	8,555	9,798
Residential MBS | Government-guaranteed
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	995
AFS securities	995	1,380	1,868
Residential MBS | Private-label
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value	0
Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value	50
AFS securities	$ 50	$ 56	$ 65

Investment Securities Contrac47

Investment Securities Contractual Maturity Terms Held To Maturity Securities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	$ 679
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost	1,171
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost	189
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	2,118
HTM securities	$ 4,157	$ 5,072	$ 5,967
Yield On Held To Maturity Securities, Debt Maturities, Next Rolling Twelve Months	1.80%
Yield On Held To Maturity Securities, Debt Maturities, Rolling Year Two Through Five	3.34%
Yield On Held To Maturity Securities, Debt Maturities, Rolling Year Six Through Ten	4.01%
Yield On Held To Maturity Securities, Debt Maturities, Rolling After Year Ten	3.47%
Yield On Held To Maturity Securities	3.19%	3.18%	3.12%
U.S. Government & other government related
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	$ 678
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost	172
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost	115
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	566
HTM securities	1,531	$ 1,733	$ 1,932
State or local housing agency
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	0
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost	6
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost	3
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	0
HTM securities	9	13	16
Residential MBS | GSE
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	1
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost	908
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost	67
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	537
HTM securities	1,513	1,856	2,163
Residential MBS | Government-guaranteed
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	0
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost	85
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost	4
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	496
HTM securities	585	791	969
Residential MBS | Private-label
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	0
Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost	0
Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost	0
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	519
HTM securities	$ 519	$ 679	$ 887

Investment Securities Contrac48

Investment Securities Contractual Maturity Terms Investments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investment Securities, Debt Maturities, Next Rolling Twelve Months, Carrying Value	$ 883
Investment Securities, Debt Maturities, Rolling Year Two Through Five, Carrying Value	8,529
Investment Securities, Debt Maturities, Rolling Year Six Through Ten, Carrying Value	254
Investment Securities, Debt Maturities, Rolling After Year Ten, Carrying Value	7,681
Investment securities	17,347	$ 21,035	$ 24,597
Interest bearing deposits	775	650	650
Federal Funds sold	7,561	4,075	1,702
Securities purchased under agreements to resell	5,000	2,300	1,375
Investments, Maturities, Next Rolling Twelve Months, Carrying Value	14,219
Investments, Maturities, Rolling Year Two Through Five, Carrying Value	8,529
Investments, Maturities, Rolling Year Six Through Ten, Carrying Value	254
Investments, Maturities, Rolling After Year Ten, Carrying Value	7,681
Investments	$ 30,683	$ 28,060	$ 28,324

Investment Securities Aging of

Investment Securities Aging of AFS unrealized temporary losses (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 58	$ 7
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,452	1,822
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(8)	(27)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,510	1,829
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(8)	(27)
U.S. Government & other government related
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	3	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	47
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	(1)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3	47
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	(1)
State or local housing agency
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	4	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
FFELP ABS | FFELP ABS
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	644	753
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(7)	(24)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	644	753
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(7)	(24)
GSE | Residential MBS
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	51	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	801	991
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1)	(2)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	852	991
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(1)	(2)
Government-guaranteed | Residential MBS
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		23
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		23
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		0
Private-label | Residential MBS
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	7	8
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	7	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 0	$ 0

Investment Securities Aging o50

Investment Securities Aging of HTM unrealized temporary losses (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 596	$ 143
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, Fair Value	795	956
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(144)	(179)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	1,391	1,099
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	(144)	(179)
U.S. Government & other government related
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	594	26
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, Fair Value	24	17
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1)	(1)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	618	43
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	(1)	(1)
State or local housing agency
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2	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, Fair Value	0	1
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	2	1
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Residential MBS | GSE
Schedule of Held-to-maturity Securities [Line Items]
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, Fair Value	2	4
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	2	4
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Residential MBS | Government-guaranteed
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		117
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		117
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		0
Residential MBS | Private-label
Schedule of Held-to-maturity Securities [Line Items]
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, Fair Value	769	934
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(143)	(178)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	769	934
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (143)	$ (178)

Investment Securities Other-tha

Investment Securities Other-than-Temporarily Impaired Life to Date (Details) $ in Millions	Dec. 31, 2017USD ($)
Minimum
Other than Temporary Impairment, Credit Losses Recognized in Earnings Life to Date [Line Items]
Assumed Home Price Change Rate all markets	(5.00%)
Projected House Price Change Rate majority of markets	2.00%
Maximum
Other than Temporary Impairment, Credit Losses Recognized in Earnings Life to Date [Line Items]
Assumed Home Price Change Rate all markets	12.00%
Projected House Price Change Rate majority of markets	6.00%
Residential MBS | Private-label | Available-for-sale securities | Alt-A
Other than Temporary Impairment, Credit Losses Recognized in Earnings Life to Date [Line Items]
Unpaid Principal Balance	$ 61
Amortized Cost Basis	40
Noncredit OTTI in AOCI	0
Gross Unrealized Gains	9
Carrying Amount	49
Fair Value	49
Residential MBS | Private-label | Held-to-maturity Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings Life to Date [Line Items]
Unpaid Principal Balance	903
Amortized Cost Basis	624
Noncredit OTTI in AOCI	(143)
Gross Unrealized Gains	0
Carrying Amount	481
Fair Value	764
Residential MBS | Private-label | Held-to-maturity Securities | Prime
Other than Temporary Impairment, Credit Losses Recognized in Earnings Life to Date [Line Items]
Unpaid Principal Balance	535
Amortized Cost Basis	430
Noncredit OTTI in AOCI	(107)
Gross Unrealized Gains	0
Carrying Amount	323
Fair Value	479
Residential MBS | Private-label | Held-to-maturity Securities | Subprime
Other than Temporary Impairment, Credit Losses Recognized in Earnings Life to Date [Line Items]
Unpaid Principal Balance	368
Amortized Cost Basis	194
Noncredit OTTI in AOCI	(36)
Gross Unrealized Gains	0
Carrying Amount	158
Fair Value	$ 285

Investment Securities Investmen

Investment Securities Investment securities OTTI rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Beginning Balance	$ 520	$ 568	$ 620
Reductions:
Securities sold, matured, or fully prepaid over the period	(1)	0	0
Increases in expected future cash flows recorded as credit-related accretion into interest income	(42)	(48)	(52)
Ending Balance	$ 477	$ 520	$ 568

Investment Securities Ongoing L

Investment Securities Ongoing Litigation (Details) - October 15, 2010 Ongoing PLMBS Litigation - Private-label $ in Millions	Dec. 31, 2017USD ($)bonds	Oct. 15, 2010bonds
Gain Contingencies [Line Items]
Number of private label MBS bonds litigation outstanding | bonds	3	64
Aggregate original principal amount of private label MBS bonds litigation outstanding | $	$ 38

Advances (By redemption terms)

Advances (By redemption terms) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Maturity, Rolling Year, Par Value [Abstract]
Due in one year or less		$ 22,177
One to two years		2,314
Two to three years		1,698
Three to four years		1,994
Four to five years		3,168
More than five years		16,669
Par value		$ 48,020	$ 44,965
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Rolling Year [Abstract]
Due in one year or less		1.42%
One to two years		1.65%
Two to three years		1.91%
Three to four years		1.65%
Four to five years		1.78%
More than five years	[1]	1.54%
Weighted Average Interest Rate		1.52%
[1]	The weighted average interest rate is relatively lower when compared to other categories due to a majority of advances in this category consisting of variable rate advances which reset periodically at current interest rates.

Advances (By payment terms) (De

Advances (By payment terms) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, by Interest Rate Type [Abstract]
Fixed-rate due in one year or less	$ 9,544	$ 9,473
Fixed-rate due after one year	7,732	5,704
Total fixed-rate	17,276	15,177
Variable-rate due in one year or less	12,633	10,960
Variable-rate due after one year	18,111	18,828
Total variable-rate	30,744	29,788
Par value	48,020	44,965
Fair value hedging adjustments	69	98
Other adjustments	(4)	4
Advances	$ 48,085	$ 45,067

Advances (By counterparty conce

Advances (By counterparty concentration) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Par Value		$ 48,020	$ 44,965
Credit Concentration Risk [Member] | One Mortgage Partners Corp. [Member]
Concentration Risk [Line Items]
Par Value	[1]	$ 11,000
% of Total Outstanding		22.90%
Credit Concentration Risk [Member] | The Northern Trust Company [Member]
Concentration Risk [Line Items]
Par Value		$ 6,000
% of Total Outstanding		12.50%
Credit Concentration Risk [Member] | BMO Harris Bank, N.A. [Member]
Concentration Risk [Line Items]
Par Value		$ 5,975
% of Total Outstanding		12.40%
[1]	One Mortgage Partners Corp. is a subsidiary of JPMorgan Chase Bank NA.

MPF Loans Held in Portfolio (De

MPF Loans Held in Portfolio (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Mortgage Loans on Real Estate [Line Items]
Unpaid principal balance	$ 5,120	$ 4,906
Net premiums, credit enhancement and deferred loan fees	55	38
Fair value hedging adjustments	20	26
MPF Loans held in portfolio, before allowance for credit losses	5,195	4,970
Allowance for credit losses on MPF Loans	(2)	(3)
MPF Loans held in portfolio, net	5,193	4,967
Medium term (15 years or less)
Mortgage Loans on Real Estate [Line Items]
Unpaid principal balance	285	417
Long term (greater than 15 years)
Mortgage Loans on Real Estate [Line Items]
Unpaid principal balance	4,835	4,489
Conventional mortgage loans
Mortgage Loans on Real Estate [Line Items]
Unpaid principal balance	4,133	3,818
Government Loans
Mortgage Loans on Real Estate [Line Items]
Unpaid principal balance	$ 987	$ 1,088

Allowance for Credit Losses Rol

Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for (reversal of) credit losses	$ 0	$ 1	$ 5
Conventional
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	3	3	15
Losses charged to the allowance	(1)	(1)	(17)
Provision for (reversal of) credit losses	0	1	5
Balance, end of period	$ 2	$ 3	$ 3

Allowance for Credit Losses Loa

Allowance for Credit Losses Loans evaluated for impairment (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Recorded investment in conventional MPF Loans -
Recorded investment	$ 5,222	$ 4,996
Conventional
Recorded investment in conventional MPF Loans -
Individually evaluated for impairment	49	74
Collectively evaluated for impairment	4,167	3,812
Recorded investment	4,216	3,886
Allowance for credit losses on conventional MPF Loans -
Collectively evaluated for impairment	$ 2	$ 3

Allowance for Credit Losses Cre

Allowance for Credit Losses Credit Quality Indicators - MPF Loans (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 228	$ 275
Current	4,994	4,721
Recorded investment	5,222	4,996
In process of foreclosure	$ 28	$ 42
Serious delinquency rate	1.34%	1.88%
Past due 90 days or more and still accruing interest	$ 29	$ 31
On nonaccrual status	49	74
Past due 30-59 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	122	140
Past due 60-89 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	37	43
Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	69	92
Conventional
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	143	178
Current	4,073	3,708
Recorded investment	4,216	3,886
In process of foreclosure	$ 21	$ 35
Serious delinquency rate	1.16%	1.82%
Past due 90 days or more and still accruing interest	$ 8	$ 8
On nonaccrual status	49	74
Conventional | Past due 30-59 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	74	83
Conventional | Past due 60-89 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	21	26
Conventional | Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	48	69
Government
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	85	97
Current	921	1,013
Recorded investment	1,006	1,110
In process of foreclosure	$ 7	$ 7
Serious delinquency rate	2.11%	2.07%
Past due 90 days or more and still accruing interest	$ 21	$ 23
On nonaccrual status	0	0
Government | Past due 30-59 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	48	57
Government | Past due 60-89 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	16	17
Government | Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 21	$ 23

Allowance for Credit Losses Imp

Allowance for Credit Losses Impaired MPF Loans at period ends (Details) - Conventional - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance for credit losses	$ 49	$ 74
Unpaid principal balance without an allowance for credit losses	$ 53	$ 80

Derivatives and Hedging Activ62

Derivatives and Hedging Activities (Narrative) (Details) $ in Millions	Dec. 31, 2017USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Additional Collateral, Aggregate Fair Value	$ 0
Financial Instruments Owned and Pledged as Collateral, Amount Eligible to be Repledged by Counterparty	$ 67

Derivatives and Hedging Activ63

Derivatives and Hedging Activities (Derivatives in statements of condition) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional Amount		$ 47,971	$ 56,204
Netting adjustments and cash collateral	[1]	(309)	(468)
Derivatives assets on statements of condition		3	6
Netting adjustments and cash collateral	[1]	(559)	(1,118)
Derivative liabilities on statements of condition		20	43
Cash collateral received		35	40
Cash collateral posted		284	689
Derivatives in hedge accounting relationships- | Interest rate contracts
Derivatives, Fair Value [Line Items]
Notional Amount		26,655	25,999
Derivatives not in hedge accounting relationships-
Derivatives, Fair Value [Line Items]
Notional Amount		21,316	30,205
Derivatives not in hedge accounting relationships- | Interest rate contracts
Derivatives, Fair Value [Line Items]
Notional Amount		20,506	29,313
Derivatives not in hedge accounting relationships- | Other
Derivatives, Fair Value [Line Items]
Notional Amount		810	892
Derivative Assets
Derivatives, Fair Value [Line Items]
Variation margin daily settlements on cleared derivatives		(16)
Gross derivative amount before netting adjustments and cash collateral		312	474
Netting adjustments and cash collateral	[2]	(309)	(468)
Derivatives assets on statements of condition		3	6
Derivative Assets | Derivatives in hedge accounting relationships- | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		57	40
Derivative Assets | Derivatives not in hedge accounting relationships-
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		271	434
Derivative Assets | Derivatives not in hedge accounting relationships- | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		270	432
Derivative Assets | Derivatives not in hedge accounting relationships- | Other
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		1	2
Derivative Liabilities
Derivatives, Fair Value [Line Items]
Variation margin daily settlements on cleared derivatives		(168)
Gross derivative amount before netting adjustments and cash collateral		579	1,161
Netting adjustments and cash collateral	[2]	(559)	(1,118)
Derivative liabilities on statements of condition		20	43
Derivative Liabilities | Derivatives in hedge accounting relationships- | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		589	898
Derivative Liabilities | Derivatives not in hedge accounting relationships-
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		158	263
Derivative Liabilities | Derivatives not in hedge accounting relationships- | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		157	260
Derivative Liabilities | Derivatives not in hedge accounting relationships- | Other
Derivatives, Fair Value [Line Items]
Gross derivative amount before netting adjustments and cash collateral		$ 1	$ 3
[1]	The netting adjustment amount includes cash collateral (either received or paid by us) and related accrued interest in cases where we have a legal right of setoff, by contract (e.g., master netting agreement) or otherwise, to discharge all or a portion of the debt owed to our counterparty by applying against the debt an amount that our counterparty owes to us. See Note 9 - Derivatives and Hedging Activities
[2]	Cash collateral received was $35 million and $40 million , and cash collateral posted was $284 million and $689 million at December 31, 2017 , and December 31, 2016

Derivatives and Hedging Activ64

Derivatives and Hedging Activities (Derivatives in Statement of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Economic hedges	$ 7	$ (11)	$ 16
Variation margin on daily settled cleared derivatives	2	0	0
Noninterest income on derivatives and hedging activities	8	1	(16)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Fair value hedges - interest rate contracts	(4)	7	(35)
Cash flow hedges - interest rate contracts	3	5	3
Economic hedges	4	(15)	15
Other
Derivative Instruments, Gain (Loss) [Line Items]
Economic hedges	$ 3	$ 4	$ 1

Derivatives and Hedging Activ65

Derivatives and Hedging Activities Derivative assets with legal right of offset (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Derivatives with legal right of offset -
Gross recognized amount		$ 311	$ 472
Netting adjustments and cash collateral	[1]	(309)	(468)
Derivatives with legal right of offset - net		2	4
Derivatives without legal right of offset		1	2
Derivatives on statements of condition		3	6
Noncash collateral received and cannot be sold or repledged		0	0
Cash collateral for initial margin			(1)
Noncash collateral pledged and cannot be sold or repledged		(1)	(2)
Net amount		4	9
Bilateral
Derivatives with legal right of offset -
Gross recognized amount		216	339
Netting adjustments and cash collateral		(214)	(335)
Derivatives with legal right of offset - net		2	4
Derivatives without legal right of offset		1	2
Derivatives on statements of condition		3	6
Noncash collateral received and cannot be sold or repledged		0	0
Net amount		3	6
Cleared
Derivatives with legal right of offset -
Gross recognized amount		95	133
Netting adjustments and cash collateral		(95)	(133)
Derivatives with legal right of offset - net		0	0
Derivatives without legal right of offset		0	0
Derivatives on statements of condition		0	0
Cash collateral for initial margin			(1)
Noncash collateral pledged and cannot be sold or repledged		(1)	(2)
Net amount		$ 1	$ 3
[1]	The netting adjustment amount includes cash collateral (either received or paid by us) and related accrued interest in cases where we have a legal right of setoff, by contract (e.g., master netting agreement) or otherwise, to discharge all or a portion of the debt owed to our counterparty by applying against the debt an amount that our counterparty owes to us. See Note 9 - Derivatives and Hedging Activities

Derivatives and Hedging Activ66

Derivatives and Hedging Activities Derivative liabilities with legal right of offset (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Derivatives with legal right of offset -
Gross recognized amount		$ 578	$ 1,159
Netting adjustments and cash collateral	[1]	(559)	(1,118)
Derivatives with legal right of offset - net		19	41
Derivatives without legal right of offset		1	2
Derivatives on statements of condition		20	43
Noncash collateral pledged and cannot be sold or repledged		6	9
Net amount		14	34
Credit Exposure On Overcollateralized Pledged Securities Exceeding Derivative Liability		60	86
Bilateral
Derivatives with legal right of offset -
Gross recognized amount		476	820
Netting adjustments and cash collateral		(463)	(788)
Derivatives with legal right of offset - net		13	32
Derivatives without legal right of offset		1	2
Derivatives on statements of condition		14	34
Noncash collateral pledged and cannot be sold or repledged		0	0
Net amount		14	34
Cleared
Derivatives with legal right of offset -
Gross recognized amount		102	339
Netting adjustments and cash collateral		(96)	(330)
Derivatives with legal right of offset - net		6	9
Derivatives without legal right of offset		0	0
Derivatives on statements of condition		6	9
Noncash collateral pledged and cannot be sold or repledged		6	9
Net amount		$ 0	$ 0
[1]	The netting adjustment amount includes cash collateral (either received or paid by us) and related accrued interest in cases where we have a legal right of setoff, by contract (e.g., master netting agreement) or otherwise, to discharge all or a portion of the debt owed to our counterparty by applying against the debt an amount that our counterparty owes to us. See Note 9 - Derivatives and Hedging Activities

Derivatives and Hedging Activ67

Derivatives and Hedging Activities (Fair Value Hedges) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recorded in Net Interest Income	$ 483	$ 456	$ 508
Fair Value Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Hedging Instrument	127	12	95
Gain (Loss) on Hedged Item	(131)	(5)	(130)
Total Ineffectiveness Recognized in Derivatives and Hedging Activities	(4)	7	(35)
Amount Recorded in Net Interest Income	(97)	(139)	(38)
Fair Value Hedges | Available-for-sale securities
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Hedging Instrument	91	86	43
Gain (Loss) on Hedged Item	(100)	(85)	(56)
Total Ineffectiveness Recognized in Derivatives and Hedging Activities	(9)	1	(13)
Amount Recorded in Net Interest Income	(90)	(122)	(146)
Fair Value Hedges | Advances
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Hedging Instrument	31	66	6
Gain (Loss) on Hedged Item	(29)	(59)	(5)
Total Ineffectiveness Recognized in Derivatives and Hedging Activities	2	7	1
Amount Recorded in Net Interest Income	(32)	(70)	(84)
Fair Value Hedges | MPF Loans held in portfolio
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Hedging Instrument	0	0	0
Gain (Loss) on Hedged Item	0	0	0
Total Ineffectiveness Recognized in Derivatives and Hedging Activities	0	0	0
Amount Recorded in Net Interest Income	(6)	(9)	(13)
Fair Value Hedges | Consolidated obligation bonds
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Hedging Instrument	5	(140)	46
Gain (Loss) on Hedged Item	(2)	139	(69)
Total Ineffectiveness Recognized in Derivatives and Hedging Activities	3	(1)	(23)
Amount Recorded in Net Interest Income	$ 31	$ 62	$ 205

Derivatives and Hedging Activ68

Derivatives and Hedging Activities (Cash Flow Hedges) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recorded in Net Interest Income	$ 483	$ 456	$ 508
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified Next 12 Months, Net	$ 0
Maximum Hedging Period For Forecasted Cash Flows	3 years
Ineffectiveness Recorded in Derivatives and Hedging Activities	$ 3	5	3
Effective Portion Recorded in AOCI	173	161	125
Amount Recorded in Net Interest Income	(161)	(188)	(235)
Cash Flow Hedges | Advances
Derivative Instruments, Gain (Loss) [Line Items]
Ineffectiveness Recorded in Derivatives and Hedging Activities	0	0	0
Effective Portion Recorded in AOCI	0	0	0
Amount Recorded in Net Interest Income	10	10	10
Cash Flow Hedges | Discount Notes
Derivative Instruments, Gain (Loss) [Line Items]
Ineffectiveness Recorded in Derivatives and Hedging Activities	3	5	3
Effective Portion Recorded in AOCI	173	161	125
Amount Recorded in Net Interest Income	(168)	(195)	(242)
Cash Flow Hedges | Consolidated obligation bonds
Derivative Instruments, Gain (Loss) [Line Items]
Ineffectiveness Recorded in Derivatives and Hedging Activities	0	0	0
Effective Portion Recorded in AOCI	0	0	0
Amount Recorded in Net Interest Income	$ (3)	$ (3)	$ (3)

Consolidated Obligations (Short

Consolidated Obligations (Short term discount notes) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Carrying Amount	$ 41,191	$ 35,949
Weighted Average Interest Rate	1.23%	0.46%

Consolidated Obligations (Bonds

Consolidated Obligations (Bonds by maturity date) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Contractual Maturity
Due in one year or less	$ 16,616
One to two years	7,919
Two to three years	2,734
Three to four years	3,739
Four to five years	2,823
Thereafter	3,516
Total par value	$ 37,347	$ 37,134
Weighted Average Interest Rate
Due in one year or less	1.25%
One to two years	1.32%
Two to three years	1.38%
Three to four years	1.97%
Four to five years	2.46%
Thereafter	2.70%
Total par value	1.58%
By Maturity or Next Call Date
Contractual Maturity
Due in one year or less	$ 27,347
One to two years	6,749
Two to three years	1,959
Three to four years	374
Four to five years	575
Thereafter	343
Total par value	$ 37,347
Minimum
Extinguishment of Debt [Line Items]
Debt Instrument, Term	1 year
Maximum
Extinguishment of Debt [Line Items]
Debt Instrument, Term	20 years

Consolidated Obligations (bon71

Consolidated Obligations (bonds by callable feature) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value	$ 37,347	$ 37,134
Fair value hedging adjustments	(214)	(229)
Other adjustments	(12)	(2)
Consolidated obligation bonds	37,121	36,903
Noncallable
Debt Instrument [Line Items]
Par value	23,644	22,356
Callable
Debt Instrument [Line Items]
Par value	$ 13,703	$ 14,778

Consolidated Obligations Intere

Consolidated Obligations Interest rate payment terms (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value	$ 37,347	$ 37,134
Fixed-rate	21,357	22,389
Variable-rate	12,884	11,615
Step-up
Debt Instrument [Line Items]
Variable-rate	2,730	2,650
Step-down
Debt Instrument [Line Items]
Variable-rate	366	480
Other
Debt Instrument [Line Items]
Variable-rate	$ 10	$ 0

Consolidated Obligations System

Consolidated Obligations Systemwide joint and several liability (Details) - Guarantee of Indebtedness of Others [Member] - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Obligation with Joint and Several Liability Arrangement [Line Items]
FHLB System total consolidated obligations	$ 1,034,260	$ 989,311
FHLB Chicago as primary obligor	$ 78,582	$ 73,103
As a percent of the FHLB System	8.00%	7.00%
Consolidated obligation bonds
Obligation with Joint and Several Liability Arrangement [Line Items]
FHLB System total consolidated obligations	$ 642,211	$ 579,189
FHLB Chicago as primary obligor	$ 37,347	$ 37,134
As a percent of the FHLB System	6.00%	6.00%
Discount Notes
Obligation with Joint and Several Liability Arrangement [Line Items]
FHLB System total consolidated obligations	$ 392,049	$ 410,122
FHLB Chicago as primary obligor	$ 41,235	$ 35,969
As a percent of the FHLB System	11.00%	9.00%

Affordable Housing Program Affo

Affordable Housing Program Affordable Housing Program AHP (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assessments [Abstract]
Affordable Housing Program FHLB Systemwide minimum annual assessment	$ 100
Affordable Housing Assessment Rate	10.00%
Interest Expense on MRCS, excluded from calculation of income for assessment	$ 10	$ 6	$ 0

Affordable Housing Program AHP

Affordable Housing Program AHP Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Affordable housing program assessment [Roll Forward]
AHP balance at beginning of year	$ 86	$ 89	$ 90
AHP expense accrual	36	37	39
Cash disbursements for AHP	(34)	(40)	(40)
AHP balance at end of year	$ 88	$ 86	$ 89

Subordinated Notes Subordinated

Subordinated Notes Subordinated Notes (Details) - USD ($) $ in Millions	Jun. 13, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2006
Subordinated Debt [Abstract]
Proceeds from Issuance of Subordinated Long-term Debt						$ 1,000
Early Repayment of Subordinated Debt					$ 56
Maturities of Subordinated Debt	$ 944	$ 0	$ 944	$ 0

Capital and Mandatorily Redee77

Capital and Mandatorily Redeemable Capital Stock (MRCS) Capital Rules (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Banks [Abstract]
Capital stock par value	$ 100	$ 100
Capital Stock, Redemption, Period of Written Notice	5 years

Capital and Mandatorily Redee78

Capital and Mandatorily Redeemable Capital Stock (MRCS) Regulatory capital requirements and actuals (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Banks [Abstract]
Risk Based Capital, Requirement	$ 1,075	$ 1,088
Risk Based Capital, Actual	5,051	5,032
Regulatory Capital, Requirement	3,374	3,148
Regulatory Capital, Actual	$ 5,051	$ 5,032
Regulatory Capital Ratio, Requirement	4.00%	4.00%
Regulatory Capital Ratio, Actual	5.99%	6.40%
Leverage Capital, Requirement	$ 4,218	$ 3,935
Leverage Capital, Actual	$ 7,577	$ 7,549
Leverage Ratio, Requirement	5.00%	5.00%
Leverage Ratio, Actual	8.98%	9.59%

Capital and Mandatorily Redee79

Capital and Mandatorily Redeemable Capital Stock (MRCS) Stockholder concentration (Details) - USD ($) $ in Millions		3 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Amount of Which is Classified as a Liability (MRCS)		$ 311	$ 301
Stockholders' Equity, Total [Member] | BMO Harris Bank, N.A. [Member]
Concentration Risk [Line Items]
Regulatory Capital Stock Outstanding		$ 269
% of Total Outstanding		15.30%
Amount of Which is Classified as a Liability (MRCS)		$ 0
Stockholders' Equity, Total [Member] | One Mortgage Partners Corp. [Member]
Concentration Risk [Line Items]
Regulatory Capital Stock Outstanding	[1]	$ 245
% of Total Outstanding		14.00%
Amount of Which is Classified as a Liability (MRCS)		$ 245
[1]	One Mortgage Partners Corp. is a subsidiary of JPMorgan Chase Bank NA.

Capital and Mandatorily Redee80

Capital and Mandatorily Redeemable Capital Stock (MRCS) Repurchase of excess capital stock (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Repurchase of excess capital stock [Abstract]
Regulatory Capital Stock	$ 1,754
Net Change In Regulatory Capital Stock	$ (258)

Capital and Mandatorily Redee81

Capital and Mandatorily Redeemable Capital Stock (MRCS) Joint capital enhancement agreement (Details)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Joint Capital Enhancement Agreement contribution rate to Restricted Retained Earnings	20.00%
Joint Capital Enhancement Agreement Restricted Retained Earnings limit as a percent of consolidated obligation debt	1.00%

Capital and Mandatorily Redee82

Capital and Mandatorily Redeemable Capital Stock (MRCS) Transfer of capital stock to MRCS (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Banks [Abstract]
Due in one year or less	$ 1
One to two years	2
Two to three years	1
Three to four years	5
Four to five years	4
After five years	298
MRCS	$ 311	$ 301

Accumulated Other Comprehensi83

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (36)
Amounts reclassified in period to statements of income:
Ending balance	112	$ (36)
AOCI
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(36)	(28)	$ 217
Change in the period recorded to the statements of condition, before reclassifications to statements of income	156	2	(237)
Amounts reclassified in period to statements of income:
Net interest income	(5)	(5)	(5)
Noninterest income on derivatives and hedging activities	(3)	(5)	(3)
Ending balance	112	(36)	(28)
Net Unrealized - | Available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	459	658	1,060
Change in the period recorded to the statements of condition, before reclassifications to statements of income	(52)	(199)	(402)
Amounts reclassified in period to statements of income:
Net interest income	0	0	0
Noninterest income on derivatives and hedging activities	0	0	0
Ending balance	407	459	658
Noncredit OTTI - | Held-to-maturity Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(177)	(217)	(264)
Change in the period recorded to the statements of condition, before reclassifications to statements of income	34	40	47
Amounts reclassified in period to statements of income:
Net interest income	0	0	0
Noninterest income on derivatives and hedging activities	0	0	0
Ending balance	(143)	(177)	(217)
Net Unrealized - Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(312)	(463)	(580)
Change in the period recorded to the statements of condition, before reclassifications to statements of income	173	161	125
Amounts reclassified in period to statements of income:
Net interest income	(5)	(5)	(5)
Noninterest income on derivatives and hedging activities	(3)	(5)	(3)
Ending balance	(147)	(312)	(463)
Post-retirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(6)	(6)	1
Change in the period recorded to the statements of condition, before reclassifications to statements of income	1	0	(7)
Amounts reclassified in period to statements of income:
Net interest income	0	0	0
Noninterest income on derivatives and hedging activities	0	0	0
Ending balance	$ (5)	$ (6)	$ (6)

Employee retirement plans Multi

Employee retirement plans Multiemployer pension plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Pentegra Defined Benefit Plan [Member]
Multiemployer Plans [Line Items]
Entity Tax Identification Number	135,645,888
Multiemployer Plan Number	333
Net pension cost (minimum required contribution) including administrative fees, charged to compensation and benefits expense for the years ended December 31,	$ 7	$ 7	$ 3
Actual cash paid including administrative fees for calendar year ended December 31,	9	9	5
Prepaid pension contributions, in other assets, as of December 31,	$ 19	$ 17	$ 15
Defined Benefit Plan, Funded Percentage				111.00%	104.00%	107.00%
Federal Home Loan Bank of Chicago portion [Member]
Multiemployer Plans [Line Items]
Defined Benefit Plan, Funded Percentage				120.00%	112.00%	121.00%

Fair Value (Significant inputs)

Fair Value (Significant inputs) (Details) - Level 3 - Residential MBS - Private-label residential MBS - Third Party Pricing Service $ in Millions	Dec. 31, 2017USD ($)
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale securities	$ 50
Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale securities	48
Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale securities	$ 51

Fair Value Fair Value Estimates

Fair Value Fair Value Estimates (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities		$ 4,538	$ 5,516
Advances		776	672
Derivative assets		3	6
Netting derivative assets	[1]	(309)	(468)
Other assets		118	44
Total assets		84,355	78,692
Consolidated obligation discount notes		(749)	(6,368)
Consolidated obligation bonds		(5,260)	(5,443)
Derivative liabilities		(20)	(43)
Netting derivative liabilities	[1]	559	1,118
Total liabilities		(79,503)	(73,997)
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		42	351
Interest bearing deposits		775	650
Federal Funds sold and securities purchased under agreements to resell		12,561	6,375
Held-to-maturity securities		4,157	5,072
Advances		47,309	44,395
MPF Loans held in portfolio, net		5,186	4,941
Other assets		228	188
Total assets		84,355	78,692
Deposits		(524)	(496)
Consolidated obligation discount notes		(40,442)	(29,581)
Consolidated obligation bonds		(31,861)	(31,460)
Mandatorily redeemable capital stock		(311)	(301)
Other liabilities		(336)	(305)
Total liabilities		(79,503)	(73,997)
Carrying Amount | Carried at fair value on a recurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		233	1,045
Available-for-sale securities		12,957	14,918
Advances		776	672
Derivative assets		3	6
Other assets		118	44
Consolidated obligation discount notes		(749)	(6,368)
Consolidated obligation bonds		(5,260)	(5,443)
Derivative liabilities		(20)	(43)
Carrying Amount | Carried at fair value on a recurring basis- | U.S. Government & other government related non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		202	1,005
Available-for-sale securities		271	336
Carrying Amount | Carried at fair value on a recurring basis- | State or local housing agency non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		21	19
Carrying Amount | Carried at fair value on a recurring basis- | FFELP ABS | FFELP ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		4,214	4,572
Carrying Amount | Carried at fair value on a recurring basis- | Residential MBS | GSE residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		30	39
Available-for-sale securities		7,406	8,555
Carrying Amount | Carried at fair value on a recurring basis- | Residential MBS | U.S. Government-guaranteed residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		1	1
Available-for-sale securities		995	1,380
Carrying Amount | Carried at fair value on a recurring basis- | Residential MBS | Private-label residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		50	56
Carrying Amount | Carried at fair value on a nonrecurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
MPF Loans held in portfolio, net		7	26
Other assets		3	9
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		42	351
Interest bearing deposits		775	650
Federal Funds sold and securities purchased under agreements to resell		12,561	6,375
Held-to-maturity securities		4,538	5,516
Advances		47,336	44,393
MPF Loans held in portfolio, net		5,306	5,136
Other assets		228	188
Total assets		84,883	79,329
Deposits		(524)	(496)
Consolidated obligation discount notes		(40,437)	(29,581)
Consolidated obligation bonds		(32,011)	(31,706)
Mandatorily redeemable capital stock		(311)	(301)
Other liabilities		(336)	(305)
Total liabilities		(79,648)	(74,243)
Fair Value | Carried at fair value on a recurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		233	1,045
Available-for-sale securities		12,957	14,918
Advances		776	672
Derivative assets		3	6
Other assets		118	44
Consolidated obligation discount notes		(749)	(6,368)
Consolidated obligation bonds		(5,260)	(5,443)
Derivative liabilities		(20)	(43)
Fair Value | Carried at fair value on a recurring basis- | U.S. Government & other government related non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		202	1,005
Available-for-sale securities		271	336
Fair Value | Carried at fair value on a recurring basis- | State or local housing agency non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		21	19
Fair Value | Carried at fair value on a recurring basis- | FFELP ABS | FFELP ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		4,214	4,572
Fair Value | Carried at fair value on a recurring basis- | Residential MBS | GSE residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		30	39
Available-for-sale securities		7,406	8,555
Fair Value | Carried at fair value on a recurring basis- | Residential MBS | U.S. Government-guaranteed residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		1	1
Available-for-sale securities		995	1,380
Fair Value | Carried at fair value on a recurring basis- | Residential MBS | Private-label residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		50	56
Fair Value | Carried at fair value on a nonrecurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
MPF Loans held in portfolio, net		7	26
Other assets		3	9
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		42	351
Interest bearing deposits		775	650
Federal Funds sold and securities purchased under agreements to resell		0	0
Held-to-maturity securities		0	0
Advances		0	0
MPF Loans held in portfolio, net		0	0
Other assets		0	0
Total assets		817	1,001
Deposits		0	0
Consolidated obligation discount notes		0	0
Consolidated obligation bonds		0	0
Mandatorily redeemable capital stock		(311)	(301)
Other liabilities		0	0
Total liabilities		(311)	(301)
Level 1 | Carried at fair value on a recurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Advances		0	0
Derivative assets		0	0
Other assets		0	0
Consolidated obligation discount notes		0	0
Consolidated obligation bonds		0	0
Derivative liabilities		0	0
Level 1 | Carried at fair value on a recurring basis- | U.S. Government & other government related non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Level 1 | Carried at fair value on a recurring basis- | State or local housing agency non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		0	0
Level 1 | Carried at fair value on a recurring basis- | FFELP ABS | FFELP ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		0	0
Level 1 | Carried at fair value on a recurring basis- | Residential MBS | GSE residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Level 1 | Carried at fair value on a recurring basis- | Residential MBS | U.S. Government-guaranteed residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Level 1 | Carried at fair value on a recurring basis- | Residential MBS | Private-label residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		0	0
Level 1 | Carried at fair value on a nonrecurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
MPF Loans held in portfolio, net		0	0
Other assets		0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		0	0
Interest bearing deposits		0	0
Federal Funds sold and securities purchased under agreements to resell		12,561	6,375
Held-to-maturity securities		3,734	4,544
Advances		47,336	44,393
MPF Loans held in portfolio, net		5,295	5,136
Other assets		228	188
Total assets		83,500	77,733
Deposits		(524)	(496)
Consolidated obligation discount notes		(40,437)	(29,581)
Consolidated obligation bonds		(32,011)	(31,706)
Mandatorily redeemable capital stock		0	0
Other liabilities		(336)	(305)
Total liabilities		(79,896)	(75,060)
Level 2 | Carried at fair value on a recurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		233	1,045
Available-for-sale securities		12,907	14,862
Advances		776	672
Derivative assets		312	474
Other assets		118	44
Consolidated obligation discount notes		(749)	(6,368)
Consolidated obligation bonds		(5,260)	(5,443)
Derivative liabilities		(579)	(1,161)
Level 2 | Carried at fair value on a recurring basis- | U.S. Government & other government related non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		202	1,005
Available-for-sale securities		271	336
Level 2 | Carried at fair value on a recurring basis- | State or local housing agency non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		21	19
Level 2 | Carried at fair value on a recurring basis- | FFELP ABS | FFELP ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		4,214	4,572
Level 2 | Carried at fair value on a recurring basis- | Residential MBS | GSE residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		30	39
Available-for-sale securities		7,406	8,555
Level 2 | Carried at fair value on a recurring basis- | Residential MBS | U.S. Government-guaranteed residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		1	1
Available-for-sale securities		995	1,380
Level 2 | Carried at fair value on a recurring basis- | Residential MBS | Private-label residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		0	0
Level 2 | Carried at fair value on a nonrecurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
MPF Loans held in portfolio, net		0	0
Other assets		0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		0	0
Interest bearing deposits		0	0
Federal Funds sold and securities purchased under agreements to resell		0	0
Held-to-maturity securities		804	972
Advances		0	0
MPF Loans held in portfolio, net		11	0
Other assets		0	0
Total assets		875	1,063
Deposits		0	0
Consolidated obligation discount notes		0	0
Consolidated obligation bonds		0	0
Mandatorily redeemable capital stock		0	0
Other liabilities		0	0
Total liabilities		0	0
Level 3 | Carried at fair value on a recurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		50	56
Advances		0	0
Derivative assets		0	0
Other assets		0	0
Consolidated obligation discount notes		0	0
Consolidated obligation bonds		0	0
Derivative liabilities		0	0
Level 3 | Carried at fair value on a recurring basis- | U.S. Government & other government related non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Level 3 | Carried at fair value on a recurring basis- | State or local housing agency non-MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		0	0
Level 3 | Carried at fair value on a recurring basis- | FFELP ABS | FFELP ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		0	0
Level 3 | Carried at fair value on a recurring basis- | Residential MBS | GSE residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Level 3 | Carried at fair value on a recurring basis- | Residential MBS | U.S. Government-guaranteed residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Level 3 | Carried at fair value on a recurring basis- | Residential MBS | Private-label residential MBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		50	56
Level 3 | Carried at fair value on a nonrecurring basis-
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
MPF Loans held in portfolio, net		7	26
Other assets		$ 3	$ 9
[1]	The netting adjustment amount includes cash collateral (either received or paid by us) and related accrued interest in cases where we have a legal right of setoff, by contract (e.g., master netting agreement) or otherwise, to discharge all or a portion of the debt owed to our counterparty by applying against the debt an amount that our counterparty owes to us. See Note 9 - Derivatives and Hedging Activities

Fair Value Level 3 Reconciliati

Fair Value Level 3 Reconciliation Assets (Details) - Private-label residential MBS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 56	$ 65	$ 71
Paydowns and settlements	(13)	(16)	(9)
Balance at end of period	50	56	65
Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end	3	4	4
Interest income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) included in earnings	4	5	4
Net unrealized on AFS securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) included in OCI	$ 3	$ 2	$ (1)

Fair Value Level 3 Reconcilia88

Fair Value Level 3 Reconciliation Derivatives (Details) - Derivative Assets Interest-Rate Related - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 0	$ 5	$ 13
Paydowns and settlements	0	0	0
Balance at end of period	0	0	5
Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end	0	0	0
Derivatives and hedging activities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) included in earnings	$ 0	$ (5)	$ (8)

Fair Value Level 3 Reconcilia89

Fair Value Level 3 Reconciliation Liabilities (Details) - Consolidated obligation bonds - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 0	$ (55)	$ (63)
Paydowns and settlements	0	0	0
Balance at end of period	0	0	(55)
Unrealized gains (losses) recorded in earnings and attributable to instruments still held at period end	0	0	8
Derivatives and hedging activities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) included in earnings	$ 0	$ 55	$ 8

Fair Value Fair Value Option Ga

Fair Value Fair Value Option Gain (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (2)	$ 5	$ 8
Advances
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(5)	(7)	(2)
Mortgage loans held for sale (in other assets)
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(4)	(4)	(1)
Discount Notes
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	(2)	2
Consolidated obligation bonds
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 7	$ 18	$ 9

Fair Value (Fair Value Option D

Fair Value (Fair Value Option Difference Between Fair Value and Unpaid Principal Balance) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Option, Quantitative Disclosures [Line Items]
Unpaid principal balance	$ 48,020	$ 44,965
Fair value	776	672
Unpaid principal balance	37,347	37,134
Fair value	5,260	5,443
Advances
Fair Value, Option, Quantitative Disclosures [Line Items]
Unpaid principal balance	786	677
Fair value over (under) UPB	(10)	(5)
Fair value	776	672
Consolidated obligation bonds
Fair Value, Option, Quantitative Disclosures [Line Items]
Unpaid principal balance	5,270	5,447
Fair value over (under) UPB	(10)	(4)
Fair value	$ 5,260	$ 5,443

Commitments and Contingencies92

Commitments and Contingencies (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Commitments
Expire within one year		$ 16,239	$ 8,950
Expire after one year		4,206	2,651
Total		20,445	11,601
Unsettled consolidated obligation bonds
Commitments
Expire within one year		0	10
Expire after one year		0	0
Total		0	10
Member standby letters of credit
Commitments
Expire within one year		15,703	8,459
Expire after one year	[1]	3,869	2,369
Total		19,572	10,828
Portion renewable annually		750	486
Housing authority standby bond purchase agreements
Commitments
Expire within one year		0	25
Expire after one year		337	281
Total		$ 337	306
Original expiration period		5 years
Expiration date		Dec. 31, 2022
Advance commitments
Commitments
Expire within one year		$ 151	15
Expire after one year		0	1
Total		151	16
MPF delivery commitments
Commitments
Expire within one year		371	417
Expire after one year		0	0
Total		371	417
Other
Commitments
Expire within one year		14	24
Expire after one year		0	0
Total		$ 14	$ 24
[1]	Contains $750 million and $486 million of member standby letters of credit at December 31, 2017 and December 31, 2016 , which were renewable annually.

Transactions with Related Par93

Transactions with Related Parties and Other FHLBs (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts With Related Party Transactions [Line Items]
Assets - Advances	$ 48,085	$ 45,067
Liabilities - Deposits	524	496
Equity - Capital Stock	1,443	1,711
Transactions with members
Accounts With Related Party Transactions [Line Items]
Assets - Advances	165	107
Liabilities - Deposits	13	8
Equity - Capital Stock	$ 10	$ 18