Federal Home Loan Bank of Boston 10-Q 14 May 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	000-51402
Entity Registrant Name	FEDERAL HOME LOAN BANK OF BOSTON
Entity Tax Identification Number	04-6002575
Entity Address, Address Line One	800 Boylston Street,
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199
City Area Code	(617)
Local Phone Number	292-9600
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Entity Central Index Key	0001331463
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Incorporation, State or Country Code	X1
Common Class A [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		0
Common Class B [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		18,705,358

Statements of Condition

Statements of Condition - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks		$ 806,985	$ 69,416
Interest-bearing deposits		1,130,563	1,253,873
Securities purchased under agreements to resell		2,000,000	3,500,000
Federal funds sold		3,455,000	860,000
Investment securities:
Trading securities		3,563,368	2,250,264
Available-for-sale securities		7,246,334	7,409,000
Held-to-maturity securities, net of allowance for credit losses of $3,768 at March 31, 2020 -includes $92 pledged as collateral at December 31, 2019, that may be repledged	[1],[2]	676,888	871,107
Total investment securities		11,486,590	10,530,371
Advances	[3]	45,076,223	34,595,363
Mortgage loans held for portfolio, net of allowance for credit losses of $3,500 and $500 at March 31, 2020, and December 31, 2019		4,528,474	4,501,251
Accrued interest receivable		109,878	112,163
Derivative assets, net		227,720	159,731
Other assets		79,432	80,643
Total Assets		68,900,865	55,662,811
Deposits
Interest-bearing		785,782	616,532
Non-interest-bearing		74,034	57,777
Total deposits		859,816	674,309
Consolidated obligations (COs):
Bonds		24,576,586	23,888,493
Discount notes		39,692,253	27,681,169
Total consolidated obligations		64,268,839	51,569,662
Mandatorily redeemable capital stock		6,112	5,806
Accrued interest payable		108,010	104,477
Affordable Housing Program (AHP) payable		85,082	86,131
Derivative liabilities, net		24,404	10,271
Other liabilities		57,361	66,843
Total liabilities		65,409,624	52,517,499
Commitments and contingencies (Note 14)
Capital
Capital stock – Class B – putable ($100 par value), 22,663 shares and 18,691 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively		2,266,329	1,869,130
Retained earnings:
Unrestricted		1,116,001	1,114,337
Restricted		357,148	348,817
Total retained earnings		1,473,149	1,463,154
Accumulated other comprehensive loss		(248,237)	(186,972)
Total capital		3,491,241	3,145,312
Total Liabilities and Capital		$ 68,900,865	$ 55,662,811
[1]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss and the allowance for credit losses.
[2]	Fair values of held-to-maturity securities were $ 733,970 and $1,035,410 at March 31, 2020 , and December 31, 2019 , respectively.
[3]	Excludes accrued interest receivable of $46.4 million and $48.1 million at March 31, 2020 , and December 31, 2019 .

Statements of Condition (Parent

Statements of Condition (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2020		Dec. 31, 2019
Statement of Financial Position [Abstract]
Held-to-maturity securities - pledged as collateral that may be repledged (a)	$ 0		$ 92
Allowance for credit losses - held-to-maturity securities	3,768	[1]	0
Allowance for credit losses - mortgage loans held for portfolio	3,500		500
Fair value of held-to-maturity securities	$ 733,970		$ 1,035,410
Common Class B [Member]
Common Stock, Class B, putable shares issued	22,663		18,691
Common Stock, Class B, putable par value per share	$ 100		$ 100
Common Stock, Class B, putable shares outstanding	22,663		18,691
[1]	With the adoption of changes to accounting standards on credit impairment on January 1, 2020, the other-than-temporary impairment approach was replaced with an allowance for credit loss; however, other-than-temporary impairment remains for those securities that had credit impairment prior to the adoption date. See Note 2 — Summary of Significant Accounting Policies and Note 3 — Recently Issued and Adopted Accounting Guidance for further information.

Statements of Operations

Statements of Operations - USD ($)		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
INTEREST INCOME
Advances		$ 168,659,000	$ 247,877,000
Prepayment fees on advances, net		838,000	26,931,000
Interest-bearing deposits		4,969,000	3,670,000
Securities purchased under agreements to resell		14,361,000	39,861,000
Federal funds sold		16,717,000	24,294,000
Investment securities:
Trading securities		17,580,000	1,745,000
Available-for-sale securities		12,361,000	21,291,000
Held-to-maturity securities		10,138,000	18,397,000
Total investment securities		40,079,000	41,433,000
Mortgage loans held for portfolio		36,846,000	37,369,000
Other		47,000	5,000
Total interest income		282,516,000	421,440,000
Consolidated obligations:
Bonds		123,547,000	154,817,000
Discount notes		127,482,000	177,939,000
Total consolidated obligations		251,029,000	332,756,000
Deposits		838,000	1,805,000
Mandatorily redeemable capital stock		74,000	307,000
Other borrowings		224,000	4,000
Total interest expense		252,165,000	334,872,000
NET INTEREST INCOME		30,351,000	86,568,000
(Reduction of ) provision for credit losses		(684,000)	3,000
NET INTEREST INCOME AFTER (REDUCTION OF) PROVISION FOR CREDIT LOSSES		31,035,000	86,565,000
OTHER INCOME (LOSS)
Loss on early extinguishment of debt		0	(9,865,000)
Service fees		3,322,000	2,964,000
Net unrealized gains (losses) on trading securities		46,120,000	(274,000)
Net (losses) gains on derivatives and hedging activities		(52,558,000)	548,000
Realized net gain from sale of held-to-maturity securities	[1]	40,733,000	0
Other		(20,000)	(109,000)
Total other income (loss)		37,597,000	(6,736,000)
OTHER EXPENSE
Compensation and benefits		12,139,000	10,619,000
Other operating expenses		5,983,000	5,791,000
Federal Housing Finance Agency (the FHFA)		947,000	989,000
Office of Finance		1,097,000	817,000
Other		2,175,000	1,071,000
Total other expense		22,341,000	19,287,000
INCOME BEFORE ASSESSMENTS		46,291,000	60,542,000
AHP assessments		4,636,000	6,085,000
NET INCOME		$ 41,655,000	$ 54,457,000
[1]	The securities sold had less than 15 percent of the acquired principal outstanding at the time of the sale. Such sales are treated as maturities for the purposes of security classification. The sale does not impact our ability and intent to hold the remaining investments classified as held-to-maturity through their stated maturity dates.

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 41,655	$ 54,457
Other comprehensive income:
Net unrealized (losses) gains on available-for-sale securities	(85,737)	34,065
Net noncredit portion of other-than-temporary impairment gains on held-to-maturity securities	23,044	6,241
Net unrealized gains (losses) relating to hedging activities	632	(2,593)
Pension and postretirement benefits	796	161
Total other comprehensive (loss) income	(61,265)	37,874
Comprehensive (loss) income	$ (19,610)	$ 92,331

Statements of Capital

Statements of Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period	$ 3,145,312	$ 3,607,359
Cumulative effect of change in accounting principle	(7,530)	0
Comprehensive income	(19,610)	92,331
Proceeds from issuance of capital stock	1,466,215	281,392
Repurchase of capital stock	(1,068,710)	(980,006)
Shares reclassified to mandatorily redeemable capital stock, value	(306)
Cash dividends on capital stock	(24,130)	(37,272)
Period end	3,491,241	2,963,804
Retained Earnings, Unrestricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period	1,114,337	1,084,342
Comprehensive income	33,324	43,566
Cash dividends on capital stock	(24,130)	(37,272)
Period end	1,116,001	1,090,811
Retained Earnings, Restricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period	348,817	310,670
Comprehensive income	8,331	10,891
Period end	357,148	321,561
Retained Earnings, Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period	1,463,154	1,395,012
Comprehensive income	41,655	54,457
Cash dividends on capital stock	(24,130)	(37,272)
Period end	1,473,149	1,412,372
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period	(186,972)	(316,507)
Cumulative effect of change in accounting principle		(175)
Comprehensive income	(61,265)	37,874
Period end	$ (248,237)	$ (278,808)
Common Class B [Member] | Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period, shares	18,691	25,289
Beginning of period	$ 1,869,130	$ 2,528,854
Proceeds from issuance of capital stock, shares	14,662	2,813
Proceeds from issuance of capital stock	$ 1,466,215	$ 281,392
Repurchase of capital stock, shares	(10,687)	(9,800)
Repurchase of capital stock	$ (1,068,710)	$ (980,006)
Shares reclassified to mandatorily redeemable capital stock, shares	(3)
Shares reclassified to mandatorily redeemable capital stock, value	$ (306)
Period end, shares	22,663	18,302
Period end	$ 2,266,329	$ 1,830,240
Accounting Standards Update 2017-12 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Retained Earnings, Unrestricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle		175
Accounting Standards Update 2017-12 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Retained Earnings, Restricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle		0
Accounting Standards Update 2017-12 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Retained Earnings, Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle		175
Accounting Standards Update 2017-12 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle		$ (175)
Accounting Standards Update 2016-13 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Retained Earnings, Unrestricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	(7,530)
Accounting Standards Update 2016-13 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Retained Earnings, Restricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	0
Accounting Standards Update 2016-13 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Retained Earnings, Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	(7,530)
Accounting Standards Update 2016-13 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member] | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	$ 0

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
OPERATING ACTIVITIES
Net Income		$ 41,655	$ 54,457
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		25,271	(174)
(Reduction of ) provision for credit losses		(684)	3
Net change in derivatives and hedging activities		(294,892)	(279,554)
Loss on early extinguishment of debt		0	9,865
Other adjustments		912	512
Realized net gain from sale of held-to-maturity securities	[1]	(40,733)	0
Net change in:
Market value of trading securities		(46,120)	274
Accrued interest receivable		2,285	6,528
Other assets		4,143	(3,228)
Accrued interest payable		3,533	22,593
Other liabilities		(9,862)	375
Total adjustments		(356,147)	(242,806)
Net cash used in operating activities		(314,492)	(188,349)
INVESTING ACTIVITIES
Interest-bearing deposits		23,464	49,939
Securities purchased under agreements to resell		1,500,000	749,000
Federal funds sold		(2,595,000)	(850,000)
Trading securities:
Proceeds		486	5,194
Purchases		(1,267,471)	0
Available-for-sale securities:
Proceeds		422,388	379,659
Held-to-maturity securities:
Proceeds		257,384	59,680
Advances to members:
Repaid		145,011,185	144,182,259
Originated		(155,343,704)	(133,106,358)
Mortgage loans held for portfolio:
Proceeds		181,907	84,505
Purchases		(215,458)	(155,055)
Other investing activities, net		841	(173)
Net cash (used in) provided by investing activities		(12,023,978)	11,398,650
FINANCING ACTIVITIES
Net change in deposits		186,175	79,824
Net payments on derivatives with a financing element		(107,123)	(4,002)
Net proceeds from issuance of consolidated obligations:
Discount notes		50,410,176	36,748,358
Bonds		3,733,068	1,548,338
Payments for maturing and retiring consolidated obligations:
Discount notes		(38,412,037)	(46,229,722)
Bonds		(3,107,595)	(2,585,153)
Proceeds from issuance of capital stock		1,466,215	281,392
Payments for repurchase of capital stock		(1,068,710)	(980,006)
Payments for redemption of mandatorily redeemable capital stock		0	(14,455)
Cash dividends paid		(24,130)	(37,272)
Net cash provided by (used in) financing activities		13,076,039	(11,192,698)
Net increase in cash and due from banks		737,569	17,603
Cash and due from banks at beginning of the period		69,416	10,431	$ 10,431
Cash and due from banks at end of the period		806,985	28,034	69,416
Supplemental disclosures:
Interest paid		245,004	317,374
AHP payments		4,672	2,281	$ 15,723
Noncash transfers of mortgage loans held for portfolio to other assets		363	405
Lease liabilities arising from obtaining right-of-use assets		$ 0	$ 11,946
[1]	The securities sold had less than 15 percent of the acquired principal outstanding at the time of the sale. Such sales are treated as maturities for the purposes of security classification. The sale does not impact our ability and intent to hold the remaining investments classified as held-to-maturity through their stated maturity dates.

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting [Text Block]	Basis of Presentation The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information. In the opinion of management, all adjustments considered necessary have been included. All such adjustments consist of normal recurring accruals. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. The results of operations for interim periods are not necessarily indicative of the results to be expected for the year ending December 31, 2020. These interim financial statements do not include all the information and footnotes required by GAAP for complete annual financial statements and accordingly should be read in conjunction with the Federal Home Loan Bank of Boston's audited financial statements and related notes in our Annual Report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission (the SEC) on March 20, 2020 (the 2019 Annual Report). Unless otherwise indicated or the context requires otherwise, all references in this discussion to “the Bank,” "we," "us," "our," or similar references mean the Federal Home Loan Bank of Boston.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Credit Losses on Financial Instruments Beginning January 1, 2020, the Bank adopted new accounting guidance pertaining to the measurement of credit losses on financial instruments that requires a financial asset or group of financial assets measured at amortized cost to be presented at the net amount expected to be collected. The new guidance also requires credit losses relating to these financial instruments as well as available-for-sale securities be recorded through the allowance for credit losses. Key changes as compared to prior accounting guidance are detailed below. Consistent with the modified retrospective method of adoption, the prior period has not been revised to conform to the new basis of accounting. See Part II — Item 8 — Financial Statements and Supplementary Data — Note 2 — Summary of Significant Accounting Policies in the 2019 Annual Report for information on the prior accounting treatment. Interest-Bearing Deposits, Securities Purchased Under Agreements to Resell, and Federal Funds Sold Interest-bearing deposits, securities purchased under agreements to resell, and federal funds sold are evaluated quarterly for expected credit losses. If applicable, an allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. We use the collateral maintenance provision practical expedient for securities purchased under agreements to resell. Consequently, a credit loss would be recognized if there is a collateral shortfall which we do not believe the counterparty will replenish in accordance with its contractual terms. The credit loss would be limited to the difference between the fair value of the collateral and the investment’s amortized cost. Accrued interest receivable is recorded separately on the statements of condition. See Note 4 — Investments for details on the allowance methodologies relating to these investments. Investment Securities - Available-for-Sale For securities classified as available-for-sale, we evaluate an individual security for impairment on a quarterly basis by comparing the security’s fair value to its amortized cost. Accrued interest receivable is recorded separately on the statements of condition and is not included in the amortized cost basis. Impairment exists when the fair value of the investment is less than its amortized cost. In assessing whether a credit loss exists on an impaired security, we consider whether there would be a shortfall in receiving all cash flows contractually due on the investment. When a shortfall is considered possible, we compare the present value of cash flows to be collected from the security with the amortized cost basis of the security. If the present value of cash flows is less than amortized cost, an allowance-for-credit losses is recorded with a corresponding adjustment to the provision for credit losses. The allowance is limited to the amount of the unrealized loss on the individual security and excludes uncollectible accrued interest receivable, which is measured separately. If management intends to sell an impaired security classified as available-for-sale, or more likely than not will be required to sell the security before expected recovery of its amortized cost basis, any allowance for credit losses is written off and the amortized cost basis is written down to the security’s fair value at the reporting date with any incremental impairment reported in earnings as net gains (losses) on available-for-sale securities. If management does not intend to sell an impaired security classified as available-for-sale and it is not more likely than not that management will be required to sell the debt security, then the credit portion of the difference is recognized as an allowance for credit losses and any remaining difference between the security’s fair value and amortized cost is recorded to net unrealized gains (losses) on available-for-sale securities within other comprehensive income (loss). Investment Securities - Held-to-Maturity Securities that we classified as held-to-maturity are carried at amortized cost, which is original cost net of periodic principal repayments and amortization of premiums and accretion of discounts, adjusted for other-than-temporary impairment losses recorded prior to January 1, 2020. Accrued interest receivable is recorded separately on the statements of condition. Held-to-maturity securities are evaluated quarterly for expected credit losses on a pool basis unless an individual assessment is deemed necessary because the securities do not possess similar risk characteristics. An allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. The allowance for credit losses excludes uncollectible accrued interest receivable, which is measured separately. Prior to January 1, 2020, credit losses were recorded as a direct write-down of the held-to-maturity security carrying value. For improvements in expected future cash flows for held-to-maturity securities impaired prior to January 1, 2020, interest income continues to follow the recognition pattern pursuant to the impairment guidance in effect prior to January 1, 2020. Any additional recoveries of amounts previously written off prior to January 1, 2020, are recorded when received. For any improvements in expected future cash flows for held-to-maturity securities with an allowance for credit losses recognized after the adoption of the new guidance, the allowance for credit losses associated with recoveries may be derecognized up to its full amount immediately in the current period. See Note 4 — Investments for details on the allowance methodologies relating to available-for-sale and held-to-maturity securities. Advances Advances are carried at amortized cost, which is original cost net of periodic principal repayments, amortization of premiums and accretion of discounts, and fair value hedge adjustments. We amortize the premiums and accrete the discounts on advances to interest income using the level-yield method. We record interest on advances to interest income as earned. Accrued interest receivable is recorded separately on the statements of condition. Advances are evaluated quarterly for expected credit losses. If deemed necessary, an allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. See Note 5 — Advances for details on the allowance methodology. Mortgage Loans Held for Portfolio Mortgage loans held for portfolio are recorded at amortized cost, which is original cost, net of periodic principal repayments and amortization of premiums and accretion of discounts, and direct write-downs. Accrued interest receivable is recorded separately on the statements of condition. We perform a quarterly assessment of our mortgage loans held for portfolio to estimate expected credit losses. An allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. We do not purchase mortgage loans with credit deterioration present at the time of purchase. We measure expected credit losses on mortgage loans on a collective basis, pooling loans with similar risk characteristics. If a mortgage loan no longer shares risk characteristics with other loans, it is removed from the pool and evaluated for expected credit losses on an individual basis. In our assessment, we measure the expected loss over the remaining life of a mortgage loan, which considers the mitigation of expected losses through credit enhancements and any expected recoveries. If a loan is purchased at a discount, the discount does not offset the allowance for credit losses. The allowance excludes uncollectible accrued interest receivable, which is reversed out of interest income when a mortgage loan is placed on nonaccrual status. See Note 6 — Mortgage Loans Held for Portfolio for details on the allowance methodologies relating to mortgage loans. Off-Balance Sheet Credit Exposures We evaluate our off-balance sheet credit exposures on a quarterly basis for expected credit losses. If deemed necessary, an allowance for expected credit losses on these off-balance sheet exposures is recorded in other liabilities with a corresponding adjustment to the provision for credit losses. See Note 14 — Commitments and Contingencies for details on the allowance methodologies relating to off-balance sheet credit exposures.

Recently Issued and Adopted Acc

Recently Issued and Adopted Accounting Guidance	3 Months Ended
	Mar. 31, 2020
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Recently Issued and Adopted Accounting Guidance Effective January 1, 2020 Facilitation of the Effects of Reference Rate Reform on Financial Reporting . On March 12, 2020, the Financial Accounting Standards Board (FASB) released temporary optional guidance that provides transition relief for reference rate reform. The guidance contains optional expedients and exceptions for applying generally accepted accounting principles to contract modifications, hedging relationships, and other transactions that reference London Interbank Offered Rate (LIBOR) or a reference rate that is expected to be discontinued as a result of reference rate reform if certain criteria are met. In addition to the optional expedients for contract modifications and hedging relationships, this update provides a one-time election to sell, transfer, or both sell and transfer debt securities classified as held-to-maturity that reference a rate affected by reference rate reform and that are classified as held-to-maturity before January 1, 2020. This standard is effective upon issuance and the provisions generally can be applied prospectively as of January 1, 2020 through December 31, 2022. We are in the process of evaluating this guidance, and its anticipated effect on our financial condition, results of operations, and cash flows has not yet been determined. Financial Instruments - Credit Losses. On June 16, 2016, the FASB issued amended guidance for the accounting of credit losses on financial instruments. The amendments require entities to measure expected credit losses based on relevant information about past events (including historical experience), current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The new guidance requires a financial asset, or a group of financial assets, measured at amortized cost to be presented at the net amount expected to be collected over the contractual term of the financial asset(s). The guidance also requires, among other things, that we: • Reflect in the statement of operations the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. • Determine the allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination that are measured at amortized cost in a similar manner to other financial assets measured at amortized cost. The initial allowance for credit losses is required to be added to the purchase price. • Record credit losses relating to available-for-sale debt securities through an allowance for credit losses. The amendments limit the allowance for credit losses to the amount by which fair value is below amortized cost. • Further disaggregate the current disclosure of credit quality indicators in relation to the amortized cost of financing receivables by the year of origination. We adopted this guidance on January 1, 2020, using a modified-retrospective approach. Upon adoption, we recognized an increase in the allowance for credit losses of $7.5 million as a cumulative-effect adjustment to retained earnings.

Investments

Investments	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Investments Interest-Bearing Deposits, Securities Purchased under Agreements to Resell, and Federal Funds Sold We invest in interest-bearing deposits, securities purchased under agreements to resell, and federal funds sold to provide short-term liquidity. These investments are generally transacted with counterparties that have received a credit rating of triple-B or greater (investment grade) by a nationally recognized statistical rating organization. At March 31, 2020 , none of these investments were with counterparties rated below triple-B. Federal funds sold are unsecured loans that are generally transacted on an overnight term. FHFA regulations include a limit on the amount of unsecured credit we may extend to a counterparty. At March 31, 2020 and December 31, 2019 , all investments in interest-bearing deposits and federal funds sold were repaid according to the contractual terms. No allowance for credit losses was recorded for these assets at March 31, 2020 . Carrying values of interest-bearing deposits and federal funds sold exclude accrued interest receivable of $294 thousand and $8 thousand , respectively, at March 31, 2020 , and $682 thousand and $37 thousand , respectively, at December 31, 2019 . Securities purchased under agreements to resell are short-term and are structured such that they are evaluated regularly to determine if the market value of the underlying securities decreases below the market value required as collateral (i.e. subject to collateral maintenance provisions). If so, the counterparty must place an equivalent amount of additional securities as collateral or remit an equivalent amount of cash, generally by the next business day. Based upon the collateral held as security and collateral maintenance provisions with our counterparties, we determined that no allowance for credit losses was needed for our securities purchased under agreements to resell at March 31, 2020 . The carrying value of securities purchased under agreements excludes accrued interest receivable of $1 thousand and $348 thousand at March 31, 2020 and December 31, 2019 , respectively. The COVID-19 pandemic effects on the global economies and the financial markets are expected to put pressure on our bank counterparties’ profitability, asset quality, and in some cases, capitalization. We continually monitor the creditworthiness of our counterparties and may reduce or suspend individual credit lines as conditions warrant. Debt Securities We invest in debt securities, which are classified as either trading, available-for-sale, or held-to-maturity. Within these investments, we are primarily subject to credit risk related to private-label mortgage-backed securities (MBS) that are supported by underlying mortgage loans. We are prohibited by FHFA regulations from purchasing certain higher-risk securities, such as equity securities and debt instruments that are not investment quality, other than certain investments targeted at low-income persons or communities and instruments that experienced credit deterioration after their purchase. Trading Securities Table 4.1 - Trading Securities by Major Security Type (dollars in thousands) March 31, 2020 December 31, 2019 Corporate bonds $ 5,330 $ 5,896 U.S. Treasury obligations 3,554,179 2,240,236 3,559,509 2,246,132 MBS U.S. government-guaranteed – single-family 3,794 4,047 Government-sponsored enterprise (GSE) – single-family 65 85 3,859 4,132 Total $ 3,563,368 $ 2,250,264 For the three months ended March 31, 2020 and 2019 , net unrealized gains (losses) on trading securities held at period end were $46.1 million and $(274) thousand , respectively. Available-for-sale Securities Table 4.2 - Available-for-Sale Securities by Major Security Type (dollars in thousands) March 31, 2020 Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value State housing-finance-agency obligations (HFA securities) $ 69,320 $ — $ (3,925 ) $ 65,395 Supranational institutions 457,721 — (19,437 ) 438,284 U.S. government-owned corporations 376,711 — (61,987 ) 314,724 GSE 149,068 — (15,279 ) 133,789 1,052,820 — (100,628 ) 952,192 MBS U.S. government guaranteed – single-family 52,820 — (234 ) 52,586 U.S. government guaranteed – multifamily 247,526 917 (15 ) 248,428 GSE – single-family 2,317,683 28,079 (3,122 ) 2,342,640 GSE – multifamily 3,735,144 6,220 (90,876 ) 3,650,488 6,353,173 35,216 (94,247 ) 6,294,142 Total $ 7,405,993 $ 35,216 $ (194,875 ) $ 7,246,334 December 31, 2019 Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value HFA securities $ 69,320 $ — $ (4,668 ) $ 64,652 Supranational institutions 429,354 — (12,925 ) 416,429 U.S. government-owned corporations 323,192 — (26,431 ) 296,761 GSE 130,935 — (7,149 ) 123,786 952,801 — (51,173 ) 901,628 MBS U.S. government guaranteed – single-family 60,003 — (2,289 ) 57,714 U.S. government guaranteed – multifamily 283,674 — (1,057 ) 282,617 GSE – single-family 2,598,325 5,323 (13,377 ) 2,590,271 GSE – multifamily 3,588,119 3,109 (14,458 ) 3,576,770 6,530,121 8,432 (31,181 ) 6,507,372 Total $ 7,482,922 $ 8,432 $ (82,354 ) $ 7,409,000 _______________________ (1) Amortized cost of available-for-sale securities includes adjustments made to the cost basis of an investment for accretion, amortization, collection of cash, and fair-value hedge accounting adjustments. Amortized cost excludes accrued interest receivable of $20.0 million and $27.5 million at March 31, 2020 , and December 31, 2019 . Table 4.3 - Available-for-Sale Securities in a Continuous Unrealized Loss Position (dollars in thousands) March 31, 2020 Continuous Unrealized Loss Less than 12 Months Continuous Unrealized Loss 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 12,497 $ (1,323 ) $ 45,298 $ (2,602 ) $ 57,795 $ (3,925 ) Supranational institutions — — 438,284 (19,437 ) 438,284 (19,437 ) U.S. government-owned corporations — — 314,724 (61,987 ) 314,724 (61,987 ) GSE — — 133,789 (15,279 ) 133,789 (15,279 ) 12,497 (1,323 ) 932,095 (99,305 ) 944,592 (100,628 ) MBS U.S. government guaranteed – single-family 1,294 (8 ) 51,292 (226 ) 52,586 (234 ) U.S. government guaranteed – multifamily — — 39,735 (15 ) 39,735 (15 ) GSE – single-family 126,722 (605 ) 397,329 (2,517 ) 524,051 (3,122 ) GSE – multifamily 2,796,682 (87,572 ) 288,652 (3,304 ) 3,085,334 (90,876 ) 2,924,698 (88,185 ) 777,008 (6,062 ) 3,701,706 (94,247 ) Total temporarily impaired $ 2,937,195 $ (89,508 ) $ 1,709,103 $ (105,367 ) $ 4,646,298 $ (194,875 ) December 31, 2019 Continuous Unrealized Loss Less than 12 Months Continuous Unrealized Loss 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 12,229 $ (1,591 ) $ 52,423 $ (3,077 ) $ 64,652 $ (4,668 ) Supranational institutions — — 416,429 (12,925 ) 416,429 (12,925 ) U.S. government-owned corporations — — 296,761 (26,431 ) 296,761 (26,431 ) GSE — — 123,786 (7,149 ) 123,786 (7,149 ) 12,229 (1,591 ) 889,399 (49,582 ) 901,628 (51,173 ) MBS U.S. government guaranteed – single-family 10,885 (1 ) 45,490 (2,288 ) 56,375 (2,289 ) U.S. government guaranteed – multifamily — — 282,617 (1,057 ) 282,617 (1,057 ) GSE – single-family 189,402 (968 ) 1,423,927 (12,409 ) 1,613,329 (13,377 ) GSE – multifamily 1,800,586 (13,242 ) 405,778 (1,216 ) 2,206,364 (14,458 ) 2,000,873 (14,211 ) 2,157,812 (16,970 ) 4,158,685 (31,181 ) Total temporarily impaired $ 2,013,102 $ (15,802 ) $ 3,047,211 $ (66,552 ) $ 5,060,313 $ (82,354 ) Table 4.4 - Available-for-Sale Securities by Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Year of Maturity Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 7,600 $ 7,600 $ 7,600 $ 7,563 Due after one year through five years 61,720 57,795 61,720 57,089 Due after five years through 10 years 509,594 488,131 477,232 463,465 Due after 10 years 473,906 398,666 406,249 373,511 1,052,820 952,192 952,801 901,628 MBS (1) 6,353,173 6,294,142 6,530,121 6,507,372 Total $ 7,405,993 $ 7,246,334 $ 7,482,922 $ 7,409,000 _______________________ (1) MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay obligations with or without call or prepayment fees. Held-to-Maturity Securities Table 4.5 - Held-to-Maturity Securities by Major Security Type (dollars in thousands) March 31, 2020 Amortized Cost (1) Allowance for Credit Losses (2) Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss (2) Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value HFA securities $ 79,680 $ — $ — $ 79,680 $ — $ (10,319 ) $ 69,361 MBS U.S. government guaranteed – single-family 6,686 — — 6,686 76 — 6,762 GSE – single-family 281,285 — — 281,285 5,464 (510 ) 286,239 GSE – multifamily 90,927 — — 90,927 518 — 91,445 Private-label 275,069 (3,768 ) (52,991 ) 218,310 62,591 (738 ) 280,163 653,967 (3,768 ) (52,991 ) 597,208 68,649 (1,248 ) 664,609 Total $ 733,647 $ (3,768 ) $ (52,991 ) $ 676,888 $ 68,649 $ (11,567 ) $ 733,970 December 31, 2019 Amortized Cost (1) Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss (2) Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value HFA securities $ 87,250 $ — $ 87,250 $ — $ (3,845 ) $ 83,405 MBS U.S. government guaranteed – single-family 6,987 — 6,987 129 — 7,116 GSE – single-family 303,604 — 303,604 5,197 (246 ) 308,555 GSE – multifamily 140,661 — 140,661 612 (2 ) 141,271 Private-label 408,640 (76,035 ) 332,605 162,904 (446 ) 495,063 859,892 (76,035 ) 783,857 168,842 (694 ) 952,005 Total $ 947,142 $ (76,035 ) $ 871,107 $ 168,842 $ (4,539 ) $ 1,035,410 _______________________ (1) Amortized cost of held-to-maturity securities includes adjustments made to the cost basis of an investment for accretion, amortization, and collection of cash. Amortized cost excludes accrued interest receivable of $1.6 million and $2.0 million at March 31, 2020 , and December 31, 2019 . (2) With the adoption of changes to accounting standards on credit impairment on January 1, 2020, the other-than-temporary impairment approach was replaced with an allowance for credit loss; however, other-than-temporary impairment remains for those securities that had credit impairment prior to the adoption date. See Note 2 — Summary of Significant Accounting Policies and Note 3 — Recently Issued and Adopted Accounting Guidance for further information. Table 4.6 - Held-to-Maturity Securities by Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Year of Maturity Amortized Cost Carrying Value (1) Fair Value Amortized Cost Carrying Value (1) Fair Value Due in one year or less $ 3,090 $ 3,090 $ 3,083 $ 3,090 $ 3,090 $ 3,089 Due after one year through five years — — — — — — Due after five years through 10 years 15,405 15,405 14,903 15,405 15,405 15,270 Due after 10 years 61,185 61,185 51,375 68,755 68,755 65,046 79,680 79,680 69,361 87,250 87,250 83,405 MBS (2) 653,967 597,208 664,609 859,892 783,857 952,005 Total $ 733,647 $ 676,888 $ 733,970 $ 947,142 $ 871,107 $ 1,035,410 _______________________ (1) Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss and the allowance for credit losses. (2) MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay their obligations with or without call or prepayment fees. Table 4.7 - Proceeds from Sale and Gains and Losses on Held-to-Maturity Securities (1) (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Proceeds from sale of held-to-maturity securities $ 161,743 $ — Amortized cost of held-to-maturity securities 121,010 — Realized net gain from sale of held-to-maturity securities $ 40,733 $ — _______________________ (1) The securities sold had less than 15 percent of the acquired principal outstanding at the time of the sale. Such sales are treated as maturities for the purposes of security classification. The sale does not impact our ability and intent to hold the remaining investments classified as held-to-maturity through their stated maturity dates. Allowance for Credit Losses on Available-for-Sale Securities and Held-to-Maturity Securities We evaluate available-for-sale and held-to-maturity investment securities for credit losses on a quarterly basis. We adopted new accounting guidance for the measurement of credit losses on financial instruments on January 1, 2020. See Note 3 — Recently Issued and Adopted Accounting Guidance for additional information. See Item 8 — Financial Statements and Supplementary Data — Notes to Financial Statements — Note 2 — Summary of Significant Accounting Policies — Investment Securities – Other-than-Temporary Impairment in the 2019 Annual Report, for information on the prior methodology for evaluating credit losses. Upon adoption of new accounting guidance for credit impairment, on January 1, 2020 we recorded through a cumulative effect adjustment to retained earnings an increase in the allowance for credit losses associated with held-to-maturity private-label MBS totaling $5.3 million . During the three months ended March 31, 2020 , we recognized a net decrease to the allowance for credit losses of $1.5 million associated with held-to-maturity private-label MBS. Under the previous accounting methodology of security impairment, we recognized net credit losses of $103 thousand during the three months ended March 31, 2019 . To evaluate investment securities for credit loss at March 31, 2020 , we employed the following methodologies, based on the type of security. Available-for-Sale Securities and Held-to-Maturity Securities (Excluding Private-Label MBS). Our available-for-sale and held-to-maturity securities are principally GSE and U.S. government-owned corporations, supranational institutions, state or local housing finance agency obligations, and MBS issued by Ginnie Mae, Freddie Mac, and Fannie Mae that are backed by single-family or multifamily mortgage loans. We only purchase securities considered investment quality. Excluding private-label MBS investments, at March 31, 2020 , approximately 99.8 percent of available-for-sale securities and 92.4 percent of held-to-maturity securities, based on amortized cost, were rated single-A, or above, by a nationally recognized statistical ratings organization (NRSRO), based on the lowest long-term credit rating for each security. We evaluate our individual available-for-sale securities for impairment by comparing the security’s fair value to its amortized cost. Impairment may exist when the fair value of the investment is less than its amortized cost (i.e. in an unrealized loss position). At March 31, 2020 , certain available-for-sale securities were in an unrealized loss position. These losses are considered temporary as we expect to recover the entire amortized cost basis on these available-for-sale investment securities and we neither intend to sell these securities nor do we consider it more likely than not that we will be required to sell these securities before the anticipated recovery of each security's remaining amortized cost basis. Further, we have not experienced any payment defaults on the instruments. In addition, substantially all of these securities carry an implicit or explicit government guarantee. As a result, no allowance for credit losses was recorded on these available-for-sale securities at March 31, 2020 . We evaluate our held-to-maturity securities for impairment on a collective or pooled basis unless an individual assessment is deemed necessary because the securities do not possess similar risk characteristics. As of March 31, 2020 , we had not established an allowance for credit loss on any of our HTM securities (excluding private-label MBS) because the securities: (1) were all highly-rated and/or had short remaining terms to maturity, (2) had not experienced, nor did we expect, any payment default on the instruments, and (3) in the case of U.S., GSE, or other agency obligations, carry an implicit or explicit government guarantee such that we consider the risk of nonpayment to be zero. Private-label MBS. We also hold investments in private-label MBS. We have not purchased private-label mortgage-backed securities since the third quarter of 2007 . However, many of these securities have subsequently experienced significant credit deterioration. As of March 31, 2020 , none of our private-label MBS (based on amortized cost) were rated single-A or above by a NRSRO and the remaining securities were either rated less than single-A or were unrated. To determine whether an allowance for credit losses is necessary on these securities, we use cash flow analyses. Our evaluation includes estimating the projected cash flows that we are likely to collect based on an assessment of available information, including the structure of the applicable security and certain assumptions such as: • the remaining payment terms for the security; • prepayment speeds; • default rates; • loss severity on the collateral supporting each security based on underlying loan-level borrower and loan characteristics; • expected housing price changes; and • interest-rate assumptions. We performed a cash flow analysis using third-party models to assess whether the entire amortized cost basis of our private-label MBS securities will be recovered. The projected cash flows are based on a number of assumptions and expectations, and the results of these models can vary significantly with changes in assumptions and expectations. The projected cash flows, determined based on the model approach, reflect a best estimate scenario and include a base case housing price forecast and a base case housing price recovery path.

Advances

Advances	3 Months Ended
	Mar. 31, 2020
Advances [Abstract]
Federal Home Loan Bank, Advances [Text Block]	Advances General Terms. At March 31, 2020 , and December 31, 2019 , we had advances outstanding with interest rates ranging from (1.08) percent to 7.72 percent and (0.35) percent to 7.72 percent , respectively. Advances with negative interest rates contain embedded interest-rate features that have met the requirements to be separated from the host contract and are recorded as stand-alone derivatives, and which we economically hedge with derivatives containing offsetting interest-rate features. Table 5.1 - Advances Outstanding by Year of Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Amount Weighted Average Rate Amount Weighted Average Rate Overdrawn demand-deposit accounts $ 2,841 0.57 % $ 5,101 2.05 % Due in one year or less 25,324,147 1.09 18,972,466 1.96 Due after one year through two years 11,478,292 1.05 8,600,922 2.16 Due after two years through three years 2,653,833 2.15 2,200,019 2.16 Due after three years through four years 1,756,774 2.44 1,766,314 2.71 Due after four years through five years 2,335,849 1.75 1,726,754 2.15 Thereafter 1,364,666 2.62 1,312,311 2.68 Total par value 44,916,402 1.28 % 34,583,887 2.10 % Premiums 3,227 3,397 Discounts (41,391 ) (41,744 ) Fair value of bifurcated derivatives (1) 53,783 29,983 Hedging adjustments 144,202 19,840 Total (2) $ 45,076,223 $ 34,595,363 _________________________ (1) At March 31, 2020 , and December 31, 2019 , we had certain advances with embedded features that met the requirements to be separated from the host contract and designated as stand-alone derivatives. (2) Excludes accrued interest receivable of $46.4 million and $48.1 million at March 31, 2020 , and December 31, 2019 . Table 5.2 - Advances Outstanding by Year of Contractual Maturity or Next Call Date (dollars in thousands) March 31, 2020 December 31, 2019 Overdrawn demand-deposit accounts $ 2,841 $ 5,101 Due in one year or less 34,501,542 25,116,961 Due after one year through two years 3,328,292 3,450,922 Due after two years through three years 2,300,413 1,949,499 Due after three years through four years 1,266,774 1,461,314 Due after four years through five years 2,173,774 1,309,679 Thereafter 1,342,766 1,290,411 Total par value $ 44,916,402 $ 34,583,887 We currently hold putable advances that provide us with the right to require repayment prior to maturity of the advance (and thereby extinguish the advance) on predetermined exercise dates (put dates). Generally, we would exercise the put options when interest rates increase relative to contractual rates. Table 5.3 - Advances Outstanding by Year of Contractual Maturity or Next Put Date (dollars in thousands) March 31, 2020 December 31, 2019 Overdrawn demand-deposit accounts $ 2,841 $ 5,101 Due in one year or less 27,048,822 20,240,466 Due after one year through two years 11,616,542 8,603,422 Due after two years through three years 2,119,533 2,001,019 Due after three years through four years 1,248,574 965,814 Due after four years through five years 1,657,924 1,598,254 Thereafter 1,222,166 1,169,811 Total par value $ 44,916,402 $ 34,583,887 Table 5.4 - Advances by Current Interest Rate Terms (dollars in thousands) March 31, 2020 December 31, 2019 Fixed-rate $ 35,460,466 $ 28,106,591 Variable-rate 9,455,936 6,477,296 Total par value $ 44,916,402 $ 34,583,887 Credit Risk Exposure and Security Terms. Our advances are principally concentrated in commercial banks, insurance companies, savings institutions, and credit unions. We manage our credit exposure to secured member credit products through an integrated approach that generally includes establishing a credit limit for each borrower. This approach includes an ongoing review of each borrower's financial condition, and collateral and lending policies that are intended to limit risk of loss while balancing borrowers' needs for a reliable source of funding. In addition, we lend to eligible borrowers in accordance with federal law and FHFA regulations. Specifically, we are required to obtain sufficient collateral to fully secure credit products up to the counterparty’s total credit limit. Collateral eligible to secure new or renewed advances includes: • fully disbursed, first-mortgage loans on improved residential property (provided that the borrower is not in arrears by two or more payments), or securities representing a whole interest in such mortgages; • securities issued, insured, or guaranteed by the U.S. government or any agency thereof (including without limitation, MBS issued or guaranteed by Freddie Mac, Fannie Mae, and Ginnie Mae); • cash or deposits in a collateral account with us; and • other real-estate-related collateral acceptable to us if such collateral has a readily ascertainable value and we can perfect our security interest in the collateral. Residential mortgage loans are the principal form of collateral for advances. The estimated value of the collateral pledged to secure each borrower's credit products is calculated by applying collateral discounts, or haircuts, to the market value or unpaid principal balance of the collateral, as applicable. We require all borrowers that pledge securities collateral to place physical possession of such securities collateral with our safekeeping agent, the borrower's approved designated agent, or the borrower's securities corporation, subject to a control agreement giving us appropriate control over such collateral. In addition, community financial institutions are eligible to use expanded statutory collateral provisions for small-business and agriculture loans. Members also pledge their Bank capital stock as collateral. Collateral arrangements may vary depending upon borrower credit quality, financial condition, performance, borrowing capacity, and our overall credit exposure to the borrower. We can call for additional or substitute collateral to further safeguard our security interest. We also have policies and procedures for validating the reasonableness of our collateral valuations. In addition, we perform collateral verifications based on the risk profile of the borrower. Management believes that these policies effectively manage our credit risk from advances. We either allow the borrower to retain possession of loan collateral pledged to us while agreeing to hold such collateral for our benefit or require the borrower to specifically assign or place physical possession of such loan collateral with us or a third-party custodian that we approve. We are provided an additional safeguard for our security interests by Section 10(e) of the FHLBank Act, which generally affords any security interest granted by a borrower to the Bank priority over the claims and rights of any other party. The exceptions to this prioritization are limited to claims that would be entitled to priority under otherwise applicable law and are held by bona fide purchasers for value or by secured parties with higher priority perfected security interests. The priority granted to our security interests under Section 10(e) of the FHLBank Act may not apply when lending to insurance company members due to the anti-preemption provision contained in the McCarran-Ferguson Act, which provides that federal law does not preempt state insurance law unless the federal law expressly regulates the business of insurance. Thus, if state law conflicts with Section 10(e) of the FHLBank Act, the protection afforded by this provision may not be available to us. However, we perfect our security interests in the collateral pledged by our members, including insurance company members, by filing Uniform Commercial Code (UCC)-1 financing statements, taking possession or control of such collateral, or taking other appropriate steps. Using a risk-based approach and taking into consideration each borrower's financial strength, we consider the types and level of collateral to be the primary indicator of credit quality on our credit products. At March 31, 2020 , and December 31, 2019 , we had rights to collateral, on a borrower-by-borrower basis, with an estimated value in excess of our outstanding extensions of credit. We continue to evaluate and make changes to our collateral guidelines based on market conditions. At March 31, 2020 , and December 31, 2019 , none of our advances were past due, on nonaccrual status, or considered impaired. In addition, there were no troubled debt restructurings related to advances during the three months ended March 31, 2020 , and March 31, 2019 . Based upon the collateral held as security, our credit extension and collateral policies, management's credit analysis, and the repayment history on advances, we have not recorded any allowance for credit losses on our advances at March 31, 2020 , and December 31, 2019 . Prepayment Fees. Table 5.5 - Advances Prepayment Fees (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Prepayment fees received from borrowers $ 838 $ 26,186 Hedging fair-value adjustments on prepaid advances — 527 Net discounts associated with prepaid advances — 218 Advance prepayment fees recognized in income, net $ 838 $ 26,931

Mortgage Loans Held for Portfol

Mortgage Loans Held for Portfolio	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Mortgage Loans Held for Portofolio [Text Block]	Mortgage Loans Held for Portfolio We invest in mortgage loans through the Mortgage Partnership Finance (MPF) program. These mortgage loans are either guaranteed or insured by federal agencies, as is the case with government mortgage loans, or are credit-enhanced, directly or indirectly, by the related entity that sold the loan (a participating financial institution), as is the case with conventional mortgage loans. All such investments are held for portfolio. Table 6.1 - Mortgage Loans Held for Portfolio (dollars in thousands) March 31, 2020 December 31, 2019 Real estate Fixed-rate 15-year single-family mortgages $ 327,700 $ 339,042 Fixed-rate 20- and 30-year single-family mortgages 4,134,314 4,093,416 Premiums 66,933 66,776 Discounts (1,535 ) (1,607 ) Deferred derivative gains, net 4,562 4,124 Total mortgage loans held for portfolio (1) 4,531,974 4,501,751 Less: allowance for credit losses (3,500 ) (500 ) Total mortgage loans, net of allowance for credit losses $ 4,528,474 $ 4,501,251 _________________________ (1) Excludes accrued interest receivable of $23.5 million at both March 31, 2020 , and December 31, 2019 . Table 6.2 - Mortgage Loans Held for Portfolio by Collateral/Guarantee Type (dollars in thousands) March 31, 2020 December 31, 2019 Conventional mortgage loans $ 4,180,145 $ 4,140,255 Government mortgage loans 281,869 292,203 Total par value $ 4,462,014 $ 4,432,458 Credit Enhancements. Our allowance for credit losses factors in the credit-enhancements associated with conventional mortgage loans under the MPF program. These credit-enhancements can include primary and/or supplemental mortgage insurance or other kinds of credit enhancement. Potential recoveries from credit enhancements for conventional loans are evaluated at the individual master commitment level to determine the credit-enhancements available to recover losses on loans under each individual master commitment. Payment Status of Mortgage Loans. Payment status is a key credit quality indicator for conventional mortgage loans and allows us to monitor the migration of past due loans. Past due loans are those where the borrower has failed to make timely payments of principal and/or interest in accordance with the terms of the loan. Other delinquency statistics include non-accrual loans and loans in process of foreclosure. Tables 6.3 and 6.4 present the payment status for conventional mortgage loans and other delinquency statistics for all mortgage loans at March 31, 2020 , and December 31, 2019 . Table 6.3 - Credit Quality Indicator for Conventional Mortgage Loans (dollars in thousands) March 31, 2020 Origination Year Payment Status at Amortized Cost (1) Prior to 2016 2016 to 2020 Total Past due 30-59 days delinquent $ 14,166 $ 14,575 $ 28,741 Past due 60-89 days delinquent 3,502 3,717 7,219 Past due 90 days or more delinquent 6,830 4,129 10,959 Total past due 24,498 22,421 46,919 Total current loans 1,643,888 2,553,578 4,197,466 Total mortgage loans $ 1,668,386 $ 2,575,999 $ 4,244,385 December 31, 2019 Payment Status at Recorded Investment (1) Conventional Mortgage Loans Past due 30-59 days delinquent $ 36,336 Past due 60-89 days delinquent 6,911 Past due 90 days or more delinquent 10,696 Total past due 53,943 Total current loans 4,171,676 Total mortgage loans $ 4,225,619 _________________________ (1) The amortized cost at March 31, 2020 , excludes accrued interest receivable whereas the recorded investment at December 31, 2019 , includes accrued interest receivable. Table 6.4 - Other Delinquency Statistics of Mortgage Loans (dollars in thousands) March 31, 2020 Amortized Cost in Conventional Mortgage Loans Amortized Cost in Government Mortgage Loans Total In process of foreclosure (1) $ 2,816 $ 1,655 $ 4,471 Serious delinquency rate (2) 0.26 % 1.85 % 0.36 % Past due 90 days or more still accruing interest $ — $ 5,317 $ 5,317 Loans on nonaccrual status (3) $ 11,890 $ — $ 11,890 December 31, 2019 Recorded Investment in Conventional Mortgage Loans Recorded Investment in Government Mortgage Loans Total In process of foreclosure (1) $ 2,813 $ 2,222 $ 5,035 Serious delinquency rate (2) 0.26 % 1.86 % 0.36 % Past due 90 days or more still accruing interest $ — $ 5,570 $ 5,570 Loans on nonaccrual status (3) $ 11,510 $ — $ 11,510 _______________________ (1) Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu of foreclosure has been reported. (2) Loans that are 90 days or more past due or in the process of foreclosure expressed as a percentage of the recorded investment in the total loan portfolio class. (3) Includes conventional mortgage loans with contractual principal or interest payments 90 days or more past due and not accruing interest as well as loans modified within the previous six months under our temporary loan modification plan. As of March 31, 2020 , $4.6 million of these conventional mortgage loans on non-accrual status did not have an associated allowance for credit losses. Allowance for Credit Losses. See Part II — Item 8 — Financial Statements and Supplementary Data — Note 11 — Allowance for Credit Losses in the 2019 Annual Report for information on the prior methodology for evaluating credit losses, as well as a discussion on classes of financing receivables, our policies for impairing financing receivables, placing them on non-accrual status, and charging them off when necessary. Conventional Mortgage Loans. Conventional loans are evaluated collectively when similar risk characteristics exist. Conventional loans that do not share risk characteristics with other pools are evaluated for expected credit losses on an individual basis. We determine our allowance for credit losses on conventional loans through analyses that include consideration of various loan portfolio and collateral-related characteristics, such as past performance, current conditions, and reasonable and supportable forecasts of expected economic conditions. We use a discounted cash flow model to project our expected losses. We use a third-party model to project cash flows to estimate the expected credit losses over the life of the loans. The model relies on a number of inputs, such as both current and forecasted property values and interest rates as well as historical borrower behavior. We incorporate associated credit enhancements and expected recoveries, if any, to determine our estimate of expected credit losses. Certain conventional loans may be evaluated for credit losses by using the practical expedient for collateral dependent assets. A mortgage loan is considered collateral dependent if repayment is expected to be provided by the sale of the underlying property, that is, if it is considered likely that the borrower will default. We estimate the fair value of this collateral by using a third-party property valuation model. The expected credit loss of a collateral dependent mortgage loan is equal to the difference between the amortized cost of the loan and the estimated fair value of the collateral, less estimated selling costs. We will reserve for these estimated losses or record a direct charge-off of the loan balance if certain triggering criteria are met. Table 6.5 presents a roll forward of the allowance for credit losses on conventional mortgage loans for the three months ended March 31, 2020 and 2019 . Table 6.5 - Allowance for Credit Losses on Conventional Mortgage Loans (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Allowance for credit losses Balance, beginning of period $ 500 $ 500 Adjustment for cumulative effect of accounting change 2,221 — Charge-offs (77 ) (3 ) Provision for credit losses 856 3 Balance, end of period $ 3,500 $ 500 Government Mortgage Loans Held for Portfolio. We invest in government mortgage loans secured by one- to four-family residential properties. Government mortgage loans are mortgage loans insured or guaranteed by the Federal Housing Administration (the FHA), the U.S. Department of Veterans Affairs (the VA), the Rural Housing Service of the U.S. Department of Agriculture (RHS), or by the U.S. Department of Housing and Urban Development (HUD). The servicer provides and maintains insurance or a guarantee from the applicable government agency. The servicer is responsible for compliance with all government agency requirements and for obtaining the benefit of the applicable insurance or guaranty with respect to defaulted government-guaranteed mortgage loans. Any losses incurred on these loans that are not recovered from the insurer or guarantor are absorbed by the related servicer. Therefore, we only have credit risk for these loans if the servicer fails to pay for losses not covered by insurance or guarantees. Due to government guarantees or insurance on our government loans, there is no allowance for credit losses for the government mortgage loan portfolio as of March 31, 2020 , and December 31, 2019 . Additionally, these mortgage loans are not placed on nonaccrual status due to the government guarantee or insurance on these loans and the contractual obligation of the loan servicers to repurchase their related loans when certain criteria are met.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities [Text Block]	Derivatives and Hedging Activities Table 7.1 - Fair Value of Derivative Instruments (dollars in thousands) March 31, 2020 December 31, 2019 Notional Amount of Derivatives Derivative Assets Derivative Liabilities Notional Derivative Derivative Derivatives designated as hedging instruments Interest-rate swaps $ 12,808,610 $ 30,660 $ (48,635 ) $ 12,128,105 $ 14,734 $ (12,805 ) Forward-start interest-rate swaps 17,000 24 — 17,000 19 — Total derivatives designated as hedging instruments 12,825,610 30,684 (48,635 ) 12,145,105 14,753 (12,805 ) Derivatives not designated as hedging instruments Economic hedges: Interest-rate swaps 4,142,300 28 (55,319 ) 2,902,300 349 (31,000 ) Mortgage-delivery commitments (1) 98,765 147 (695 ) 49,911 227 — Total derivatives not designated as hedging instruments 4,241,065 175 (56,014 ) 2,952,211 576 (31,000 ) Total notional amount of derivatives $ 17,066,675 $ 15,097,316 Total derivatives before netting and collateral adjustments 30,859 (104,649 ) 15,329 (43,805 ) Netting adjustments and cash collateral, including related accrued interest (2) 196,861 80,245 144,402 33,534 Derivative assets and derivative liabilities $ 227,720 $ (24,404 ) $ 159,731 $ (10,271 ) _______________________ (1) Mortgage-delivery commitments are classified as derivatives with changes in fair value recorded in other income. (2) Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty. Cash collateral and related accrued interest posted was $278.3 million and $178.5 million at March 31, 2020 , and December 31, 2019 , respectively. The change in cash collateral posted is included in the net change in interest-bearing deposits in the statement of cash flows. Cash collateral and related accrued interest received was $1.2 million and $561 thousand at March 31, 2020 , and December 31, 2019 . Changes in fair value of the derivative hedging instrument and the hedged item attributable to the hedged risk for designated fair-value hedges are recorded in net interest income in the same line as the earnings effect of the hedged item. For designated cash-flow hedges, the entire change in the fair value of the hedging instrument (assuming it is included in the assessment of hedge effectiveness) is reported in other comprehensive income until the hedged transaction affects earnings. At that time, this amount is reclassified from other comprehensive income and recorded in net interest income in the same line as the earnings effect of the hedged item. Tables 7.2 presents the net gains (losses) on qualifying fair-value and cash flow hedging relationships. Gains (losses) on derivatives include unrealized changes in fair value as well as net interest settlements. Table 7.2 - Net Gains (Losses) on Hedging Relationships (dollars in thousands) For the Three Months Ended March 31, 2020 Advances Available-for-sale Securities CO Bonds Total interest income (expense) in the statements of operations $ 168,659 $ 12,361 $ (123,547 ) Gains (losses) on hedging relationships Changes in fair value: Derivatives $ (127,568 ) $ (376,494 ) $ 63,735 Hedged items 124,692 366,518 (64,058 ) Net changes in fair value before price alignment interest (2,876 ) (9,976 ) (323 ) Price alignment interest (1) 389 1,035 (177 ) Net interest settlements on derivatives (2)(3) (2,625 ) (9,098 ) 2,956 Net (losses) gains on qualifying hedging relationships (5,112 ) (18,039 ) 2,456 Amortization/accretion of discontinued hedging relationships (337 ) — (888 ) Net (losses) gains on derivatives and hedging activities recorded in net interest income $ (5,449 ) $ (18,039 ) $ 1,568 For the Three Months Ended March 31, 2019 Advances Available-for-sale Securities CO Bonds Total interest income (expense) in the statements of operations $ 247,877 $ 21,291 $ (154,817 ) Gains (losses) on hedging relationships Changes in fair value: Derivatives $ (24,897 ) $ (23,197 ) $ 33,636 Hedged items 25,672 19,115 (34,633 ) Net changes in fair value before price alignment interest 775 (4,082 ) (997 ) Price alignment interest (1) 286 8 5 Net interest settlements on derivatives (2)(3) 16,251 (5,791 ) (9,080 ) Net gains (losses) on qualifying hedging relationships 17,312 (9,865 ) (10,072 ) Amortization/accretion of discontinued hedging relationships (444 ) — (75 ) Net gains (losses) on derivatives and hedging activities recorded in net interest income $ 16,868 $ (9,865 ) $ (10,147 ) _______________________ (1) Relates to derivatives for which variation margin payments are characterized as daily settled contracts. (2) Represents interest income/expense on derivatives in qualifying fair-value hedging relationships. Net interest settlements on derivatives that are not in qualifying fair-value hedging relationships are reported in other income. (3) Excludes the interest income/expense of the respective hedged items recorded in net interest income. Tables 7.3 presents the net gains (losses) on qualifying cash flow hedging relationships. Table 7.3 - Net Gains (Losses) on Cash Flow Hedging Relationships (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Forward-start interest rate swaps - CO Bonds Losses reclassified from accumulated other comprehensive loss into interest expense $ (1,757 ) $ (786 ) Losses recognized in other comprehensive income (1,125 ) (3,379 ) For the three months ended March 31, 2020 and 2019 , there were no reclassifications from accumulated other comprehensive loss into earnings as a result of the discontinuance of cash-flow hedges because the original forecasted transactions were not expected to occur by the end of the originally specified time period or within a two-month period thereafter. As of March 31, 2020 , the maximum length of time over which we are hedging our exposure to the variability in future cash flows for forecasted transactions is one year . As of March 31, 2020 , the amount of deferred net losses on derivatives accumulated in other comprehensive loss related to cash flow hedges expected to be reclassified to earnings during the next 12 months is $6.8 million . Table 7.4 - Cumulative Basis Adjustments for Fair-Value Hedges (dollars in thousands) March 31, 2020 Line Item in Statement of Condition of Hedged Item Amortized Cost of Hedged Asset/ Liability (1) Basis Adjustments for Active Hedging Relationships Included in Amortized Cost Basis Adjustments for Discontinued Hedging Relationships Included in Amortized Cost Cumulative Amount of Fair Value Hedging Basis Adjustments Advances $ 6,241,203 $ 187,480 $ 10,505 $ 197,985 Available-for-sale securities 4,419,656 595,088 — 595,088 Consolidated bonds 3,130,935 59,218 41,687 100,905 _______________________ (1) Includes only the portion of amortized cost representing the hedged items in fair-value hedging relationships. Table 7.5 - Net Gains and Losses on Derivatives not Designated as Hedging Instruments (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Interest-rate swaps $ (52,569 ) $ (60 ) Mortgage-delivery commitments (62 ) 608 Price alignment interest (1) 73 — Net (losses) gains on derivatives not designated as hedging instruments $ (52,558 ) $ 548 ______________________ (1) Relates to derivatives for which variation margin payments are characterized as daily settled contracts. Managing Credit Risk on Derivatives. We enter into derivatives that we clear (cleared derivatives) with a derivatives clearing organization (DCO), our counterparty for such derivatives. We also enter into derivatives that are not cleared (uncleared derivatives) under master-netting agreements. Certain of our uncleared derivatives master-netting agreements contain provisions that require us to post additional collateral with our uncleared derivatives counterparties if our credit ratings are lowered. Under the terms that govern such agreements, if our credit rating is lowered by Moody's or S&P to a certain level, we are required to deliver additional collateral on uncleared derivatives in a net liability position. In the event of a split between such credit ratings, the lower rating governs. The aggregate fair value of all uncleared derivatives with these provisions that were in a net-liability position (before cash collateral and related accrued interest) at March 31, 2020 , was $88.3 million for which we had delivered collateral with a post-haircut value of $86.2 million in accordance with the terms of the master-netting agreements. Securities collateral is subject to valuation haircuts in accordance with the terms of the master-netting arrangements. Table 7.6 sets forth the post-haircut value of incremental collateral that certain uncleared derivatives counterparties could have required us to deliver based on incremental credit rating downgrades at March 31, 2020 . Table 7.6 - Post Haircut Value of Incremental Collateral to be Delivered as of March 31, 2020 (dollars in thousands) Ratings Downgrade (1) From To Incremental Collateral AA+ AA or AA- $ 579 AA- A+, A or A- — A- below A- 7,513 _______________________ (1) Ratings are expressed in this table according to S&P's conventions but include the equivalent of such rating by Moody's. If there is a split rating, the lower rating is used. Cleared Derivatives. For cleared derivatives, the DCO is our counterparty. The DCO notifies the clearing member of the required initial and variation margin and our agent (clearing member) in turn notifies us. We utilize two DCOs, for all cleared derivative transactions, Chicago Mercantile Exchange, Inc. (CME Inc.) and LCH Limited (LCH Ltd.). Based upon their rulebooks, we characterize variation margin payments as daily settlement payments, rather than as collateral. At both DCOs, posted initial margin is considered collateral. We post initial margin and exchange variation margin through a clearing member which acts as our agent to the DCO and which guarantees our performance to the DCO, subject to the terms of relevant agreements. These arrangements expose us to credit risk in the event that one of our clearing members or one of the DCOs fails to meet its obligations. The use of cleared derivatives is intended to mitigate credit risk exposure because the DCO, which is fully secured at all times through margin received from its clearing members, is substituted for the credit risk exposure of individual counterparties in uncleared derivatives, and collateral is posted at least once daily for changes in the fair value of cleared derivatives through a clearing member. For cleared derivatives, the DCO determines initial margin requirements. We clear our trades via clearing members of the DCOs. These clearing members who act as our agent to the DCOs are the U.S. Commodity Futures Trading Commission (CFTC)-registered futures commission merchants. Our clearing members may require us to post margin in excess of DCO requirements based on our credit or other considerations, including but not limited to, credit rating downgrades. We were not required to post any such excess margin by our clearing members based on credit considerations at March 31, 2020 . Impacts on Statement of Cash Flows . Due to declines in market values of cleared derivatives during the three months ended March 31, 2020 , there was an increase in variation margin posted on cleared derivatives to the DCOs totaling $480.4 million . On the statement of cash flows, $373.3 million of the variation margin cash payment is included in net change in derivatives and hedging activities, as an operating activity, while $107.1 million of the variation margin cash payment is included in net payments on derivatives with a financing element, as a financing activity. During the three months ended March 31, 2019 , we terminated certain uncleared interest-rate exchange agreements with a total notional amount of $611.9 million which were indexed to three-month LIBOR on the floating leg of the swaps. The net fair value of these derivative transactions, from our perspective, was $(251.5) million , which was transferred to the bilateral counterparty upon termination, and securities collateral that we had pledged against this obligation was returned to us. This cash payment is included in net change in derivatives and hedging activities, as an operating activity in the statement of cash flows. Simultaneously with the termination of these derivatives, we entered into replacement interest-rate exchange agreements (the replacement derivatives) having the same notional amount of $611.9 million and which are indexed to the OIS rate based on the federal funds effective rate on the floating leg of the swaps. Upon settlement of the replacement derivatives, the Bank received an initial upfront payment of $251.5 million . The replacement derivatives are cleared through a DCO, which called for variation margin to be delivered. Because the replacement derivatives include off-market terms and this large initial upfront payment, all payments for the replacement derivatives are classified as net payments on derivative contracts with a financing element, within the financing activities section of the statement of cash flows. Offsetting of Certain Derivatives. We present derivatives, any related cash collateral received or pledged, and associated accrued interest, on a net basis by counterparty. We have analyzed the rights, rules, and regulations governing our cleared and non-cleared derivatives and determined that those rights, rules, and regulations should result in a net claim with each of our counterparties (which, in the context of cleared derivatives is through each of our clearing members with the related DCO) upon an event of default (solely in the case of non-cleared derivatives) or the bankruptcy, insolvency or a similar proceeding involving our counterparty (and/or one of our clearing members, in the case of cleared derivatives). For this purpose, "net claim" generally means a single net amount reflecting the aggregation of all amounts indirectly owed by us to the relevant counterparty and indirectly payable to us from the relevant counterparty. Table 7.7 presents separately the fair value of derivatives that are subject to netting due to a legal right of offset based on the terms of our master netting arrangements or similar agreements as of March 31, 2020 , and December 31, 2019 , and the fair value of derivatives that are not subject to such netting. Derivatives subject to netting include any related cash collateral received from or pledged to counterparties. Table 7.7 - Netting of Derivative Assets and Derivative Liabilities (dollars in thousands) March 31, 2020 Derivative Instruments Meeting Netting Requirements Non-cash Collateral (Received) or Pledged Not Offset (2) Gross Recognized Amount Gross Amounts of Netting Adjustments (1) Mortgage Delivery Commitments Total Derivative Assets and Total Derivative Liabilities Can Be Sold or Repledged Cannot Be Sold or Repledged Net Amount Derivative Assets Uncleared $ 13,187 $ (13,187 ) $ 147 $ 147 $ — $ — $ 147 Cleared 17,526 210,047 227,573 — — 227,573 Total $ 227,720 $ 227,720 Derivative Liabilities Uncleared $ (100,449 ) $ 76,740 $ (695 ) $ (24,404 ) $ — $ 21,442 $ (2,962 ) Cleared (3,506 ) 3,506 — — — — Total $ (24,404 ) $ (2,962 ) _______________________ (1) Includes gross amounts of netting adjustments and cash collateral. (2) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At March 31, 2020 , we had additional net credit exposure of $158 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position. December 31, 2019 Derivative Instruments Meeting Netting Requirements Non-cash Collateral (Received) or Pledged Not Offset (2) Gross Recognized Amount Gross Amounts of Netting Adjustments (1) Mortgage Delivery Commitments Total Derivative Assets and Total Derivative Liabilities Can Be Sold or Repledged Cannot Be Sold or Repledged Net Amount Derivative Assets Uncleared $ 4,950 $ (3,519 ) $ 227 $ 1,658 $ (995 ) $ — $ 663 Cleared 10,152 147,921 158,073 — — 158,073 Total $ 159,731 $ 158,736 Derivative Liabilities Uncleared $ (42,199 ) $ 31,928 $ — $ (10,271 ) $ 82 $ 9,333 $ (856 ) Cleared (1,606 ) 1,606 — — — — Total $ (10,271 ) $ (856 ) _______________________ (1) Includes gross amounts of netting adjustments and cash collateral. (2) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At December 31, 2019 , we had additional net credit exposure of $300 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.

Deposits

Deposits	3 Months Ended
	Mar. 31, 2020
Deposits [Abstract]
Deposits [Text Block]	Deposits We offer demand, overnight and term deposits for members and qualifying nonmembers. Members that service mortgage loans may deposit funds collected in connection with mortgage loans pending disbursement of such funds to the owners of the mortgage loans, which we classify as "other" in the following table. Table 8.1 - Deposits (dollars in thousands) March 31, 2020 December 31, 2019 Interest-bearing Demand and overnight $ 782,943 $ 613,143 Term 1,200 800 Other 1,639 2,589 Noninterest-bearing Other 74,034 57,777 Total deposits $ 859,816 $ 674,309

Consolidated Obligations

Consolidated Obligations	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Consolidated Obligations [Text Block]	Consolidated Obligations CO Bonds. CO bonds for which we have received issuance proceeds and are primarily liable were as follows: Table 9.1 - CO Bonds Outstanding by Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Amount Weighted Average Rate (1) Amount Weighted Average Rate (1) Due in one year or less $ 11,488,560 1.13 % $ 9,455,725 2.03 % Due after one year through two years 4,990,405 1.80 6,442,960 2.02 Due after two years through three years 2,269,475 2.07 2,154,920 2.18 Due after three years through four years 1,211,550 2.47 1,319,915 2.45 Due after four years through five years 1,474,280 2.40 1,211,080 2.48 Thereafter 2,978,540 3.43 3,220,205 3.33 Total par value 24,412,810 1.78 % 23,804,805 2.26 % Premiums 74,030 63,056 Discounts (11,159 ) (11,434 ) Hedging adjustments 100,905 32,066 Total $ 24,576,586 $ 23,888,493 _______________________ (1) The CO bonds' weighted-average rate excludes concession fees. Table 9.2 - CO Bonds Outstanding by Call Feature (dollars in thousands) Par Value of CO bonds March 31, 2020 December 31, 2019 Noncallable and nonputable $ 21,805,810 $ 20,954,805 Callable 2,607,000 2,850,000 Total par value $ 24,412,810 $ 23,804,805 Table 9.3 - CO Bonds Outstanding by Contractual Maturity or Next Call Date (dollars in thousands) March 31, 2020 December 31, 2019 Due in one year or less $ 13,165,560 $ 11,297,725 Due after one year through two years 5,055,405 6,432,960 Due after two years through three years 2,189,475 2,019,920 Due after three years through four years 1,209,550 1,332,915 Due after four years through five years 1,134,280 926,080 Thereafter 1,658,540 1,795,205 Total par value $ 24,412,810 $ 23,804,805 Table 9.4 - CO Bonds by Interest Rate-Payment Type (dollars in thousands) Par Value of CO bonds March 31, 2020 December 31, 2019 Fixed-rate $ 17,068,810 $ 17,681,805 Simple variable-rate 6,959,000 5,568,000 Step-up (1) 385,000 555,000 Total par value $ 24,412,810 $ 23,804,805 _______________________ (1) Step-up bonds pay interest at increasing fixed rates for specified intervals over the life of the CO bond and can be called at our option on the step-up dates. CO Discount Notes. Outstanding CO discount notes for which we were primarily liable, all of which are due within one year, were as follows: Table 9.5 - CO Discount Notes Outstanding (dollars in thousands) Book Value Par Value Weighted Average Rate (1) March 31, 2020 $ 39,692,253 $ 39,743,071 1.10 % December 31, 2019 $ 27,681,169 $ 27,733,146 1.59 % _______________________ (1) The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable Housing Program

Affordable Housing Program	3 Months Ended
	Mar. 31, 2020
Affordable Housing Program [Abstract]
Affordable Housing Program [Text Block]	Affordable Housing Program Table 10.1 - AHP Liability (dollars in thousands) March 31, 2020 December 31, 2019 Balance at beginning of period $ 86,131 $ 83,965 AHP expense for the period 4,636 21,302 AHP direct grant disbursements (4,672 ) (15,723 ) AHP subsidy for AHP advance disbursements (1,026 ) (3,450 ) Return of previously disbursed grants and subsidies 13 37 Balance at end of period $ 85,082 $ 86,131

Capital

Capital	3 Months Ended
	Mar. 31, 2020
Capital [Abstract]
Capital [Text Block]	Capital We are subject to capital requirements under our capital plan, the FHLBank Act, and FHFA regulations and guidance: 1. Risk-based capital. We are required to maintain at all times permanent capital, defined as Class B stock, including Class B stock classified as mandatorily redeemable capital stock, and retained earnings, in an amount at least equal to the sum of our credit-risk capital requirement, market-risk capital requirement, and operations-risk capital requirement, calculated in accordance with FHFA rules and regulations, referred to herein as the risk-based capital requirement. Only permanent capital satisfies the risk-based capital requirement. 2. Total regulatory capital. We are required to maintain at all times a total capital-to-assets ratio of at least four percent . Total regulatory capital is the sum of permanent capital, the amount paid-in for Class A stock, the amount of any general loss allowance if consistent with GAAP and not established for specific assets, and other amounts from sources determined by the FHFA as available to absorb losses. We have never issued Class A stock. 3. Leverage capital. We are required to maintain at all times a leverage capital-to-assets ratio of at least five percent . Leverage capital is defined as the sum of permanent capital weighted 1.5 times and all other capital without a weighting factor. The FHFA has authority to require us to maintain a greater amount of permanent capital than is required as defined by the risk-based capital requirements. Table 11.1 - Regulatory Capital Requirements (dollars in thousands) Risk-Based Capital Requirements March 31, December 31, Permanent capital Class B capital stock $ 2,266,329 $ 1,869,130 Mandatorily redeemable capital stock 6,112 5,806 Retained earnings 1,473,149 1,463,154 Total permanent capital $ 3,745,590 $ 3,338,090 Risk-based capital requirement Credit-risk capital $ 212,510 $ 235,213 Market-risk capital 155,678 207,426 Operations-risk capital 110,456 132,792 Total risk-based capital requirement $ 478,644 $ 575,431 Permanent capital in excess of risk-based capital requirement $ 3,266,946 $ 2,762,659 March 31, 2020 December 31, 2019 Required Actual Required Actual Capital Ratio Risk-based capital $ 478,644 $ 3,745,590 $ 575,431 $ 3,338,090 Total regulatory capital $ 2,756,035 $ 3,745,590 $ 2,226,512 $ 3,338,090 Total capital-to-asset ratio 4.0 % 5.4 % 4.0 % 6.0 % Leverage Ratio Leverage capital $ 3,445,043 $ 5,618,385 $ 2,783,141 $ 5,007,135 Leverage capital-to-assets ratio 5.0 % 8.2 % 5.0 % 9.0 % We are a cooperative whose members own most of our capital stock. Former members (including certain nonmembers that own our capital stock as a result of merger or acquisition, relocation, or involuntary termination of membership) own the remaining capital stock to support business transactions still carried on our statement of condition. Shares of capital stock cannot be purchased or sold except between us and our members at $100 per share par value. We have only issued Class B stock and each member is required to purchase Class B stock equal to the sum of 0.20 percent of certain member assets eligible (provided that this amount is not less than $10 thousand nor more than $10.0 million ) to secure advances under the FHLBank Act (the membership stock investment requirement), and 3.00 percent for overnight advances, 4.00 percent for all other advances, and 0.25 percent for outstanding letters of credit (collectively, the activity-based stock-investment requirement). Prior to January 16, 2019, the membership stock investment requirement was equal to 0.35 percent of certain member assets eligible to secure advances under the FHLBank Act (provided that this amount was not less than $10 thousand nor more than $25.0 million ).

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2020
AOCI Attributable to Parent [Abstract]
Accumulated Other Comprehensive Loss [Text Block]	Accumulated Other Comprehensive Loss Table 12.1 - Accumulated Other Comprehensive Loss (dollars in thousands) Net Unrealized Loss on Available-for-sale Securities Noncredit Portion of Other-than-temporary Impairment Losses on Held-to-maturity Securities Net Unrealized Loss Relating to Hedging Activities Pension and Postretirement Benefits Total Balance, December 31, 2018 $ (152,958 ) $ (129,154 ) $ (29,119 ) $ (5,276 ) $ (316,507 ) Cumulative effect of change in accounting principle — — (175 ) — (175 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 34,065 — (3,379 ) — 30,686 Noncredit other-than-temporary impairment losses — (80 ) — — (80 ) Accretion of noncredit loss — 6,291 — — 6,291 Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 30 — — 30 Amortization - hedging activities (2) — — 786 — 786 Amortization - pension and postretirement benefits (3) — — — 161 161 Other comprehensive income (loss) 34,065 6,241 (2,593 ) 161 37,874 Balance, March 31, 2019 $ (118,893 ) $ (122,913 ) $ (31,887 ) $ (5,115 ) $ (278,808 ) Balance, December 31, 2019 $ (73,922 ) $ (76,036 ) $ (30,207 ) $ (6,807 ) $ (186,972 ) Other comprehensive (loss) income before reclassifications: Net unrealized losses (85,737 ) — (1,125 ) — (86,862 ) Noncredit losses included in basis of securities sold — 20,239 — — 20,239 Accretion of noncredit loss — 2,805 — — 2,805 Net actuarial loss — — — 501 501 Reclassifications from other comprehensive income to net income Amortization - hedging activities (2) — — 1,757 — 1,757 Amortization - pension and postretirement benefits (3) — — — 295 295 Other comprehensive (loss) income (85,737 ) 23,044 632 796 (61,265 ) Balance, March 31, 2020 $ (159,659 ) $ (52,992 ) $ (29,575 ) $ (6,011 ) $ (248,237 ) _______________________ (1) Recorded in other income (loss) in the statement of operations. (2) Recorded in CO bond interest expense. (3) Recorded in other expenses in the statement of operations.

Fair Values

Fair Values	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value [Text Block]	Fair Values A fair-value hierarchy is used to prioritize the inputs of valuation techniques used to measure fair value. A description of the application of the fair-value hierarchy, valuation techniques, and significant inputs is disclosed in Part II — Item 8 — Financial Statements and Supplementary Data — Note 19 — Fair Values in the 2019 Annual Report. There have been no material changes in the fair-value hierarchy classification of financial assets and liabilities, valuation techniques, or significant inputs during the three months ended March 31, 2020 . Table 13.1 presents the carrying value, fair value, and fair value hierarchy of our financial assets and liabilities at March 31, 2020 , and December 31, 2019 . We record trading securities, available-for-sale securities, derivative assets, derivative liabilities, and certain other assets at fair value on a recurring basis, and certain mortgage loans and certain other assets at fair value on a non-recurring basis. We record all other financial assets and liabilities at amortized cost. Refer to Table 13.2 for further details about the financial assets and liabilities held at fair value on either a recurring or non-recurring basis. Table 13.1 - Fair Value Summary (dollars in thousands) March 31, 2020 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral (2) Financial instruments Assets: Cash and due from banks $ 806,985 $ 806,985 $ 806,985 $ — $ — $ — Interest-bearing deposits 1,130,563 1,130,563 1,130,563 — — — Securities purchased under agreements to resell 2,000,000 1,999,954 — 1,999,954 — — Federal funds sold 3,455,000 3,454,927 — 3,454,927 — — Trading securities (1) 3,563,368 3,563,368 — 3,563,368 — — Available-for-sale securities (1) 7,246,334 7,246,334 — 7,180,939 65,395 — Held-to-maturity securities 676,888 733,970 — 384,446 349,524 — Advances 45,076,223 45,434,302 — 45,434,302 — — Mortgage loans, net 4,528,474 4,766,735 — 4,747,540 19,195 — Accrued interest receivable 109,878 109,878 — 109,878 — — Derivative assets (1) 227,720 227,720 — 30,859 — 196,861 Other assets (1) 30,926 30,926 16,238 14,688 — — Liabilities: Deposits (859,816 ) (859,815 ) — (859,815 ) — — COs: Bonds (24,576,586 ) (25,122,573 ) — (25,122,573 ) — — Discount notes (39,692,253 ) (39,735,774 ) — (39,735,774 ) — — Mandatorily redeemable capital stock (6,112 ) (6,112 ) (6,112 ) — — — Accrued interest payable (108,010 ) (108,010 ) — (108,010 ) — — Derivative liabilities (1) (24,404 ) (24,404 ) — (104,649 ) — 80,245 Other: Commitments to extend credit for advances — (2,623 ) — (2,623 ) — — Standby letters of credit (1,540 ) (1,540 ) — (1,540 ) — — December 31, 2019 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral (2) Financial instruments Assets: Cash and due from banks $ 69,416 $ 69,416 $ 69,416 $ — $ — $ — Interest-bearing deposits 1,253,873 1,253,873 1,253,873 — — — Securities purchased under agreements to resell 3,500,000 3,500,003 — 3,500,003 — — Federal funds sold 860,000 859,999 — 859,999 — — Trading securities (1) 2,250,264 2,250,264 — 2,250,264 — — Available-for-sale securities (1) 7,409,000 7,409,000 — 7,344,348 64,652 — Held-to-maturity securities 871,107 1,035,410 — 456,942 578,468 — Advances 34,595,363 34,735,775 — 34,735,775 — — Mortgage loans, net 4,501,251 4,634,141 — 4,615,737 18,404 — Accrued interest receivable 112,163 112,163 — 112,163 — — Derivative assets (1) 159,731 159,731 — 15,329 — 144,402 Other assets (1) 31,939 31,939 13,894 18,045 — — Liabilities: Deposits (674,309 ) (674,269 ) — (674,269 ) — — COs: Bonds (23,888,493 ) (24,226,123 ) — (24,226,123 ) — — Discount notes (27,681,169 ) (27,681,470 ) — (27,681,470 ) — — Mandatorily redeemable capital stock (5,806 ) (5,806 ) (5,806 ) — — — Accrued interest payable (104,477 ) (104,477 ) — (104,477 ) — — Derivative liabilities (1) (10,271 ) (10,271 ) — (43,805 ) — 33,534 Other: Commitments to extend credit for advances — (3,884 ) — (3,884 ) — — Standby letters of credit (1,723 ) (1,723 ) — (1,723 ) — — _______________________ (1) Carried at fair value and measured on a recurring basis. (2) These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty. Fair Value Measured on a Recurring and Nonrecurring Basis. Table 13.2 - Fair Value of Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (dollars in thousands) March 31, 2020 Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral (1) Total Assets: Carried at fair value on a recurring basis Trading securities: Corporate bonds $ — $ 5,330 $ — $ — $ 5,330 U.S. Treasury obligations — 3,554,179 — — 3,554,179 U.S. government-guaranteed – single-family MBS — 3,794 — — 3,794 GSE – single-family MBS — 65 — — 65 Total trading securities — 3,563,368 — — 3,563,368 Available-for-sale securities: HFA securities — — 65,395 — 65,395 Supranational institutions — 438,284 — — 438,284 U.S. government-owned corporations — 314,724 — — 314,724 GSE — 133,789 — — 133,789 U.S. government guaranteed – single-family MBS — 52,586 — — 52,586 U.S. government guaranteed – multifamily MBS — 248,428 — — 248,428 GSE – single-family MBS — 2,342,640 — — 2,342,640 GSE – multifamily MBS — 3,650,488 — — 3,650,488 Total available-for-sale securities — 7,180,939 65,395 — 7,246,334 Derivative assets: Interest-rate-exchange agreements — 30,712 — 196,861 227,573 Mortgage delivery commitments — 147 — — 147 Total derivative assets — 30,859 — 196,861 227,720 Other assets 16,238 14,688 — — 30,926 Total assets carried at fair value on a recurring basis $ 16,238 $ 10,789,854 $ 65,395 $ 196,861 $ 11,068,348 Carried at fair value on a nonrecurring basis (2) Mortgage loans held for portfolio $ — $ — $ 1,269 $ — $ 1,269 REO — — 110 — 110 Total assets carried at fair value on a nonrecurring basis $ — $ — $ 1,379 $ — $ 1,379 Liabilities: Carried at fair value on a recurring basis Derivative liabilities Interest-rate-exchange agreements $ — $ (103,954 ) $ — $ 80,245 $ (23,709 ) Mortgage delivery commitments — (695 ) — — (695 ) Total liabilities carried at fair value on a recurring basis $ — $ (104,649 ) $ — $ 80,245 $ (24,404 ) December 31, 2019 Level 1 Level 2 Level 3 Netting (1) Total Assets: Carried at fair value on a recurring basis Trading securities: Corporate bonds $ — $ 5,896 $ — $ — $ 5,896 U.S. Treasury obligations — 2,240,236 — — 2,240,236 U.S. government guaranteed – single-family MBS — 4,047 — — 4,047 GSE – single-family MBS — 85 — — 85 Total trading securities — 2,250,264 — — 2,250,264 Available-for-sale securities: HFA securities — — 64,652 — 64,652 Supranational institutions — 416,429 — — 416,429 U.S. government-owned corporations — 296,761 — — 296,761 GSE — 123,786 — — 123,786 U.S. government guaranteed – single-family MBS — 57,714 — — 57,714 U.S. government guaranteed – multifamily MBS — 282,617 — — 282,617 GSE – single-family MBS — 2,590,271 — — 2,590,271 GSE – multifamily MBS — 3,576,770 — — 3,576,770 Total available-for-sale securities — 7,344,348 64,652 — 7,409,000 Derivative assets: Interest-rate-exchange agreements — 15,102 — 144,402 159,504 Mortgage delivery commitments — 227 — — 227 Total derivative assets — 15,329 — 144,402 159,731 Other assets 13,894 18,045 — — 31,939 Total assets carried at fair value on a recurring basis $ 13,894 $ 9,627,986 $ 64,652 $ 144,402 $ 9,850,934 Carried at fair value on a nonrecurring basis (2) Held-to-maturity securities: Private-label MBS $ — $ — $ 6,856 $ — $ 6,856 Mortgage loans held for portfolio — — 1,198 — 1,198 REO — — 78 — 78 Total assets carried at fair value on a nonrecurring basis $ — $ — $ 8,132 $ — $ 8,132 Liabilities: Carried at fair value on a recurring basis Derivative liabilities Interest-rate-exchange agreements $ — $ (43,805 ) $ — $ 33,534 $ (10,271 ) Total liabilities carried at fair value on a recurring basis $ — $ (43,805 ) $ — $ 33,534 $ (10,271 ) _______________________ (1) These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty. (2) We measure certain held-to-maturity investment securities, mortgage loans held for portfolio, and REO at fair value on a nonrecurring basis, that is, they are not measured at fair value on an ongoing basis but are subject to fair-value adjustments only in certain circumstances. The fair values presented are as of the date the fair value adjustment was recorded. Table 13.3 presents a reconciliation of available-for-sale securities that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the three months ended March 31, 2020 and 2019 . Table 13.3 - Roll Forward of Level 3 Available-for-Sale Securities (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Balance at beginning of period $ 64,652 $ 49,601 Unrealized gains included in other comprehensive income 743 747 Balance at end of period $ 65,395 $ 50,348

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies [Text Block]	Commitments and Contingencies Joint and Several Liability. COs are backed by the financial resources of the FHLBanks. The FHFA has authority to require any FHLBank to repay all or a portion of the principal and interest on COs for which another FHLBank is the primary obligor. No FHLBank has ever been asked or required to repay the principal or interest on any CO on behalf of another FHLBank. We evaluate the financial condition of the other FHLBanks primarily based on known regulatory actions, publicly available financial information, and individual long-term credit-rating action as of each period-end presented. Based on this evaluation, as of March 31, 2020 , and through the filing of this report, we do not believe it is likely that we will be required to repay the principal or interest on any CO on behalf of another FHLBank. We have considered applicable FASB guidance and determined it is not necessary to recognize a liability for the fair value of our joint and several liability for all of the COs. The joint and several obligation is mandated by the FHLBank Act, as implemented by FHFA regulations, and is not the result of an arms-length transaction among the FHLBanks. The FHLBanks have no control over the amount of the guaranty or the determination of how each FHLBank would perform under the joint and several obligation. Because the FHLBanks are subject to the authority of the FHFA as it relates to decisions involving the allocation of the joint and several liability for the FHLBanks' COs, the FHLBanks' joint and several obligation is excluded from the initial recognition and measurement provisions. Accordingly, we have not recognized a liability for our joint and several obligation related to other FHLBanks' COs at March 31, 2020 , and December 31, 2019 . The par amounts of other FHLBanks' outstanding COs for which we are jointly and severally liable totaled $ 1.1 trillion and $974.4 billion at March 31, 2020 , and December 31, 2019 , respectively. See Note 9 — Consolidated Obligations for additional information. Off-Balance-Sheet Commitments Table 14.1 - Off-Balance Sheet Commitments (1) (dollars in thousands) March 31, 2020 December 31, 2019 Expire within one year Expire after one year Total Expire within one year Expire after one year Total Standby letters of credit outstanding (2) $ 7,468,699 $ 216,679 $ 7,685,378 $ 7,484,754 $ 215,014 $ 7,699,768 Commitments for unused lines of credit - advances (3) 1,134,788 — 1,134,788 1,143,828 — 1,143,828 Commitments to make additional advances 277,891 70,320 348,211 434,253 88,167 522,420 Commitments to invest in mortgage loans 98,765 — 98,765 49,911 — 49,911 Unsettled CO bonds, at par 711,500 — 711,500 — — — Unsettled CO discount notes, at par 1,227,230 — 1,227,230 500,000 — 500,000 __________________________ (1) We have deemed it unnecessary to record any liability for credit losses on these agreements. (2) The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year. At March 31, 2020 , and December 31, 2019 , these amounts totaled $ 11.5 million and $27.2 million , respectively. Also excluded are commitments to issue standby letters of credit that expire after one year totaling $550 thousand and $1.8 million at March 31, 2020 , and December 31, 2019 , respectively. (3) Commitments for unused line-of-credit advances are generally for periods of up to 12 months . Since many of these commitments are not expected to be drawn upon, the total commitment amount does not necessarily indicate future liquidity requirements. Standby Letters of Credit. We issue standby letters of credit on behalf of our members to support certain obligations of the members to third-party beneficiaries. These standby letters of credit are subject to the same collateralization and borrowing limits that are applicable to advances. Standby letters of credit may be offered to assist members in facilitating residential housing finance, community lending, and asset-liability management, and to provide liquidity. In particular, members often use standby letters of credit as collateral for deposits from state and local government agencies. Standby letters of credit are executed for members for a fee. If we are required to make payment for a beneficiary's draw, our strategy is to take prompt action to recover the funds paid to the third-party beneficiary, including converting the payment amount into a collateralized advance to the primary obligor, withdrawing the payment amount from the primary obligor's demand deposit account with us, or selling collateral pledged by the primary obligor in a commercially reasonable manner to offset the payment amount. Historically, standby letters of credit usually expire without being drawn upon. At March 31, 2020 , the terms of these standby letters of credit have original expiration periods of up to 20 years , expiring no later than 2027 . Currently, we offer new standby letters of credit with expiration periods of up to 10 years . Unearned fees for the value of the guarantees related to standby letters of credit are recorded in other liabilities and totaled $1.5 million and $1.7 million at March 31, 2020 , and December 31, 2019 , respectively. Commitments to Invest in Mortgage Loans. Commitments to invest in mortgage loans are generally for periods not to exceed 60 business days. Such commitments are recorded as derivatives at their fair values on the statement of condition. Pledged Collateral. We have pledged securities as collateral related to derivatives. See Note 7 — Derivatives and Hedging Activities for additional information about our pledged collateral and other credit-risk-related contingent features. Legal Proceedings . We are subject to various legal proceedings arising in the normal course of business from time to time. We would record an accrual for a loss contingency when it is probable that a loss has been incurred and the amount can be reasonably estimated. Management does not anticipate that the ultimate liability, if any, arising out of these matters will have a material effect on our financial condition, results of operations, or cash flows.

Transactions with Shareholders

Transactions with Shareholders	3 Months Ended
	Mar. 31, 2020
Transactions with Shareholders [Abstract]
Transactions with Shareholders [Text Block]	Transactions with Shareholders . Shareholder Concentrations. We consider shareholder concentrations as members or nonmembers whose capital stock holdings (including mandatorily redeemable capital stock) are in excess of 10 percent of total capital stock outstanding at March 31, 2020 . Table 15.1 - Shareholder Concentrations, Balance Sheet (dollars in thousands) Capital Stock Outstanding Percent of Total Capital Stock Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances March 31, 2020 Citizens Bank, N.A. $ 342,580 15.1 % $ 8,005,678 17.8 % $ 1,072 2.3 % December 31, 2019 Citizens Bank, N.A. $ 222,684 11.9 % $ 5,005,773 14.5 % $ 1,678 3.5 % We held sufficient collateral to support the advances to the above institution such that we do not expect to incur any credit losses on these advances. Table 15.2 - Shareholder Concentrations, Income Statement (dollars in thousands) Interest Income on Advances Percent of Total Advances Interest Income Fees on Letters of Credit Percent of Total Fees on Letters of Credit Citizens Bank, N.A. For the three months ended March 31, 2020 $ 23,750 14.1 % $ 1,586 61.8 % For the three months ended March 31, 2019 $ 39,113 15.8 % $ 1,878 81.4 % Transactions with Directors' Institutions. We provide, in the ordinary course of business, products and services to members whose officers or directors serve on our board of directors. In accordance with FHFA regulations, transactions with directors' institutions are conducted on the same terms as those with any other member. Table 15.3 - Transactions with Directors' Institutions (dollars in thousands) Capital Stock Outstanding Percent of Total Capital Stock Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances March 31, 2020 $ 452,365 19.9 % $ 10,137,669 22.6 % $ 4,120 8.9 % December 31, 2019 112,811 6.0 2,224,141 6.4 3,581 7.4

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On April 24, 2020 , the board of directors declared a cash dividend at an annualized rate of 5.06 percent based on capital stock balances outstanding during the first quarter of 2020 . The dividend, including dividends classified as interest on mandatorily redeemable capital stock, amounted to $24.2 million and was paid on May 4, 2020 .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Credit Loss, Financial Instrument [Policy Text Block]	Credit Losses on Financial Instruments
Investment, Policy [Policy Text Block]	Investment Securities - Available-for-Sale For securities classified as available-for-sale, we evaluate an individual security for impairment on a quarterly basis by comparing the security’s fair value to its amortized cost. Accrued interest receivable is recorded separately on the statements of condition and is not included in the amortized cost basis. Impairment exists when the fair value of the investment is less than its amortized cost. In assessing whether a credit loss exists on an impaired security, we consider whether there would be a shortfall in receiving all cash flows contractually due on the investment. When a shortfall is considered possible, we compare the present value of cash flows to be collected from the security with the amortized cost basis of the security. If the present value of cash flows is less than amortized cost, an allowance-for-credit losses is recorded with a corresponding adjustment to the provision for credit losses. The allowance is limited to the amount of the unrealized loss on the individual security and excludes uncollectible accrued interest receivable, which is measured separately. If management intends to sell an impaired security classified as available-for-sale, or more likely than not will be required to sell the security before expected recovery of its amortized cost basis, any allowance for credit losses is written off and the amortized cost basis is written down to the security’s fair value at the reporting date with any incremental impairment reported in earnings as net gains (losses) on available-for-sale securities. If management does not intend to sell an impaired security classified as available-for-sale and it is not more likely than not that management will be required to sell the debt security, then the credit portion of the difference is recognized as an allowance for credit losses and any remaining difference between the security’s fair value and amortized cost is recorded to net unrealized gains (losses) on available-for-sale securities within other comprehensive income (loss). Investment Securities - Held-to-Maturity Securities that we classified as held-to-maturity are carried at amortized cost, which is original cost net of periodic principal repayments and amortization of premiums and accretion of discounts, adjusted for other-than-temporary impairment losses recorded prior to January 1, 2020. Accrued interest receivable is recorded separately on the statements of condition. Held-to-maturity securities are evaluated quarterly for expected credit losses on a pool basis unless an individual assessment is deemed necessary because the securities do not possess similar risk characteristics. An allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. The allowance for credit losses excludes uncollectible accrued interest receivable, which is measured separately. Prior to January 1, 2020, credit losses were recorded as a direct write-down of the held-to-maturity security carrying value. For improvements in expected future cash flows for held-to-maturity securities impaired prior to January 1, 2020, interest income continues to follow the recognition pattern pursuant to the impairment guidance in effect prior to January 1, 2020. Any additional recoveries of amounts previously written off prior to January 1, 2020, are recorded when received. For any improvements in expected future cash flows for held-to-maturity securities with an allowance for credit losses recognized after the adoption of the new guidance, the allowance for credit losses associated with recoveries may be derecognized up to its full amount immediately in the current period. Interest-Bearing Deposits, Securities Purchased Under Agreements to Resell, and Federal Funds Sold Interest-bearing deposits, securities purchased under agreements to resell, and federal funds sold are evaluated quarterly for expected credit losses. If applicable, an allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. We use the collateral maintenance provision practical expedient for securities purchased under agreements to resell. Consequently, a credit loss would be recognized if there is a collateral shortfall which we do not believe the counterparty will replenish in accordance with its contractual terms. The credit loss would be limited to the difference between the fair value of the collateral and the investment’s amortized cost. Accrued interest receivable is recorded separately on the statements of condition.
Federal Home Loan Bank Advances , Policy	Advances
Financing Receivable, Held-for-investment [Policy Text Block]	Mortgage Loans Held for Portfolio Mortgage loans held for portfolio are recorded at amortized cost, which is original cost, net of periodic principal repayments and amortization of premiums and accretion of discounts, and direct write-downs. Accrued interest receivable is recorded separately on the statements of condition. We perform a quarterly assessment of our mortgage loans held for portfolio to estimate expected credit losses. An allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. We do not purchase mortgage loans with credit deterioration present at the time of purchase. Credit Enhancements. Our allowance for credit losses factors in the credit-enhancements associated with conventional mortgage loans under the MPF program. These credit-enhancements can include primary and/or supplemental mortgage insurance or other kinds of credit enhancement. Potential recoveries from credit enhancements for conventional loans are evaluated at the individual master commitment level to determine the credit-enhancements available to recover losses on loans under each individual master commitment.
Finance, Loan and Lease Receivables, Held-for-investment, Allowance and Nonperforming Loans, Policy [Policy Text Block]	Mortgage Loans Held for Portfolio Mortgage loans held for portfolio are recorded at amortized cost, which is original cost, net of periodic principal repayments and amortization of premiums and accretion of discounts, and direct write-downs. Accrued interest receivable is recorded separately on the statements of condition. We perform a quarterly assessment of our mortgage loans held for portfolio to estimate expected credit losses. An allowance for credit losses is recorded with a corresponding adjustment to the provision for credit losses. We do not purchase mortgage loans with credit deterioration present at the time of purchase. We measure expected credit losses on mortgage loans on a collective basis, pooling loans with similar risk characteristics. If a mortgage loan no longer shares risk characteristics with other loans, it is removed from the pool and evaluated for expected credit losses on an individual basis. In our assessment, we measure the expected loss over the remaining life of a mortgage loan, which considers the mitigation of expected losses through credit enhancements and any expected recoveries. If a loan is purchased at a discount, the discount does not offset the allowance for credit losses. The allowance excludes uncollectible accrued interest receivable, which is reversed out of interest income when a mortgage loan is placed on nonaccrual status. Conventional Mortgage Loans. Conventional loans are evaluated collectively when similar risk characteristics exist. Conventional loans that do not share risk characteristics with other pools are evaluated for expected credit losses on an individual basis. We determine our allowance for credit losses on conventional loans through analyses that include consideration of various loan portfolio and collateral-related characteristics, such as past performance, current conditions, and reasonable and supportable forecasts of expected economic conditions. We use a discounted cash flow model to project our expected losses. We use a third-party model to project cash flows to estimate the expected credit losses over the life of the loans. The model relies on a number of inputs, such as both current and forecasted property values and interest rates as well as historical borrower behavior. We incorporate associated credit enhancements and expected recoveries, if any, to determine our estimate of expected credit losses. Certain conventional loans may be evaluated for credit losses by using the practical expedient for collateral dependent assets. A mortgage loan is considered collateral dependent if repayment is expected to be provided by the sale of the underlying property, that is, if it is considered likely that the borrower will default. We estimate the fair value of this collateral by using a third-party property valuation model. The expected credit loss of a collateral dependent mortgage loan is equal to the difference between the amortized cost of the loan and the estimated fair value of the collateral, less estimated selling costs. We will reserve for these estimated losses or record a direct charge-off of the loan balance if certain triggering criteria are met. Government Mortgage Loans Held for Portfolio. We invest in government mortgage loans secured by one- to four-family residential properties. Government mortgage loans are mortgage loans insured or guaranteed by the Federal Housing Administration (the FHA), the U.S. Department of Veterans Affairs (the VA), the Rural Housing Service of the U.S. Department of Agriculture (RHS), or by the U.S. Department of Housing and Urban Development (HUD). The servicer provides and maintains insurance or a guarantee from the applicable government agency. The servicer is responsible for compliance with all government agency requirements and for obtaining the benefit of the applicable insurance or guaranty with respect to defaulted government-guaranteed mortgage loans. Any losses incurred on these loans that are not recovered from the insurer or guarantor are absorbed by the related servicer. Therefore, we only have credit risk for these loans if the servicer fails to pay for losses not covered by insurance or guarantees. Due to government guarantees or insurance on our government loans, there is no allowance for credit losses for the government mortgage loan portfolio as of March 31, 2020 , and December 31, 2019 . Additionally, these mortgage loans are not placed on nonaccrual status due to the government guarantee or insurance on these loans and the contractual obligation of the loan servicers to repurchase their related loans when certain criteria are met.
Off-Balance-Sheet Credit Exposure, Policy [Policy Text Block]	Off-Balance Sheet Credit Exposures
Derivatives, Policy [Policy Text Block]	Changes in fair value of the derivative hedging instrument and the hedged item attributable to the hedged risk for designated fair-value hedges are recorded in net interest income in the same line as the earnings effect of the hedged item. For designated cash-flow hedges, the entire change in the fair value of the hedging instrument (assuming it is included in the assessment of hedge effectiveness) is reported in other comprehensive income until the hedged transaction affects earnings. At that time, this amount is reclassified from other comprehensive income and recorded in net interest income in the same line as the earnings effect of the hedged item. Managing Credit Risk on Derivatives.
Fair Value of Financial Instruments, Policy [Policy Text Block]	We record trading securities, available-for-sale securities, derivative assets, derivative liabilities, and certain other assets at fair value on a recurring basis, and certain mortgage loans and certain other assets at fair value on a non-recurring basis. We record all other financial assets and liabilities at amortized cost.
Joint and Several Liability Policy [Policy Text Block]	We evaluate the financial condition of the other FHLBanks primarily based on known regulatory actions, publicly available financial information, and individual long-term credit-rating action as of each period-end presented.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block]	Table 4.1 - Trading Securities by Major Security Type (dollars in thousands) March 31, 2020 December 31, 2019 Corporate bonds $ 5,330 $ 5,896 U.S. Treasury obligations 3,554,179 2,240,236 3,559,509 2,246,132 MBS U.S. government-guaranteed – single-family 3,794 4,047 Government-sponsored enterprise (GSE) – single-family 65 85 3,859 4,132 Total $ 3,563,368 $ 2,250,264
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	Table 4.2 - Available-for-Sale Securities by Major Security Type (dollars in thousands) March 31, 2020 Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value State housing-finance-agency obligations (HFA securities) $ 69,320 $ — $ (3,925 ) $ 65,395 Supranational institutions 457,721 — (19,437 ) 438,284 U.S. government-owned corporations 376,711 — (61,987 ) 314,724 GSE 149,068 — (15,279 ) 133,789 1,052,820 — (100,628 ) 952,192 MBS U.S. government guaranteed – single-family 52,820 — (234 ) 52,586 U.S. government guaranteed – multifamily 247,526 917 (15 ) 248,428 GSE – single-family 2,317,683 28,079 (3,122 ) 2,342,640 GSE – multifamily 3,735,144 6,220 (90,876 ) 3,650,488 6,353,173 35,216 (94,247 ) 6,294,142 Total $ 7,405,993 $ 35,216 $ (194,875 ) $ 7,246,334 December 31, 2019 Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value HFA securities $ 69,320 $ — $ (4,668 ) $ 64,652 Supranational institutions 429,354 — (12,925 ) 416,429 U.S. government-owned corporations 323,192 — (26,431 ) 296,761 GSE 130,935 — (7,149 ) 123,786 952,801 — (51,173 ) 901,628 MBS U.S. government guaranteed – single-family 60,003 — (2,289 ) 57,714 U.S. government guaranteed – multifamily 283,674 — (1,057 ) 282,617 GSE – single-family 2,598,325 5,323 (13,377 ) 2,590,271 GSE – multifamily 3,588,119 3,109 (14,458 ) 3,576,770 6,530,121 8,432 (31,181 ) 6,507,372 Total $ 7,482,922 $ 8,432 $ (82,354 ) $ 7,409,000 _______________________ (1) Amortized cost of available-for-sale securities includes adjustments made to the cost basis of an investment for accretion, amortization, collection of cash, and fair-value hedge accounting adjustments. Amortized cost excludes accrued interest receivable of $20.0 million and $27.5 million at March 31, 2020 , and December 31, 2019 .
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block]	Table 4.3 - Available-for-Sale Securities in a Continuous Unrealized Loss Position (dollars in thousands) March 31, 2020 Continuous Unrealized Loss Less than 12 Months Continuous Unrealized Loss 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 12,497 $ (1,323 ) $ 45,298 $ (2,602 ) $ 57,795 $ (3,925 ) Supranational institutions — — 438,284 (19,437 ) 438,284 (19,437 ) U.S. government-owned corporations — — 314,724 (61,987 ) 314,724 (61,987 ) GSE — — 133,789 (15,279 ) 133,789 (15,279 ) 12,497 (1,323 ) 932,095 (99,305 ) 944,592 (100,628 ) MBS U.S. government guaranteed – single-family 1,294 (8 ) 51,292 (226 ) 52,586 (234 ) U.S. government guaranteed – multifamily — — 39,735 (15 ) 39,735 (15 ) GSE – single-family 126,722 (605 ) 397,329 (2,517 ) 524,051 (3,122 ) GSE – multifamily 2,796,682 (87,572 ) 288,652 (3,304 ) 3,085,334 (90,876 ) 2,924,698 (88,185 ) 777,008 (6,062 ) 3,701,706 (94,247 ) Total temporarily impaired $ 2,937,195 $ (89,508 ) $ 1,709,103 $ (105,367 ) $ 4,646,298 $ (194,875 ) December 31, 2019 Continuous Unrealized Loss Less than 12 Months Continuous Unrealized Loss 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 12,229 $ (1,591 ) $ 52,423 $ (3,077 ) $ 64,652 $ (4,668 ) Supranational institutions — — 416,429 (12,925 ) 416,429 (12,925 ) U.S. government-owned corporations — — 296,761 (26,431 ) 296,761 (26,431 ) GSE — — 123,786 (7,149 ) 123,786 (7,149 ) 12,229 (1,591 ) 889,399 (49,582 ) 901,628 (51,173 ) MBS U.S. government guaranteed – single-family 10,885 (1 ) 45,490 (2,288 ) 56,375 (2,289 ) U.S. government guaranteed – multifamily — — 282,617 (1,057 ) 282,617 (1,057 ) GSE – single-family 189,402 (968 ) 1,423,927 (12,409 ) 1,613,329 (13,377 ) GSE – multifamily 1,800,586 (13,242 ) 405,778 (1,216 ) 2,206,364 (14,458 ) 2,000,873 (14,211 ) 2,157,812 (16,970 ) 4,158,685 (31,181 ) Total temporarily impaired $ 2,013,102 $ (15,802 ) $ 3,047,211 $ (66,552 ) $ 5,060,313 $ (82,354 )
Investments Classified by Contractual Maturity Date [Table Text Block]	Table 4.6 - Held-to-Maturity Securities by Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Year of Maturity Amortized Cost Carrying Value (1) Fair Value Amortized Cost Carrying Value (1) Fair Value Due in one year or less $ 3,090 $ 3,090 $ 3,083 $ 3,090 $ 3,090 $ 3,089 Due after one year through five years — — — — — — Due after five years through 10 years 15,405 15,405 14,903 15,405 15,405 15,270 Due after 10 years 61,185 61,185 51,375 68,755 68,755 65,046 79,680 79,680 69,361 87,250 87,250 83,405 MBS (2) 653,967 597,208 664,609 859,892 783,857 952,005 Total $ 733,647 $ 676,888 $ 733,970 $ 947,142 $ 871,107 $ 1,035,410 _______________________ (1) Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss and the allowance for credit losses. (2) MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay their obligations with or without call or prepayment fees. Table 4.4 - Available-for-Sale Securities by Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Year of Maturity Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 7,600 $ 7,600 $ 7,600 $ 7,563 Due after one year through five years 61,720 57,795 61,720 57,089 Due after five years through 10 years 509,594 488,131 477,232 463,465 Due after 10 years 473,906 398,666 406,249 373,511 1,052,820 952,192 952,801 901,628 MBS (1) 6,353,173 6,294,142 6,530,121 6,507,372 Total $ 7,405,993 $ 7,246,334 $ 7,482,922 $ 7,409,000 _______________________ (1) MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay obligations with or without call or prepayment fees.
Debt Securities, Held-to-maturity [Table Text Block]	Table 4.5 - Held-to-Maturity Securities by Major Security Type (dollars in thousands) March 31, 2020 Amortized Cost (1) Allowance for Credit Losses (2) Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss (2) Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value HFA securities $ 79,680 $ — $ — $ 79,680 $ — $ (10,319 ) $ 69,361 MBS U.S. government guaranteed – single-family 6,686 — — 6,686 76 — 6,762 GSE – single-family 281,285 — — 281,285 5,464 (510 ) 286,239 GSE – multifamily 90,927 — — 90,927 518 — 91,445 Private-label 275,069 (3,768 ) (52,991 ) 218,310 62,591 (738 ) 280,163 653,967 (3,768 ) (52,991 ) 597,208 68,649 (1,248 ) 664,609 Total $ 733,647 $ (3,768 ) $ (52,991 ) $ 676,888 $ 68,649 $ (11,567 ) $ 733,970 December 31, 2019 Amortized Cost (1) Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss (2) Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value HFA securities $ 87,250 $ — $ 87,250 $ — $ (3,845 ) $ 83,405 MBS U.S. government guaranteed – single-family 6,987 — 6,987 129 — 7,116 GSE – single-family 303,604 — 303,604 5,197 (246 ) 308,555 GSE – multifamily 140,661 — 140,661 612 (2 ) 141,271 Private-label 408,640 (76,035 ) 332,605 162,904 (446 ) 495,063 859,892 (76,035 ) 783,857 168,842 (694 ) 952,005 Total $ 947,142 $ (76,035 ) $ 871,107 $ 168,842 $ (4,539 ) $ 1,035,410 _______________________ (1) Amortized cost of held-to-maturity securities includes adjustments made to the cost basis of an investment for accretion, amortization, and collection of cash. Amortized cost excludes accrued interest receivable of $1.6 million and $2.0 million at March 31, 2020 , and December 31, 2019 . (2) With the adoption of changes to accounting standards on credit impairment on January 1, 2020, the other-than-temporary impairment approach was replaced with an allowance for credit loss; however, other-than-temporary impairment remains for those securities that had credit impairment prior to the adoption date. See Note 2 — Summary of Significant Accounting Policies and Note 3 — Recently Issued and Adopted Accounting Guidance for further information.
Realized Gain (Loss) on Investments [Table Text Block]	Table 4.7 - Proceeds from Sale and Gains and Losses on Held-to-Maturity Securities (1) (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Proceeds from sale of held-to-maturity securities $ 161,743 $ — Amortized cost of held-to-maturity securities 121,010 — Realized net gain from sale of held-to-maturity securities $ 40,733 $ — _______________________ (1) The securities sold had less than 15 percent of the acquired principal outstanding at the time of the sale. Such sales are treated as maturities for the purposes of security classification. The sale does not impact our ability and intent to hold the remaining investments classified as held-to-maturity through their stated maturity dates.

Advances (Tables)

Advances (Tables)	3 Months Ended
	Mar. 31, 2020
Advances [Abstract]
Advances [Table Text Block]	Table 5.5 - Advances Prepayment Fees (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Prepayment fees received from borrowers $ 838 $ 26,186 Hedging fair-value adjustments on prepaid advances — 527 Net discounts associated with prepaid advances — 218 Advance prepayment fees recognized in income, net $ 838 $ 26,931 Table 5.3 - Advances Outstanding by Year of Contractual Maturity or Next Put Date (dollars in thousands) March 31, 2020 December 31, 2019 Overdrawn demand-deposit accounts $ 2,841 $ 5,101 Due in one year or less 27,048,822 20,240,466 Due after one year through two years 11,616,542 8,603,422 Due after two years through three years 2,119,533 2,001,019 Due after three years through four years 1,248,574 965,814 Due after four years through five years 1,657,924 1,598,254 Thereafter 1,222,166 1,169,811 Total par value $ 44,916,402 $ 34,583,887 Table 5.2 - Advances Outstanding by Year of Contractual Maturity or Next Call Date (dollars in thousands) March 31, 2020 December 31, 2019 Overdrawn demand-deposit accounts $ 2,841 $ 5,101 Due in one year or less 34,501,542 25,116,961 Due after one year through two years 3,328,292 3,450,922 Due after two years through three years 2,300,413 1,949,499 Due after three years through four years 1,266,774 1,461,314 Due after four years through five years 2,173,774 1,309,679 Thereafter 1,342,766 1,290,411 Total par value $ 44,916,402 $ 34,583,887 Table 5.4 - Advances by Current Interest Rate Terms (dollars in thousands) March 31, 2020 December 31, 2019 Fixed-rate $ 35,460,466 $ 28,106,591 Variable-rate 9,455,936 6,477,296 Total par value $ 44,916,402 $ 34,583,887 Table 5.1 - Advances Outstanding by Year of Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Amount Weighted Average Rate Amount Weighted Average Rate Overdrawn demand-deposit accounts $ 2,841 0.57 % $ 5,101 2.05 % Due in one year or less 25,324,147 1.09 18,972,466 1.96 Due after one year through two years 11,478,292 1.05 8,600,922 2.16 Due after two years through three years 2,653,833 2.15 2,200,019 2.16 Due after three years through four years 1,756,774 2.44 1,766,314 2.71 Due after four years through five years 2,335,849 1.75 1,726,754 2.15 Thereafter 1,364,666 2.62 1,312,311 2.68 Total par value 44,916,402 1.28 % 34,583,887 2.10 % Premiums 3,227 3,397 Discounts (41,391 ) (41,744 ) Fair value of bifurcated derivatives (1) 53,783 29,983 Hedging adjustments 144,202 19,840 Total (2) $ 45,076,223 $ 34,595,363 _________________________ (1) At March 31, 2020 , and December 31, 2019 , we had certain advances with embedded features that met the requirements to be separated from the host contract and designated as stand-alone derivatives. (2) Excludes accrued interest receivable of $46.4 million and $48.1 million at March 31, 2020 , and December 31, 2019

Mortgage Loans Held for Portf_2

Mortgage Loans Held for Portfolio (Tables)	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Mortgage Loans Held for Portfolio [Table Text Block]	Table 6.2 - Mortgage Loans Held for Portfolio by Collateral/Guarantee Type (dollars in thousands) March 31, 2020 December 31, 2019 Conventional mortgage loans $ 4,180,145 $ 4,140,255 Government mortgage loans 281,869 292,203 Total par value $ 4,462,014 $ 4,432,458 Table 6.1 - Mortgage Loans Held for Portfolio (dollars in thousands) March 31, 2020 December 31, 2019 Real estate Fixed-rate 15-year single-family mortgages $ 327,700 $ 339,042 Fixed-rate 20- and 30-year single-family mortgages 4,134,314 4,093,416 Premiums 66,933 66,776 Discounts (1,535 ) (1,607 ) Deferred derivative gains, net 4,562 4,124 Total mortgage loans held for portfolio (1) 4,531,974 4,501,751 Less: allowance for credit losses (3,500 ) (500 ) Total mortgage loans, net of allowance for credit losses $ 4,528,474 $ 4,501,251 _________________________ (1) Excludes accrued interest receivable of $23.5 million at both March 31, 2020 , and December 31, 2019 .
Financing Receivable Credit Quality Indicators [Table Text Block]	Table 6.3 - Credit Quality Indicator for Conventional Mortgage Loans (dollars in thousands) March 31, 2020 Origination Year Payment Status at Amortized Cost (1) Prior to 2016 2016 to 2020 Total Past due 30-59 days delinquent $ 14,166 $ 14,575 $ 28,741 Past due 60-89 days delinquent 3,502 3,717 7,219 Past due 90 days or more delinquent 6,830 4,129 10,959 Total past due 24,498 22,421 46,919 Total current loans 1,643,888 2,553,578 4,197,466 Total mortgage loans $ 1,668,386 $ 2,575,999 $ 4,244,385 December 31, 2019 Payment Status at Recorded Investment (1) Conventional Mortgage Loans Past due 30-59 days delinquent $ 36,336 Past due 60-89 days delinquent 6,911 Past due 90 days or more delinquent 10,696 Total past due 53,943 Total current loans 4,171,676 Total mortgage loans $ 4,225,619 _________________________ (1) The amortized cost at March 31, 2020 , excludes accrued interest receivable whereas the recorded investment at December 31, 2019 , includes accrued interest receivable.
Financing Receivable, Past Due [Table Text Block]	Table 6.4 - Other Delinquency Statistics of Mortgage Loans (dollars in thousands) March 31, 2020 Amortized Cost in Conventional Mortgage Loans Amortized Cost in Government Mortgage Loans Total In process of foreclosure (1) $ 2,816 $ 1,655 $ 4,471 Serious delinquency rate (2) 0.26 % 1.85 % 0.36 % Past due 90 days or more still accruing interest $ — $ 5,317 $ 5,317 Loans on nonaccrual status (3) $ 11,890 $ — $ 11,890 December 31, 2019 Recorded Investment in Conventional Mortgage Loans Recorded Investment in Government Mortgage Loans Total In process of foreclosure (1) $ 2,813 $ 2,222 $ 5,035 Serious delinquency rate (2) 0.26 % 1.86 % 0.36 % Past due 90 days or more still accruing interest $ — $ 5,570 $ 5,570 Loans on nonaccrual status (3) $ 11,510 $ — $ 11,510 _______________________ (1) Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu of foreclosure has been reported. (2) Loans that are 90 days or more past due or in the process of foreclosure expressed as a percentage of the recorded investment in the total loan portfolio class. (3) Includes conventional mortgage loans with contractual principal or interest payments 90 days or more past due and not accruing interest as well as loans modified within the previous six months under our temporary loan modification plan. As of March 31, 2020 , $4.6 million of these conventional mortgage loans on non-accrual status did not have an associated allowance for credit losses.
Financing Receivable, Allowance for Credit Loss [Table Text Block]	Table 6.5 presents a roll forward of the allowance for credit losses on conventional mortgage loans for the three months ended March 31, 2020 and 2019 . Table 6.5 - Allowance for Credit Losses on Conventional Mortgage Loans (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Allowance for credit losses Balance, beginning of period $ 500 $ 500 Adjustment for cumulative effect of accounting change 2,221 — Charge-offs (77 ) (3 ) Provision for credit losses 856 3 Balance, end of period $ 3,500 $ 500

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments [Table Text Block]	Table 7.1 - Fair Value of Derivative Instruments (dollars in thousands) March 31, 2020 December 31, 2019 Notional Amount of Derivatives Derivative Assets Derivative Liabilities Notional Derivative Derivative Derivatives designated as hedging instruments Interest-rate swaps $ 12,808,610 $ 30,660 $ (48,635 ) $ 12,128,105 $ 14,734 $ (12,805 ) Forward-start interest-rate swaps 17,000 24 — 17,000 19 — Total derivatives designated as hedging instruments 12,825,610 30,684 (48,635 ) 12,145,105 14,753 (12,805 ) Derivatives not designated as hedging instruments Economic hedges: Interest-rate swaps 4,142,300 28 (55,319 ) 2,902,300 349 (31,000 ) Mortgage-delivery commitments (1) 98,765 147 (695 ) 49,911 227 — Total derivatives not designated as hedging instruments 4,241,065 175 (56,014 ) 2,952,211 576 (31,000 ) Total notional amount of derivatives $ 17,066,675 $ 15,097,316 Total derivatives before netting and collateral adjustments 30,859 (104,649 ) 15,329 (43,805 ) Netting adjustments and cash collateral, including related accrued interest (2) 196,861 80,245 144,402 33,534 Derivative assets and derivative liabilities $ 227,720 $ (24,404 ) $ 159,731 $ (10,271 ) _______________________ (1) Mortgage-delivery commitments are classified as derivatives with changes in fair value recorded in other income. (2) Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty. Cash collateral and related accrued interest posted was $278.3 million and $178.5 million at March 31, 2020 , and December 31, 2019 , respectively. The change in cash collateral posted is included in the net change in interest-bearing deposits in the statement of cash flows. Cash collateral and related accrued interest received was $1.2 million and $561 thousand at March 31, 2020 , and December 31, 2019 .
Net Gains (Losses) on Derivatives and Hedging Activities [Table Text Block]	Tables 7.2 presents the net gains (losses) on qualifying fair-value and cash flow hedging relationships. Gains (losses) on derivatives include unrealized changes in fair value as well as net interest settlements. Table 7.2 - Net Gains (Losses) on Hedging Relationships (dollars in thousands) For the Three Months Ended March 31, 2020 Advances Available-for-sale Securities CO Bonds Total interest income (expense) in the statements of operations $ 168,659 $ 12,361 $ (123,547 ) Gains (losses) on hedging relationships Changes in fair value: Derivatives $ (127,568 ) $ (376,494 ) $ 63,735 Hedged items 124,692 366,518 (64,058 ) Net changes in fair value before price alignment interest (2,876 ) (9,976 ) (323 ) Price alignment interest (1) 389 1,035 (177 ) Net interest settlements on derivatives (2)(3) (2,625 ) (9,098 ) 2,956 Net (losses) gains on qualifying hedging relationships (5,112 ) (18,039 ) 2,456 Amortization/accretion of discontinued hedging relationships (337 ) — (888 ) Net (losses) gains on derivatives and hedging activities recorded in net interest income $ (5,449 ) $ (18,039 ) $ 1,568 For the Three Months Ended March 31, 2019 Advances Available-for-sale Securities CO Bonds Total interest income (expense) in the statements of operations $ 247,877 $ 21,291 $ (154,817 ) Gains (losses) on hedging relationships Changes in fair value: Derivatives $ (24,897 ) $ (23,197 ) $ 33,636 Hedged items 25,672 19,115 (34,633 ) Net changes in fair value before price alignment interest 775 (4,082 ) (997 ) Price alignment interest (1) 286 8 5 Net interest settlements on derivatives (2)(3) 16,251 (5,791 ) (9,080 ) Net gains (losses) on qualifying hedging relationships 17,312 (9,865 ) (10,072 ) Amortization/accretion of discontinued hedging relationships (444 ) — (75 ) Net gains (losses) on derivatives and hedging activities recorded in net interest income $ 16,868 $ (9,865 ) $ (10,147 ) _______________________ (1) Relates to derivatives for which variation margin payments are characterized as daily settled contracts. (2) Represents interest income/expense on derivatives in qualifying fair-value hedging relationships. Net interest settlements on derivatives that are not in qualifying fair-value hedging relationships are reported in other income. (3) Excludes the interest income/expense of the respective hedged items recorded in net interest income. Tables 7.3 presents the net gains (losses) on qualifying cash flow hedging relationships. Table 7.3 - Net Gains (Losses) on Cash Flow Hedging Relationships (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Forward-start interest rate swaps - CO Bonds Losses reclassified from accumulated other comprehensive loss into interest expense $ (1,757 ) $ (786 ) Losses recognized in other comprehensive income (1,125 ) (3,379 )
Gains (Losses) By Type of Hedged Item [Table Text Block]	Table 7.4 - Cumulative Basis Adjustments for Fair-Value Hedges (dollars in thousands) March 31, 2020 Line Item in Statement of Condition of Hedged Item Amortized Cost of Hedged Asset/ Liability (1) Basis Adjustments for Active Hedging Relationships Included in Amortized Cost Basis Adjustments for Discontinued Hedging Relationships Included in Amortized Cost Cumulative Amount of Fair Value Hedging Basis Adjustments Advances $ 6,241,203 $ 187,480 $ 10,505 $ 197,985 Available-for-sale securities 4,419,656 595,088 — 595,088 Consolidated bonds 3,130,935 59,218 41,687 100,905 _______________________ (1) Includes only the portion of amortized cost representing the hedged items in fair-value hedging relationships.
Derivatives Not Designated as Hedging Instruments [Table Text Block]	Table 7.5 - Net Gains and Losses on Derivatives not Designated as Hedging Instruments (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Interest-rate swaps $ (52,569 ) $ (60 ) Mortgage-delivery commitments (62 ) 608 Price alignment interest (1) 73 — Net (losses) gains on derivatives not designated as hedging instruments $ (52,558 ) $ 548 ______________________ (1) Relates to derivatives for which variation margin payments are characterized as daily settled contracts.
Post-haircut Value of Incremental Collateral Based on Incremental Credit Rating Downgrades [Table Text Block]	Table 7.6 sets forth the post-haircut value of incremental collateral that certain uncleared derivatives counterparties could have required us to deliver based on incremental credit rating downgrades at March 31, 2020 . Table 7.6 - Post Haircut Value of Incremental Collateral to be Delivered as of March 31, 2020 (dollars in thousands) Ratings Downgrade (1) From To Incremental Collateral AA+ AA or AA- $ 579 AA- A+, A or A- — A- below A- 7,513 _______________________ (1) Ratings are expressed in this table according to S&P's conventions but include the equivalent of such rating by Moody's. If there is a split rating, the lower rating is used.
Offsetting Assets [Table Text Block]	Table 7.7 presents separately the fair value of derivatives that are subject to netting due to a legal right of offset based on the terms of our master netting arrangements or similar agreements as of March 31, 2020 , and December 31, 2019 , and the fair value of derivatives that are not subject to such netting. Derivatives subject to netting include any related cash collateral received from or pledged to counterparties. Table 7.7 - Netting of Derivative Assets and Derivative Liabilities (dollars in thousands) March 31, 2020 Derivative Instruments Meeting Netting Requirements Non-cash Collateral (Received) or Pledged Not Offset (2) Gross Recognized Amount Gross Amounts of Netting Adjustments (1) Mortgage Delivery Commitments Total Derivative Assets and Total Derivative Liabilities Can Be Sold or Repledged Cannot Be Sold or Repledged Net Amount Derivative Assets Uncleared $ 13,187 $ (13,187 ) $ 147 $ 147 $ — $ — $ 147 Cleared 17,526 210,047 227,573 — — 227,573 Total $ 227,720 $ 227,720 Derivative Liabilities Uncleared $ (100,449 ) $ 76,740 $ (695 ) $ (24,404 ) $ — $ 21,442 $ (2,962 ) Cleared (3,506 ) 3,506 — — — — Total $ (24,404 ) $ (2,962 ) _______________________ (1) Includes gross amounts of netting adjustments and cash collateral. (2) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At March 31, 2020 , we had additional net credit exposure of $158 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position. December 31, 2019 Derivative Instruments Meeting Netting Requirements Non-cash Collateral (Received) or Pledged Not Offset (2) Gross Recognized Amount Gross Amounts of Netting Adjustments (1) Mortgage Delivery Commitments Total Derivative Assets and Total Derivative Liabilities Can Be Sold or Repledged Cannot Be Sold or Repledged Net Amount Derivative Assets Uncleared $ 4,950 $ (3,519 ) $ 227 $ 1,658 $ (995 ) $ — $ 663 Cleared 10,152 147,921 158,073 — — 158,073 Total $ 159,731 $ 158,736 Derivative Liabilities Uncleared $ (42,199 ) $ 31,928 $ — $ (10,271 ) $ 82 $ 9,333 $ (856 ) Cleared (1,606 ) 1,606 — — — — Total $ (10,271 ) $ (856 ) _______________________ (1) Includes gross amounts of netting adjustments and cash collateral. (2) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At December 31, 2019 , we had additional net credit exposure of $300 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.
Offsetting Liabilities [Table Text Block]	Table 7.7 presents separately the fair value of derivatives that are subject to netting due to a legal right of offset based on the terms of our master netting arrangements or similar agreements as of March 31, 2020 , and December 31, 2019 , and the fair value of derivatives that are not subject to such netting. Derivatives subject to netting include any related cash collateral received from or pledged to counterparties. Table 7.7 - Netting of Derivative Assets and Derivative Liabilities (dollars in thousands) March 31, 2020 Derivative Instruments Meeting Netting Requirements Non-cash Collateral (Received) or Pledged Not Offset (2) Gross Recognized Amount Gross Amounts of Netting Adjustments (1) Mortgage Delivery Commitments Total Derivative Assets and Total Derivative Liabilities Can Be Sold or Repledged Cannot Be Sold or Repledged Net Amount Derivative Assets Uncleared $ 13,187 $ (13,187 ) $ 147 $ 147 $ — $ — $ 147 Cleared 17,526 210,047 227,573 — — 227,573 Total $ 227,720 $ 227,720 Derivative Liabilities Uncleared $ (100,449 ) $ 76,740 $ (695 ) $ (24,404 ) $ — $ 21,442 $ (2,962 ) Cleared (3,506 ) 3,506 — — — — Total $ (24,404 ) $ (2,962 ) _______________________ (1) Includes gross amounts of netting adjustments and cash collateral. (2) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At March 31, 2020 , we had additional net credit exposure of $158 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position. December 31, 2019 Derivative Instruments Meeting Netting Requirements Non-cash Collateral (Received) or Pledged Not Offset (2) Gross Recognized Amount Gross Amounts of Netting Adjustments (1) Mortgage Delivery Commitments Total Derivative Assets and Total Derivative Liabilities Can Be Sold or Repledged Cannot Be Sold or Repledged Net Amount Derivative Assets Uncleared $ 4,950 $ (3,519 ) $ 227 $ 1,658 $ (995 ) $ — $ 663 Cleared 10,152 147,921 158,073 — — 158,073 Total $ 159,731 $ 158,736 Derivative Liabilities Uncleared $ (42,199 ) $ 31,928 $ — $ (10,271 ) $ 82 $ 9,333 $ (856 ) Cleared (1,606 ) 1,606 — — — — Total $ (10,271 ) $ (856 ) _______________________ (1) Includes gross amounts of netting adjustments and cash collateral. (2) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At December 31, 2019 , we had additional net credit exposure of $300 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.

Deposits (Tables)

Deposits (Tables)	3 Months Ended
	Mar. 31, 2020
Deposits [Abstract]
Interest-bearing and Non-interest-bearing Deposits [Table Text Block]	Table 8.1 - Deposits (dollars in thousands) March 31, 2020 December 31, 2019 Interest-bearing Demand and overnight $ 782,943 $ 613,143 Term 1,200 800 Other 1,639 2,589 Noninterest-bearing Other 74,034 57,777 Total deposits $ 859,816 $ 674,309

Consolidated Obligations (Table

Consolidated Obligations (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
CO Bonds by Year of Contractual Maturity [Table Text Block]	Table 9.3 - CO Bonds Outstanding by Contractual Maturity or Next Call Date (dollars in thousands) March 31, 2020 December 31, 2019 Due in one year or less $ 13,165,560 $ 11,297,725 Due after one year through two years 5,055,405 6,432,960 Due after two years through three years 2,189,475 2,019,920 Due after three years through four years 1,209,550 1,332,915 Due after four years through five years 1,134,280 926,080 Thereafter 1,658,540 1,795,205 Total par value $ 24,412,810 $ 23,804,805 Table 9.1 - CO Bonds Outstanding by Contractual Maturity (dollars in thousands) March 31, 2020 December 31, 2019 Amount Weighted Average Rate (1) Amount Weighted Average Rate (1) Due in one year or less $ 11,488,560 1.13 % $ 9,455,725 2.03 % Due after one year through two years 4,990,405 1.80 6,442,960 2.02 Due after two years through three years 2,269,475 2.07 2,154,920 2.18 Due after three years through four years 1,211,550 2.47 1,319,915 2.45 Due after four years through five years 1,474,280 2.40 1,211,080 2.48 Thereafter 2,978,540 3.43 3,220,205 3.33 Total par value 24,412,810 1.78 % 23,804,805 2.26 % Premiums 74,030 63,056 Discounts (11,159 ) (11,434 ) Hedging adjustments 100,905 32,066 Total $ 24,576,586 $ 23,888,493 _______________________ (1) The CO bonds' weighted-average rate excludes concession fees.
CO Bonds Long-term Debt Instruments [Table Text Block]	Table 9.4 - CO Bonds by Interest Rate-Payment Type (dollars in thousands) Par Value of CO bonds March 31, 2020 December 31, 2019 Fixed-rate $ 17,068,810 $ 17,681,805 Simple variable-rate 6,959,000 5,568,000 Step-up (1) 385,000 555,000 Total par value $ 24,412,810 $ 23,804,805 _______________________ (1) Step-up bonds pay interest at increasing fixed rates for specified intervals over the life of the CO bond and can be called at our option on the step-up dates. Table 9.2 - CO Bonds Outstanding by Call Feature (dollars in thousands) Par Value of CO bonds March 31, 2020 December 31, 2019 Noncallable and nonputable $ 21,805,810 $ 20,954,805 Callable 2,607,000 2,850,000 Total par value $ 24,412,810 $ 23,804,805
CO Discount Notes [Table Text Block]	Outstanding CO discount notes for which we were primarily liable, all of which are due within one year, were as follows: Table 9.5 - CO Discount Notes Outstanding (dollars in thousands) Book Value Par Value Weighted Average Rate (1) March 31, 2020 $ 39,692,253 $ 39,743,071 1.10 % December 31, 2019 $ 27,681,169 $ 27,733,146 1.59 % _______________________ (1) The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable Housing Program (Tab

Affordable Housing Program (Tables)	3 Months Ended
	Mar. 31, 2020
Affordable Housing Program [Abstract]
Roll-forward of the AHP Liability[Table Text Block]	Table 10.1 - AHP Liability (dollars in thousands) March 31, 2020 December 31, 2019 Balance at beginning of period $ 86,131 $ 83,965 AHP expense for the period 4,636 21,302 AHP direct grant disbursements (4,672 ) (15,723 ) AHP subsidy for AHP advance disbursements (1,026 ) (3,450 ) Return of previously disbursed grants and subsidies 13 37 Balance at end of period $ 85,082 $ 86,131

Capital (Tables)

Capital (Tables)	3 Months Ended
	Mar. 31, 2020
Capital [Abstract]
Compliance with Regulatory Capital Requirements [Table Text Block]	Table 11.1 - Regulatory Capital Requirements (dollars in thousands) Risk-Based Capital Requirements March 31, December 31, Permanent capital Class B capital stock $ 2,266,329 $ 1,869,130 Mandatorily redeemable capital stock 6,112 5,806 Retained earnings 1,473,149 1,463,154 Total permanent capital $ 3,745,590 $ 3,338,090 Risk-based capital requirement Credit-risk capital $ 212,510 $ 235,213 Market-risk capital 155,678 207,426 Operations-risk capital 110,456 132,792 Total risk-based capital requirement $ 478,644 $ 575,431 Permanent capital in excess of risk-based capital requirement $ 3,266,946 $ 2,762,659 March 31, 2020 December 31, 2019 Required Actual Required Actual Capital Ratio Risk-based capital $ 478,644 $ 3,745,590 $ 575,431 $ 3,338,090 Total regulatory capital $ 2,756,035 $ 3,745,590 $ 2,226,512 $ 3,338,090 Total capital-to-asset ratio 4.0 % 5.4 % 4.0 % 6.0 % Leverage Ratio Leverage capital $ 3,445,043 $ 5,618,385 $ 2,783,141 $ 5,007,135 Leverage capital-to-assets ratio 5.0 % 8.2 % 5.0 % 9.0 %

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2020
AOCI Attributable to Parent [Abstract]
Schedule of Accumulated Other Comprehensive Loss [Table Text Block]	Table 12.1 - Accumulated Other Comprehensive Loss (dollars in thousands) Net Unrealized Loss on Available-for-sale Securities Noncredit Portion of Other-than-temporary Impairment Losses on Held-to-maturity Securities Net Unrealized Loss Relating to Hedging Activities Pension and Postretirement Benefits Total Balance, December 31, 2018 $ (152,958 ) $ (129,154 ) $ (29,119 ) $ (5,276 ) $ (316,507 ) Cumulative effect of change in accounting principle — — (175 ) — (175 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 34,065 — (3,379 ) — 30,686 Noncredit other-than-temporary impairment losses — (80 ) — — (80 ) Accretion of noncredit loss — 6,291 — — 6,291 Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 30 — — 30 Amortization - hedging activities (2) — — 786 — 786 Amortization - pension and postretirement benefits (3) — — — 161 161 Other comprehensive income (loss) 34,065 6,241 (2,593 ) 161 37,874 Balance, March 31, 2019 $ (118,893 ) $ (122,913 ) $ (31,887 ) $ (5,115 ) $ (278,808 ) Balance, December 31, 2019 $ (73,922 ) $ (76,036 ) $ (30,207 ) $ (6,807 ) $ (186,972 ) Other comprehensive (loss) income before reclassifications: Net unrealized losses (85,737 ) — (1,125 ) — (86,862 ) Noncredit losses included in basis of securities sold — 20,239 — — 20,239 Accretion of noncredit loss — 2,805 — — 2,805 Net actuarial loss — — — 501 501 Reclassifications from other comprehensive income to net income Amortization - hedging activities (2) — — 1,757 — 1,757 Amortization - pension and postretirement benefits (3) — — — 295 295 Other comprehensive (loss) income (85,737 ) 23,044 632 796 (61,265 ) Balance, March 31, 2020 $ (159,659 ) $ (52,992 ) $ (29,575 ) $ (6,011 ) $ (248,237 ) _______________________ (1) Recorded in other income (loss) in the statement of operations. (2) Recorded in CO bond interest expense. (3) Recorded in other expenses in the statement of operations.

Fair Values (Tables)

Fair Values (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments [Table Text Block]	Table 13.1 presents the carrying value, fair value, and fair value hierarchy of our financial assets and liabilities at March 31, 2020 , and December 31, 2019 . We record trading securities, available-for-sale securities, derivative assets, derivative liabilities, and certain other assets at fair value on a recurring basis, and certain mortgage loans and certain other assets at fair value on a non-recurring basis. We record all other financial assets and liabilities at amortized cost. Refer to Table 13.2 for further details about the financial assets and liabilities held at fair value on either a recurring or non-recurring basis. Table 13.1 - Fair Value Summary (dollars in thousands) March 31, 2020 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral (2) Financial instruments Assets: Cash and due from banks $ 806,985 $ 806,985 $ 806,985 $ — $ — $ — Interest-bearing deposits 1,130,563 1,130,563 1,130,563 — — — Securities purchased under agreements to resell 2,000,000 1,999,954 — 1,999,954 — — Federal funds sold 3,455,000 3,454,927 — 3,454,927 — — Trading securities (1) 3,563,368 3,563,368 — 3,563,368 — — Available-for-sale securities (1) 7,246,334 7,246,334 — 7,180,939 65,395 — Held-to-maturity securities 676,888 733,970 — 384,446 349,524 — Advances 45,076,223 45,434,302 — 45,434,302 — — Mortgage loans, net 4,528,474 4,766,735 — 4,747,540 19,195 — Accrued interest receivable 109,878 109,878 — 109,878 — — Derivative assets (1) 227,720 227,720 — 30,859 — 196,861 Other assets (1) 30,926 30,926 16,238 14,688 — — Liabilities: Deposits (859,816 ) (859,815 ) — (859,815 ) — — COs: Bonds (24,576,586 ) (25,122,573 ) — (25,122,573 ) — — Discount notes (39,692,253 ) (39,735,774 ) — (39,735,774 ) — — Mandatorily redeemable capital stock (6,112 ) (6,112 ) (6,112 ) — — — Accrued interest payable (108,010 ) (108,010 ) — (108,010 ) — — Derivative liabilities (1) (24,404 ) (24,404 ) — (104,649 ) — 80,245 Other: Commitments to extend credit for advances — (2,623 ) — (2,623 ) — — Standby letters of credit (1,540 ) (1,540 ) — (1,540 ) — — December 31, 2019 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral (2) Financial instruments Assets: Cash and due from banks $ 69,416 $ 69,416 $ 69,416 $ — $ — $ — Interest-bearing deposits 1,253,873 1,253,873 1,253,873 — — — Securities purchased under agreements to resell 3,500,000 3,500,003 — 3,500,003 — — Federal funds sold 860,000 859,999 — 859,999 — — Trading securities (1) 2,250,264 2,250,264 — 2,250,264 — — Available-for-sale securities (1) 7,409,000 7,409,000 — 7,344,348 64,652 — Held-to-maturity securities 871,107 1,035,410 — 456,942 578,468 — Advances 34,595,363 34,735,775 — 34,735,775 — — Mortgage loans, net 4,501,251 4,634,141 — 4,615,737 18,404 — Accrued interest receivable 112,163 112,163 — 112,163 — — Derivative assets (1) 159,731 159,731 — 15,329 — 144,402 Other assets (1) 31,939 31,939 13,894 18,045 — — Liabilities: Deposits (674,309 ) (674,269 ) — (674,269 ) — — COs: Bonds (23,888,493 ) (24,226,123 ) — (24,226,123 ) — — Discount notes (27,681,169 ) (27,681,470 ) — (27,681,470 ) — — Mandatorily redeemable capital stock (5,806 ) (5,806 ) (5,806 ) — — — Accrued interest payable (104,477 ) (104,477 ) — (104,477 ) — — Derivative liabilities (1) (10,271 ) (10,271 ) — (43,805 ) — 33,534 Other: Commitments to extend credit for advances — (3,884 ) — (3,884 ) — — Standby letters of credit (1,723 ) (1,723 ) — (1,723 ) — — _______________________ (1) Carried at fair value and measured on a recurring basis. (2) These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
Fair Value Measured on Recurring and Nonrecurring Basis [Table Text Block]	Table 13.2 - Fair Value of Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (dollars in thousands) March 31, 2020 Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral (1) Total Assets: Carried at fair value on a recurring basis Trading securities: Corporate bonds $ — $ 5,330 $ — $ — $ 5,330 U.S. Treasury obligations — 3,554,179 — — 3,554,179 U.S. government-guaranteed – single-family MBS — 3,794 — — 3,794 GSE – single-family MBS — 65 — — 65 Total trading securities — 3,563,368 — — 3,563,368 Available-for-sale securities: HFA securities — — 65,395 — 65,395 Supranational institutions — 438,284 — — 438,284 U.S. government-owned corporations — 314,724 — — 314,724 GSE — 133,789 — — 133,789 U.S. government guaranteed – single-family MBS — 52,586 — — 52,586 U.S. government guaranteed – multifamily MBS — 248,428 — — 248,428 GSE – single-family MBS — 2,342,640 — — 2,342,640 GSE – multifamily MBS — 3,650,488 — — 3,650,488 Total available-for-sale securities — 7,180,939 65,395 — 7,246,334 Derivative assets: Interest-rate-exchange agreements — 30,712 — 196,861 227,573 Mortgage delivery commitments — 147 — — 147 Total derivative assets — 30,859 — 196,861 227,720 Other assets 16,238 14,688 — — 30,926 Total assets carried at fair value on a recurring basis $ 16,238 $ 10,789,854 $ 65,395 $ 196,861 $ 11,068,348 Carried at fair value on a nonrecurring basis (2) Mortgage loans held for portfolio $ — $ — $ 1,269 $ — $ 1,269 REO — — 110 — 110 Total assets carried at fair value on a nonrecurring basis $ — $ — $ 1,379 $ — $ 1,379 Liabilities: Carried at fair value on a recurring basis Derivative liabilities Interest-rate-exchange agreements $ — $ (103,954 ) $ — $ 80,245 $ (23,709 ) Mortgage delivery commitments — (695 ) — — (695 ) Total liabilities carried at fair value on a recurring basis $ — $ (104,649 ) $ — $ 80,245 $ (24,404 ) December 31, 2019 Level 1 Level 2 Level 3 Netting (1) Total Assets: Carried at fair value on a recurring basis Trading securities: Corporate bonds $ — $ 5,896 $ — $ — $ 5,896 U.S. Treasury obligations — 2,240,236 — — 2,240,236 U.S. government guaranteed – single-family MBS — 4,047 — — 4,047 GSE – single-family MBS — 85 — — 85 Total trading securities — 2,250,264 — — 2,250,264 Available-for-sale securities: HFA securities — — 64,652 — 64,652 Supranational institutions — 416,429 — — 416,429 U.S. government-owned corporations — 296,761 — — 296,761 GSE — 123,786 — — 123,786 U.S. government guaranteed – single-family MBS — 57,714 — — 57,714 U.S. government guaranteed – multifamily MBS — 282,617 — — 282,617 GSE – single-family MBS — 2,590,271 — — 2,590,271 GSE – multifamily MBS — 3,576,770 — — 3,576,770 Total available-for-sale securities — 7,344,348 64,652 — 7,409,000 Derivative assets: Interest-rate-exchange agreements — 15,102 — 144,402 159,504 Mortgage delivery commitments — 227 — — 227 Total derivative assets — 15,329 — 144,402 159,731 Other assets 13,894 18,045 — — 31,939 Total assets carried at fair value on a recurring basis $ 13,894 $ 9,627,986 $ 64,652 $ 144,402 $ 9,850,934 Carried at fair value on a nonrecurring basis (2) Held-to-maturity securities: Private-label MBS $ — $ — $ 6,856 $ — $ 6,856 Mortgage loans held for portfolio — — 1,198 — 1,198 REO — — 78 — 78 Total assets carried at fair value on a nonrecurring basis $ — $ — $ 8,132 $ — $ 8,132 Liabilities: Carried at fair value on a recurring basis Derivative liabilities Interest-rate-exchange agreements $ — $ (43,805 ) $ — $ 33,534 $ (10,271 ) Total liabilities carried at fair value on a recurring basis $ — $ (43,805 ) $ — $ 33,534 $ (10,271 ) _______________________ (1) These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty. (2) We measure certain held-to-maturity investment securities, mortgage loans held for portfolio, and REO at fair value on a nonrecurring basis, that is, they are not measured at fair value on an ongoing basis but are subject to fair-value adjustments only in certain circumstances. The fair values presented are as of the date the fair value adjustment was recorded.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Table 13.3 presents a reconciliation of available-for-sale securities that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the three months ended March 31, 2020 and 2019 . Table 13.3 - Roll Forward of Level 3 Available-for-Sale Securities (dollars in thousands) For the Three Months Ended March 31, 2020 2019 Balance at beginning of period $ 64,652 $ 49,601 Unrealized gains included in other comprehensive income 743 747 Balance at end of period $ 65,395 $ 50,348

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Off-Balance Sheet Commitments [Table Text Block]	Table 14.1 - Off-Balance Sheet Commitments (1) (dollars in thousands) March 31, 2020 December 31, 2019 Expire within one year Expire after one year Total Expire within one year Expire after one year Total Standby letters of credit outstanding (2) $ 7,468,699 $ 216,679 $ 7,685,378 $ 7,484,754 $ 215,014 $ 7,699,768 Commitments for unused lines of credit - advances (3) 1,134,788 — 1,134,788 1,143,828 — 1,143,828 Commitments to make additional advances 277,891 70,320 348,211 434,253 88,167 522,420 Commitments to invest in mortgage loans 98,765 — 98,765 49,911 — 49,911 Unsettled CO bonds, at par 711,500 — 711,500 — — — Unsettled CO discount notes, at par 1,227,230 — 1,227,230 500,000 — 500,000 __________________________ (1) We have deemed it unnecessary to record any liability for credit losses on these agreements. (2) The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year. At March 31, 2020 , and December 31, 2019 , these amounts totaled $ 11.5 million and $27.2 million , respectively. Also excluded are commitments to issue standby letters of credit that expire after one year totaling $550 thousand and $1.8 million at March 31, 2020 , and December 31, 2019 , respectively. (3) Commitments for unused line-of-credit advances are generally for periods of up to 12 months . Since many of these commitments are not expected to be drawn upon, the total commitment amount does not necessarily indicate future liquidity requirements.

Transactions with Shareholders

Transactions with Shareholders (Tables)	3 Months Ended
	Mar. 31, 2020
Transactions with Shareholders [Abstract]
Schedule of Transactions with Shareholders [Table Text Block]	Shareholder Concentrations. We consider shareholder concentrations as members or nonmembers whose capital stock holdings (including mandatorily redeemable capital stock) are in excess of 10 percent of total capital stock outstanding at March 31, 2020 . Table 15.1 - Shareholder Concentrations, Balance Sheet (dollars in thousands) Capital Stock Outstanding Percent of Total Capital Stock Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances March 31, 2020 Citizens Bank, N.A. $ 342,580 15.1 % $ 8,005,678 17.8 % $ 1,072 2.3 % December 31, 2019 Citizens Bank, N.A. $ 222,684 11.9 % $ 5,005,773 14.5 % $ 1,678 3.5 %
Schedule of Transactions with Shareholders, Interest Income [Table Text Block]	Table 15.2 - Shareholder Concentrations, Income Statement (dollars in thousands) Interest Income on Advances Percent of Total Advances Interest Income Fees on Letters of Credit Percent of Total Fees on Letters of Credit Citizens Bank, N.A. For the three months ended March 31, 2020 $ 23,750 14.1 % $ 1,586 61.8 % For the three months ended March 31, 2019 $ 39,113 15.8 % $ 1,878 81.4 %
Schedule of Transactions with Shareholders, Transactions with Directors' Financial Institutions [Table Text Block]	Transactions with Directors' Institutions. We provide, in the ordinary course of business, products and services to members whose officers or directors serve on our board of directors. In accordance with FHFA regulations, transactions with directors' institutions are conducted on the same terms as those with any other member. Table 15.3 - Transactions with Directors' Institutions (dollars in thousands) Capital Stock Outstanding Percent of Total Capital Stock Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances March 31, 2020 $ 452,365 19.9 % $ 10,137,669 22.6 % $ 4,120 8.9 % December 31, 2019 112,811 6.0 2,224,141 6.4 3,581 7.4

Recently Issued and Adopted A_2

Recently Issued and Adopted Accounting Guidance Financial Instruments - Credit Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in the allowance for credit losses as a cumulative-effect adjustment to retained earnings upon adoption of ASU 2016-13	$ (7,530)		$ 0
Cumulative Effect Period Of Adoption Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in the allowance for credit losses as a cumulative-effect adjustment to retained earnings upon adoption of ASU 2016-13		$ 7,500

Investments Trading Securities

Investments Trading Securities by Major Security Type (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	$ 3,563,368	$ 2,250,264
Corporate bonds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	5,330	5,896
US Treasury obligations [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	3,554,179	2,240,236
Other Than MBS [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	3,559,509	2,246,132
U.S. government-guaranteed - single-family MBS [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	3,794	4,047
MBS [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	3,859	4,132
GSE - single-family [Member] | Government Sponsored Enterprises [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	$ 65	$ 85

Investments Available-for-Sale

Investments Available-for-Sale Securities by Major Security Type (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	$ 7,405,993	$ 7,482,922
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		35,216	8,432
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(194,875)	(82,354)
Available-for-sale securities Fair Value		7,246,334	7,409,000
Available-for-sale securities - accrued interest receivable		20,000	27,500
State housing-finance-agency obligations (HFA securities) [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	69,320	69,320
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		0	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(3,925)	(4,668)
Available-for-sale securities Fair Value		65,395	64,652
Supranational institutions [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	457,721	429,354
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		0	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(19,437)	(12,925)
Available-for-sale securities Fair Value		438,284	416,429
U.S. government-owned corporations [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	376,711	323,192
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		0	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(61,987)	(26,431)
Available-for-sale securities Fair Value		314,724	296,761
GSE [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	149,068	130,935
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		0	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(15,279)	(7,149)
Available-for-sale securities Fair Value		133,789	123,786
Other Than MBS [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	1,052,820	952,801
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		0	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(100,628)	(51,173)
Available-for-sale securities Fair Value		952,192	901,628
U.S. government-guaranteed - single-family MBS [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	52,820	60,003
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		0	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(234)	(2,289)
Available-for-sale securities Fair Value		52,586	57,714
U.S. government-guaranteed - multifamily MBS [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	247,526	283,674
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		917	0
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(15)	(1,057)
Available-for-sale securities Fair Value		248,428	282,617
MBS [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	6,353,173	6,530,121
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		35,216	8,432
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(94,247)	(31,181)
Available-for-sale securities Fair Value		6,294,142	6,507,372
GSE - single-family [Member] | Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	2,317,683	2,598,325
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		28,079	5,323
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(3,122)	(13,377)
Available-for-sale securities Fair Value		2,342,640	2,590,271
GSE - multifamily [Member] | Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	3,735,144	3,588,119
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Gains		6,220	3,109
Amounts Recorded in Accumulated Other Comprehensive Loss - Unrealized Losses		(90,876)	(14,458)
Available-for-sale securities Fair Value		$ 3,650,488	$ 3,576,770
[1]	Amortized cost of available-for-sale securities includes adjustments made to the cost basis of an investment for accretion, amortization, collection of cash, and fair-value hedge accounting adjustments. Amortized cost excludes accrued interest receivable of $20.0 million and $27.5 million at March 31, 2020 , and December 31, 2019 .

Investments Available-for-Sal_2

Investments Available-for-Sale Securities in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	$ 2,937,195	$ 2,013,102
Less than 12 Months - Unrealized Losses	(89,508)	(15,802)
12 Months or More - Fair Value	1,709,103	3,047,211
12 Months or More - Unrealized Losses	(105,367)	(66,552)
Total - Fair Value	4,646,298	5,060,313
Total - Unrealized Losses	(194,875)	(82,354)
HFA securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	12,497	12,229
Less than 12 Months - Unrealized Losses	(1,323)	(1,591)
12 Months or More - Fair Value	45,298	52,423
12 Months or More - Unrealized Losses	(2,602)	(3,077)
Total - Fair Value	57,795	64,652
Total - Unrealized Losses	(3,925)	(4,668)
Supranational institutions [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	0	0
Less than 12 Months - Unrealized Losses	0	0
12 Months or More - Fair Value	438,284	416,429
12 Months or More - Unrealized Losses	(19,437)	(12,925)
Total - Fair Value	438,284	416,429
Total - Unrealized Losses	(19,437)	(12,925)
U.S. government-owned corporations [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	0	0
Less than 12 Months - Unrealized Losses	0	0
12 Months or More - Fair Value	314,724	296,761
12 Months or More - Unrealized Losses	(61,987)	(26,431)
Total - Fair Value	314,724	296,761
Total - Unrealized Losses	(61,987)	(26,431)
GSE [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	0	0
Less than 12 Months - Unrealized Losses	0	0
12 Months or More - Fair Value	133,789	123,786
12 Months or More - Unrealized Losses	(15,279)	(7,149)
Total - Fair Value	133,789	123,786
Total - Unrealized Losses	(15,279)	(7,149)
Other Than MBS [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	12,497	12,229
Less than 12 Months - Unrealized Losses	(1,323)	(1,591)
12 Months or More - Fair Value	932,095	889,399
12 Months or More - Unrealized Losses	(99,305)	(49,582)
Total - Fair Value	944,592	901,628
Total - Unrealized Losses	(100,628)	(51,173)
U.S. government-guaranteed - single-family MBS [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	1,294	10,885
Less than 12 Months - Unrealized Losses	(8)	(1)
12 Months or More - Fair Value	51,292	45,490
12 Months or More - Unrealized Losses	(226)	(2,288)
Total - Fair Value	52,586	56,375
Total - Unrealized Losses	(234)	(2,289)
U.S. government-guaranteed - multifamily MBS [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	0	0
Less than 12 Months - Unrealized Losses	0	0
12 Months or More - Fair Value	39,735	282,617
12 Months or More - Unrealized Losses	(15)	(1,057)
Total - Fair Value	39,735	282,617
Total - Unrealized Losses	(15)	(1,057)
MBS [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	2,924,698	2,000,873
Less than 12 Months - Unrealized Losses	(88,185)	(14,211)
12 Months or More - Fair Value	777,008	2,157,812
12 Months or More - Unrealized Losses	(6,062)	(16,970)
Total - Fair Value	3,701,706	4,158,685
Total - Unrealized Losses	(94,247)	(31,181)
GSE - single-family [Member] | Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	126,722	189,402
Less than 12 Months - Unrealized Losses	(605)	(968)
12 Months or More - Fair Value	397,329	1,423,927
12 Months or More - Unrealized Losses	(2,517)	(12,409)
Total - Fair Value	524,051	1,613,329
Total - Unrealized Losses	(3,122)	(13,377)
GSE - multifamily [Member] | Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Less than 12 Months - Fair Value	2,796,682	1,800,586
Less than 12 Months - Unrealized Losses	(87,572)	(13,242)
12 Months or More - Fair Value	288,652	405,778
12 Months or More - Unrealized Losses	(3,304)	(1,216)
Total - Fair Value	3,085,334	2,206,364
Total - Unrealized Losses	$ (90,876)	$ (14,458)

Investments Available-for-Sal_3

Investments Available-for-Sale Securities by Contractual Maturity (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost	[1]	$ 7,405,993	$ 7,482,922
Fair Value		7,246,334	7,409,000
Other Than MBS [Member]
Available-for-sale Securities, Debt Maturities [Abstract]
Due in one year or less - Amortized Cost		7,600	7,600
Due in one year or less - Fair Value		7,600	7,563
Due after one year through five years - Amortized Cost		61,720	61,720
Due after one year through five years - Fair Value		57,795	57,089
Due after five years through 10 years - Amortized Cost		509,594	477,232
Due after five years through 10 years - Fair Value		488,131	463,465
Due after 10 years - Amortized Cost		473,906	406,249
Due after 10 years - Fair Value		398,666	373,511
Amortized Cost	[1]	1,052,820	952,801
Fair Value		952,192	901,628
MBS [Member]
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost	[1]	6,353,173	6,530,121
Fair Value		6,294,142	6,507,372
Amortized Cost - MBS	[2]	6,353,173	6,530,121
Fair Value - MBS	[2]	$ 6,294,142	$ 6,507,372
[1]	Amortized cost of available-for-sale securities includes adjustments made to the cost basis of an investment for accretion, amortization, collection of cash, and fair-value hedge accounting adjustments. Amortized cost excludes accrued interest receivable of $20.0 million and $27.5 million at March 31, 2020 , and December 31, 2019 .
[2]	MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay obligations with or without call or prepayment fees.

Investments Held-to-Maturity Se

Investments Held-to-Maturity Securities by Major Security Type (Details) - USD ($) $ in Thousands		Mar. 31, 2020		Dec. 31, 2019
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	$ 733,647		$ 947,142
Allowance for Credit Losses		(3,768)	[2]	0
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	(52,991)		(76,035)
Carrying Value	[3],[4]	676,888		871,107
Gross Unrecognized Holding Gains		68,649		168,842
Gross Unrecognized Holding Loss		(11,567)		(4,539)
Fair Value		733,970		1,035,410
Held-to-maturity securities - accrued interest receivable		1,600		2,000
HFA securities [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	79,680		87,250
Allowance for Credit Losses	[2]	0
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	0		0
Carrying Value		79,680		87,250
Gross Unrecognized Holding Gains		0		0
Gross Unrecognized Holding Loss		(10,319)		(3,845)
Fair Value		69,361		83,405
U.S. government-guaranteed - single-family MBS [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	6,686		6,987
Allowance for Credit Losses	[2]	0
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	0		0
Carrying Value		6,686		6,987
Gross Unrecognized Holding Gains		76		129
Gross Unrecognized Holding Loss		0		0
Fair Value		6,762		7,116
Private-label [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	275,069		408,640
Allowance for Credit Losses	[2]	(3,768)
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	(52,991)		(76,035)
Carrying Value		218,310		332,605
Gross Unrecognized Holding Gains		62,591		162,904
Gross Unrecognized Holding Loss		(738)		(446)
Fair Value		280,163		495,063
MBS [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1],[5]	653,967		859,892
Allowance for Credit Losses	[2]	(3,768)
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	(52,991)		(76,035)
Carrying Value	[3],[5]	597,208		783,857
Gross Unrecognized Holding Gains		68,649		168,842
Gross Unrecognized Holding Loss		(1,248)		(694)
Fair Value	[5]	664,609		952,005
GSE - single-family [Member] | Government Sponsored Enterprises [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	281,285		303,604
Allowance for Credit Losses	[2]	0
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	0		0
Carrying Value		281,285		303,604
Gross Unrecognized Holding Gains		5,464		5,197
Gross Unrecognized Holding Loss		(510)		(246)
Fair Value		286,239		308,555
GSE - multifamily [Member] | Government Sponsored Enterprises [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	[1]	90,927		140,661
Allowance for Credit Losses	[2]	0
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	[2]	0		0
Carrying Value		90,927		140,661
Gross Unrecognized Holding Gains		518		612
Gross Unrecognized Holding Loss		0		(2)
Fair Value		$ 91,445		$ 141,271
[1]	Amortized cost of held-to-maturity securities includes adjustments made to the cost basis of an investment for accretion, amortization, and collection of cash. Amortized cost excludes accrued interest receivable of $1.6 million and $2.0 million at March 31, 2020 , and December 31, 2019 .
[2]	With the adoption of changes to accounting standards on credit impairment on January 1, 2020, the other-than-temporary impairment approach was replaced with an allowance for credit loss; however, other-than-temporary impairment remains for those securities that had credit impairment prior to the adoption date. See Note 2 — Summary of Significant Accounting Policies and Note 3 — Recently Issued and Adopted Accounting Guidance for further information.
[3]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss and the allowance for credit losses.
[4]	Fair values of held-to-maturity securities were $ 733,970 and $1,035,410 at March 31, 2020 , and December 31, 2019 , respectively.
[5]	MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay their obligations with or without call or prepayment fees.

Investments Held-to-Maturity _2

Investments Held-to-Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Maturity [Abstract]
Amortized Cost	[1]	$ 733,647	$ 947,142
Carrying Value	[2],[3]	676,888	871,107
Fair Value		733,970	1,035,410
Other Than MBS [Member]
Debt Securities, Held-to-maturity, Maturity [Abstract]
Due in one year or less - Amortized Cos		3,090	3,090
Due in one year or less - Carrying Value	[2]	3,090	3,090
Due in one year or less - Fair Value		3,083	3,089
Due after one year through five years - Amortized Cost		0	0
Due after one year through five years - Carrying Value	[2]	0	0
Due after one year through five years - Fair Value		0	0
Due after five years through 10 years - Amortized Cost		15,405	15,405
Due after five years through 10 years - Carrying Value	[2]	15,405	15,405
Due after five years through 10 years - Fair Value		14,903	15,270
Due after 10 years - Amortized Cost		61,185	68,755
Due after 10 years - Carrying Value	[2]	61,185	68,755
Due after 10 years - Fair Value		51,375	65,046
Amortized Cost		79,680	87,250
Carrying Value	[2]	79,680	87,250
Fair Value		69,361	83,405
MBS [Member]
Debt Securities, Held-to-maturity, Maturity [Abstract]
Amortized Cost	[1],[4]	653,967	859,892
Carrying Value	[2],[4]	597,208	783,857
Fair Value	[4]	$ 664,609	$ 952,005
[1]	Amortized cost of held-to-maturity securities includes adjustments made to the cost basis of an investment for accretion, amortization, and collection of cash. Amortized cost excludes accrued interest receivable of $1.6 million and $2.0 million at March 31, 2020 , and December 31, 2019 .
[2]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss and the allowance for credit losses.
[3]	Fair values of held-to-maturity securities were $ 733,970 and $1,035,410 at March 31, 2020 , and December 31, 2019 , respectively.
[4]	MBS are not presented by contractual maturity because their expected maturities will likely differ from contractual maturities because borrowers of the underlying loans may have the right to call or prepay their obligations with or without call or prepayment fees.

Investments Proceeds from Sale

Investments Proceeds from Sale and Gains and Losses on Held-to-Maturity Securities (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Debt Securities, Held-to-maturity, Sale, Excluding Other-than-temporary Impairment [Abstract]
Proceeds from sale of held-to-maturity securities	[1]	$ 161,743	$ 0
Amortized cost of held-to-maturity securities	[1]	121,010	0
Realized net gain from sale of held-to-maturity securities	[1]	$ 40,733	$ 0
[1]	The securities sold had less than 15 percent of the acquired principal outstanding at the time of the sale. Such sales are treated as maturities for the purposes of security classification. The sale does not impact our ability and intent to hold the remaining investments classified as held-to-maturity through their stated maturity dates.

Investments Narrative (Details)

Investments Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020	Dec. 31, 2019
Percentage of short-term investments in interest-bearing deposits, securities purchased under agreements to resell, and federal funds sold assets rated below triple-B	0.00%
Allowance for credit losses for securities purchased under agreements to resell	$ 0			$ 0
Net unrealized gains (losses) on trading securities	46,120,000	$ (274,000)
Increase in the allowance for credit losses as a cumulative-effect adjustment to retained earnings upon adoption of ASU 2016-13	$ (7,530,000)	0
Net credit losses recognized under previous accounting metodology		$ 103,000
Available-for-sale securities rated single-A or above, excluding private-label MBS based on amortized cost	99.80%
Held-to-maturity securities rated single-A or above, excluding private-label MBS based on amortized cost	92.40%
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 0
Allowance for credit loss on any HTM securities excluding private-label MBS	0
Interest Bearing Deposits And Federal Funds Sold [Member]
Allowance for credit loss for interest-bearing deposits and federal funds	0			0
Interest-bearing Deposits [Member]
Accrued interest receivable	294,000			682,000
Federal Funds Sold [Member]
Accrued interest receivable	8,000			37,000
Securities Borrowed Or Purchased Under Agreements To Resell [Member]
Accrued interest receivable	$ 1,000			$ 348,000
Private-label [Member]
Private-label MBS based on amortized cost rated single-A or above	0.00%
Held-to-maturity Securities [Member] | Private-label [Member]
Net decrease in allowance for credit losses	$ 1,500,000
Cumulative Effect Period Of Adoption Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Increase in the allowance for credit losses as a cumulative-effect adjustment to retained earnings upon adoption of ASU 2016-13			$ 7,500,000
Cumulative Effect Period Of Adoption Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Held-to-maturity Securities [Member] | Private-label [Member]
Increase in the allowance for credit losses as a cumulative-effect adjustment to retained earnings upon adoption of ASU 2016-13			$ 5,300,000

Advances Outstanding by Year of

Advances Outstanding by Year of Contractual Maturity (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Maturity, Rolling Year, Par Value [Abstract]
Overdrawn demand-deposit accounts		$ 2,841	$ 5,101
Due in one year or less		25,324,147	18,972,466
Due after one year through two years		11,478,292	8,600,922
Due after two years through three years		2,653,833	2,200,019
Due after three years through four years		1,756,774	1,766,314
Due after four years through five years		2,335,849	1,726,754
Thereafter		1,364,666	1,312,311
Total par value		$ 44,916,402	$ 34,583,887
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Rolling Year [Abstract]
Overdrawn demand-deposit accounts, Weighted average rate		0.57%	2.05%
Due in one year or less, Weighted average rate		1.09%	1.96%
Due after one year through two years, Weighted average rate		1.05%	2.16%
Due after two years through three years, Weighted average rate		2.15%	2.16%
Due after three years through four years, Weighted average rate		2.44%	2.71%
Due after four years through five years, Weighted average rate		1.75%	2.15%
Thereafter, Weighted average rate		2.62%	2.68%
Total Weighted average rate		1.28%	2.10%
Premiums		$ 3,227	$ 3,397
Discounts		(41,391)	(41,744)
Fair value of bifurcated derivatives	[1]	53,783	29,983
Hedging adjustments		144,202	19,840
Total Advances	[2]	45,076,223	34,595,363
Federal Home Loan Bank Advances Receivable [Member]
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Rolling Year [Abstract]
Advances - accrued interest receivable		$ 46,400	$ 48,100
[1]	At March 31, 2020 , and December 31, 2019 , we had certain advances with embedded features that met the requirements to be separated from the host contract and designated as stand-alone derivatives.
[2]	Excludes accrued interest receivable of $46.4 million and $48.1 million at March 31, 2020 , and December 31, 2019 .

Advances Outstanding by Year _2

Advances Outstanding by Year of Contractual Maturity or Next Call Date (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Call Date, Rolling Year, Par Value [Abstract]
Overdrawn demand-deposit accounts	$ 2,841	$ 5,101
Due in one year or less	34,501,542	25,116,961
Due after one year through two years	3,328,292	3,450,922
Due after two years through three years	2,300,413	1,949,499
Due after three years through four years	1,266,774	1,461,314
Due after four years through five years	2,173,774	1,309,679
Thereafter	1,342,766	1,290,411
Total par value	$ 44,916,402	$ 34,583,887

Advances Outstanding by Year _3

Advances Outstanding by Year of Contractual Maturity or Next Put Date (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, Rolling Year, Par Value [Abstract]
Overdrawn demand-deposit accounts	$ 2,841	$ 5,101
Due in one year or less	27,048,822	20,240,466
Due after one year through two years	11,616,542	8,603,422
Due after two years through three years	2,119,533	2,001,019
Due after three years through four years	1,248,574	965,814
Due after four years through five years	1,657,924	1,598,254
Thereafter	1,222,166	1,169,811
Total par value	$ 44,916,402	$ 34,583,887

Advances by Current Interest Ra

Advances by Current Interest Rate Terms (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Fixed Rate [Abstract]
Fixed-rate	$ 35,460,466	$ 28,106,591
Federal Home Loan Bank, Advances, Floating Rate [Abstract]
Variable-rate	9,455,936	6,477,296
Total par value	$ 44,916,402	$ 34,583,887

Advances Advances Prepayment Fe

Advances Advances Prepayment Fees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Federal Home Loan Bank Advances Prepayment Fees [Abstract]
Prepayment fees received from borrowers	$ 838	$ 26,186
Hedging fair-value adjustments on prepaid advances	0	527
Net discounts associated with prepaid advances	0	218
Advance prepayment fees recognized in income, net	$ 838	$ 26,931

Advances - Narratives (Details)

Advances - Narratives (Details)	Mar. 31, 2020	Dec. 31, 2019
Minimum [Member]
Federal Home Loan Bank, Advances [Line Items]
Interest rates of advances outstanding	(1.08%)	(0.35%)
Maximum [Member]
Federal Home Loan Bank, Advances [Line Items]
Interest rates of advances outstanding	7.72%	7.72%

Mortgage Loans Held for Portf_3

Mortgage Loans Held for Portfolio (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Par Value		$ 4,462,014	$ 4,432,458
Premiums		66,933	66,776
Discounts		(1,535)	(1,607)
Deferred derivative gains, net		4,562	4,124
Total mortgage loans held for portfolio	[1]	4,531,974	4,501,751
Less: allowance for credit losses		(3,500)	(500)
Total mortgage loans, net of allowance for credit losses		4,528,474	4,501,251
Real Estate Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans held for portfolio - accrued interest receivable		$ 23,500	23,500
Fixed-rate 15-year single-family mortgages
Loans and Leases Receivable Disclosure [Line Items]
Original contractual terms		15 years
Fixed-rate 15-year single-family mortgages | GSE - single-family [Member]
Loans and Leases Receivable Disclosure [Line Items]
Par Value		$ 327,700	339,042
Fixed-rate 20- and 30-year single-family mortgages | GSE - single-family [Member]
Loans and Leases Receivable Disclosure [Line Items]
Par Value		$ 4,134,314	$ 4,093,416
Minimum [Member] | Fixed-rate 20- and 30-year single-family mortgages
Loans and Leases Receivable Disclosure [Line Items]
Original contractual terms		20 years
Maximum [Member] | Fixed-rate 20- and 30-year single-family mortgages
Loans and Leases Receivable Disclosure [Line Items]
Original contractual terms		30 years
[1]	Excludes accrued interest receivable of $23.5 million at both March 31, 2020 , and December 31, 2019

Mortgage Loans Held for Portf_4

Mortgage Loans Held for Portfolio by Collateral/Guarantee Type (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Total par value	$ 4,462,014	$ 4,432,458
Conventional Mortgage Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total par value	4,180,145	4,140,255
US Government Agency Insured Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total par value	$ 281,869	$ 292,203

Credit Quality Indicator for Co

Credit Quality Indicator for Conventional Mortgage Loans (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total	[1]	$ 4,531,974	$ 4,501,751
Conventional Mortgage Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Origination Year - Prior to 2016	[2]	1,668,386
Origination Year - 2016 to 2020	[2]	2,575,999
Total	[2]	4,244,385
Total past due	[2]		53,943
Total current loans	[2]		4,171,676
Total mortgage loans	[2]		4,225,619
Past due 30-59 days delinquent [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Origination Year - Prior to 2016	[2]	14,166
Origination Year - 2016 to 2020	[2]	14,575
Total	[2]	28,741
Total past due	[2]		36,336
Past due 60-89 days delinquent [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Origination Year - Prior to 2016	[2]	3,502
Origination Year - 2016 to 2020	[2]	3,717
Total	[2]	7,219
Total past due	[2]		6,911
Past due 90 days or more delinquent [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Origination Year - Prior to 2016	[2]	6,830
Origination Year - 2016 to 2020	[2]	4,129
Total	[2]	10,959
Total past due	[2]		$ 10,696
Nonperforming Financial Instruments [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Origination Year - Prior to 2016	[2]	24,498
Origination Year - 2016 to 2020	[2]	22,421
Total	[2]	46,919
Performing Financial Instruments [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Origination Year - Prior to 2016	[2]	1,643,888
Origination Year - 2016 to 2020	[2]	2,553,578
Total	[2]	$ 4,197,466
[1]	Excludes accrued interest receivable of $23.5 million at both March 31, 2020 , and December 31, 2019
[2]	The amortized cost at March 31, 2020 , excludes accrued interest receivable whereas the recorded investment at December 31, 2019 , includes accrued interest receivable.

Other Delinquency Statistics (D

Other Delinquency Statistics (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Mar. 31, 2020
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]		$ 4,471
Serious delinquency rate	[2]		0.36%
Period Loan Receivable Becomes Nonaccrual Status		90 days
Conventional Mortgage Loan [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]		$ 2,816
Serious delinquency rate	[2]		0.26%
Past due 90 days or more still accruing interest			$ 0
Loans on nonaccrual status	[3]		11,890
Conventional mortgage loans on non-accrual status with no allowance for credit losses			4,600
Real Estate Loan [Member]
Financing Receivable, Past Due [Line Items]
Past due 90 days or more still accruing interest			5,317
Loans on nonaccrual status	[3]		11,890
US Government Agency Insured Loans [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]		$ 1,655
Serious delinquency rate	[2]		1.85%
Past due 90 days or more still accruing interest			$ 5,317
Loans on nonaccrual status	[3]		$ 0
Mortgage Receivable [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]	$ 5,035
Serious delinquency rate	[2]	0.36%
Past due 90 days or more still accruing interest		$ 5,570
Loans on nonaccrual status	[3]	11,510
Mortgage Receivable [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]	$ 2,813
Serious delinquency rate	[2]	0.26%
Past due 90 days or more still accruing interest		$ 0
Loans on nonaccrual status	[3]	11,510
Mortgage Receivable [Member] | US Government Agency Insured Loans [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]	$ 2,222
Serious delinquency rate	[2]	1.86%
Past due 90 days or more still accruing interest		$ 5,570
Loans on nonaccrual status	[3]	$ 0
[1]	Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu of foreclosure has been reported.
[2]	Loans that are 90 days or more past due or in the process of foreclosure expressed as a percentage of the recorded investment in the total loan portfolio class.
[3]	Includes conventional mortgage loans with contractual principal or interest payments 90 days or more past due and not accruing interest as well as loans modified within the previous six months under our temporary loan modification plan. As of March 31, 2020 , $4.6 million of these conventional mortgage loans on non-accrual status did not have an associated allowance for credit losses.

Allowance for Credit Losses on

Allowance for Credit Losses on Conventional Mortgage Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 500
Provision for credit losses	(684)	$ 3
Balance, end of period	3,500
Conventional Mortgage Loan [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	500	500
Charge-offs	(77)	(3)
Provision for credit losses	856	3
Balance, end of period	3,500	500
Accounting Standards Update 2016-13 [Member] | Conventional Mortgage Loan [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Adjustment for cumulative effect of accounting change	$ 2,221	$ 0

Mortgage Loans Held for Portf_5

Mortgage Loans Held for Portfolio Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses - mortgage loans held for portfolio	$ 3,500	$ 500
US Government Agency Insured Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses - mortgage loans held for portfolio	$ 0	$ 0

Derivatives in Statement of Con

Derivatives in Statement of Condition (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		$ 17,066,675	$ 15,097,316
Derivative Assets, before netting and collateral adjustments		30,859	15,329
Derivative Liabilities, before netting and collateral adjustments		(104,649)	(43,805)
Derivative Asset, netting adjustments and cash collateral including related accrued interest	[1],[2]	196,861	144,402
Derivative Liability, netting adjustments and cash collateral including related accrued interest	[1],[2]	80,245	33,534
Derivative assets		227,720	159,731
Derivative liabilities		(24,404)	(10,271)
Cash collateral and related accrued interest posted		278,300	178,500
Cash collateral and related accrued interest received		1,200	561
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		12,825,610	12,145,105
Derivative Assets, before netting and collateral adjustments		30,684	14,753
Derivative Liabilities, before netting and collateral adjustments		(48,635)	(12,805)
Designated as Hedging Instrument [Member] | Interest-rate swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		12,808,610	12,128,105
Derivative Assets, before netting and collateral adjustments		30,660	14,734
Derivative Liabilities, before netting and collateral adjustments		(48,635)	(12,805)
Designated as Hedging Instrument [Member] | Forward-start interest-rate swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		17,000	17,000
Derivative Assets, before netting and collateral adjustments		24	19
Derivative Liabilities, before netting and collateral adjustments		0	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		4,241,065	2,952,211
Derivative Assets, before netting and collateral adjustments		175	576
Derivative Liabilities, before netting and collateral adjustments		(56,014)	(31,000)
Not Designated as Hedging Instrument [Member] | Interest-rate swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		4,142,300	2,902,300
Derivative Assets, before netting and collateral adjustments		28	349
Derivative Liabilities, before netting and collateral adjustments		(55,319)	(31,000)
Mortgage Receivable [Member] | Not Designated as Hedging Instrument [Member] | Mortgage-delivery commitments [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	[3]	98,765	49,911
Derivative Assets, before netting and collateral adjustments	[3]	147	227
Derivative Liabilities, before netting and collateral adjustments	[3]	$ (695)	$ 0
[1]	Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty. Cash collateral and related accrued interest posted was $278.3 million and $178.5 million at March 31, 2020 , and December 31, 2019 , respectively. The change in cash collateral posted is included in the net change in interest-bearing deposits in the statement of cash flows. Cash collateral and related accrued interest received was $1.2 million and $561 thousand at March 31, 2020 , and December 31, 2019 .
[2]	These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
[3]	Mortgage-delivery commitments are classified as derivatives with changes in fair value recorded in other income.

Derivatives in Statement of Inc

Derivatives in Statement of Income and Impact on Interest Income/Expense (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Interest income on advances		$ 168,659	$ 247,877
Interest income on available-for-sale securities		12,361	21,291
Interest expense on consolidated obligations bonds		(123,547)	(154,817)
Advances [Member] | Interest Rate Contract [Member] | Interest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives		(127,568)	(24,897)
Hedge items		124,692	25,672
Net changes in fair value before price alignment interest		(2,876)	775
Price alignment interest	[1]	389	286
Net interest settlements on derivatives	[2],[3]	(2,625)	16,251
Net (losses) gains on qualifying fair-value hedging relationships		(5,112)	17,312
Amortization/accretion of discontinued hedging relationships		(337)	(444)
Net (losses) gains on derivatives and hedging activities recorded in net interest income		(5,449)	16,868
Available-for-sale Securities [Member] | Interest Rate Contract [Member] | Interest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives		(376,494)	(23,197)
Hedge items		366,518	19,115
Net changes in fair value before price alignment interest		(9,976)	(4,082)
Price alignment interest	[1]	1,035	8
Net interest settlements on derivatives	[2],[3]	(9,098)	(5,791)
Net (losses) gains on qualifying fair-value hedging relationships		(18,039)	(9,865)
Amortization/accretion of discontinued hedging relationships		0	0
Net (losses) gains on derivatives and hedging activities recorded in net interest income		(18,039)	(9,865)
COs - bonds [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives		63,735	33,636
Hedge items		(64,058)	(34,633)
Net changes in fair value before price alignment interest		(323)	(997)
Price alignment interest	[1]	(177)	5
Net interest settlements on derivatives	[2],[3]	2,956	(9,080)
Net (losses) gains on qualifying fair-value hedging relationships		2,456	(10,072)
Amortization/accretion of discontinued hedging relationships		(888)	(75)
Net (losses) gains on derivatives and hedging activities recorded in net interest income		$ 1,568	$ (10,147)
[1]	Relates to derivatives for which variation margin payments are characterized as daily settled contracts.
[2]	Excludes the interest income/expense of the respective hedged items recorded in net interest income.
[3]	Represents interest income/expense on derivatives in qualifying fair-value hedging relationships. Net interest settlements on derivatives that are not in qualifying fair-value hedging relationships are reported in other income.

Net Gains (Losses) on Cash Flow

Net Gains (Losses) on Cash Flow Hedging Relationships (Details) - Forward-start interest rate swaps [Member] - COs - bonds [Member] - Designated as Hedging Instrument [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Losses reclassified from accumulated other comprehensive loss into interest expense	$ (1,757)
Losses reclassified from accumulated other comprehensive loss into interest expense		$ (786)
Other Comprehensive Income (Loss) [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gains (losses) recognized in other comprehensive income	$ (1,125)	$ (3,379)

Basis Adjustments for Fair Valu

Basis Adjustments for Fair Value Hedges (Details) $ in Thousands	Mar. 31, 2020USD ($)
Advances [Member]
Derivatives, Fair Value [Line Items]
Amortized Cost of Hedged Asset/(Liability)	$ 6,241,203	[1]
Basis Adjustments for Active Hedging Relationships Included in Amortized Cost	187,480
Basis Adjustments for Discontinued Hedging Relationships Included in Amortized Cost	10,505
Cumulative Amount of Fair Value Hedging Basis Adjustments	197,985
Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Amortized Cost of Hedged Asset/(Liability)	4,419,656	[1]
Basis Adjustments for Active Hedging Relationships Included in Amortized Cost	595,088
Basis Adjustments for Discontinued Hedging Relationships Included in Amortized Cost	0
Cumulative Amount of Fair Value Hedging Basis Adjustments	595,088
COs - bonds [Member]
Derivatives, Fair Value [Line Items]
Amortized Cost of Hedged Asset/(Liability)	3,130,935	[1]
Basis Adjustments for Active Hedging Relationships Included in Amortized Cost	59,218
Basis Adjustments for Discontinued Hedging Relationships Included in Amortized Cost	41,687
Cumulative Amount of Fair Value Hedging Basis Adjustments	$ 100,905
[1]	Includes only the portion of amortized cost representing the hedged items in fair-value hedging relationships.

Derivatives in Statement of I_2

Derivatives in Statement of Income and Impact on Other Income/Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Total net (losses) gains related to derivatives not designated as hedging instruments		$ (52,558)	$ 548
Net (losses) gains on derivatives not designated as hedging instruments		(52,558)	548
Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net (losses) gains related to derivatives not designated as hedging instruments			548
Price alignment interest	[1]		0
Net (losses) gains on derivatives not designated as hedging instruments			548
Gain (Loss) on Derivative Instruments [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Price alignment interest	[1]	73
Gain (Loss) on Derivative Instruments [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net (losses) gains related to derivatives not designated as hedging instruments		(52,558)
Net (losses) gains on derivatives not designated as hedging instruments		(52,558)
Interest-rate swaps [Member] | Gain (Loss) on Derivative Instruments [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net (losses) gains related to derivatives not designated as hedging instruments		(52,569)	(60)
Net (losses) gains on derivatives not designated as hedging instruments		(52,569)	(60)
Mortgage Receivable [Member] | Mortgage-delivery commitments [Member] | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net (losses) gains related to derivatives not designated as hedging instruments		(62)	608
Net (losses) gains on derivatives not designated as hedging instruments		$ (62)	$ 608
[1]	Relates to derivatives for which variation margin payments are characterized as daily settled contracts.

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities Narratives (Details) - USD ($)		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018	Mar. 28, 2019
Derivative [Line Items]
Variation margin cash payment reported as a finacing activity in the statements of cash flows		$ 107,123,000	$ 4,002,000
Reclassifications from accumulated other comprehensive loss into earnings as a result of the discontinuance of cash-flow hedges		$ 0	$ 0	$ 0
Maximum length of time which we are hedging our exposure to the variability in future cash flows for forecasted transactions		1 year
Deferred net losses on derivatives accumulated in other comprehensive loss related to cash flow hedges expected to be reclassified to earnings during the next 12 months		$ 6,800,000
Aggregate fair value of all uncleared derivatives in a net-liability position (before cash collateral and related accrued interest)		88,300,000
Post-haircut value of collateral already posted		86,200,000
Rating Downgrade from AAPlus to AA or AAMinus [Member]
Derivative [Line Items]
Incremental collateral	[1]	579,000
Rating Downgrade From AAMinus to APlus, A or AMinus [Member]
Derivative [Line Items]
Incremental collateral	[1]	0
Rating Downgrade From AMinus to below AMinus [Member]
Derivative [Line Items]
Incremental collateral	[1]	7,513,000
Terminated Derivative [Member]
Derivative [Line Items]
Terminated derivatives notional amount					$ 611,900,000
Terminated derivatives settlement amount					(251,500,000)
Replacement Derivatives [Member]
Derivative [Line Items]
Replacement derivatives notional amount					611,900,000
Replacement derivatives settlement amount					$ 251,500,000
Cleared derivatives [Member]
Derivative [Line Items]
Delivered variation margin to clearing members		480,400,000
Variation margin cash payment reported as an operating activity in the statements of cash flows		373,300,000
Variation margin cash payment reported as a finacing activity in the statements of cash flows		$ 107,100,000
[1]	Ratings are expressed in this table according to S&P's conventions but include the equivalent of such rating by Moody's. If there is a split rating, the lower rating is used.

Netting of Derivative Assets an

Netting of Derivative Assets and Derivative Liabiities (Details) - USD ($) $ in Thousands		Mar. 31, 2020		Dec. 31, 2019
Derivative [Line Items]
Derivative Assets, Netting Adjustments and Cash Collateral	[1],[2]	$ 196,861		$ 144,402
Derivative liability, Netting Adjustments and Cash Collateral	[1],[2]	80,245		33,534
Derivative assets		227,720		159,731
Derivative liabilities		(24,404)		(10,271)
Derivative Asset, Fair value, amount offset against collateral		227,720		158,736
Derivative Liability, Fair value, amount offset against collateral		(2,962)		(856)
Derivative Liabilities, additional net exposure, collateral pledged to counterparties in excess of net liabilities		158		300
Uncleared derivatives [Member]
Derivative [Line Items]
Derivative Asset, total gross recognized amount		13,187		4,950
Derivative Liability, total gross recognized amount		(100,449)		(42,199)
Derivative Assets, Netting Adjustments and Cash Collateral		(13,187)	[3]	(3,519)	[4]
Derivative liability, Netting Adjustments and Cash Collateral		76,740	[3]	31,928	[4]
Derivative assets		147		1,658
Derivative liabilities		(24,404)		(10,271)
Derivative Assets, fair value of securities pledged as collateral than can be sold or repledged		0	[5]	(995)	[6]
Derivative Liabilities, fair value of securities pledged as collateral that can be sold or repledged		0	[5]	82	[6]
Derivative Assets, fair value of securities pledged as collateral that cannot be sold or repledged		0	[5]	0	[6]
Derivative Liabilities, fair value of securities pledged as collateral that cannot be sold or repledged		21,442	[5]	9,333	[6]
Derivative Asset, Fair value, amount offset against collateral		147		663
Derivative Liability, Fair value, amount offset against collateral		(2,962)		(856)
Cleared derivatives [Member]
Derivative [Line Items]
Derivative Asset, total gross recognized amount		17,526		10,152
Derivative Liability, total gross recognized amount		(3,506)		(1,606)
Derivative Assets, Netting Adjustments and Cash Collateral		210,047	[3]	147,921	[4]
Derivative liability, Netting Adjustments and Cash Collateral		3,506	[3]	1,606	[4]
Derivative assets		227,573		158,073
Derivative liabilities		0		0
Derivative Assets, fair value of securities pledged as collateral than can be sold or repledged		0	[5]	0	[6]
Derivative Liabilities, fair value of securities pledged as collateral that can be sold or repledged		0	[5]	0	[6]
Derivative Assets, fair value of securities pledged as collateral that cannot be sold or repledged		0	[5]	0	[6]
Derivative Liabilities, fair value of securities pledged as collateral that cannot be sold or repledged		0	[5]	0	[6]
Derivative Asset, Fair value, amount offset against collateral		227,573		158,073
Derivative Liability, Fair value, amount offset against collateral		0		0
Mortgage Receivable [Member] | Uncleared derivatives [Member] | Mortgage-delivery commitments [Member]
Derivative [Line Items]
Derivative Asset, Mortgage delivery commitments		147		227
Derivative Liabilities, Mortgage delivery commitments		$ (695)		$ 0
[1]	Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty. Cash collateral and related accrued interest posted was $278.3 million and $178.5 million at March 31, 2020 , and December 31, 2019 , respectively. The change in cash collateral posted is included in the net change in interest-bearing deposits in the statement of cash flows. Cash collateral and related accrued interest received was $1.2 million and $561 thousand at March 31, 2020 , and December 31, 2019 .
[2]	These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
[3]	Includes gross amounts of netting adjustments and cash collateral.
[4]	Includes gross amounts of netting adjustments and cash collateral.
[5]	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At March 31, 2020 , we had additional net credit exposure of $158 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.
[6]	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At December 31, 2019 , we had additional net credit exposure of $300 thousand due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.

Deposits Narratives (Details)

Deposits Narratives (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Deposits [Abstract]
Interest-bearing deposits demand and overnight	$ 782,943	$ 613,143
Interest-bearing deposits Term	1,200	800
Interest-bearing deposits other	1,639	2,589
Non-interest bearing deposits other	74,034	57,777
Total deposits	$ 859,816	$ 674,309

Consolidated Obligations CO Bon

Consolidated Obligations CO Bonds Outstanding by Contractual Maturity (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Schedule of Short-term and Long-term Debt [Line Items]
Due in one year or less		$ 11,488,560	$ 9,455,725
Due in one year or less, weighted average rate	[1]	1.13%	2.03%
Due after one year through two years		$ 4,990,405	$ 6,442,960
Due after one year through two years, weighted average rate	[1]	1.80%	2.02%
Due after two years through three years		$ 2,269,475	$ 2,154,920
Due after two years through three years, weighted average rate	[1]	2.07%	2.18%
Due after three years through four years		$ 1,211,550	$ 1,319,915
Due after three years through four years, weighted average rate	[1]	2.47%	2.45%
Due after four years through five years		$ 1,474,280	$ 1,211,080
Due after four years through five years, weighted average rate	[1]	2.40%	2.48%
Thereafter		$ 2,978,540	$ 3,220,205
Thereafter, weighted average rate	[1]	3.43%	3.33%
Total par value		$ 24,412,810	$ 23,804,805
Hedging adjustments		100,905	32,066
Total		$ 24,576,586	$ 23,888,493
COs - bonds [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Total par value, weighted average rate	[1]	1.78%	2.26%
Premiums		$ 74,030	$ 63,056
Discounts		$ (11,159)	$ (11,434)
[1]	The CO bonds' weighted-average rate excludes concession fees.

Consolidated Obligations CO B_2

Consolidated Obligations CO Bonds Outstanding By Call Feature (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Short-term and Long-term Debt [Line Items]
Total par value	$ 24,412,810	$ 23,804,805
Noncallable and nonputable [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Total par value	21,805,810	20,954,805
Callable [Member]
Schedule of Short-term and Long-term Debt [Line Items]
Total par value	$ 2,607,000	$ 2,850,000

Consolidated Obligations CO B_3

Consolidated Obligations CO Bonds Outstanding by Contractual Maturity or Next Call Date (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Due in one year or less	$ 11,488,560	$ 9,455,725
Due after one year through two years	4,990,405	6,442,960
Due after two years through three years	2,269,475	2,154,920
Due after three years through four years	1,211,550	1,319,915
Due after four years through five years	1,474,280	1,211,080
Thereafter	2,978,540	3,220,205
Total par value	24,412,810	23,804,805
Earlier Of Contractual Maturity Or Next Call Date [Member]
Debt Instrument [Line Items]
Due in one year or less	13,165,560	11,297,725
Due after one year through two years	5,055,405	6,432,960
Due after two years through three years	2,189,475	2,019,920
Due after three years through four years	1,209,550	1,332,915
Due after four years through five years	1,134,280	926,080
Thereafter	1,658,540	1,795,205
Total par value	$ 24,412,810	$ 23,804,805

Consolidated Obligations CO B_4

Consolidated Obligations CO Bonds by Interest Rate-Payment Type (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total par value		$ 24,412,810	$ 23,804,805
Fixed-rate [Member]
Debt Instrument [Line Items]
Total par value		17,068,810	17,681,805
Simple variable-rate [Member]
Debt Instrument [Line Items]
Total par value		6,959,000	5,568,000
Step-up [Member]
Debt Instrument [Line Items]
Total par value	[1]	$ 385,000	$ 555,000
[1]	Step-up bonds pay interest at increasing fixed rates for specified intervals over the life of the CO bond and can be called at our option on the step-up dates.

Consolidated Obligations CO - D

Consolidated Obligations CO - Discount Notes Outstanding (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Federal Home Loan Bank, Consolidated Obligations, Discount Notes		$ 39,692,253	$ 27,681,169
Par value		$ 39,743,071	$ 27,733,146
Weighted Average Rate	[1]	1.10%	1.59%
[1]	The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable Housing Program Narr

Affordable Housing Program Narratives (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Affordable Housing Program [Roll Forward]
Balance at beginning of period	$ 86,131	$ 83,965	$ 83,965
AHP expense for the period	4,636	6,085	21,302
AHP direct grant disbursements	(4,672)	$ (2,281)	(15,723)
AHP subsidy for AHP advance disbursements	(1,026)		(3,450)
Return of previously disbursed grants and subsidies	13		37
Balance at end of period	$ 85,082		$ 86,131

Capital Requirements (Details)

Capital Requirements (Details) $ in Thousands	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Capital [Abstract]
Capital-to-asset ratio, Required	4.00%	4.00%
Leverage capital-to-assets ratio, Required	5.00%	5.00%
Multiplier for Determining Permanent Capital in Leverage Capital Calculation	1.5
Class B capital stock	$ 2,266,329	$ 1,869,130
Mandatorily redeemable capital stock	6,112	5,806
Retained earnings	1,473,149	1,463,154
Total permanent capital	3,745,590	3,338,090
Credit-risk capital	212,510	235,213
Market-risk capital	155,678	207,426
Operations-risk capital	110,456	132,792
Total risk-based capital requirement	478,644	575,431
Permanent capital in excess of risk-based capital requirement	3,266,946	2,762,659
Risk-based capital, Actual	3,745,590	3,338,090
Regulatory capital, Required	2,756,035	2,226,512
Regulatory capital, Actual	$ 3,745,590	$ 3,338,090
Capital-to-asset ratio, Actual	5.40%	6.00%
Leverage capital, Actual	$ 5,618,385	$ 5,007,135
Leverage capital, Required	$ 3,445,043	$ 2,783,141
Leverage capital-to-assets ratio, Actual	8.20%	9.00%

Capital Narratives (Details)

Capital Narratives (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Jan. 16, 2019
Certain member assets eligible to secure advances [Member]
Class B stock purchase requirement percentage	0.20%
Overnight advances [Member]
Class B stock purchase requirement percentage	3.00%
All other advances greater than overnight [Member]
Class B stock purchase requirement percentage	4.00%
Outstanding letters of credit [Member]
Class B stock purchase requirement percentage	0.25%
Certain member assets eligible to secure advances prior to January 16, 2019 [Member]
Class B stock purchase requirement percentage			0.35%
Common Class B [Member]
Common Stock, Class B, putable par value per share	$ 100	$ 100
Minimum [Member] | Certain member assets eligible to secure advances [Member]
Class B stock purchase requirement amount	$ 10
Minimum [Member] | Certain member assets eligible to secure advances prior to January 16, 2019 [Member]
Class B stock purchase requirement amount			$ 10
Maximum [Member] | Certain member assets eligible to secure advances [Member]
Class B stock purchase requirement amount	$ 10,000
Maximum [Member] | Certain member assets eligible to secure advances prior to January 16, 2019 [Member]
Class B stock purchase requirement amount			$ 25,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) Before Tax1 [Roll Forward]
Beginning of period		$ 3,145,312	$ 3,607,359
Cumulative effect of change in accounting principle		(7,530)	0
Other comprehensive income (loss)		(61,265)	37,874
Period end		3,491,241	2,963,804
Net Unrealized Loss Relating to Hedging Activities [Member]
Accumulated Other Comprehensive Income (Loss) Before Tax1 [Roll Forward]
Beginning of period		(30,207)	(29,119)
Cumulative effect of change in accounting principle			(175)
Net unrealized gains (losses)		(1,125)	(3,379)
Amortization - hedging activities	[1]	1,757	786
Other comprehensive income (loss)		632	(2,593)
Period end		(29,575)	(31,887)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) Before Tax1 [Roll Forward]
Beginning of period		(6,807)	(5,276)
Net actuarial loss		501
Amortization - pension and postretirement benefits	[2]	295	161
Other comprehensive income (loss)		796	161
Period end		(6,011)	(5,115)
Total [Member]
Accumulated Other Comprehensive Income (Loss) Before Tax1 [Roll Forward]
Beginning of period		(186,972)	(316,507)
Cumulative effect of change in accounting principle			(175)
Net unrealized gains (losses)		(86,862)	30,686
Noncredit other-than-temporary impairment losses			(80)
Noncredit losses included in basis of securities sold		20,239
Accretion of noncredit loss		2,805	6,291
Net actuarial loss		501
Noncredit other-than-temporary impairment losses reclassified to credit loss	[3]		30
Amortization - hedging activities	[1]	1,757	786
Amortization - pension and postretirement benefits	[2]	295	161
Other comprehensive income (loss)		(61,265)	37,874
Period end		(248,237)	(278,808)
Available-for-sale Securities [Member] | Net Unrealized Loss on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) Before Tax1 [Roll Forward]
Beginning of period		(73,922)	(152,958)
Net unrealized gains (losses)		(85,737)	34,065
Other comprehensive income (loss)		(85,737)	34,065
Period end		(159,659)	(118,893)
Held-to-maturity Securities [Member] | Noncredit Portion of Other-Than-Temporary Impairment Losses on Held-to-Maturity Securities [Member]
Accumulated Other Comprehensive Income (Loss) Before Tax1 [Roll Forward]
Beginning of period		(76,036)	(129,154)
Noncredit other-than-temporary impairment losses			(80)
Noncredit losses included in basis of securities sold		20,239
Accretion of noncredit loss		2,805	6,291
Noncredit other-than-temporary impairment losses reclassified to credit loss	[3]		30
Other comprehensive income (loss)		23,044	6,241
Period end		$ (52,992)	$ (122,913)
[1]	Recorded in CO bond interest expense.
[2]	Recorded in other expenses in the statement of operations.
[3]	Recorded in other income (loss) in the statement of operations.

Carrying Value and Fair Value o

Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		$ 806,985	$ 69,416
Trading securities		3,563,368	2,250,264
Available-for-sale securities Fair Value		7,246,334	7,409,000
Held-to-maturity securities	[1],[2]	676,888	871,107
Fair value of held-to-maturity securities		733,970	1,035,410
Accrued interest receivable		109,878	112,163
Derivative assets		227,720	159,731
Derivative Assets, Netting Adjustments and Cash Collateral	[3],[4]	196,861	144,402
Mandatorily redeemable capital stock		(6,112)	(5,806)
Accrued interest payable		(108,010)	(104,477)
Derivative liabilities		(24,404)	(10,271)
Derivative liability, Netting Adjustments and Cash Collateral	[3],[4]	80,245	33,534
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		806,985	69,416
Interest-bearing deposits		1,130,563	1,253,873
Securities purchased under agreements to resell		0	0
Federal funds sold		0	0
Trading securities	[5]	0	0
Available-for-sale securities Fair Value	[5]	0	0
Fair value of held-to-maturity securities		0	0
Advances		0	0
Mortgage loans, net		0	0
Accrued interest receivable		0	0
Derivative assets	[5]	0	0
Other assets	[5]	16,238	13,894
Deposits		0	0
Mandatorily redeemable capital stock		(6,112)	(5,806)
Accrued interest payable		0	0
Derivative liabilities	[5]	0	0
Level 1 [Member] | Commitments to make additional advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		0	0
Level 1 [Member] | Standby Letters of Credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		0	0
Level 1 [Member] | COs - Discount notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount notes		0	0
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		0	0
Interest-bearing deposits		0	0
Securities purchased under agreements to resell		1,999,954	3,500,003
Federal funds sold		3,454,927	859,999
Trading securities	[5]	3,563,368	2,250,264
Available-for-sale securities Fair Value	[5]	7,180,939	7,344,348
Fair value of held-to-maturity securities		384,446	456,942
Advances		45,434,302	34,735,775
Mortgage loans, net		4,747,540	4,615,737
Accrued interest receivable		109,878	112,163
Derivative assets	[5]	30,859	15,329
Other assets	[5]	14,688	18,045
Deposits		(859,815)	(674,269)
Mandatorily redeemable capital stock		0	0
Accrued interest payable		(108,010)	(104,477)
Derivative liabilities	[5]	(104,649)	(43,805)
Level 2 [Member] | Commitments to make additional advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(2,623)	(3,884)
Level 2 [Member] | Standby Letters of Credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(1,540)	(1,723)
Level 2 [Member] | COs - Discount notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount notes		(39,735,774)	(27,681,470)
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		0	0
Interest-bearing deposits		0	0
Securities purchased under agreements to resell		0	0
Federal funds sold		0	0
Trading securities	[5]	0	0
Available-for-sale securities Fair Value	[5]	65,395	64,652
Fair value of held-to-maturity securities		349,524	578,468
Advances		0	0
Mortgage loans, net		19,195	18,404
Accrued interest receivable		0	0
Derivative assets	[5]	0	0
Other assets	[5]	0	0
Deposits		0	0
Mandatorily redeemable capital stock		0	0
Accrued interest payable		0	0
Derivative liabilities	[5]	0	0
Level 3 [Member] | Commitments to make additional advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		0	0
Level 3 [Member] | Standby Letters of Credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		0	0
Level 3 [Member] | COs - Discount notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount notes		0	0
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		806,985	69,416
Interest-bearing deposits		1,130,563	1,253,873
Securities purchased under agreements to resell		2,000,000	3,500,000
Federal funds sold		3,455,000	860,000
Trading securities	[5]	3,563,368	2,250,264
Available-for-sale securities Fair Value	[5]	7,246,334	7,409,000
Held-to-maturity securities		676,888	871,107
Advances		45,076,223	34,595,363
Mortgage loans, net		4,528,474	4,501,251
Accrued interest receivable		109,878	112,163
Derivative assets	[5]	227,720	159,731
Other assets	[5]	30,926	31,939
Deposits		(859,816)	(674,309)
Mandatorily redeemable capital stock		(6,112)	(5,806)
Accrued interest payable		(108,010)	(104,477)
Derivative liabilities	[5]	(24,404)	(10,271)
Carrying Value [Member] | Commitments to make additional advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		0	0
Carrying Value [Member] | Standby Letters of Credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(1,540)	(1,723)
Carrying Value [Member] | COs - Discount notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount notes		(39,692,253)	(27,681,169)
Total Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		806,985	69,416
Interest-bearing deposits		1,130,563	1,253,873
Securities purchased under agreements to resell		1,999,954	3,500,003
Federal funds sold		3,454,927	859,999
Trading securities	[5]	3,563,368	2,250,264
Available-for-sale securities Fair Value	[5]	7,246,334	7,409,000
Fair value of held-to-maturity securities		733,970	1,035,410
Advances		45,434,302	34,735,775
Mortgage loans, net		4,766,735	4,634,141
Accrued interest receivable		109,878	112,163
Derivative assets	[5]	227,720	159,731
Other assets	[5]	30,926	31,939
Deposits		(859,815)	(674,269)
Mandatorily redeemable capital stock		(6,112)	(5,806)
Accrued interest payable		(108,010)	(104,477)
Derivative liabilities	[5]	(24,404)	(10,271)
Total Fair Value [Member] | Commitments to make additional advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(2,623)	(3,884)
Total Fair Value [Member] | Standby Letters of Credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(1,540)	(1,723)
Total Fair Value [Member] | COs - Discount notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount notes		(39,735,774)	(27,681,470)
COs - bonds [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Bonds		0	0
COs - bonds [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Bonds		(25,122,573)	(24,226,123)
COs - bonds [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Bonds		0	0
COs - bonds [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Bonds		(24,576,586)	(23,888,493)
COs - bonds [Member] | Total Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Bonds		$ (25,122,573)	$ (24,226,123)
[1]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss and the allowance for credit losses.
[2]	Fair values of held-to-maturity securities were $ 733,970 and $1,035,410 at March 31, 2020 , and December 31, 2019 , respectively.
[3]	Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty. Cash collateral and related accrued interest posted was $278.3 million and $178.5 million at March 31, 2020 , and December 31, 2019 , respectively. The change in cash collateral posted is included in the net change in interest-bearing deposits in the statement of cash flows. Cash collateral and related accrued interest received was $1.2 million and $561 thousand at March 31, 2020 , and December 31, 2019 .
[4]	These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
[5]	Carried at fair value and measured on a recurring basis.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		$ 3,563,368	$ 2,250,264
Available-for-sale securities Fair Value		7,246,334	7,409,000
Derivative assets		227,720	159,731
Derivative Assets, Netting Adjustments and Cash Collateral	[1],[2]	196,861	144,402
Fair value of held-to-maturity securities		733,970	1,035,410
Derivative liabilities		(24,404)	(10,271)
Derivative liability, Netting Adjustments and Cash Collateral	[1],[2]	80,245	33,534
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities	[3]	0	0
Available-for-sale securities Fair Value	[3]	0	0
Derivative assets	[3]	0	0
Other assets	[3]	16,238	13,894
Fair value of held-to-maturity securities		0	0
Mortgage loans held for portfolio		0	0
Derivative liabilities	[3]	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities	[3]	3,563,368	2,250,264
Available-for-sale securities Fair Value	[3]	7,180,939	7,344,348
Derivative assets	[3]	30,859	15,329
Other assets	[3]	14,688	18,045
Fair value of held-to-maturity securities		384,446	456,942
Mortgage loans held for portfolio		4,747,540	4,615,737
Derivative liabilities	[3]	(104,649)	(43,805)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities	[3]	0	0
Available-for-sale securities Fair Value	[3]	65,395	64,652
Derivative assets	[3]	0	0
Other assets	[3]	0	0
Fair value of held-to-maturity securities		349,524	578,468
Mortgage loans held for portfolio		19,195	18,404
Derivative liabilities	[3]	0	0
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Netting Adjustments and Cash Collateral	[4]	196,861	144,402
Derivative liability, Netting Adjustments and Cash Collateral	[4]	80,245	33,534
Recurring [Member] | Interest-rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Netting Adjustments and Cash Collateral	[4]	196,861	144,402
Derivative liability, Netting Adjustments and Cash Collateral	[4]	80,245	33,534
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Available-for-sale securities Fair Value		0	0
Derivative assets		0	0
Other assets		16,238	13,894
Total assets carried at fair value		16,238	13,894
Total liabilities carried at fair value		0	0
Recurring [Member] | Level 1 [Member] | Interest-rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,563,368	2,250,264
Available-for-sale securities Fair Value		7,180,939	7,344,348
Derivative assets		30,859	15,329
Other assets		14,688	18,045
Total assets carried at fair value		10,789,854	9,627,986
Total liabilities carried at fair value		(104,649)	(43,805)
Recurring [Member] | Level 2 [Member] | Interest-rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		30,712	15,102
Derivative liabilities		(103,954)	(43,805)
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Available-for-sale securities Fair Value		65,395	64,652
Derivative assets		0	0
Other assets		0	0
Total assets carried at fair value		65,395	64,652
Total liabilities carried at fair value		0	0
Recurring [Member] | Level 3 [Member] | Interest-rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets carried at fair value	[5]	0	0
Mortgage loans held for portfolio	[5]	0	0
REO	[5]	0	0
Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets carried at fair value	[5]	0	0
Mortgage loans held for portfolio	[5]	0	0
REO	[5]	0	0
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets carried at fair value	[5]	1,379	8,132
Mortgage loans held for portfolio	[5]	1,269	1,198
REO	[5]	110	78
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities	[3]	3,563,368	2,250,264
Available-for-sale securities Fair Value	[3]	7,246,334	7,409,000
Derivative assets	[3]	227,720	159,731
Other assets	[3]	30,926	31,939
Fair value of held-to-maturity securities		733,970	1,035,410
Mortgage loans held for portfolio		4,766,735	4,634,141
Derivative liabilities	[3]	(24,404)	(10,271)
Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,563,368	2,250,264
Available-for-sale securities Fair Value		7,246,334	7,409,000
Derivative assets		227,720	159,731
Other assets		30,926	31,939
Total assets carried at fair value		11,068,348	9,850,934
Total liabilities carried at fair value		(24,404)	(10,271)
Estimate of Fair Value Measurement [Member] | Recurring [Member] | Interest-rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		227,573	159,504
Derivative liabilities		(23,709)	(10,271)
Estimate of Fair Value Measurement [Member] | Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets carried at fair value	[5]	1,379	8,132
Mortgage loans held for portfolio	[5]	1,269	1,198
REO	[5]	110	78
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		5,330	5,896
Corporate bonds [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Corporate bonds [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		5,330	5,896
Corporate bonds [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Corporate bonds [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		5,330	5,896
US Treasury obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,554,179	2,240,236
US Treasury obligations [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
US Treasury obligations [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,554,179	2,240,236
US Treasury obligations [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
US Treasury obligations [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,554,179	2,240,236
U.S. government-guaranteed - single-family MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,794	4,047
Available-for-sale securities Fair Value		52,586	57,714
Fair value of held-to-maturity securities		6,762	7,116
U.S. government-guaranteed - single-family MBS [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Available-for-sale securities Fair Value		0	0
U.S. government-guaranteed - single-family MBS [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,794	4,047
Available-for-sale securities Fair Value		52,586	57,714
U.S. government-guaranteed - single-family MBS [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Available-for-sale securities Fair Value		0	0
U.S. government-guaranteed - single-family MBS [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		3,794	4,047
Available-for-sale securities Fair Value		52,586	57,714
U.S. government-guaranteed - multifamily MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		248,428	282,617
U.S. government-guaranteed - multifamily MBS [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
U.S. government-guaranteed - multifamily MBS [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		248,428	282,617
U.S. government-guaranteed - multifamily MBS [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
U.S. government-guaranteed - multifamily MBS [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		248,428	282,617
Mortgage Receivable [Member] | Recurring [Member] | Level 1 [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Mortgage Receivable [Member] | Recurring [Member] | Level 2 [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		147	227
Mortgage Receivable [Member] | Recurring [Member] | Level 3 [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Mortgage Receivable [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		147	227
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities		280,163	495,063
HFA securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		65,395	64,652
Fair value of held-to-maturity securities		69,361	83,405
HFA securities [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
HFA securities [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
HFA securities [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		65,395	64,652
HFA securities [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		65,395	64,652
Supranational institutions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		438,284	416,429
Supranational institutions [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
Supranational institutions [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		438,284	416,429
Supranational institutions [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
Supranational institutions [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		438,284	416,429
U.S. government-owned corporations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		314,724	296,761
U.S. government-owned corporations [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
U.S. government-owned corporations [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		314,724	296,761
U.S. government-owned corporations [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
U.S. government-owned corporations [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		314,724	296,761
GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		133,789	123,786
GSE [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
GSE [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		133,789	123,786
GSE [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
GSE [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		133,789	123,786
GSE - single-family [Member] | Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		65	85
Available-for-sale securities Fair Value		2,342,640	2,590,271
Fair value of held-to-maturity securities		286,239	308,555
GSE - single-family [Member] | Government Sponsored Enterprises [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Available-for-sale securities Fair Value		0	0
GSE - single-family [Member] | Government Sponsored Enterprises [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		65	85
Available-for-sale securities Fair Value		2,342,640	2,590,271
GSE - single-family [Member] | Government Sponsored Enterprises [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		0	0
Available-for-sale securities Fair Value		0	0
GSE - single-family [Member] | Government Sponsored Enterprises [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total trading securities		65	85
Available-for-sale securities Fair Value		2,342,640	2,590,271
GSE - multifamily [Member] | Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		3,650,488	3,576,770
Fair value of held-to-maturity securities		91,445	141,271
GSE - multifamily [Member] | Government Sponsored Enterprises [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
GSE - multifamily [Member] | Government Sponsored Enterprises [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		3,650,488	3,576,770
GSE - multifamily [Member] | Government Sponsored Enterprises [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		0	0
GSE - multifamily [Member] | Government Sponsored Enterprises [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities Fair Value		3,650,488	3,576,770
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] | Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	[5]		0
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] | Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	[5]		0
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] | Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	[5]		6,856
Residential Mortgage Backed Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] | Estimate of Fair Value Measurement [Member] | Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	[5]		$ 6,856
Mortgages [Member] | Recurring [Member] | Level 1 [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Mortgages [Member] | Recurring [Member] | Level 2 [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		(695)
Mortgages [Member] | Recurring [Member] | Level 3 [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Mortgages [Member] | Estimate of Fair Value Measurement [Member] | Recurring [Member] | Mortgage-delivery commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		$ (695)
[1]	Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty. Cash collateral and related accrued interest posted was $278.3 million and $178.5 million at March 31, 2020 , and December 31, 2019 , respectively. The change in cash collateral posted is included in the net change in interest-bearing deposits in the statement of cash flows. Cash collateral and related accrued interest received was $1.2 million and $561 thousand at March 31, 2020 , and December 31, 2019 .
[2]	These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
[3]	Carried at fair value and measured on a recurring basis.
[4]	These amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
[5]	We measure certain held-to-maturity investment securities, mortgage loans held for portfolio, and REO at fair value on a nonrecurring basis, that is, they are not measured at fair value on an ongoing basis but are subject to fair-value adjustments only in certain circumstances. The fair values presented are as of the date the fair value adjustment was recorded.

Estimated Fair Value Level 3 Re

Estimated Fair Value Level 3 Reconciliation - Roll Forward (Details) - HFA securities [Member] - Level 3 [Member] - Recurring [Member] - Available-for-sale Securities [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 64,652	$ 49,601
Unrealized gains included in other comprehensive income	743	747
Balance at end of period	$ 65,395	$ 50,348

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Value of the guarantees related to standby letters of credit		$ 57,361	$ 66,843
Maximum term of commitments to invest in mortgage loans		60 days
Other FHLBanks [Member]
Loss Contingencies [Line Items]
Par value of other FHLBanks' outstanding COs for which we are jointly and severally liable		$ 1,100,000,000	974,400,000
Maximum [Member]
Loss Contingencies [Line Items]
Standby letters of credit, original terms		20 years
Standby letters of credit, current terms		10 years
Standby letters of credit [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[1],[2]	$ 7,468,699	7,484,754
Off-balance-sheet Commitments Expiring After One Year	[1],[2]	216,679	215,014
Total Off-balance Sheet Commitments	[1],[2]	7,685,378	7,699,768
Value of the guarantees related to standby letters of credit		1,500	1,700
Commitments of unused lines of credit - advances [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[2],[3]	1,134,788	1,143,828
Off-balance-sheet Commitments Expiring After One Year	[2],[3]	0	0
Total Off-balance Sheet Commitments	[2],[3]	$ 1,134,788	1,143,828
Commitments of unused lines of credit - advances [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Period for commitments for unused line-of-credit advances		12 months
Commitments to make additional advances [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[2]	$ 277,891	434,253
Off-balance-sheet Commitments Expiring After One Year	[2]	70,320	88,167
Total Off-balance Sheet Commitments	[2]	348,211	522,420
Unsettled CO bonds, at par [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[2]	711,500	0
Off-balance-sheet Commitments Expiring After One Year	[2]	0	0
Total Off-balance Sheet Commitments	[2]	711,500	0
Unsettled CO discount notes, at par [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[2]	1,227,230	500,000
Off-balance-sheet Commitments Expiring After One Year	[2]	0	0
Total Off-balance Sheet Commitments	[2]	1,227,230	500,000
Standby Letters of Credit Issuance Commitments [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year		11,500	27,200
Off-balance-sheet Commitments Expiring After One Year		550	1,800
Mortgage Receivable [Member] | Commitments to invest in mortgage loans [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[2]	98,765	49,911
Off-balance-sheet Commitments Expiring After One Year	[2]	0	0
Total Off-balance Sheet Commitments	[2]	$ 98,765	$ 49,911
[1]	The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year. At March 31, 2020 , and December 31, 2019 , these amounts totaled $ 11.5 million and $27.2 million , respectively. Also excluded are commitments to issue standby letters of credit that expire after one year totaling $550 thousand and $1.8 million at March 31, 2020 , and December 31, 2019 , respectively.
[2]	We have deemed it unnecessary to record any liability for credit losses on these agreements.
[3]	Commitments for unused line-of-credit advances are generally for periods of up to 12 months . Since many of these commitments are not expected to be drawn upon, the total commitment amount does not necessarily indicate future liquidity requirements.

Transactions with Shareholder_2

Transactions with Shareholders (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Transactions with Shareholders [Line Items]
Capital Stock Outstanding	$ 2,266,329		$ 1,869,130
Par Value of Advances	44,916,402		34,583,887
Total Accrued Interest Receivable	109,878		112,163
Interest income on advances	168,659	$ 247,877
Fees on letters of credit	3,322	2,964
Citizens Bank, N.A. [Member]
Transactions with Shareholders [Line Items]
Capital Stock Outstanding	$ 342,580		$ 222,684
Percent of Total Capital Stock Outstanding	15.10%		11.90%
Par Value of Advances	$ 8,005,678		$ 5,005,773
Percentage of total par value of advances	17.80%		14.50%
Total Accrued Interest Receivable	$ 1,072		$ 1,678
Percent of Total Accrued Interest Receivable on Advances	2.30%		3.50%
Interest income on advances	$ 23,750	$ 39,113
Percent of total advances interest income	14.10%	15.80%
Fees on letters of credit	$ 1,586	$ 1,878
Percent of total fees on letters of credit	61.80%	81.40%
Directors' Financial Institutions [Member]
Transactions with Shareholders [Line Items]
Capital Stock Outstanding	$ 452,365		$ 112,811
Percent of Total Capital Stock Outstanding	19.90%		6.00%
Par Value of Advances	$ 10,137,669		$ 2,224,141
Percentage of total par value of advances	22.60%		6.40%
Total Accrued Interest Receivable	$ 4,120		$ 3,581
Percent of Total Accrued Interest Receivable on Advances	8.90%		7.40%
Minimum [Member]
Transactions with Shareholders [Line Items]
Definition of shareholder concentration, minimum percent	10.00%

Subsequent Events (Details)

Subsequent Events (Details) - Common Class B [Member] - Subsequent Event [Member] - USD ($) $ in Millions	May 04, 2020	Apr. 24, 2020
Subsequent Event [Line Items]
Annualized rate of cash dividend		5.06%
Dividend, including dividends on mandatorily redeemable capital stock	$ 24.2