Federal Home Loan Bank of Boston 10-Q 7 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Entity Information [Line Items]
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Entity Registrant Name	Federal Home Loan Bank of Boston
Entity Central Index Key	1,331,463
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
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		25,613,237

Statements of Condition (unaudi

Statements of Condition (unaudited) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
ASSETS
Cash and due from banks		$ 844,228	$ 1,124,536
Interest-bearing deposits		267	163
Securities purchased under agreements to resell		5,050,000	5,250,000
Federal funds sold		3,530,000	2,550,000
Investment securities:
Trading securities		237,414	244,969
Available-for-sale securities - includes $21,817 and $641 pledged as collateral at June 30, 2015, and December 31, 2014, that may be repledged		6,011,270	5,481,978
Held-to-maturity securities - includes $64,334 and $66,279 pledged as collateral at June 30, 2015, and December 31, 2014, respectively that may be repledged	[1],[2]	2,939,093	3,352,189
Total investment securities		9,187,777	9,079,136
Advances		34,105,443	33,482,074
Mortgage loans held for portfolio, net of allowance for credit losses of $1,100 and $2,012 at June 30, 2015, and December 31, 2014, respectively		3,574,835	3,483,948
Accrued interest receivable		77,828	77,411
Premises, software, and equipment, net		3,693	3,951
Derivative assets, net		28,443	14,548
Other assets		47,351	40,910
Total Assets		56,449,865	55,106,677
LIABILITIES
Interest-bearing		371,616	345,561
Non-interest-bearing		30,450	23,770
Total deposits		402,066	369,331
Consolidated obligations (COs):
Bonds		26,075,429	25,505,774
Discount notes		25,972,593	25,309,608
Total consolidated obligations		52,048,022	50,815,382
Mandatorily redeemable capital stock		57,268	298,599
Accrued interest payable		79,508	91,225
Affordable Housing Program (AHP) payable		77,600	66,993
Derivative liabilities, net		476,415	558,889
Other liabilities		157,951	28,472
Total liabilities		$ 53,298,830	$ 52,228,891
Commitments and contingencies (Note 18)
CAPITAL
Capital stock – Class B – putable ($100 par value), 24,822 shares and 24,131 shares issued and outstanding at June 30, 2015, and December 31, 2014, respectively		$ 2,482,244	$ 2,413,114
Retained earnings:
Unrestricted		890,443	764,888
Restricted		173,411	136,770
Total retained earnings		1,063,854	901,658
Accumulated other comprehensive loss		(395,063)	(436,986)
Total capital		3,151,035	2,877,786
Total Liabilities and Capital		$ 56,449,865	$ 55,106,677
[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.
[2]	Fair values of held-to-maturity securities were $3,260,144 and $3,710,815 at June 30, 2015, and December 31, 2014, respectively.

Statements of Condition (Parent

Statements of Condition (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Available-for-sale securities pledged as collateral that may be repledged	$ 21,817	$ 641
Held-to-maturity securities pledged as collateral that may be repledged	64,334	66,279
Allowance for credit losses	1,100	2,012
Fair value of held-to-maturity securities	$ 3,260,144	$ 3,710,815
Common Class B [Member]
Capital stock - Class B - putable shares issued	24,822	24,131
Capital stock - Class B - putable par value per share	$ 100	$ 100
Capital stock - Class B - putable shares outstanding	24,822	24,131

Statements of Operations (unaud

Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
INTEREST INCOME
Advances	$ 58,441	$ 56,821	$ 115,849	$ 112,692
Prepayment fees on advances, net	279	768	4,021	3,262
Securities purchased under agreements to resell	1,104	788	1,907	1,381
Federal funds sold	1,223	904	2,850	1,389
Trading securities	2,296	2,351	4,614	4,705
Available-for-sale securities	23,603	14,333	44,175	27,284
Held-to-maturity securities	24,264	28,455	49,135	58,470
Prepayment fees on investments	94	931	257	1,110
Mortgage loans held for portfolio	30,190	31,459	61,241	63,218
Other	14	2	25	2
Total interest income	141,508	136,812	284,074	273,513
INTEREST EXPENSE
Consolidated obligations - bonds	79,923	80,193	162,164	155,704
Consolidated obligations - discount notes	4,909	3,873	10,422	6,895
Deposits	19	14	33	21
Mandatorily redeemable capital stock	468	2,683	803	6,274
Other borrowings	2	2	2	3
Total interest expense	85,321	86,765	173,424	168,897
NET INTEREST INCOME	56,187	50,047	110,650	104,616
(Reduction of) provision for credit losses	(223)	243	(283)	(79)
NET INTEREST INCOME AFTER (REDUCTION OF) PROVISION FOR CREDIT LOSSES	56,410	49,804	110,933	104,695
OTHER INCOME (LOSS)
Total other-than-temporary impairment losses on investment securities	(356)	0	(580)	0
Net amount of impairment losses reclassified from accumulated other comprehensive loss	(1,073)	(399)	(1,195)	(857)
Net other-than-temporary impairment losses on investment securities, credit portion	(1,429)	(399)	(1,775)	(857)
Litigation settlements	134,690	159	134,713	4,469
Loss on early extinguishment of debt	(129)	(369)	(129)	(2,592)
Service fees	2,089	1,615	4,008	3,285
Net unrealized (losses) gains on trading securities	(2,393)	2,209	(1,112)	2,963
Net losses on derivatives and hedging activities	(1,142)	(1,292)	(4,501)	(2,675)
Other	(333)	(263)	(452)	(399)
Total other income	131,353	1,660	130,752	4,194
OTHER EXPENSE
Compensation and benefits	13,865	9,066	23,298	18,857
Other operating expenses	5,303	5,243	10,156	10,312
Federal Housing Finance Agency (the FHFA)	883	576	1,903	1,384
Office of Finance	836	758	1,527	1,409
Other	563	730	1,150	1,365
Total other expense	21,450	16,373	38,034	33,327
INCOME BEFORE ASSESSMENTS	166,313	35,091	203,651	75,562
AHP	16,678	3,778	20,445	8,184
NET INCOME	$ 149,635	$ 31,313	$ 183,206	$ 67,378

Statements of Comprehensive Inc

Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 149,635	$ 31,313	$ 183,206	$ 67,378
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent [Abstract]
Net unrealized (losses) gains on available-for-sale securities	(14,793)	24,842	5,796	29,671
Net noncredit portion of other-than-temporary impairment losses on held-to-maturity securities
Net amount of impairment losses reclassified to non-interest income	1,073	399	1,195	857
Accretion of noncredit portion	11,990	12,612	23,453	24,747
Total net noncredit portion of other-than-temporary impairment losses on held-to-maturity securities	13,063	13,011	24,648	25,604
Net unrealized (losses) gains relating to hedging activities
Unrealized gains (losses)	12,773	(13,726)	630	(19,740)
Reclassification adjustment for previously deferred hedging gains and losses included in net income	5,631	724	10,527	729
Total net unrealized gains (losses) relating to hedging activities	18,404	(13,002)	11,157	(19,011)
Pension and postretirement benefits	92	(247)	322	(135)
Total other comprehensive income	16,766	24,604	41,923	36,129
Comprehensive income	$ 166,401	$ 55,917	$ 225,129	$ 103,507

Statements of Capital (unaudite

Statements of Capital (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period			$ 2,877,786	$ 2,837,745
Proceeds from sale of capital stock			98,708	86,021
Repurchase of capital stock			(29,524)	(126,296)
Shares reclassified to mandatorily redeemable capital stock			(54)	(337)
Comprehensive income	$ 166,401	$ 55,917	225,129	103,507
Cash dividends on capital stock			(21,010)	(18,609)
Period end	3,151,035	2,882,031	3,151,035	2,882,031
Retained Earnings, Unrestricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period			764,888	681,978
Comprehensive income			146,565	53,902
Cash dividends on capital stock			(21,010)	(18,609)
Period end	890,443	717,271	890,443	717,271
Retained Earnings, Restricted
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period			136,770	106,812
Comprehensive income			36,641	13,476
Period end	173,411	120,288	173,411	120,288
Retained Earnings, Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period			901,658	788,790
Comprehensive income			183,206	67,378
Cash dividends on capital stock			(21,010)	(18,609)
Period end	1,063,854	837,559	1,063,854	837,559
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period			(436,986)	(481,516)
Comprehensive income			41,923	36,129
Period end	$ (395,063)	$ (445,387)	$ (395,063)	$ (445,387)
Capital Stock Class B - Putable [Member] | Capital Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning of period, shares			24,131	25,305
Beginning of period			$ 2,413,114	$ 2,530,471
Proceeds from sale of capital stock, shares			987	860
Proceeds from sale of capital stock			$ 98,708	$ 86,021
Repurchase of capital stock, shares			(295)	(1,263)
Repurchase of capital stock			$ (29,524)	$ (126,296)
Shares reclassified to mandatorily redeemable capital stock, shares			(1)	(3)
Shares reclassified to mandatorily redeemable capital stock			$ (54)	$ (337)
Period end, shares	24,822	24,899	24,822	24,899
Period end	$ 2,482,244	$ 2,489,859	$ 2,482,244	$ 2,489,859

Statements of Cash Flows (unaud

Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
OPERATING ACTIVITIES
Net income	$ 149,635	$ 31,313	$ 183,206	$ 67,378
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization			(29,823)	(38,070)
Reduction of provision for credit losses	(223)	243	(283)	(79)
Change in net fair-value adjustments on derivatives and hedging activities			3,124	(24,262)
Net other-than-temporary impairment losses on investment securities, credit portion	1,429	399	1,775	857
Loss on early extinguishment of debt	129	369	129	2,592
Other adjustments			(202)	305
Net change in:
Market value of trading securities			1,112	(2,963)
Accrued interest receivable			(417)	8,803
Other assets			(2,412)	4,333
Accrued interest payable			(11,717)	7,391
Other liabilities			10,515	129
Total adjustments			(28,199)	(40,964)
Net cash provided by operating activities			155,007	26,414
INVESTING ACTIVITIES
Interest-bearing deposits			(15,297)	(16,491)
Securities purchased under agreements to resell			200,000	(4,050,000)
Federal funds sold			(980,000)	(1,100,000)
Premises, software, and equipment			(551)	(396)
Trading securities:
Proceeds from long-term			6,443	1,640
Available-for-sale securities:
Proceeds from long-term			441,729	974,949
Purchases of long-term			(873,647)	(1,680,449)
Held-to-maturity securities:
Proceeds from long-term			452,744	421,568
Advances to members:
Proceeds			160,347,563	143,670,518
Disbursements			(161,008,371)	(148,487,199)
Mortgage loans held for portfolio:
Proceeds			286,838	183,591
Purchases			(388,956)	(177,407)
Proceeds from sale of foreclosed assets			4,273	4,293
Net cash used in investing activities			(1,527,232)	(10,255,383)
FINANCING ACTIVITIES
Net change in deposits			34,724	(49,419)
Net payments on derivatives with a financing element			(7,996)	(8,816)
Net proceeds from issuance of consolidated obligations:
Discount notes			72,190,118	65,226,706
Bonds			5,262,645	5,827,667
Bonds transferred from other Federal Home Loan Banks (the FHLBanks)			87,782	0
Payments for maturing and retiring consolidated obligations:
Discount notes			(71,527,562)	(55,226,237)
Bonds			(4,754,583)	(5,482,099)
Proceeds from issuance of capital stock			98,708	86,021
Payments for redemption of mandatorily redeemable capital stock			(241,385)	(373,698)
Payments for repurchase of capital stock			(29,524)	(126,296)
Cash dividends paid			(21,010)	(18,553)
Net cash provided by financing activities			1,091,917	9,855,276
Net decrease in cash and due from banks			(280,308)	(373,693)
Cash and due from banks at beginning of the year			1,124,536	641,033	$ 641,033
Cash and due from banks at end of the period	$ 844,228	$ 267,340	844,228	267,340	1,124,536
Supplemental disclosures:
Interest paid			218,112	201,627
AHP payments			9,233	5,758	$ 12,012
Noncash transfers of mortgage loans held for portfolio to real-estaste-owned (REO)			$ 3,698	$ 5,468

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2015
Basis Of Presentation [Abstract]
Basis of Presentation [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. Accordingly, they do not include all of the information and footnotes required by GAAP for complete annual financial statements. In the opinion of management, all adjustments considered necessary have been included. All such adjustments consist of normal recurring accruals. The presentation 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, 2015. The unaudited financial statements 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, 2014, filed with the Securities and Exchange Commission (the SEC) on March 23, 2015 (the 2014 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.

Recently Issued and Adopted Acc

Recently Issued and Adopted Accounting Guidance	6 Months Ended
	Jun. 30, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recently Issued and Adopted Accounting Guidance [Text Block]	Recently Issued and Adopted Accounting Guidance Accounting for Cloud Computing Arrangements. On April 15, 2015, the Financial Accounting Standards Board (FASB) issued amendments to clarify a customer's accounting for fees paid in a cloud computing arrangement. The amendments provide guidance to customers on determining whether a cloud computing arrangement includes a software license that should be accounted for as internal-use software. If the arrangement does not contain a software license, it would be accounted for as a service contract. This guidance becomes effective for us for the interim and annual periods beginning after December 15, 2015, and early adoption is permitted. We can elect to adopt the amendments either (1) prospectively to all arrangements entered into or materially modified after the effective date or (2) retrospectively. We are in the process of evaluating this guidance and its effect on our financial condition, results of operations, and cash flows. Simplifying the Presentation of Debt Issuance Costs. On April 7, 2015, the FASB issued guidance intended to simplify the presentation of debt issuance costs. This guidance requires a reclassification on the statement of condition of debt issuance costs related to a recognized debt liability from other assets to a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This guidance becomes effective for us for the interim and annual periods beginning after December 15, 2015, and early adoption is permitted for the financial statements that have not been previously issued. The period-specific effects as a result of applying this guidance are required to be adjusted retrospectively to each individual period presented on the statement of condition. The adoption of this guidance will result in a reclassification of debt issuance costs from other assets to COs on our statement of condition. We do not expect that this guidance will have a material impact on our financial condition, results of operations, and cash flows. Framework for Adversely Classifying Loans, Other REO, and Other Assets and Listing Assets for Special Mention . On April 9, 2012, the FHFA issued Advisory Bulletin 2012-02, Framework for Adversely Classifying Loans, Other REO, and Other Assets and Listing Assets for Special Mention (AB 2012-02). AB 2012-02 establishes a standard and uniform methodology for adversely classifying loans, other REO, and certain other assets (excluding investment securities), and prescribes the timing of asset charge-offs based on these classifications. The guidance is generally consistent with the Uniform Retail Credit Classification and Account Management Policy issued by the federal banking regulators in June 2000. The adverse classification requirements were implemented as of January 1, 2014, and did not have a material effect on our results of operations or financial condition. The charge-off requirements were implemented on January 1, 2015, and did not have a material effect on our results of operations or financial condition.

Trading Securities

Trading Securities	6 Months Ended
	Jun. 30, 2015
Trading Securities [Abstract]
Trading Securities [Text Block]	Trading Securities Major Security Types . Our trading securities as of June 30, 2015 , and December 31, 2014 , were (dollars in thousands): June 30, 2015 December 31, 2014 Mortgage-backed securities (MBS) U.S. government-guaranteed – single-family $ 11,254 $ 12,235 Government-sponsored enterprise (GSE) – single-family 1,859 2,300 GSEs – multifamily 224,301 230,434 Total $ 237,414 $ 244,969 Net unrealized losses or gains on trading securities for the six months ended June 30, 2015 and 2014 , amounted to losses of $1.1 million and gains of $3.0 million for securities held on June 30, 2015 and 2014 , respectively. We do not participate in speculative trading practices and typically hold these investments over a longer time horizon.

Available-for-Sale Securities

Available-for-Sale Securities	6 Months Ended
	Jun. 30, 2015
Available-for-sale Securities [Abstract]
Available-for-Sale Securities [Text Block]	Available-for-Sale Securities Major Security Types . Our available-for-sale securities as of June 30, 2015 , were (dollars in thousands): Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value Supranational institutions $ 461,402 $ — $ (22,571 ) $ 438,831 U.S. government-owned corporations 311,311 — (41,408 ) 269,903 GSEs 129,544 — (11,838 ) 117,706 902,257 — (75,817 ) 826,440 MBS U.S. government guaranteed – single-family 180,356 246 (1,692 ) 178,910 U.S. government guaranteed – multifamily 823,275 1,492 (904 ) 823,863 GSEs – single-family 4,173,209 19,945 (11,097 ) 4,182,057 5,176,840 21,683 (13,693 ) 5,184,830 Total $ 6,079,097 $ 21,683 $ (89,510 ) $ 6,011,270 _______________________ (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. Our available-for-sale securities as of December 31, 2014 , were (dollars in thousands): Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value Supranational institutions $ 472,440 $ — $ (24,755 ) $ 447,685 U.S. government-owned corporations 322,436 — (37,439 ) 284,997 GSEs 133,748 — (10,295 ) 123,453 928,624 — (72,489 ) 856,135 MBS U.S. government guaranteed – single-family 207,090 375 (1,437 ) 206,028 U.S. government guaranteed – multifamily 874,817 204 (3,598 ) 871,423 GSEs – single-family 3,545,070 14,742 (11,420 ) 3,548,392 4,626,977 15,321 (16,455 ) 4,625,843 Total $ 5,555,601 $ 15,321 $ (88,944 ) $ 5,481,978 _______________________ (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. The following table summarizes our available-for-sale securities with unrealized losses as of June 30, 2015 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands): Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Supranational institutions $ — $ — $ 438,831 $ (22,571 ) $ 438,831 $ (22,571 ) U.S. government-owned corporations — — 269,903 (41,408 ) 269,903 (41,408 ) GSEs — — 117,706 (11,838 ) 117,706 (11,838 ) — — 826,440 (75,817 ) 826,440 (75,817 ) MBS U.S. government guaranteed – single-family — — 131,472 (1,692 ) 131,472 (1,692 ) U.S. government guaranteed – multifamily 155,776 (244 ) 203,264 (660 ) 359,040 (904 ) GSEs – single-family 1,277,232 (5,061 ) 415,932 (6,036 ) 1,693,164 (11,097 ) 1,433,008 (5,305 ) 750,668 (8,388 ) 2,183,676 (13,693 ) Total temporarily impaired $ 1,433,008 $ (5,305 ) $ 1,577,108 $ (84,205 ) $ 3,010,116 $ (89,510 ) The following table summarizes our available-for-sale securities with unrealized losses as of December 31, 2014 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands): Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Supranational institutions $ — $ — $ 447,685 $ (24,755 ) $ 447,685 $ (24,755 ) U.S. government-owned corporations — — 284,997 (37,439 ) 284,997 (37,439 ) GSEs — — 123,453 (10,295 ) 123,453 (10,295 ) — — 856,135 (72,489 ) 856,135 (72,489 ) MBS U.S. government guaranteed – single-family — — 154,665 (1,437 ) 154,665 (1,437 ) U.S. government guaranteed – multifamily 610,470 (3,497 ) 23,567 (101 ) 634,037 (3,598 ) GSEs – single-family 453,043 (888 ) 915,354 (10,532 ) 1,368,397 (11,420 ) 1,063,513 (4,385 ) 1,093,586 (12,070 ) 2,157,099 (16,455 ) Total temporarily impaired $ 1,063,513 $ (4,385 ) $ 1,949,721 $ (84,559 ) $ 3,013,234 $ (88,944 ) Redemption Terms. The amortized cost and fair value of our available-for-sale securities by contractual maturity at June 30, 2015 , and December 31, 2014 , were (dollars in thousands): June 30, 2015 December 31, 2014 Year of Maturity Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ — $ — $ — $ — Due after one year through five years — — — — Due after five years through 10 years 16,988 16,378 — — Due after 10 years 885,269 810,062 928,624 856,135 902,257 826,440 928,624 856,135 MBS (1) 5,176,840 5,184,830 4,626,977 4,625,843 Total $ 6,079,097 $ 6,011,270 $ 5,555,601 $ 5,481,978 _______________________ (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

Held-to-Maturity Securities	6 Months Ended
	Jun. 30, 2015
Held-to-maturity Securities, Unclassified [Abstract]
Held-to-maturity Securities [Text Block]	Held-to-Maturity Securities Major Security Types . Our held-to-maturity securities as of June 30, 2015 , were (dollars in thousands): Amortized Cost Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value U.S. agency obligations $ 4,739 $ — $ 4,739 $ 286 $ — $ 5,025 State or local housing-finance-agency obligations (HFA securities) 175,692 — 175,692 30 (18,748 ) 156,974 180,431 — 180,431 316 (18,748 ) 161,999 MBS U.S. government guaranteed – single-family 17,965 — 17,965 413 — 18,378 U.S. government guaranteed – multifamily 39,755 — 39,755 92 — 39,847 GSEs – single-family 1,256,108 — 1,256,108 36,320 (137 ) 1,292,291 GSEs – multifamily 418,302 — 418,302 24,710 — 443,012 Private-label – residential 1,261,450 (250,575 ) 1,010,875 291,252 (12,990 ) 1,289,137 Asset-backed securities (ABS) backed by home equity loans 16,376 (719 ) 15,657 775 (952 ) 15,480 3,009,956 (251,294 ) 2,758,662 353,562 (14,079 ) 3,098,145 Total $ 3,190,387 $ (251,294 ) $ 2,939,093 $ 353,878 $ (32,827 ) $ 3,260,144 Our held-to-maturity securities as of December 31, 2014 , were (dollars in thousands): Amortized Cost Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value U.S. agency obligations $ 5,777 $ — $ 5,777 $ 360 $ — $ 6,137 HFA securities 178,387 — 178,387 30 (18,136 ) 160,281 184,164 — 184,164 390 (18,136 ) 166,418 MBS U.S. government guaranteed – single-family 20,399 — 20,399 487 — 20,886 U.S. government guaranteed – multifamily 115,712 — 115,712 298 (6 ) 116,004 GSEs – single-family 1,420,801 — 1,420,801 40,518 (157 ) 1,461,162 GSEs – multifamily 542,130 — 542,130 29,949 — 572,079 Private-label – residential 1,327,967 (275,158 ) 1,052,809 319,306 (13,957 ) 1,358,158 ABS backed by home equity loans 16,958 (784 ) 16,174 856 (922 ) 16,108 3,443,967 (275,942 ) 3,168,025 391,414 (15,042 ) 3,544,397 Total $ 3,628,131 $ (275,942 ) $ 3,352,189 $ 391,804 $ (33,178 ) $ 3,710,815 The following table summarizes our held-to-maturity securities with unrealized losses as of June 30, 2015 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands). Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 14,916 $ (84 ) $ 136,316 $ (18,664 ) $ 151,232 $ (18,748 ) MBS GSEs – single-family — — 17,469 (137 ) 17,469 (137 ) Private-label – residential 87,923 (1,636 ) 490,916 (41,992 ) 578,839 (43,628 ) ABS backed by home equity loans — — 14,054 (1,107 ) 14,054 (1,107 ) 87,923 (1,636 ) 522,439 (43,236 ) 610,362 (44,872 ) Total $ 102,839 $ (1,720 ) $ 658,755 $ (61,900 ) $ 761,594 $ (63,620 ) The following table summarizes our held-to-maturity securities with unrealized losses as of December 31, 2014 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands). Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 14,850 $ (150 ) $ 139,544 $ (17,986 ) $ 154,394 $ (18,136 ) MBS U.S. government guaranteed – multifamily 9,282 (6 ) — — 9,282 (6 ) GSEs – single-family — — 38,121 (157 ) 38,121 (157 ) Private-label – residential 80,439 (1,028 ) 544,369 (45,104 ) 624,808 (46,132 ) ABS backed by home equity loans 206 (3 ) 14,641 (1,074 ) 14,847 (1,077 ) 89,927 (1,037 ) 597,131 (46,335 ) 687,058 (47,372 ) Total $ 104,777 $ (1,187 ) $ 736,675 $ (64,321 ) $ 841,452 $ (65,508 ) Redemption Terms. The amortized cost and fair value of our held-to-maturity securities by contractual maturity at June 30, 2015 , and December 31, 2014 , are shown below (dollars in thousands). Expected maturities of some securities and MBS may 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. June 30, 2015 December 31, 2014 Year of Maturity Amortized Cost Carrying Value (1) Fair Value Amortized Cost Carrying Value (1) Fair Value Due in one year or less $ 100 $ 100 $ 100 $ 150 $ 150 $ 150 Due after one year through five years 8,331 8,331 8,639 9,369 9,369 9,751 Due after five years through 10 years 17,020 17,020 16,944 17,115 17,115 16,973 Due after 10 years 154,980 154,980 136,316 157,530 157,530 139,544 180,431 180,431 161,999 184,164 184,164 166,418 MBS (2) 3,009,956 2,758,662 3,098,145 3,443,967 3,168,025 3,544,397 Total $ 3,190,387 $ 2,939,093 $ 3,260,144 $ 3,628,131 $ 3,352,189 $ 3,710,815 _______________________ (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. (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.

Other-Than-Temporary Impairment

Other-Than-Temporary Impairment	6 Months Ended
	Jun. 30, 2015
Other-Than-Temporary Impairment Analysis [Abstract]
Other-than-Temporary Impairment [Text Block]	Other-Than-Temporary Impairment We evaluate our available-for-sale and held-to-maturity securities on an individual basis for other-than-temporary impairment each quarter. Available-for-Sale Securities We determined that none of our available-for-sale securities were other-than-temporarily impaired at June 30, 2015 . At June 30, 2015 , we held certain available-for-sale securities in an unrealized loss position. These unrealized losses reflect the impact of normal yield and spread fluctuations attendant with security markets. We consider these unrealized losses temporary because we expect to recover the entire amortized cost basis on these available-for-sale securities in an unrealized loss position and neither intend to sell these securities nor is 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. Additionally, there have been no shortfalls of principal or interest on any available-for-sale security. Regarding securities that were in an unrealized loss position as of June 30, 2015 : • We expect debentures issued by a supranational institution that were in an unrealized loss position as of June 30, 2015 , to return contractual principal and interest based on our review and analysis of independent third-party credit reports on the supranational institution, and the supranational institution's triple-A (or equivalent) rating by each of the nationally recognized statistical rating organizations (NRSROs) that rates it. • Debentures issued by U.S. government-owned corporations are not obligations of the U.S. government and not guaranteed by the U.S. government. However, these securities are rated at the same level as the U.S. government by the NRSROs. These ratings reflect the U.S. government's implicit support of the government-owned corporation as well as the entity's underlying business and financial risk. • The probability of default on debt issued by the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac) is remote given their status as GSEs and their support from the U.S. government. • The U.S. government-guaranteed securities that we hold are MBS issued by the Government National Mortgage Association (Ginnie Mae). The strength of Ginnie Mae's guarantees as a direct obligation from the U.S. government is sufficient to protect us from losses based on current expectations. • For MBS issued by Fannie Mae and Freddie Mac, which we sometimes refer to as agency MBS in this report, the strength of the issuers' guarantees through direct obligation or support from the U.S. government is sufficient to protect us from losses based on current expectations. Held-to-Maturity Securities HFA Securities. We have reviewed our investments in HFA securities and have determined that unrealized losses reflect the impact of normal market yield and spread fluctuations and illiquidity in the credit markets. We have determined that all unrealized losses are temporary given the creditworthiness of the issuers and the underlying collateral, including an assessment of past payment history (no shortfalls of principal or interest), property vacancy rates, debt service ratios, over-collateralization and other credit enhancement, and third-party bond insurance as applicable. As of June 30, 2015 , none of our held-to-maturity investments in HFA securities that are in an unrealized loss position were rated below investment grade by an NRSRO. Because the decline in market value is attributable to changes in interest rates, credit spreads, and illiquidity in this market and not to a significant deterioration in the fundamental credit quality of these obligations, and because we do not intend to sell the investments nor is it more likely than not that we will be required to sell the investments before recovery of the amortized cost basis, we do not consider these investments to be other-than-temporarily impaired at June 30, 2015 . Agency MBS. For agency MBS, we determined that the strength of the issuers' guarantees through direct obligation or support from the U.S. government is sufficient to protect us from losses based on current expectations. Additionally, there have been no shortfalls of principal or interest on any such security. As a result, we have determined that, as of June 30, 2015 , all of the gross unrealized losses on such MBS are temporary. We do not believe that the declines in market value of these securities are attributable to credit quality, and because we do not intend to sell the investments, nor is it more likely than not that we will be required to sell the investments before recovery of the amortized cost basis, we do not consider any of these investments to be other-than-temporarily impaired at June 30, 2015 . Private-Label Residential MBS and ABS Backed by Home Equity Loans. To ensure consistency when determining the other-than-temporary impairment for private-label residential MBS and certain home equity loan investments (including home equity ABS) among all FHLBanks, the FHLBanks use an FHLBank System governance committee (the OTTI Governance Committee) and a formal process to ensure consistency in key other-than-temporary impairment modeling assumptions used for purposes of their cash-flow analyses for the majority of these securities. We use the FHLBanks' uniform framework and approved assumptions for purposes of our other-than-temporary impairment cash-flow analyses of our private-label residential MBS and certain home equity loan investments. For additional information see Item 8 — Financial Statements and Supplementary Data — Note 7 — Other-Than-Temporary Impairment in the 2014 Annual Report. To assess whether the entire amortized cost basis of private-label residential MBS will be recovered, cash-flow analyses for each of our private-label residential MBS were performed. These analyses use two third-party models. The first third-party model considers borrower characteristics and the particular attributes of the loans underlying our securities, in conjunction with assumptions about current home prices and future changes in home prices and interest rates, producing monthly projections of prepayments, defaults, loan modifications, and loss severities. A significant input to the first model is the forecast of future housing-price changes, based on an assessment of individual housing markets for the relevant states and core-based statistical areas (CBSA), as defined by the United States Office of Management and Budget. The OTTI Governance Committee developed a short-term housing-price forecast, with projected changes ranging from a decrease of 2.0 percent to an increase of 8.0 percent over the 12-month period beginning April 1, 2015. For the vast majority of markets, the projected short-term housing-price changes range from an increase of 2.0 percent to an increase of 5.0 percent . Thereafter, we have projected a unique recovery path for each relevant geographic area based on an internally developed framework derived from historical data. The month-by-month projections of future loan level performance are derived from the first model to determine projected prepayments, defaults, loan modifications, and loss severities. These projections are then input into a second model that allocates the cash flows and losses among the various classes in the securitization structure in accordance with the cash-flow and loss-allocation rules prescribed by the securitization structure. In a securitization in which the credit enhancement for the senior securities is derived from the presence of subordinate securities, losses are generally allocated first to the subordinate securities until their principal balance is reduced to zero. 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 scenario of cash flows determined based on the model approach described above reflects a best estimate scenario and includes a base case current-to-trough housing price forecast and a base case housing price recovery path described in the prior paragraph. For those securities for which an other-than-temporary impairment was determined to have occurred during the three months ended June 30, 2015 , the following table presents a summary of the average projected values over the remaining lives of the securities for the significant inputs used to measure the amount of the credit loss recognized in earnings, as well as related current credit enhancement. Credit enhancement is defined as the percentage of subordinated tranches, over-collateralization, and other credit enhancement, if any, in a security structure that will generally absorb losses before we will experience a credit loss on the security. The calculated averages represent the dollar-weighted averages of all the private-label residential MBS and home equity loan investments in each category shown (dollars in thousands). Weighted Average of Significant Inputs Weighted Average Current Credit Enhancement Private-label MBS by Year of Securitization Par Value Projected Prepayment Rates Projected Default Rates Projected Loss Severities Alt-A Private-label residential MBS (1) 2007 $ 50,731 6.3 % 44.1 % 37.5 % — % 2006 60,688 10.3 27.8 38.5 — 2005 23,273 7.0 26.8 38.0 30.6 2004 and prior 2,584 13.1 16.2 5.0 3.8 Total $ 137,276 8.3 % 33.4 % 37.4 % 5.3 % _______________________ (1) Securities are classified in the table above based upon the current performance characteristics of the underlying loan pool and therefore the manner in which the loan pool backing the security has been modeled (as prime, Alt-A, or subprime), rather than their classification of the security at the time of issuance. The following table sets forth our securities for which other-than-temporary impairment credit losses were recognized during the life of the security through June 30, 2015 (dollars in thousands). Securities are classified in the table below based on their classifications at the time of issuance. June 30, 2015 Other-Than-Temporarily Impaired Investment (1) Par Value Amortized Cost Carrying Value Fair Value Private-label residential MBS – Prime $ 54,384 $ 46,936 $ 37,272 $ 47,621 Private-label residential MBS – Alt-A 1,369,762 1,007,710 766,799 1,047,631 ABS backed by home equity loans – Subprime 4,101 3,680 2,961 3,735 Total other-than-temporarily impaired securities $ 1,428,247 $ 1,058,326 $ 807,032 $ 1,098,987 _______________________ (1) We have instituted litigation in relation to certain of the private-label MBS in which we invested. Our complaint asserts, among others, claims for untrue or misleading statements in the sale of securities. It is possible that classifications of private-label MBS as provided herein when based on classification at the time of issuance as disclosed by those securities' issuance documents, as well as other statements about the securities, are inaccurate. The following table presents a roll-forward of the amounts related to credit losses recognized in earnings. The roll-forward is the amount of credit losses on investment securities on which we recognized a portion of other-than-temporary impairment charges into accumulated other comprehensive loss (dollars in thousands). For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Balance at beginning of year $ 559,725 $ 595,560 $ 568,652 $ 603,786 Additions: Additional credit losses for which an other-than-temporary impairment charge was previously recognized (1) 1,429 399 1,775 857 Reductions: Increase in cash flows expected to be collected which are recognized over the remaining life of the security (2) (9,813 ) (8,625 ) (19,086 ) (17,309 ) Balance at end of period $ 551,341 $ 587,334 $ 551,341 $ 587,334 _______________________ (1) For the three months ended June 30, 2015 and 2014 , additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to April 1, 2015 and 2014 . For the six months ended June 30, 2015 and 2014 , additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to January 1, 2015 and 2014 . (2) Represents amounts accreted as interest income during the current period.

Advances

Advances	6 Months Ended
	Jun. 30, 2015
Advances [Abstract]
Advances [Text Block]	Advances General Terms. At June 30, 2015 , and December 31, 2014 , we had advances outstanding with interest rates ranging from (0.17) percent to 7.72 percent and (0.22) percent to 8.37 percent , respectively, as summarized below (dollars in thousands). 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. June 30, 2015 December 31, 2014 Year of Contractual Maturity Amount Weighted Average Rate Amount Weighted Average Rate Overdrawn demand-deposit accounts $ 8,879 0.45 % $ 19,863 0.44 % Due in one year or less 21,799,346 0.45 20,561,912 0.41 Due after one year through two years 3,718,382 2.17 4,114,587 1.63 Due after two years through three years 3,327,720 2.27 3,564,747 2.68 Due after three years through four years 1,801,212 2.09 2,299,457 2.16 Due after four years through five years 1,555,863 1.95 1,087,673 2.11 Thereafter 1,721,263 2.91 1,626,475 2.98 Total par value 33,932,665 1.10 % 33,274,714 1.11 % Premiums 30,128 32,887 Discounts (17,980 ) (18,549 ) Market value of bifurcated derivatives (1) 1,953 1,467 Hedging adjustments 158,677 191,555 Total $ 34,105,443 $ 33,482,074 _________________________ (1) At June 30, 2015 , and December 31, 2014 , we had certain advances with embedded features that met the requirements to be separated from the host contract and designated as a stand-alone derivative. At June 30, 2015 , and December 31, 2014 , we had putable advances outstanding totaling $ 2.2 billion and $2.3 billion , respectively. The following table sets forth our advances outstanding by the year of contractual maturity or next put date for putable advances (dollars in thousands): Year of Contractual Maturity or Next Put Date, Par Value June 30, 2015 December 31, 2014 Overdrawn demand-deposit accounts $ 8,879 $ 19,863 Due in one year or less 23,765,671 22,737,137 Due after one year through two years 2,883,357 3,767,187 Due after two years through three years 2,355,670 2,155,922 Due after three years through four years 1,661,962 1,931,707 Due after four years through five years 1,535,863 1,036,423 Thereafter 1,721,263 1,626,475 Total par value $ 33,932,665 $ 33,274,714 At both June 30, 2015 , and December 31, 2014 , we had callable advances outstanding totaling $ 30.0 million . Interest-Rate-Payment Terms. The following table details interest-rate-payment types for our outstanding advances (dollars in thousands): Par value of advances June 30, 2015 December 31, 2014 Fixed-rate $ 28,097,886 $ 27,236,551 Variable-rate 5,834,779 6,038,163 Total par value $ 33,932,665 $ 33,274,714 Credit-Risk Exposure and Security Terms . At June 30, 2015 , and December 31, 2014 , we had $11.6 billion and $10.7 billion , respectively, of advances issued to members with at least $1.0 billion of advances outstanding. These advances were made to four borrowers at June 30, 2015 , and three borrowers at December 31, 2014 , representing 34.1 percent and 32.0 percent , respectively, of total par value of outstanding advances. For information related to our credit risk on advances and allowance for credit losses, see Note 9 — Allowance for Credit Losses. Prepayment Fees. For the three and six months ended June 30, 2015 and 2014 , net advance prepayment fees recognized in income are reflected in the following table (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Prepayment fees received from borrowers $ 279 $ 1,127 $ 3,896 $ 7,822 Less: hedging fair-value adjustments on prepaid advances — (359 ) (2,731 ) (552 ) Less: net premiums associated with prepaid advances — — — (3,928 ) Less: deferred recognition of prepayment fees received from borrowers on advance prepayments deemed to be loan modifications — — (246 ) (80 ) Prepayment fees recognized in income on advance restructurings deemed to be extinguishments — — 3,102 — Net prepayment fees recognized in income $ 279 $ 768 $ 4,021 $ 3,262

Mortgage Loans Held for Portfol

Mortgage Loans Held for Portfolio	6 Months Ended
	Jun. 30, 2015
Mortgage Loans on Real Estate [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 investments (MPF loans) are either guaranteed or insured by federal agencies, as is the case with government mortgage loans, or are credit-enhanced 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. The following table presents certain characteristics of these investments (dollars in thousands): June 30, 2015 December 31, 2014 Real estate Fixed-rate 15-year single-family mortgages $ 587,679 $ 570,663 Fixed-rate 20- and 30-year single-family mortgages 2,924,304 2,852,669 Premiums 63,971 62,554 Discounts (2,442 ) (2,761 ) Deferred derivative gains, net 2,423 2,835 Total mortgage loans held for portfolio 3,575,935 3,485,960 Less: allowance for credit losses (1,100 ) (2,012 ) Total mortgage loans, net of allowance for credit losses $ 3,574,835 $ 3,483,948 The following table details the par value of mortgage loans held for portfolio (dollars in thousands): June 30, 2015 December 31, 2014 Conventional mortgage loans $ 3,091,973 $ 2,997,669 Government mortgage loans 420,010 425,663 Total par value $ 3,511,983 $ 3,423,332 See Note 9 — Allowance for Credit Losses for information related to our credit risk from our investments in mortgage loans and allowance for credit losses based on these investments. "Mortgage Partnership Finance," and "MPF," are registered trademarks of the Federal Home Loan Bank of Chicago.

Allowance for Credit Losses

Allowance for Credit Losses	6 Months Ended
	Jun. 30, 2015
Allowance for Credit Losses [Abstract]
Allowance for Credit Losses [Text Block]	Allowance for Credit Losses An allowance for credit losses is a valuation allowance separately established for each identified portfolio segment, if necessary, to provide for probable losses inherent in our portfolio as of the statement of condition date. To the extent necessary, an allowance for credit losses for off-balance-sheet credit exposure is recorded as a liability. For additional information see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2014 Annual Report. Secured Member Credit Products We manage our credit exposure to secured member credit products through an integrated approach that generally includes establishing a credit limit for each borrower, 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. At June 30, 2015 , and December 31, 2014 , none of our secured member credit products outstanding were past due, on nonaccrual status, or considered impaired. In addition, there were no troubled debt restructurings related to credit products during the three months ended June 30, 2015 and 2014 . Based upon the collateral held as security, our credit extension and collateral policies, management's credit analysis, and the repayment history on secured member credit products, we have not recorded any allowance for credit losses on our secured member credit products at June 30, 2015 , and December 31, 2014 . At June 30, 2015 , and December 31, 2014 , no liability to reflect an allowance for credit losses for off-balance-sheet credit exposures was recorded. See Note 18 — Commitments and Contingencies for additional information on our off-balance-sheet credit exposure. For additional information see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2014 Annual Report. Government Mortgage Loans Held for Portfolio Based on our assessment of our servicers for our government loans, there is no allowance for credit losses for the government mortgage loan portfolio as of June 30, 2015 , and December 31, 2014 . In addition, 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. For additional information see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2014 Annual Report. Conventional Mortgage Loans Held for Portfolio For information on our conventional mortgage loans held for portfolio see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2014 Annual Report. Credit Quality Indicators. Key credit quality indicators for mortgage loans include the migration of past due loans, nonaccrual loans, loans in process of foreclosure, and impaired loans. The tables below set forth certain key credit quality indicators for our investments in mortgage loans at June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 Recorded Investment in Conventional Mortgage Loans Recorded Investment in Government Mortgage Loans Total Past due 30-59 days delinquent $ 23,477 $ 17,516 $ 40,993 Past due 60-89 days delinquent 9,177 4,700 13,877 Past due 90 days or more delinquent 26,684 7,095 33,779 Total past due 59,338 29,311 88,649 Total current loans 3,103,513 402,429 3,505,942 Total mortgage loans $ 3,162,851 $ 431,740 $ 3,594,591 Other delinquency statistics In process of foreclosure, included above (1) $ 13,968 $ 2,393 $ 16,361 Serious delinquency rate (2) 0.89 % 1.64 % 0.98 % Past due 90 days or more still accruing interest $ — $ 7,095 $ 7,095 Loans on nonaccrual status (3) $ 27,313 $ — $ 27,313 _______________________ (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. December 31, 2014 Recorded Investment in Conventional Mortgage Loans Recorded Investment in Government Mortgage Loans Total Past due 30-59 days delinquent $ 32,068 $ 19,811 $ 51,879 Past due 60-89 days delinquent 9,834 4,591 14,425 Past due 90 days or more delinquent 37,927 7,467 45,394 Total past due 79,829 31,869 111,698 Total current loans 2,986,749 405,808 3,392,557 Total mortgage loans $ 3,066,578 $ 437,677 $ 3,504,255 Other delinquency statistics In process of foreclosure, included above (1) $ 13,709 $ 2,786 $ 16,495 Serious delinquency rate (2) 1.27 % 1.71 % 1.32 % Past due 90 days or more still accruing interest $ — $ 7,467 $ 7,467 Loans on nonaccrual status (3) $ 38,832 $ — $ 38,832 _______________________ (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. Collectively Evaluated Mortgage Loans . We evaluate the credit risk of our investments in conventional mortgage loans for impairment on a collective basis that considers loan-pool-specific attribute data at the master commitment pool level, applies estimated loss severities, and incorporates available credit enhancements to establish our best estimate of probable incurred losses at the reporting date. We do not consider credit-enhancement cash flows that are projected and assessed as not probable of receipt in reducing estimated losses. Migration analysis is a methodology for estimating the rate of default experienced on pools of similar loans based on our historical experience. We apply migration analysis to conventional loans that are currently not past due, loans that are 30 to 59 days past due, 60 to 89 days past due, and 90 to 179 days past due. We then estimate the dollar amount of loans in these categories that we believe are likely to migrate to a realized loss position and apply a loss severity factor to estimate losses that would be incurred at the statement of condition date. Additionally, for our investments in loans modified under our temporary loan modification plan, we measure the present value of expected future cash flows discounted at the loan's effective interest rate on the effective date of a loan modification and reduce the carrying value of the loan accordingly. Individually Evaluated Mortgage Loans . Certain conventional mortgage loans, primarily impaired mortgage loans that are considered collateral-dependent, may be specifically identified for purposes of calculating the allowance for credit losses. A mortgage loan is considered collateral-dependent if repayment is only expected to be provided by the sale of the underlying property, that is, if it is considered likely that the borrower will default and there is no credit enhancement from a participating financial institution to offset losses under the master commitment. The estimated credit losses on impaired collateral-dependent loans may be separately determined because sufficient information exists to make a reasonable estimate of the inherent loss on these loans on an individual loan basis. Loans that are considered collateral-dependent are measured for impairment based on the fair value of the underlying property less estimated selling costs. The resulting incurred loss is equal to the difference between the carrying value of the loan and the estimated fair value of the collateral less estimated selling costs. Charge-Off Policy . We evaluate whether to record a charge-off on a conventional mortgage loan upon the occurrence of a confirming event. As discussed in Note 2 — Recently Issued and Adopted Accounting Guidance, the charge-off requirements of AB 2012-02 were implemented on January 1, 2015. We now record a charge-off when a conventional mortgage loan is 180 or more days past due, when the borrower has filed for bankruptcy protection and the loan is at least 30 days past due, or when there is evidence of fraud. Confirming events also include, but are not limited to, the occurrence of foreclosure or notification of a claim against any of the credit enhancements. A charge-off is recorded if we determine that the recorded investment in the loan is not likely to be recovered. Individually Evaluated Impaired Loans. The following tables present the recorded investment, par value, and any related allowance for impaired conventional loans individually assessed for impairment at June 30, 2015 , and December 31, 2014 , and the average recorded investment and interest income recognized on these loans during the three and six months ended June 30, 2015 and 2014 (dollars in thousands). As of June 30, 2015 As of December 31, 2014 Recorded Investment Par Value Related Allowance Recorded Investment Par Value Related Allowance Individually evaluated impaired mortgage loans with no related allowance $ 31,153 $ 31,116 $ — $ 6,679 $ 6,654 $ — Individually evaluated impaired mortgage loans with a related allowance — — — 3,097 3,073 544 Total individually evaluated impaired mortgage loans $ 31,153 $ 31,116 $ — $ 9,776 $ 9,727 $ 544 For the Three Months Ended June 30, 2015 2014 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Individually evaluated impaired mortgage loans with no related allowance $ 31,759 $ 129 $ 3,637 $ 44 Individually evaluated impaired mortgage loans with a related allowance — — 2,538 2 Total individually evaluated impaired mortgage loans $ 31,759 $ 129 $ 6,175 $ 46 For the Six Months Ended June 30, 2015 2014 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Individually evaluated impaired mortgage loans with no related allowance $ 32,557 $ 249 $ 3,676 $ 92 Individually evaluated impaired mortgage loans with a related allowance — — 2,839 13 Total individually evaluated impaired mortgage loans $ 32,557 $ 249 $ 6,515 $ 105 Roll-Forward of Allowance for Credit Losses on Mortgage Loans. The following table presents a roll-forward of the allowance for credit losses on conventional mortgage loans for the three and six months ended June 30, 2015 and 2014 , as well as the recorded investment in mortgage loans by impairment methodology at June 30, 2015 and 2014 (dollars in thousands). The recorded investment in a loan is the par amount of the loan, adjusted for accrued interest, unamortized premiums or discounts, deferred derivative gains and losses, and direct write-downs. The recorded investment is net of any valuation allowance. For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Allowance for credit losses Balance, beginning of period $ 1,350 $ 1,812 $ 2,012 $ 2,221 Charge-offs, net of recoveries (27 ) (13 ) (629 ) (100 ) (Reduction of) provision for credit losses (223 ) 243 (283 ) (79 ) Balance, end of period $ 1,100 $ 2,042 $ 1,100 $ 2,042 Ending balance, individually evaluated for impairment $ — $ 605 $ — $ 605 Ending balance, collectively evaluated for impairment $ 1,100 $ 1,437 $ 1,100 $ 1,437 Recorded investment, end of period (1) Individually evaluated for impairment $ 31,153 $ 6,142 $ 31,153 $ 6,142 Collectively evaluated for impairment $ 3,131,698 $ 2,918,633 $ 3,131,698 $ 2,918,633 _________________________ (1) These amounts exclude government mortgage loans because we make no allowance for credit losses based on our investments in government mortgage loans, as discussed above under — Government Mortgage Loans Held for Portfolio. REO. At June 30, 2015 , and December 31, 2014 , we had $4.1 million and $4.3 million , respectively, in assets classified as REO. During the six months ended June 30, 2015 and 2014 , we sold REO assets with a recorded carrying value of $3.6 million and $4.4 million , respectively. Upon the sale of REO properties, and inclusive of any proceeds received from primary mortgage-insurance coverage, we recognized net gains totaling $321,000 and net losses totaling $ 387,000 during the six months ended June 30, 2015 and 2014 , respectively. Gains and losses on the sale of REO assets are recorded in other income.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities [Text Block]	Derivatives and Hedging Activities The following table presents the fair value of derivatives, including the effect of netting adjustments and cash collateral as of June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Notional Amount of Derivatives Derivative Assets Derivative Liabilities Notional Derivative Derivative Derivatives designated as hedging instruments Interest-rate swaps $ 14,534,641 $ 36,333 $ (493,603 ) $ 12,579,525 $ 26,381 $ (553,967 ) Forward-start interest-rate swaps 752,800 169 (29,652 ) 1,096,800 — (42,209 ) Total derivatives designated as hedging instruments 15,287,441 36,502 (523,255 ) 13,676,325 26,381 (596,176 ) Derivatives not designated as hedging instruments Economic hedges: Interest-rate swaps 454,000 78 (19,653 ) 423,000 31 (19,849 ) Interest-rate caps or floors 300,000 — — 300,000 — — Mortgage-delivery commitments (1) 26,986 29 (85 ) 26,927 71 (8 ) Total derivatives not designated as hedging instruments 780,986 107 (19,738 ) 749,927 102 (19,857 ) Total notional amount of derivatives $ 16,068,427 $ 14,426,252 Total derivatives before netting and collateral adjustments 36,609 (542,993 ) 26,483 (616,033 ) Netting adjustments and cash collateral including related accrued interest (2) (8,166 ) 66,578 (11,935 ) 57,144 Derivative assets and derivative liabilities $ 28,443 $ (476,415 ) $ 14,548 $ (558,889 ) _______________________ (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 $60.7 million and $45.5 million at June 30, 2015 , and December 31, 2014 , 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 $2.3 million and $290,000 at June 30, 2015 , and December 31, 2014 , respectively. Net losses on derivatives and hedging activities recorded in other (loss) income for the three and six months ended June 30, 2015 and 2014 were as follows (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Derivatives designated as hedging instruments Interest-rate swaps $ (1,087 ) $ 965 $ (1,715 ) $ 1,459 Cash flow hedge ineffectiveness 184 (35 ) 104 (170 ) Total net (losses) gains related to derivatives designated as hedging instruments (903 ) 930 (1,611 ) 1,289 Derivatives not designated as hedging instruments: Economic hedges: Interest-rate swaps 403 (2,807 ) (2,675 ) (4,643 ) Interest-rate caps or floors — (25 ) — (42 ) Mortgage-delivery commitments (642 ) 610 (215 ) 721 Total net losses related to derivatives not designated as hedging instruments (239 ) (2,222 ) (2,890 ) (3,964 ) Net losses on derivatives and hedging activities $ (1,142 ) $ (1,292 ) $ (4,501 ) $ (2,675 ) The following tables present, by type of hedged item, the gains (losses) on derivatives and the related hedged items in fair-value hedge relationships and the impact of those derivatives on our net interest income for the three and six months ended June 30, 2015 and 2014 (dollars in thousands): For the Three Months Ended June 30, 2015 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 39,168 $ (38,764 ) $ 404 $ (32,611 ) Investments 54,244 (53,694 ) 550 (9,439 ) COs – bonds (11,130 ) 9,089 (2,041 ) 15,265 Total $ 82,282 $ (83,369 ) $ (1,087 ) $ (26,785 ) For the Three Months Ended June 30, 2014 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 8,124 $ (8,040 ) $ 84 $ (33,019 ) Investments (21,709 ) 21,994 285 (9,504 ) Deposits (391 ) 391 — 397 COs – bonds 12,869 (12,273 ) 596 13,136 Total $ (1,107 ) $ 2,072 $ 965 $ (28,990 ) For the Six Months Ended June 30, 2015 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 33,311 $ (32,878 ) $ 433 $ (64,510 ) Investments 27,245 (26,368 ) 877 (18,921 ) COs – bonds 4,269 (7,294 ) (3,025 ) 30,963 Total $ 64,825 $ (66,540 ) $ (1,715 ) $ (52,468 ) For the Six Months Ended June 30, 2014 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 30,109 $ (29,881 ) $ 228 $ (66,430 ) Investments (53,269 ) 53,785 516 (18,998 ) Deposits (781 ) 781 — 794 COs – bonds 20,755 (20,040 ) 715 23,773 Total $ (3,186 ) $ 4,645 $ 1,459 $ (60,861 ) ____________ (1) The net interest on derivatives in fair-value hedge relationships is presented in the statement of operations as interest income or interest expense of the respective hedged item. The following table presents the losses recognized in accumulated other comprehensive loss, the losses reclassified from accumulated other comprehensive loss into income, and the effect of our hedging activities on our net losses on derivatives and hedging activities in the statement of income for our forward-start interest-rate swaps associated with CO bond hedged items in cash-flow hedge relationships (dollars in thousands). Derivatives and Hedged Items in Cash Flow Hedging Relationships Gains (Losses) Recognized in Other Comprehensive Loss on Derivatives (Effective Portion) Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion) (Losses) Gains Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion) Gains (Losses) Recognized in Net Losses on Derivatives and Hedging Activities (Ineffective Portion) Interest-rate swaps - CO bonds For the Three Months Ended June 30, 2015 $ 12,773 Interest expense $ (5,628 ) $ 184 For the Three Months Ended June 30, 2014 (13,726 ) Interest expense (720 ) (35 ) For the Six Months Ended June 30, 2015 630 Interest expense (10,520 ) 104 For the Six Months Ended June 30, 2014 (19,740 ) Interest expense (720 ) (170 ) For the six months ended June 30, 2015 and 2014 , 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 June 30, 2015 , the maximum length of time over which we are hedging our exposure to the variability in future cash flows for forecasted transactions is nine years . As of June 30, 2015 , 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 $27.1 million . 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 (bilateral derivatives). Certain of our bilateral derivatives master-netting agreements contain provisions that require us to post additional collateral with our bilateral derivatives counterparties if our credit ratings are lowered. Under the terms that govern such agreements, if our credit rating is lowered by Moody's Investor Services (Moody's) or Standard and Poor's Rating Service (S&P) to a certain level, we are required to deliver additional collateral on bilateral 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 bilateral derivatives with these provisions that were in a net-liability position (before cash collateral and related accrued interest) at June 30, 2015 , was $495.6 million , for which we had delivered collateral with a post-haircut value of $403.8 million in accordance with the terms of the master-netting agreements. The following table sets forth the post-haircut value of incremental collateral that certain bilateral derivatives counterparties could have required us to deliver based on incremental credit rating downgrades at June 30, 2015 (dollars in thousands). Post-Haircut Value of Incremental Collateral to be Delivered as of June 30, 2015 Ratings Downgrade (1) From To Incremental Collateral (2) AA+ AA or AA- $ 30,282 AA- A+, A or A- 35,320 A- below A- 36,673 _______________________ (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. (2) Additional collateral of $1.1 million could be called by counterparties as of June 30, 2015 , at our current credit rating of AA+ (based on the lower of our credit ratings from S&P and Moody's) and is not included in the table. For cleared derivatives, the DCO determines initial margin requirements. We note that we clear our trades via clearing members of the DCOs. These clearing members who act as our agent to the DCOs are futures commission merchants registered with the U.S. Commodity Futures Trading Commission (the CFTC). 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 June 30, 2015 . Offsetting of Certain Derivatives. We present derivatives, related cash collateral, including initial and variation margin, received or pledged, and associated accrued interest, on a net basis by clearing member and/or by counterparty. The following table presents separately the fair value of derivatives meeting or not meeting netting requirements, with and without the legal right of offset, including the related collateral received from or pledged to counterparties, based on the terms of our master netting arrangements or similar agreements as of June 30, 2015 , and December 31, 2014 (dollars in thousands). June 30, 2015 December 31, 2014 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives meeting netting requirements Gross recognized amount Bilateral derivatives $ 12,919 $ (507,233 ) $ 20,083 $ (578,073 ) Cleared derivatives 23,661 (35,675 ) 6,329 (37,952 ) Total gross recognized amount 36,580 (542,908 ) 26,412 (616,025 ) Gross amounts of netting adjustments and cash collateral Bilateral derivatives (12,622 ) 30,903 (19,481 ) 19,191 Cleared derivatives 4,456 35,675 7,546 37,953 Total gross amounts of netting adjustments and cash collateral (8,166 ) 66,578 (11,935 ) 57,144 Net amounts after netting adjustments and cash collateral Bilateral derivatives 297 (476,330 ) 602 (558,882 ) Cleared derivatives 28,117 — 13,875 1 Total net amounts after netting adjustments and cash collateral 28,414 (476,330 ) 14,477 (558,881 ) Derivatives not meeting netting requirements Mortgage delivery commitments 29 (85 ) 71 (8 ) Total derivative assets and total derivative liabilities Bilateral derivatives 297 (476,330 ) 602 (558,882 ) Cleared derivatives 28,117 — 13,875 1 Mortgage delivery commitments 29 (85 ) 71 (8 ) Total derivative assets and total derivative liabilities presented in the statement of condition 28,443 (476,415 ) 14,548 (558,889 ) Non-cash collateral received or pledged not offset (1) Can be sold or repledged Bilateral derivatives — 86,821 — 66,056 Cannot be sold or repledged Bilateral derivatives — 313,635 — 392,944 Total non-cash collateral received or pledged, not offset — 400,456 — 459,000 Net amount Bilateral derivatives 297 (75,874 ) 602 (99,882 ) Cleared derivatives 28,117 — 13,875 2 Mortgage delivery commitments 29 (85 ) 71 (8 ) Total net amount $ 28,443 $ (75,959 ) $ 14,548 $ (99,888 ) _______________________ (1) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At June 30, 2015 , and December 31, 2014 , we had additional net credit exposure of $2.9 million and $4.0 million , respectively, due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.

Deposits

Deposits	6 Months Ended
	Jun. 30, 2015
Deposits [Abstract]
Deposits [Text Block]	Deposits We offer demand and overnight deposits for members and qualifying nonmembers. In addition, we offer short-term interest-bearing deposit programs to members. 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. We classify these items as "other" in the following table. The following table details interest- and noninterest-bearing deposits (dollars in thousands): June 30, 2015 December 31, 2014 Interest-bearing Demand and overnight $ 367,032 $ 340,441 Other 4,584 5,120 Noninterest-bearing Other 30,450 23,770 Total deposits $ 402,066 $ 369,331

Consolidated Obligations

Consolidated Obligations	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Consolidated Obligations [Text Block]	Consolidated Obligations COs - Bonds. The following table sets forth the outstanding CO bonds for which we were primarily liable at June 30, 2015 , and December 31, 2014 , by year of contractual maturity (dollars in thousands): June 30, 2015 December 31, 2014 Year of Contractual Maturity Amount Weighted Average Rate (1) Amount Weighted Average Rate (1) Due in one year or less $ 7,751,955 1.17 % $ 6,675,745 1.41 % Due after one year through two years 5,921,530 1.36 5,573,745 1.46 Due after two years through three years 4,510,140 1.91 4,842,570 1.91 Due after three years through four years 2,198,780 1.67 2,392,380 1.77 Due after four years through five years 2,221,455 2.09 2,244,815 1.95 Thereafter 3,305,000 2.92 3,599,085 2.79 Total par value 25,908,860 1.69 % 25,328,340 1.79 % Premiums 178,846 199,628 Discounts (16,763 ) (19,386 ) Hedging adjustments 4,486 (2,808 ) $ 26,075,429 $ 25,505,774 _______________________ (1) The CO bonds' weighted-average rate excludes concession fees. Our CO bonds outstanding at June 30, 2015 , and December 31, 2014 , included (dollars in thousands): June 30, 2015 December 31, 2014 Par value of CO bonds Noncallable and nonputable $ 21,331,860 $ 20,853,340 Callable 4,577,000 4,475,000 Total par value $ 25,908,860 $ 25,328,340 The following is a summary of the CO bonds for which we were primarily liable at June 30, 2015 , and December 31, 2014 , by year of contractual maturity or next call date for callable CO bonds (dollars in thousands): Year of Contractual Maturity or Next Call Date June 30, 2015 December 31, 2014 Due in one year or less $ 12,043,955 $ 10,805,745 Due after one year through two years 5,266,530 4,928,745 Due after two years through three years 3,440,140 4,252,570 Due after three years through four years 1,948,780 2,027,380 Due after four years through five years 1,646,455 1,619,815 Thereafter 1,563,000 1,694,085 Total par value $ 25,908,860 $ 25,328,340 The following table sets forth the CO bonds for which we were primarily liable by interest-rate-payment type at June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Par value of CO bonds Fixed-rate $ 22,911,860 $ 22,513,340 Simple variable-rate 2,170,000 1,970,000 Step-up 827,000 845,000 Total par value $ 25,908,860 $ 25,328,340 COs – Discount Notes. Outstanding CO discount notes for which we were primarily liable, all of which are due within one year, were as follows (dollars in thousands): Book Value Par Value Weighted Average Rate (1) June 30, 2015 $ 25,972,593 $ 25,974,666 0.08 % December 31, 2014 $ 25,309,608 $ 25,312,040 0.08 % _______________________ (1) The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable Housing Program

Affordable Housing Program	6 Months Ended
	Jun. 30, 2015
Affordable Housing Program [Abstract]
Affordable Housing Program [Text Block]	Affordable Housing Program The following table presents a roll-forward of the AHP liability for the six months ended June 30, 2015 , and year ended December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Balance at beginning of year $ 66,993 $ 62,591 AHP expense for the period 20,445 17,623 AHP direct grant disbursements (9,233 ) (12,012 ) AHP subsidy for AHP advance disbursements (625 ) (1,321 ) Return of previously disbursed grants and subsidies 20 112 Balance at end of period $ 77,600 $ 66,993

Capital

Capital	6 Months Ended
	Jun. 30, 2015
Capital [Abstract]
Capital [Text Block]	Capital We are subject to capital requirements under our capital plan, the Federal Home Loan Bank Act of 1932, as amended (the FHLBank Act), and FHFA regulations: 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 may require us to maintain a greater amount of permanent capital than is required as defined by the risk-based capital requirements. The following tables demonstrate our compliance with our regulatory capital requirements at June 30, 2015 , and December 31, 2014 (dollars in thousands): Risk-Based Capital Requirements June 30, December 31, Permanent capital Class B capital stock $ 2,482,244 $ 2,413,114 Mandatorily redeemable capital stock 57,268 298,599 Retained earnings 1,063,854 901,658 Total permanent capital $ 3,603,366 $ 3,613,371 Risk-based capital requirement Credit-risk capital $ 399,363 $ 414,765 Market-risk capital 93,498 75,560 Operations-risk capital 147,858 147,097 Total risk-based capital requirement $ 640,719 $ 637,422 Permanent capital in excess of risk-based capital requirement $ 2,962,647 $ 2,975,949 June 30, 2015 December 31, 2014 Required Actual Required Actual Capital Ratio Risk-based capital $ 640,719 $ 3,603,366 $ 637,422 $ 3,613,371 Total regulatory capital $ 2,257,995 $ 3,603,366 $ 2,204,267 $ 3,613,371 Total capital-to-asset ratio 4.0 % 6.4 % 4.0 % 6.6 % Leverage Ratio Leverage capital $ 2,822,493 $ 5,405,049 $ 2,755,334 $ 5,420,057 Leverage capital-to-assets ratio 5.0 % 9.6 % 5.0 % 9.8 %

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Loss [Text Block]	Accumulated Other Comprehensive Loss The following table presents a summary of changes in accumulated other comprehensive loss for the three and six months ended June 30, 2015 and 2014 (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 Accumulated Other Comprehensive Loss Balance, March 31, 2014 $ (96,936 ) $ (312,335 ) $ (57,603 ) $ (3,117 ) $ (469,991 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 24,842 — (13,726 ) — 11,116 Accretion of noncredit loss — 12,612 — — 12,612 Net actuarial loss — — — (373 ) (373 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 399 — — 399 Amortization - hedging activities (2) — — 724 — 724 Amortization - pension and postretirement benefits (3) — — — 126 126 Other comprehensive income (loss) 24,842 13,011 (13,002 ) (247 ) 24,604 Balance, June 30, 2014 $ (72,094 ) $ (299,324 ) $ (70,605 ) $ (3,364 ) $ (445,387 ) Balance, March 31, 2015 $ (53,034 ) $ (264,357 ) $ (88,675 ) $ (5,763 ) $ (411,829 ) Other comprehensive income (loss) before reclassifications: Net unrealized (losses) gains (14,793 ) — 12,773 — (2,020 ) Accretion of noncredit loss — 11,990 — — 11,990 Net actuarial loss — — — (8 ) (8 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 1,073 — — 1,073 Amortization - hedging activities (4) — — 5,631 — 5,631 Amortization - pension and postretirement benefits (3) — — — 100 100 Other comprehensive (loss) income (14,793 ) 13,063 18,404 92 16,766 Balance, June 30, 2015 $ (67,827 ) $ (251,294 ) $ (70,271 ) $ (5,671 ) $ (395,063 ) _______________________ (1) Recorded in net amount of impairment losses reclassified from accumulated other comprehensive loss in the statement of operations. (2) Amortization of hedging activities includes $720,000 recorded in CO bond interest expense and $4,000 recorded in net losses on derivatives and hedging activities in the statement of operations. (3) Recorded in other operating expenses in the statement of operations. (4) Amortization of hedging activities includes $5.6 million recorded in CO bond interest expense and $4,000 recorded in net losses on derivatives and hedging activities in the statement of operations. 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 Accumulated Other Comprehensive Loss Balance, December 31, 2013 $ (101,765 ) $ (324,928 ) $ (51,594 ) $ (3,229 ) $ (481,516 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 29,671 — (19,740 ) — 9,931 Accretion of noncredit loss — 24,747 — — 24,747 Net actuarial loss (373 ) (373 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 857 — — 857 Amortization - hedging activities (2) — — 729 — 729 Amortization - pension and postretirement benefits (3) — — — 238 238 Other comprehensive income (loss) 29,671 25,604 (19,011 ) (135 ) 36,129 Balance, June 30, 2014 $ (72,094 ) $ (299,324 ) $ (70,605 ) $ (3,364 ) $ (445,387 ) Balance, December 31, 2014 $ (73,623 ) $ (275,942 ) $ (81,428 ) $ (5,993 ) $ (436,986 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 5,796 — 630 — 6,426 Accretion of noncredit loss — 23,453 — — 23,453 Net actuarial loss — — — (8 ) (8 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 1,195 — — 1,195 Amortization - hedging activities (4) — — 10,527 — 10,527 Amortization - pension and postretirement benefits (3) — — — 330 330 Other comprehensive income 5,796 24,648 11,157 322 41,923 Balance, June 30, 2015 $ (67,827 ) $ (251,294 ) $ (70,271 ) $ (5,671 ) $ (395,063 ) _______________________ (1) Recorded in net amount of impairment losses reclassified from accumulated other comprehensive loss in the statement of operations. (2) Amortization of hedging activities includes $720,000 recorded in CO bond interest expense and $9,000 recorded in net losses on derivatives and hedging activities in the statement of operations. (3) Recorded in other operating expenses in the statement of operations. (4) Amortization of hedging activities includes $10.5 million recorded in CO bond interest expense and $7,000 recorded in net losses on derivatives and hedging activities in the statement of operations.

Employee Retirement Plans

Employee Retirement Plans	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Retirement Plans [Text Block]	Employee Retirement Plans Qualified Defined Benefit Multiemployer Plan. We participate in the Pentegra Defined Benefit Plan for Financial Institutions (the Pentegra Defined Benefit Plan), a funded, tax-qualified, noncontributory defined-benefit pension plan. The Pentegra Defined Benefit Plan is treated as a multiemployer plan for accounting purposes, but operates as a multiple-employer plan under the Employee Retirement Income Security Act of 1974, as amended (ERISA), and the Internal Revenue Code. The plan covers substantially all of our officers and employees. During the quarter ending June 30, 2015 , in addition to our required contribution, we made a voluntary contribution of $5.0 million to the Pentegra Defined Benefit Plan. Qualified Defined Contribution Plan. We also participate in the Pentegra Defined Contribution Plan for Financial Institutions, a tax-qualified defined contribution plan. The plan covers substantially all of our officers and employees. We contribute a percentage of the participants' compensation by making a matching contribution equal to a percentage of voluntary employee contributions, subject to certain limitations. Our matching contributions are charged to compensation and benefits expense. Nonqualified Defined Contribution Plan. We also maintain the Thrift Benefit Equalization Plan, a nonqualified, unfunded deferred compensation plan covering certain of our senior officers and directors. The plan's liability consists of the accumulated compensation deferrals and the accumulated earnings on these deferrals. The following table sets forth our net pension costs under our defined benefit plan and expenses relating to our defined contribution plans (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Qualified Defined Benefit Multiemployer Plan - Pentegra Defined Benefit Plan $ 5,102 $ 763 $ 5,205 $ 1,526 Qualified Defined Contribution Plan - Pentegra Defined Contribution Plan 280 268 528 504 Nonqualified Defined Contribution Plan - Thrift Benefit Equalization Plan 9 7 119 106 Nonqualified Supplemental Defined Benefit Retirement Plan. We also maintain a nonqualified, single-employer unfunded defined-benefit plan covering certain senior officers, for which our obligation is detailed below. We maintain a rabbi trust intended to meet future benefit obligations. Postretirement Benefits. We sponsor a fully insured postretirement benefit program that includes life insurance benefits for eligible retirees. We provide life insurance to all employees who retire on or after age 55 after completing six years of service. No contributions are required from the retirees. There are no funded plan assets that have been designated to provide postretirement benefits. The following table presents the components of net periodic benefit cost for our nonqualified supplemental defined benefit retirement plan and postretirement benefits for the three and six months ended June 30, 2015 and 2014 (dollars in thousands): Nonqualified Supplemental Defined Benefit Retirement Plan For the Three Months Ended June 30, Postretirement Benefits For the Three Months Ended June 30, 2015 2014 2015 2014 Net Periodic Benefit Cost Service cost $ 172 $ 151 $ 12 $ 5 Interest cost 121 123 9 8 Amortization of net actuarial loss 97 125 3 1 Net periodic benefit cost $ 390 $ 399 $ 24 $ 14 Nonqualified Supplemental Defined Benefit Retirement Plan For the Six Months Ended June 30, Postretirement Benefits For the Six Months Ended June 30, 2015 2014 2015 2014 Net Periodic Benefit Cost Service cost $ 343 $ 276 $ 19 $ 12 Interest cost 242 231 16 16 Amortization of net actuarial loss 326 237 4 1 Net periodic benefit cost $ 911 $ 744 $ 39 $ 29

Fair Values

Fair Values	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Values [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 Item 1 — Financial Statements and Supplementary Data — Note 18 — Fair Values in the 2014 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 six months ended June 30, 2015 , other than the following: Impaired Mortgage Loans . The fair value of impaired conventional mortgage loans is based on the lower of the carrying value of the loans or fair value of the collateral less estimated costs to sell. The fair value of impaired government mortgage loans is equal to the unpaid principal balance. The carrying values, fair values, and fair-value hierarchy of our financial instruments at June 30, 2015 , and December 31, 2014 , were as follows (dollars in thousands). These fair values do not represent an estimate of our overall market value as a going concern, which would take into account, among other things, our future business opportunities and the net profitability of our assets and liabilities. June 30, 2015 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral Financial instruments Assets: Cash and due from banks $ 844,228 $ 844,228 $ 844,228 $ — $ — $ — Interest-bearing deposits 267 267 267 — — — Securities purchased under agreements to resell 5,050,000 5,049,902 — 5,049,902 — — Federal funds sold 3,530,000 3,529,987 — 3,529,987 — — Trading securities (1) 237,414 237,414 — 237,414 — — Available-for-sale securities (1) 6,011,270 6,011,270 — 6,011,270 — — Held-to-maturity securities 2,939,093 3,260,144 — 1,798,553 1,461,591 — Advances 34,105,443 34,240,643 — 34,240,643 — — Mortgage loans, net 3,574,835 3,664,424 — 3,628,001 36,423 — Accrued interest receivable 77,828 77,828 — 77,828 — — Derivative assets (1) 28,443 28,443 — 36,609 — (8,166 ) Other assets (1) 15,312 15,312 6,965 8,347 — — Liabilities: Deposits (402,066 ) (402,066 ) — (402,066 ) — — COs: Bonds (26,075,429 ) (26,293,950 ) — (26,293,950 ) — — Discount notes (25,972,593 ) (25,973,298 ) — (25,973,298 ) — — Mandatorily redeemable capital stock (57,268 ) (57,268 ) (57,268 ) — — — Accrued interest payable (79,508 ) (79,508 ) — (79,508 ) — — Derivative liabilities (1) (476,415 ) (476,415 ) — (542,993 ) — 66,578 Other: Commitments to extend credit for advances — (157 ) — (157 ) — — Standby letters of credit (891 ) (891 ) — (891 ) — — _______________________ (1) Carried at fair value on a recurring basis. December 31, 2014 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral Financial instruments Assets: Cash and due from banks $ 1,124,536 $ 1,124,536 $ 1,124,536 $ — $ — $ — Interest-bearing deposits 163 163 163 — — — Securities purchased under agreements to resell 5,250,000 5,249,941 — 5,249,941 — — Federal funds sold 2,550,000 2,549,982 — 2,549,982 — — Trading securities (1) 244,969 244,969 — 244,969 — — Available-for-sale securities (1) 5,481,978 5,481,978 — 5,481,978 — — Held-to-maturity securities 3,352,189 3,710,815 — 2,176,268 1,534,547 — Advances 33,482,074 33,618,345 — 33,618,345 — — Mortgage loans, net 3,483,948 3,612,078 — 3,612,078 — — Accrued interest receivable 77,411 77,411 — 77,411 — — Derivative assets (1) 14,548 14,548 — 26,483 — (11,935 ) Other assets (1) 11,200 11,200 5,682 5,518 — — Liabilities: Deposits (369,331 ) (369,330 ) — (369,330 ) — — COs: Bonds (25,505,774 ) (25,741,697 ) — (25,741,697 ) — — Discount notes (25,309,608 ) (25,310,307 ) — (25,310,307 ) — — Mandatorily redeemable capital stock (298,599 ) (298,599 ) (298,599 ) — — — Accrued interest payable (91,225 ) (91,225 ) — (91,225 ) — — Derivative liabilities (1) (558,889 ) (558,889 ) — (616,033 ) — 57,144 Other: Commitments to extend credit for advances — 430 — 430 — — Standby letters of credit (745 ) (745 ) — (745 ) — — _______________________ (1) Carried at fair value on a recurring basis. Fair Value Measured on a Recurring Basis The following tables present our assets and liabilities that are measured at fair value on the statement of condition, which are recorded on a recurring basis at June 30, 2015 , and December 31, 2014 , by fair-value hierarchy level (dollars in thousands): June 30, 2015 Level 1 Level 2 Level 3 Netting Adjustment (1) Total Assets: Trading securities: U.S. government-guaranteed – single-family MBS $ — $ 11,254 $ — $ — $ 11,254 GSEs – single-family MBS — 1,859 — — 1,859 GSEs – multifamily MBS — 224,301 — — 224,301 Total trading securities — 237,414 — — 237,414 Available-for-sale securities: Supranational institutions — 438,831 — — 438,831 U.S. government-owned corporations — 269,903 — — 269,903 GSEs — 117,706 — — 117,706 U.S. government guaranteed – single-family MBS — 178,910 — — 178,910 U.S. government guaranteed – multifamily MBS — 823,863 — — 823,863 GSEs – single-family MBS — 4,182,057 — — 4,182,057 Total available-for-sale securities — 6,011,270 — — 6,011,270 Derivative assets: Interest-rate-exchange agreements — 36,580 — (8,166 ) 28,414 Mortgage delivery commitments — 29 — — 29 Total derivative assets — 36,609 — (8,166 ) 28,443 Other assets 6,965 8,347 — — 15,312 Total assets at fair value $ 6,965 $ 6,293,640 $ — $ (8,166 ) $ 6,292,439 Liabilities: Derivative liabilities Interest-rate-exchange agreements $ — $ (542,908 ) $ — $ 66,578 $ (476,330 ) Mortgage delivery commitments — (85 ) — — (85 ) Total liabilities at fair value $ — $ (542,993 ) $ — $ 66,578 $ (476,415 ) _______________________ (1) These amounts represent the application of the netting requirements that 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. December 31, 2014 Level 1 Level 2 Level 3 Netting Adjustment (1) Total Assets: Trading securities: U.S. government-guaranteed – single-family MBS $ — $ 12,235 $ — $ — $ 12,235 GSEs – single-family MBS — 2,300 — — 2,300 GSEs – multifamily MBS — 230,434 — — 230,434 Total trading securities — 244,969 — — 244,969 Available-for-sale securities: Supranational institutions — 447,685 — — 447,685 U.S. government-owned corporations — 284,997 — — 284,997 GSEs — 123,453 — — 123,453 U.S. government guaranteed – single-family MBS — 206,028 — — 206,028 U.S. government guaranteed – multifamily MBS — 871,423 — — 871,423 GSEs – single-family MBS — 3,548,392 — — 3,548,392 Total available-for-sale securities — 5,481,978 — — 5,481,978 Derivative assets: Interest-rate-exchange agreements — 26,412 — (11,935 ) 14,477 Mortgage delivery commitments — 71 — — 71 Total derivative assets — 26,483 — (11,935 ) 14,548 Other assets 5,682 5,518 — — 11,200 Total assets at fair value $ 5,682 $ 5,758,948 $ — $ (11,935 ) $ 5,752,695 Liabilities: Derivative liabilities Interest-rate-exchange agreements $ — $ (616,025 ) $ — $ 57,144 $ (558,881 ) Mortgage delivery commitments — (8 ) — — (8 ) Total liabilities at fair value $ — $ (616,033 ) $ — $ 57,144 $ (558,889 ) _______________________ (1) These amounts represent the application of the netting requirements that 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 on a Nonrecurring Basis 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 (for example, upon recognizing an other-than-temporary impairment on a held-to-maturity security). The following tables present financial assets by level within the fair-value hierarchy which are recorded at fair value on a nonrecurring basis during the six months ended June 30, 2015 , and at December 31, 2014 (dollars in thousands). For the Six Months Ended June 30, 2015 Level 1 Level 2 Level 3 Total Held-to-maturity securities: Private-label residential MBS $ — $ — $ 10,724 $ 10,724 Mortgage loans held for portfolio — — 8,052 8,052 REO — — 1,637 1,637 Total assets recorded at fair value on a nonrecurring basis $ — $ — $ 20,413 $ 20,413 December 31, 2014 Level 1 Level 2 Level 3 Total Held-to-maturity securities: Private-label residential MBS $ — $ — $ 23,259 $ 23,259 REO — — 843 843 Total assets recorded at fair value on a nonrecurring basis $ — $ — $ 24,102 $ 24,102

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2015
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 June 30, 2015 , and through the filing of this report, we believe there is a remote likelihood 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 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 June 30, 2015 , and December 31, 2014 . The par amounts of other FHLBanks' outstanding COs for which we are jointly and severally liable totaled $ 800.9 billion and $796.4 billion at June 30, 2015 , and December 31, 2014 , respectively. See Note 12 — Consolidated Obligations for additional information. Off-Balance-Sheet Commitments The following table sets forth our off-balance-sheet commitments as of June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Expire within one year Expire after one year Total Expire within one year Expire after one year Total Standby letters of credit outstanding (1) $ 4,454,029 $ 127,845 $ 4,581,874 $ 4,065,555 $ 125,381 $ 4,190,936 Commitments for unused lines of credit - advances (2) 1,262,441 — 1,262,441 1,255,445 — 1,255,445 Commitments to make additional advances 668,876 39,341 708,217 592,430 63,185 655,615 Commitments to invest in mortgage loans 26,986 — 26,986 26,927 — 26,927 Unsettled CO bonds, at par (3) 83,750 — 83,750 15,000 — 15,000 Unsettled CO discount notes, at par — — — 500,000 — 500,000 __________________________ (1) The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year. At June 30, 2015 , and December 31, 2014 , these amounts totaled $ 16.9 million and $26.2 million , respectively. Also excluded are commitments to issue standby letters of credit that expire after one year totaling $4.0 million at June 30, 2015 . (2) 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. (3) We had $70.0 million and $15.0 million in unsettled CO bonds that were hedged with associated interest-rate swaps at June 30, 2015 , and December 31, 2014 , respectively. Standby Letters of Credit. A standby letter of credit is a financing arrangement pursuant to which we agree for a fee to fund the associated obligation to a third-party beneficiary should the primary obligor fail to fund such obligation. If we are required to make payment for a beneficiary's draw, the payment amount is converted into a collateralized advance to the primary obligor. Standby letters of credit are fully collateralized at the time of issuance. Based on our credit analyses and collateral requirements, we have not deemed it necessary to record any additional liability on these commitments. The original terms of these standby letters of credit range from final expiries in 20 days to 20 years . Our unearned fees for the value of the guarantees related to standby letters of credit are recorded in other liabilities and totaled $891,000 and $745,000 at June 30, 2015 , and December 31, 2014 , respectively. Commitments to Invest in Mortgage Loans. Commitments to invest in mortgage loans are generally for periods not to exceed 45 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 10 — 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	6 Months Ended
	Jun. 30, 2015
Transactions with Shareholders [Abstract]
Transactions with Shareholders [Text Block]	Transactions with Shareholders Related Parties. We define related parties as members with 10 percent or more of the voting interests of our capital stock outstanding. Under the FHLBank Act and FHFA regulations, each member directorship is designated to one of the six states in our district. Each member eligible to vote is entitled to cast by ballot one vote for each share of stock that it was required to hold as of the record date, which is December 31, of the year prior to each election, subject to the limitation that no member may cast more votes than the average number of shares of our stock that is required to be held by all members located in such member's state. Eligible members are permitted to vote all their eligible shares for one candidate for each open member directorship in the state in which the member is located and for each open independent directorship. A nonmember stockholder is not entitled to cast votes for the election of directors unless it was a member as of the record date. At June 30, 2015 , and December 31, 2014 , no shareholder owned more than 10 percent of the total voting interests due to statutory limits on members' voting rights, therefore, we did not have any related parties. 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. The following tables present transactions with shareholders whose holdings of capital stock exceed 10 percent or more of total capital stock outstanding at June 30, 2015 , and December 31, 2014 (dollars in thousands): Capital Stock Outstanding Percent of Total Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances As of June 30, 2015 Citizens Bank, N.A. $ 317,502 12.5 % $ 5,516,467 16.3 % $ 612 2.1 % As of December 31, 2014 Citizens Bank, N.A. $ 317,502 11.7 % $ 5,768,096 17.3 % $ 283 1.0 % We held sufficient collateral to support the advances to the above institutions such that we do not expect to incur any credit losses on these advances. We recognized interest income on outstanding advances and fees on letters of credit from Citizens Bank, N.A. during the three and six months ended June 30, 2015 and 2014 as follows (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, Citizens Bank, N.A. 2015 2014 2015 2014 Interest income on advances $ 3,447 $ 3,592 $ 7,163 $ 5,750 Fees on letters of credit 1,050 868 2,039 1,658 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. The following table presents the outstanding balances of capital stock, advances, and accrued interest receivable with members whose officers or directors serve on our board of directors, and those balances as a percentage of our total balance as reported on our statement of condition (dollars in thousands): Capital Stock Outstanding Percent of Total Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances As of June 30, 2015 $ 88,897 3.5 % $ 1,198,088 3.5 % $ 1,244 4.2 % As of December 31, 2014 79,386 2.9 918,127 2.8 1,227 4.2

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On July 24, 2015 , the board of directors declared a cash dividend at an annualized rate of 3.28 percent based on capital stock balances outstanding during the second quarter of 2015. The dividend, including dividends on mandatorily redeemable capital stock, amounted to $20.6 million and was paid on August 4, 2015 .

Basis of Presentation Summary o

Basis of Presentation Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Loans and Leases Receivable, Valuation, Policy [Policy Text Block]	Collectively Evaluated Mortgage Loans . We evaluate the credit risk of our investments in conventional mortgage loans for impairment on a collective basis that considers loan-pool-specific attribute data at the master commitment pool level, applies estimated loss severities, and incorporates available credit enhancements to establish our best estimate of probable incurred losses at the reporting date. We do not consider credit-enhancement cash flows that are projected and assessed as not probable of receipt in reducing estimated losses. Migration analysis is a methodology for estimating the rate of default experienced on pools of similar loans based on our historical experience. We apply migration analysis to conventional loans that are currently not past due, loans that are 30 to 59 days past due, 60 to 89 days past due, and 90 to 179 days past due. We then estimate the dollar amount of loans in these categories that we believe are likely to migrate to a realized loss position and apply a loss severity factor to estimate losses that would be incurred at the statement of condition date. Additionally, for our investments in loans modified under our temporary loan modification plan, we measure the present value of expected future cash flows discounted at the loan's effective interest rate on the effective date of a loan modification and reduce the carrying value of the loan accordingly. Individually Evaluated Mortgage Loans . Certain conventional mortgage loans, primarily impaired mortgage loans that are considered collateral-dependent, may be specifically identified for purposes of calculating the allowance for credit losses. A mortgage loan is considered collateral-dependent if repayment is only expected to be provided by the sale of the underlying property, that is, if it is considered likely that the borrower will default and there is no credit enhancement from a participating financial institution to offset losses under the master commitment. The estimated credit losses on impaired collateral-dependent loans may be separately determined because sufficient information exists to make a reasonable estimate of the inherent loss on these loans on an individual loan basis. Loans that are considered collateral-dependent are measured for impairment based on the fair value of the underlying property less estimated selling costs. The resulting incurred loss is equal to the difference between the carrying value of the loan and the estimated fair value of the collateral less estimated selling costs.
Loans And Leases Receivable Charge Off Policy [Policy Text Block]	We now record a charge-off when a conventional mortgage loan is 180 or more days past due, when the borrower has filed for bankruptcy protection and the loan is at least 30 days past due, or when there is evidence of fraud. Confirming events also include, but are not limited to, the occurrence of foreclosure or notification of a claim against any of the credit enhancements. A charge-off is recorded if we determine that the recorded investment in the loan is not likely to be recovered. Charge-Off Policy . We evaluate whether to record a charge-off on a conventional mortgage loan upon the occurrence of a confirming event.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Impaired Mortgage Loans . The fair value of impaired conventional mortgage loans is based on the lower of the carrying value of the loans or fair value of the collateral less estimated costs to sell. Fair Value on a Nonrecurring Basis 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 (for example, upon recognizing an other-than-temporary impairment on a held-to-maturity security).
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.

Trading Securities (Tables)

Trading Securities (Tables)	6 Months Ended
	Jun. 30, 2015
Trading Securities [Abstract]
Trading Securities by Major Security Type [Table Text Block]	Our trading securities as of June 30, 2015 , and December 31, 2014 , were (dollars in thousands): June 30, 2015 December 31, 2014 Mortgage-backed securities (MBS) U.S. government-guaranteed – single-family $ 11,254 $ 12,235 Government-sponsored enterprise (GSE) – single-family 1,859 2,300 GSEs – multifamily 224,301 230,434 Total $ 237,414 $ 244,969

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	6 Months Ended
	Jun. 30, 2015
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale (AFS) securities by major security type [Table Text Block]	Our available-for-sale securities as of June 30, 2015 , were (dollars in thousands): Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value Supranational institutions $ 461,402 $ — $ (22,571 ) $ 438,831 U.S. government-owned corporations 311,311 — (41,408 ) 269,903 GSEs 129,544 — (11,838 ) 117,706 902,257 — (75,817 ) 826,440 MBS U.S. government guaranteed – single-family 180,356 246 (1,692 ) 178,910 U.S. government guaranteed – multifamily 823,275 1,492 (904 ) 823,863 GSEs – single-family 4,173,209 19,945 (11,097 ) 4,182,057 5,176,840 21,683 (13,693 ) 5,184,830 Total $ 6,079,097 $ 21,683 $ (89,510 ) $ 6,011,270 _______________________ (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. Our available-for-sale securities as of December 31, 2014 , were (dollars in thousands): Amounts Recorded in Accumulated Other Comprehensive Loss Amortized Cost (1) Unrealized Gains Unrealized Losses Fair Value Supranational institutions $ 472,440 $ — $ (24,755 ) $ 447,685 U.S. government-owned corporations 322,436 — (37,439 ) 284,997 GSEs 133,748 — (10,295 ) 123,453 928,624 — (72,489 ) 856,135 MBS U.S. government guaranteed – single-family 207,090 375 (1,437 ) 206,028 U.S. government guaranteed – multifamily 874,817 204 (3,598 ) 871,423 GSEs – single-family 3,545,070 14,742 (11,420 ) 3,548,392 4,626,977 15,321 (16,455 ) 4,625,843 Total $ 5,555,601 $ 15,321 $ (88,944 ) $ 5,481,978 _______________________ (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.
Categories of Investments, Marketable Securities, Available-for-Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
AFS securities in a continuous unrealized loss position [Table Text Block]	The following table summarizes our available-for-sale securities with unrealized losses as of June 30, 2015 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands): Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Supranational institutions $ — $ — $ 438,831 $ (22,571 ) $ 438,831 $ (22,571 ) U.S. government-owned corporations — — 269,903 (41,408 ) 269,903 (41,408 ) GSEs — — 117,706 (11,838 ) 117,706 (11,838 ) — — 826,440 (75,817 ) 826,440 (75,817 ) MBS U.S. government guaranteed – single-family — — 131,472 (1,692 ) 131,472 (1,692 ) U.S. government guaranteed – multifamily 155,776 (244 ) 203,264 (660 ) 359,040 (904 ) GSEs – single-family 1,277,232 (5,061 ) 415,932 (6,036 ) 1,693,164 (11,097 ) 1,433,008 (5,305 ) 750,668 (8,388 ) 2,183,676 (13,693 ) Total temporarily impaired $ 1,433,008 $ (5,305 ) $ 1,577,108 $ (84,205 ) $ 3,010,116 $ (89,510 ) The following table summarizes our available-for-sale securities with unrealized losses as of December 31, 2014 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands): Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Supranational institutions $ — $ — $ 447,685 $ (24,755 ) $ 447,685 $ (24,755 ) U.S. government-owned corporations — — 284,997 (37,439 ) 284,997 (37,439 ) GSEs — — 123,453 (10,295 ) 123,453 (10,295 ) — — 856,135 (72,489 ) 856,135 (72,489 ) MBS U.S. government guaranteed – single-family — — 154,665 (1,437 ) 154,665 (1,437 ) U.S. government guaranteed – multifamily 610,470 (3,497 ) 23,567 (101 ) 634,037 (3,598 ) GSEs – single-family 453,043 (888 ) 915,354 (10,532 ) 1,368,397 (11,420 ) 1,063,513 (4,385 ) 1,093,586 (12,070 ) 2,157,099 (16,455 ) Total temporarily impaired $ 1,063,513 $ (4,385 ) $ 1,949,721 $ (84,559 ) $ 3,013,234 $ (88,944 )
Investments classified by contractual maturity date [Table Text Block]	The amortized cost and fair value of our available-for-sale securities by contractual maturity at June 30, 2015 , and December 31, 2014 , were (dollars in thousands): June 30, 2015 December 31, 2014 Year of Maturity Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ — $ — $ — $ — Due after one year through five years — — — — Due after five years through 10 years 16,988 16,378 — — Due after 10 years 885,269 810,062 928,624 856,135 902,257 826,440 928,624 856,135 MBS (1) 5,176,840 5,184,830 4,626,977 4,625,843 Total $ 6,079,097 $ 6,011,270 $ 5,555,601 $ 5,481,978 _______________________ (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 (Ta

Held-to-Maturity Securities (Tables)	6 Months Ended
	Jun. 30, 2015
Schedule of Held-to-maturity Securities [Line Items]
HTM Securities by major security type [Table Text Block]	Our held-to-maturity securities as of June 30, 2015 , were (dollars in thousands): Amortized Cost Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value U.S. agency obligations $ 4,739 $ — $ 4,739 $ 286 $ — $ 5,025 State or local housing-finance-agency obligations (HFA securities) 175,692 — 175,692 30 (18,748 ) 156,974 180,431 — 180,431 316 (18,748 ) 161,999 MBS U.S. government guaranteed – single-family 17,965 — 17,965 413 — 18,378 U.S. government guaranteed – multifamily 39,755 — 39,755 92 — 39,847 GSEs – single-family 1,256,108 — 1,256,108 36,320 (137 ) 1,292,291 GSEs – multifamily 418,302 — 418,302 24,710 — 443,012 Private-label – residential 1,261,450 (250,575 ) 1,010,875 291,252 (12,990 ) 1,289,137 Asset-backed securities (ABS) backed by home equity loans 16,376 (719 ) 15,657 775 (952 ) 15,480 3,009,956 (251,294 ) 2,758,662 353,562 (14,079 ) 3,098,145 Total $ 3,190,387 $ (251,294 ) $ 2,939,093 $ 353,878 $ (32,827 ) $ 3,260,144 Our held-to-maturity securities as of December 31, 2014 , were (dollars in thousands): Amortized Cost Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss Carrying Value Gross Unrecognized Holding Gains Gross Unrecognized Holding Losses Fair Value U.S. agency obligations $ 5,777 $ — $ 5,777 $ 360 $ — $ 6,137 HFA securities 178,387 — 178,387 30 (18,136 ) 160,281 184,164 — 184,164 390 (18,136 ) 166,418 MBS U.S. government guaranteed – single-family 20,399 — 20,399 487 — 20,886 U.S. government guaranteed – multifamily 115,712 — 115,712 298 (6 ) 116,004 GSEs – single-family 1,420,801 — 1,420,801 40,518 (157 ) 1,461,162 GSEs – multifamily 542,130 — 542,130 29,949 — 572,079 Private-label – residential 1,327,967 (275,158 ) 1,052,809 319,306 (13,957 ) 1,358,158 ABS backed by home equity loans 16,958 (784 ) 16,174 856 (922 ) 16,108 3,443,967 (275,942 ) 3,168,025 391,414 (15,042 ) 3,544,397 Total $ 3,628,131 $ (275,942 ) $ 3,352,189 $ 391,804 $ (33,178 ) $ 3,710,815
Categories of Investments, Marketable Securities, Held-to-maturity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
HTM securities in a continuous unrealized loss position [Table Text Block]	The following table summarizes our held-to-maturity securities with unrealized losses as of June 30, 2015 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands). Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 14,916 $ (84 ) $ 136,316 $ (18,664 ) $ 151,232 $ (18,748 ) MBS GSEs – single-family — — 17,469 (137 ) 17,469 (137 ) Private-label – residential 87,923 (1,636 ) 490,916 (41,992 ) 578,839 (43,628 ) ABS backed by home equity loans — — 14,054 (1,107 ) 14,054 (1,107 ) 87,923 (1,636 ) 522,439 (43,236 ) 610,362 (44,872 ) Total $ 102,839 $ (1,720 ) $ 658,755 $ (61,900 ) $ 761,594 $ (63,620 ) The following table summarizes our held-to-maturity securities with unrealized losses as of December 31, 2014 , which are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands). Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses HFA securities $ 14,850 $ (150 ) $ 139,544 $ (17,986 ) $ 154,394 $ (18,136 ) MBS U.S. government guaranteed – multifamily 9,282 (6 ) — — 9,282 (6 ) GSEs – single-family — — 38,121 (157 ) 38,121 (157 ) Private-label – residential 80,439 (1,028 ) 544,369 (45,104 ) 624,808 (46,132 ) ABS backed by home equity loans 206 (3 ) 14,641 (1,074 ) 14,847 (1,077 ) 89,927 (1,037 ) 597,131 (46,335 ) 687,058 (47,372 ) Total $ 104,777 $ (1,187 ) $ 736,675 $ (64,321 ) $ 841,452 $ (65,508 )
HTM Securities by contractual maturity [Table Text Block]	The amortized cost and fair value of our held-to-maturity securities by contractual maturity at June 30, 2015 , and December 31, 2014 , are shown below (dollars in thousands). Expected maturities of some securities and MBS may 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. June 30, 2015 December 31, 2014 Year of Maturity Amortized Cost Carrying Value (1) Fair Value Amortized Cost Carrying Value (1) Fair Value Due in one year or less $ 100 $ 100 $ 100 $ 150 $ 150 $ 150 Due after one year through five years 8,331 8,331 8,639 9,369 9,369 9,751 Due after five years through 10 years 17,020 17,020 16,944 17,115 17,115 16,973 Due after 10 years 154,980 154,980 136,316 157,530 157,530 139,544 180,431 180,431 161,999 184,164 184,164 166,418 MBS (2) 3,009,956 2,758,662 3,098,145 3,443,967 3,168,025 3,544,397 Total $ 3,190,387 $ 2,939,093 $ 3,260,144 $ 3,628,131 $ 3,352,189 $ 3,710,815 _______________________ (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. (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.

Other-Than-Temporary Impairme32

Other-Than-Temporary Impairment (Tables)	6 Months Ended
	Jun. 30, 2015
Other-Than-Temporary Impairment Analysis [Abstract]
Significant Inputs for OTTI [Table Text Block]	For those securities for which an other-than-temporary impairment was determined to have occurred during the three months ended June 30, 2015 , the following table presents a summary of the average projected values over the remaining lives of the securities for the significant inputs used to measure the amount of the credit loss recognized in earnings, as well as related current credit enhancement. Credit enhancement is defined as the percentage of subordinated tranches, over-collateralization, and other credit enhancement, if any, in a security structure that will generally absorb losses before we will experience a credit loss on the security. The calculated averages represent the dollar-weighted averages of all the private-label residential MBS and home equity loan investments in each category shown (dollars in thousands). Weighted Average of Significant Inputs Weighted Average Current Credit Enhancement Private-label MBS by Year of Securitization Par Value Projected Prepayment Rates Projected Default Rates Projected Loss Severities Alt-A Private-label residential MBS (1) 2007 $ 50,731 6.3 % 44.1 % 37.5 % — % 2006 60,688 10.3 27.8 38.5 — 2005 23,273 7.0 26.8 38.0 30.6 2004 and prior 2,584 13.1 16.2 5.0 3.8 Total $ 137,276 8.3 % 33.4 % 37.4 % 5.3 % _______________________ (1) Securities are classified in the table above based upon the current performance characteristics of the underlying loan pool and therefore the manner in which the loan pool backing the security has been modeled (as prime, Alt-A, or subprime), rather than their classification of the security at the time of issuance.
Total Securities Other-than-Temporarily Impaired during the Life of the Security [Table Text Block]	The following table sets forth our securities for which other-than-temporary impairment credit losses were recognized during the life of the security through June 30, 2015 (dollars in thousands). Securities are classified in the table below based on their classifications at the time of issuance. June 30, 2015 Other-Than-Temporarily Impaired Investment (1) Par Value Amortized Cost Carrying Value Fair Value Private-label residential MBS – Prime $ 54,384 $ 46,936 $ 37,272 $ 47,621 Private-label residential MBS – Alt-A 1,369,762 1,007,710 766,799 1,047,631 ABS backed by home equity loans – Subprime 4,101 3,680 2,961 3,735 Total other-than-temporarily impaired securities $ 1,428,247 $ 1,058,326 $ 807,032 $ 1,098,987 _______________________ (1) We have instituted litigation in relation to certain of the private-label MBS in which we invested. Our complaint asserts, among others, claims for untrue or misleading statements in the sale of securities. It is possible that classifications of private-label MBS as provided herein when based on classification at the time of issuance as disclosed by those securities' issuance documents, as well as other statements about the securities, are inaccurate.
Rollforward of the Amounts Related to Credit Losses Recognized into Earnings [Table Text Block]	The following table presents a roll-forward of the amounts related to credit losses recognized in earnings. The roll-forward is the amount of credit losses on investment securities on which we recognized a portion of other-than-temporary impairment charges into accumulated other comprehensive loss (dollars in thousands). For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Balance at beginning of year $ 559,725 $ 595,560 $ 568,652 $ 603,786 Additions: Additional credit losses for which an other-than-temporary impairment charge was previously recognized (1) 1,429 399 1,775 857 Reductions: Increase in cash flows expected to be collected which are recognized over the remaining life of the security (2) (9,813 ) (8,625 ) (19,086 ) (17,309 ) Balance at end of period $ 551,341 $ 587,334 $ 551,341 $ 587,334 _______________________ (1) For the three months ended June 30, 2015 and 2014 , additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to April 1, 2015 and 2014 . For the six months ended June 30, 2015 and 2014 , additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to January 1, 2015 and 2014 . (2) Represents amounts accreted as interest income during the current period.

Advances (Tables)

Advances (Tables)	6 Months Ended
	Jun. 30, 2015
Advances [Abstract]
Federal Home Loan Bank, Advances [Table Text Block]	The following table sets forth our advances outstanding by the year of contractual maturity or next put date for putable advances (dollars in thousands): Year of Contractual Maturity or Next Put Date, Par Value June 30, 2015 December 31, 2014 Overdrawn demand-deposit accounts $ 8,879 $ 19,863 Due in one year or less 23,765,671 22,737,137 Due after one year through two years 2,883,357 3,767,187 Due after two years through three years 2,355,670 2,155,922 Due after three years through four years 1,661,962 1,931,707 Due after four years through five years 1,535,863 1,036,423 Thereafter 1,721,263 1,626,475 Total par value $ 33,932,665 $ 33,274,714 At June 30, 2015 , and December 31, 2014 , we had advances outstanding with interest rates ranging from (0.17) percent to 7.72 percent and (0.22) percent to 8.37 percent , respectively, as summarized below (dollars in thousands). 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. June 30, 2015 December 31, 2014 Year of Contractual Maturity Amount Weighted Average Rate Amount Weighted Average Rate Overdrawn demand-deposit accounts $ 8,879 0.45 % $ 19,863 0.44 % Due in one year or less 21,799,346 0.45 20,561,912 0.41 Due after one year through two years 3,718,382 2.17 4,114,587 1.63 Due after two years through three years 3,327,720 2.27 3,564,747 2.68 Due after three years through four years 1,801,212 2.09 2,299,457 2.16 Due after four years through five years 1,555,863 1.95 1,087,673 2.11 Thereafter 1,721,263 2.91 1,626,475 2.98 Total par value 33,932,665 1.10 % 33,274,714 1.11 % Premiums 30,128 32,887 Discounts (17,980 ) (18,549 ) Market value of bifurcated derivatives (1) 1,953 1,467 Hedging adjustments 158,677 191,555 Total $ 34,105,443 $ 33,482,074 _________________________ (1) At June 30, 2015 , and December 31, 2014 , we had certain advances with embedded features that met the requirements to be separated from the host contract and designated as a stand-alone derivative. The following table details interest-rate-payment types for our outstanding advances (dollars in thousands): Par value of advances June 30, 2015 December 31, 2014 Fixed-rate $ 28,097,886 $ 27,236,551 Variable-rate 5,834,779 6,038,163 Total par value $ 33,932,665 $ 33,274,714
Schedule of Prepayment Fees on Advances [Table Text Block]	For the three and six months ended June 30, 2015 and 2014 , net advance prepayment fees recognized in income are reflected in the following table (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Prepayment fees received from borrowers $ 279 $ 1,127 $ 3,896 $ 7,822 Less: hedging fair-value adjustments on prepaid advances — (359 ) (2,731 ) (552 ) Less: net premiums associated with prepaid advances — — — (3,928 ) Less: deferred recognition of prepayment fees received from borrowers on advance prepayments deemed to be loan modifications — — (246 ) (80 ) Prepayment fees recognized in income on advance restructurings deemed to be extinguishments — — 3,102 — Net prepayment fees recognized in income $ 279 $ 768 $ 4,021 $ 3,262

Mortgage Loans Held for Portf34

Mortgage Loans Held for Portfolio (Tables)	6 Months Ended
	Jun. 30, 2015
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans Held for Portfolio [Table Text Block]	The following table presents certain characteristics of these investments (dollars in thousands): June 30, 2015 December 31, 2014 Real estate Fixed-rate 15-year single-family mortgages $ 587,679 $ 570,663 Fixed-rate 20- and 30-year single-family mortgages 2,924,304 2,852,669 Premiums 63,971 62,554 Discounts (2,442 ) (2,761 ) Deferred derivative gains, net 2,423 2,835 Total mortgage loans held for portfolio 3,575,935 3,485,960 Less: allowance for credit losses (1,100 ) (2,012 ) Total mortgage loans, net of allowance for credit losses $ 3,574,835 $ 3,483,948 The following table details the par value of mortgage loans held for portfolio (dollars in thousands): June 30, 2015 December 31, 2014 Conventional mortgage loans $ 3,091,973 $ 2,997,669 Government mortgage loans 420,010 425,663 Total par value $ 3,511,983 $ 3,423,332

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2015
Allowance for Credit Losses [Abstract]
Recorded Investment in Delinquent Mortgage Loans [Table Text Block]	The tables below set forth certain key credit quality indicators for our investments in mortgage loans at June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 Recorded Investment in Conventional Mortgage Loans Recorded Investment in Government Mortgage Loans Total Past due 30-59 days delinquent $ 23,477 $ 17,516 $ 40,993 Past due 60-89 days delinquent 9,177 4,700 13,877 Past due 90 days or more delinquent 26,684 7,095 33,779 Total past due 59,338 29,311 88,649 Total current loans 3,103,513 402,429 3,505,942 Total mortgage loans $ 3,162,851 $ 431,740 $ 3,594,591 Other delinquency statistics In process of foreclosure, included above (1) $ 13,968 $ 2,393 $ 16,361 Serious delinquency rate (2) 0.89 % 1.64 % 0.98 % Past due 90 days or more still accruing interest $ — $ 7,095 $ 7,095 Loans on nonaccrual status (3) $ 27,313 $ — $ 27,313 _______________________ (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. December 31, 2014 Recorded Investment in Conventional Mortgage Loans Recorded Investment in Government Mortgage Loans Total Past due 30-59 days delinquent $ 32,068 $ 19,811 $ 51,879 Past due 60-89 days delinquent 9,834 4,591 14,425 Past due 90 days or more delinquent 37,927 7,467 45,394 Total past due 79,829 31,869 111,698 Total current loans 2,986,749 405,808 3,392,557 Total mortgage loans $ 3,066,578 $ 437,677 $ 3,504,255 Other delinquency statistics In process of foreclosure, included above (1) $ 13,709 $ 2,786 $ 16,495 Serious delinquency rate (2) 1.27 % 1.71 % 1.32 % Past due 90 days or more still accruing interest $ — $ 7,467 $ 7,467 Loans on nonaccrual status (3) $ 38,832 $ — $ 38,832 _______________________ (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.
Individually Evaluated Impaired Loans, Recorded Investment [Table Text Block]	The following tables present the recorded investment, par value, and any related allowance for impaired conventional loans individually assessed for impairment at June 30, 2015 , and December 31, 2014 , and the average recorded investment and interest income recognized on these loans during the three and six months ended June 30, 2015 and 2014 (dollars in thousands). As of June 30, 2015 As of December 31, 2014 Recorded Investment Par Value Related Allowance Recorded Investment Par Value Related Allowance Individually evaluated impaired mortgage loans with no related allowance $ 31,153 $ 31,116 $ — $ 6,679 $ 6,654 $ — Individually evaluated impaired mortgage loans with a related allowance — — — 3,097 3,073 544 Total individually evaluated impaired mortgage loans $ 31,153 $ 31,116 $ — $ 9,776 $ 9,727 $ 544
Individually Evaluated Impaired Loans, Average Recorded Investment and Interest Income Recognized [Table Text Block]	For the Three Months Ended June 30, 2015 2014 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Individually evaluated impaired mortgage loans with no related allowance $ 31,759 $ 129 $ 3,637 $ 44 Individually evaluated impaired mortgage loans with a related allowance — — 2,538 2 Total individually evaluated impaired mortgage loans $ 31,759 $ 129 $ 6,175 $ 46 For the Six Months Ended June 30, 2015 2014 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Individually evaluated impaired mortgage loans with no related allowance $ 32,557 $ 249 $ 3,676 $ 92 Individually evaluated impaired mortgage loans with a related allowance — — 2,839 13 Total individually evaluated impaired mortgage loans $ 32,557 $ 249 $ 6,515 $ 105
Rollforward of Allowance for Credit Losses on Mortgage Loans [Table Text Block]	The following table presents a roll-forward of the allowance for credit losses on conventional mortgage loans for the three and six months ended June 30, 2015 and 2014 , as well as the recorded investment in mortgage loans by impairment methodology at June 30, 2015 and 2014 (dollars in thousands). The recorded investment in a loan is the par amount of the loan, adjusted for accrued interest, unamortized premiums or discounts, deferred derivative gains and losses, and direct write-downs. The recorded investment is net of any valuation allowance. For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Allowance for credit losses Balance, beginning of period $ 1,350 $ 1,812 $ 2,012 $ 2,221 Charge-offs, net of recoveries (27 ) (13 ) (629 ) (100 ) (Reduction of) provision for credit losses (223 ) 243 (283 ) (79 ) Balance, end of period $ 1,100 $ 2,042 $ 1,100 $ 2,042 Ending balance, individually evaluated for impairment $ — $ 605 $ — $ 605 Ending balance, collectively evaluated for impairment $ 1,100 $ 1,437 $ 1,100 $ 1,437 Recorded investment, end of period (1) Individually evaluated for impairment $ 31,153 $ 6,142 $ 31,153 $ 6,142 Collectively evaluated for impairment $ 3,131,698 $ 2,918,633 $ 3,131,698 $ 2,918,633 _________________________ (1) These amounts exclude government mortgage loans because we make no allowance for credit losses based on our investments in government mortgage loans, as discussed above under — Government Mortgage Loans Held for Portfolio.

Derivatives and Hedging Activ36

Derivatives and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivative instruments [Table Text Block]	The following table presents the fair value of derivatives, including the effect of netting adjustments and cash collateral as of June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Notional Amount of Derivatives Derivative Assets Derivative Liabilities Notional Derivative Derivative Derivatives designated as hedging instruments Interest-rate swaps $ 14,534,641 $ 36,333 $ (493,603 ) $ 12,579,525 $ 26,381 $ (553,967 ) Forward-start interest-rate swaps 752,800 169 (29,652 ) 1,096,800 — (42,209 ) Total derivatives designated as hedging instruments 15,287,441 36,502 (523,255 ) 13,676,325 26,381 (596,176 ) Derivatives not designated as hedging instruments Economic hedges: Interest-rate swaps 454,000 78 (19,653 ) 423,000 31 (19,849 ) Interest-rate caps or floors 300,000 — — 300,000 — — Mortgage-delivery commitments (1) 26,986 29 (85 ) 26,927 71 (8 ) Total derivatives not designated as hedging instruments 780,986 107 (19,738 ) 749,927 102 (19,857 ) Total notional amount of derivatives $ 16,068,427 $ 14,426,252 Total derivatives before netting and collateral adjustments 36,609 (542,993 ) 26,483 (616,033 ) Netting adjustments and cash collateral including related accrued interest (2) (8,166 ) 66,578 (11,935 ) 57,144 Derivative assets and derivative liabilities $ 28,443 $ (476,415 ) $ 14,548 $ (558,889 ) _______________________ (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 $60.7 million and $45.5 million at June 30, 2015 , and December 31, 2014 , 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 $2.3 million and $290,000 at June 30, 2015 , and December 31, 2014 , respectively.
Net (losses) gains on derivatives and hedging activities [Table Text Block]	Net losses on derivatives and hedging activities recorded in other (loss) income for the three and six months ended June 30, 2015 and 2014 were as follows (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Derivatives designated as hedging instruments Interest-rate swaps $ (1,087 ) $ 965 $ (1,715 ) $ 1,459 Cash flow hedge ineffectiveness 184 (35 ) 104 (170 ) Total net (losses) gains related to derivatives designated as hedging instruments (903 ) 930 (1,611 ) 1,289 Derivatives not designated as hedging instruments: Economic hedges: Interest-rate swaps 403 (2,807 ) (2,675 ) (4,643 ) Interest-rate caps or floors — (25 ) — (42 ) Mortgage-delivery commitments (642 ) 610 (215 ) 721 Total net losses related to derivatives not designated as hedging instruments (239 ) (2,222 ) (2,890 ) (3,964 ) Net losses on derivatives and hedging activities $ (1,142 ) $ (1,292 ) $ (4,501 ) $ (2,675 )
Gains (losses) by type of hedged item [Table Text Block]	The following tables present, by type of hedged item, the gains (losses) on derivatives and the related hedged items in fair-value hedge relationships and the impact of those derivatives on our net interest income for the three and six months ended June 30, 2015 and 2014 (dollars in thousands): For the Three Months Ended June 30, 2015 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 39,168 $ (38,764 ) $ 404 $ (32,611 ) Investments 54,244 (53,694 ) 550 (9,439 ) COs – bonds (11,130 ) 9,089 (2,041 ) 15,265 Total $ 82,282 $ (83,369 ) $ (1,087 ) $ (26,785 ) For the Three Months Ended June 30, 2014 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 8,124 $ (8,040 ) $ 84 $ (33,019 ) Investments (21,709 ) 21,994 285 (9,504 ) Deposits (391 ) 391 — 397 COs – bonds 12,869 (12,273 ) 596 13,136 Total $ (1,107 ) $ 2,072 $ 965 $ (28,990 ) For the Six Months Ended June 30, 2015 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 33,311 $ (32,878 ) $ 433 $ (64,510 ) Investments 27,245 (26,368 ) 877 (18,921 ) COs – bonds 4,269 (7,294 ) (3,025 ) 30,963 Total $ 64,825 $ (66,540 ) $ (1,715 ) $ (52,468 ) For the Six Months Ended June 30, 2014 Gain/(Loss) on Derivative Gain/(Loss) on Hedged Item Net Fair-Value Hedge Ineffectiveness Effect of Derivatives on Net Interest Income (1) Hedged Item: Advances $ 30,109 $ (29,881 ) $ 228 $ (66,430 ) Investments (53,269 ) 53,785 516 (18,998 ) Deposits (781 ) 781 — 794 COs – bonds 20,755 (20,040 ) 715 23,773 Total $ (3,186 ) $ 4,645 $ 1,459 $ (60,861 ) ____________ (1) The net interest on derivatives in fair-value hedge relationships is presented in the statement of operations as interest income or interest expense of the respective hedged item.
Effect of Cash Flow Hedge-Related Derivative Instruments [Table Text Block]	The following table presents the losses recognized in accumulated other comprehensive loss, the losses reclassified from accumulated other comprehensive loss into income, and the effect of our hedging activities on our net losses on derivatives and hedging activities in the statement of income for our forward-start interest-rate swaps associated with CO bond hedged items in cash-flow hedge relationships (dollars in thousands). Derivatives and Hedged Items in Cash Flow Hedging Relationships Gains (Losses) Recognized in Other Comprehensive Loss on Derivatives (Effective Portion) Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion) (Losses) Gains Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion) Gains (Losses) Recognized in Net Losses on Derivatives and Hedging Activities (Ineffective Portion) Interest-rate swaps - CO bonds For the Three Months Ended June 30, 2015 $ 12,773 Interest expense $ (5,628 ) $ 184 For the Three Months Ended June 30, 2014 (13,726 ) Interest expense (720 ) (35 ) For the Six Months Ended June 30, 2015 630 Interest expense (10,520 ) 104 For the Six Months Ended June 30, 2014 (19,740 ) Interest expense (720 ) (170 )
Post-haircut value of incremental collateral based on incremental credit rating downgrades [Table Text Block]	The following table sets forth the post-haircut value of incremental collateral that certain bilateral derivatives counterparties could have required us to deliver based on incremental credit rating downgrades at June 30, 2015 (dollars in thousands). Post-Haircut Value of Incremental Collateral to be Delivered as of June 30, 2015 Ratings Downgrade (1) From To Incremental Collateral (2) AA+ AA or AA- $ 30,282 AA- A+, A or A- 35,320 A- below A- 36,673 _______________________ (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. (2) Additional collateral of $1.1 million could be called by counterparties as of June 30, 2015 , at our current credit rating of AA+ (based on the lower of our credit ratings from S&P and Moody's) and is not included in the table.
Fair value of derivative instruments with and without the legal right of offset [Table Text Block]	The following table presents separately the fair value of derivatives meeting or not meeting netting requirements, with and without the legal right of offset, including the related collateral received from or pledged to counterparties, based on the terms of our master netting arrangements or similar agreements as of June 30, 2015 , and December 31, 2014 (dollars in thousands). June 30, 2015 December 31, 2014 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives meeting netting requirements Gross recognized amount Bilateral derivatives $ 12,919 $ (507,233 ) $ 20,083 $ (578,073 ) Cleared derivatives 23,661 (35,675 ) 6,329 (37,952 ) Total gross recognized amount 36,580 (542,908 ) 26,412 (616,025 ) Gross amounts of netting adjustments and cash collateral Bilateral derivatives (12,622 ) 30,903 (19,481 ) 19,191 Cleared derivatives 4,456 35,675 7,546 37,953 Total gross amounts of netting adjustments and cash collateral (8,166 ) 66,578 (11,935 ) 57,144 Net amounts after netting adjustments and cash collateral Bilateral derivatives 297 (476,330 ) 602 (558,882 ) Cleared derivatives 28,117 — 13,875 1 Total net amounts after netting adjustments and cash collateral 28,414 (476,330 ) 14,477 (558,881 ) Derivatives not meeting netting requirements Mortgage delivery commitments 29 (85 ) 71 (8 ) Total derivative assets and total derivative liabilities Bilateral derivatives 297 (476,330 ) 602 (558,882 ) Cleared derivatives 28,117 — 13,875 1 Mortgage delivery commitments 29 (85 ) 71 (8 ) Total derivative assets and total derivative liabilities presented in the statement of condition 28,443 (476,415 ) 14,548 (558,889 ) Non-cash collateral received or pledged not offset (1) Can be sold or repledged Bilateral derivatives — 86,821 — 66,056 Cannot be sold or repledged Bilateral derivatives — 313,635 — 392,944 Total non-cash collateral received or pledged, not offset — 400,456 — 459,000 Net amount Bilateral derivatives 297 (75,874 ) 602 (99,882 ) Cleared derivatives 28,117 — 13,875 2 Mortgage delivery commitments 29 (85 ) 71 (8 ) Total net amount $ 28,443 $ (75,959 ) $ 14,548 $ (99,888 ) _______________________ (1) Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At June 30, 2015 , and December 31, 2014 , we had additional net credit exposure of $2.9 million and $4.0 million , respectively, due to instances where our collateral pledged to a counterparty exceeded our net derivative liability position.

Deposits (Tables)

Deposits (Tables)	6 Months Ended
	Jun. 30, 2015
Deposits [Abstract]
Interest-bearing and Non-interest-bearing Deposits [Table Text Block]	The following table details interest- and noninterest-bearing deposits (dollars in thousands): June 30, 2015 December 31, 2014 Interest-bearing Demand and overnight $ 367,032 $ 340,441 Other 4,584 5,120 Noninterest-bearing Other 30,450 23,770 Total deposits $ 402,066 $ 369,331

Consolidated Obligations (Table

Consolidated Obligations (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
CO Bonds by Year of Contractual Maturity [Table Text Block]	The following table sets forth the outstanding CO bonds for which we were primarily liable at June 30, 2015 , and December 31, 2014 , by year of contractual maturity (dollars in thousands): June 30, 2015 December 31, 2014 Year of Contractual Maturity Amount Weighted Average Rate (1) Amount Weighted Average Rate (1) Due in one year or less $ 7,751,955 1.17 % $ 6,675,745 1.41 % Due after one year through two years 5,921,530 1.36 5,573,745 1.46 Due after two years through three years 4,510,140 1.91 4,842,570 1.91 Due after three years through four years 2,198,780 1.67 2,392,380 1.77 Due after four years through five years 2,221,455 2.09 2,244,815 1.95 Thereafter 3,305,000 2.92 3,599,085 2.79 Total par value 25,908,860 1.69 % 25,328,340 1.79 % Premiums 178,846 199,628 Discounts (16,763 ) (19,386 ) Hedging adjustments 4,486 (2,808 ) $ 26,075,429 $ 25,505,774 _______________________ (1) The CO bonds' weighted-average rate excludes concession fees.
CO Bonds by Call Feature [Table Text Block]	Our CO bonds outstanding at June 30, 2015 , and December 31, 2014 , included (dollars in thousands): June 30, 2015 December 31, 2014 Par value of CO bonds Noncallable and nonputable $ 21,331,860 $ 20,853,340 Callable 4,577,000 4,475,000 Total par value $ 25,908,860 $ 25,328,340
CO Bonds by Year of Contractual Maturity or Next Call Date [Table Text Block]	The following is a summary of the CO bonds for which we were primarily liable at June 30, 2015 , and December 31, 2014 , by year of contractual maturity or next call date for callable CO bonds (dollars in thousands): Year of Contractual Maturity or Next Call Date June 30, 2015 December 31, 2014 Due in one year or less $ 12,043,955 $ 10,805,745 Due after one year through two years 5,266,530 4,928,745 Due after two years through three years 3,440,140 4,252,570 Due after three years through four years 1,948,780 2,027,380 Due after four years through five years 1,646,455 1,619,815 Thereafter 1,563,000 1,694,085 Total par value $ 25,908,860 $ 25,328,340
CO Bonds by Interest-rate-payment Type [Table Text Block]	The following table sets forth the CO bonds for which we were primarily liable by interest-rate-payment type at June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Par value of CO bonds Fixed-rate $ 22,911,860 $ 22,513,340 Simple variable-rate 2,170,000 1,970,000 Step-up 827,000 845,000 Total par value $ 25,908,860 $ 25,328,340
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 (dollars in thousands): Book Value Par Value Weighted Average Rate (1) June 30, 2015 $ 25,972,593 $ 25,974,666 0.08 % December 31, 2014 $ 25,309,608 $ 25,312,040 0.08 % _______________________ (1) The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable Housing Program (Tab

Affordable Housing Program (Tables)	6 Months Ended
	Jun. 30, 2015
Affordable Housing Program [Abstract]
Roll-forward of the AHP Liability[Table Text Block]	The following table presents a roll-forward of the AHP liability for the six months ended June 30, 2015 , and year ended December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Balance at beginning of year $ 66,993 $ 62,591 AHP expense for the period 20,445 17,623 AHP direct grant disbursements (9,233 ) (12,012 ) AHP subsidy for AHP advance disbursements (625 ) (1,321 ) Return of previously disbursed grants and subsidies 20 112 Balance at end of period $ 77,600 $ 66,993

Capital (Tables)

Capital (Tables)	6 Months Ended
	Jun. 30, 2015
Capital [Abstract]
Compliance with Regulatory Capital Requirements [Table Text Block]	The following tables demonstrate our compliance with our regulatory capital requirements at June 30, 2015 , and December 31, 2014 (dollars in thousands): Risk-Based Capital Requirements June 30, December 31, Permanent capital Class B capital stock $ 2,482,244 $ 2,413,114 Mandatorily redeemable capital stock 57,268 298,599 Retained earnings 1,063,854 901,658 Total permanent capital $ 3,603,366 $ 3,613,371 Risk-based capital requirement Credit-risk capital $ 399,363 $ 414,765 Market-risk capital 93,498 75,560 Operations-risk capital 147,858 147,097 Total risk-based capital requirement $ 640,719 $ 637,422 Permanent capital in excess of risk-based capital requirement $ 2,962,647 $ 2,975,949 June 30, 2015 December 31, 2014 Required Actual Required Actual Capital Ratio Risk-based capital $ 640,719 $ 3,603,366 $ 637,422 $ 3,613,371 Total regulatory capital $ 2,257,995 $ 3,603,366 $ 2,204,267 $ 3,613,371 Total capital-to-asset ratio 4.0 % 6.4 % 4.0 % 6.6 % Leverage Ratio Leverage capital $ 2,822,493 $ 5,405,049 $ 2,755,334 $ 5,420,057 Leverage capital-to-assets ratio 5.0 % 9.6 % 5.0 % 9.8 %

Accumulated Other Comprehensi41

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Abstract]
Schedule of Accumulated Other Comprehensive Loss [Table Text Block]	Accumulated Other Comprehensive Loss The following table presents a summary of changes in accumulated other comprehensive loss for the three and six months ended June 30, 2015 and 2014 (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 Accumulated Other Comprehensive Loss Balance, March 31, 2014 $ (96,936 ) $ (312,335 ) $ (57,603 ) $ (3,117 ) $ (469,991 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 24,842 — (13,726 ) — 11,116 Accretion of noncredit loss — 12,612 — — 12,612 Net actuarial loss — — — (373 ) (373 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 399 — — 399 Amortization - hedging activities (2) — — 724 — 724 Amortization - pension and postretirement benefits (3) — — — 126 126 Other comprehensive income (loss) 24,842 13,011 (13,002 ) (247 ) 24,604 Balance, June 30, 2014 $ (72,094 ) $ (299,324 ) $ (70,605 ) $ (3,364 ) $ (445,387 ) Balance, March 31, 2015 $ (53,034 ) $ (264,357 ) $ (88,675 ) $ (5,763 ) $ (411,829 ) Other comprehensive income (loss) before reclassifications: Net unrealized (losses) gains (14,793 ) — 12,773 — (2,020 ) Accretion of noncredit loss — 11,990 — — 11,990 Net actuarial loss — — — (8 ) (8 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 1,073 — — 1,073 Amortization - hedging activities (4) — — 5,631 — 5,631 Amortization - pension and postretirement benefits (3) — — — 100 100 Other comprehensive (loss) income (14,793 ) 13,063 18,404 92 16,766 Balance, June 30, 2015 $ (67,827 ) $ (251,294 ) $ (70,271 ) $ (5,671 ) $ (395,063 ) _______________________ (1) Recorded in net amount of impairment losses reclassified from accumulated other comprehensive loss in the statement of operations. (2) Amortization of hedging activities includes $720,000 recorded in CO bond interest expense and $4,000 recorded in net losses on derivatives and hedging activities in the statement of operations. (3) Recorded in other operating expenses in the statement of operations. (4) Amortization of hedging activities includes $5.6 million recorded in CO bond interest expense and $4,000 recorded in net losses on derivatives and hedging activities in the statement of operations. 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 Accumulated Other Comprehensive Loss Balance, December 31, 2013 $ (101,765 ) $ (324,928 ) $ (51,594 ) $ (3,229 ) $ (481,516 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 29,671 — (19,740 ) — 9,931 Accretion of noncredit loss — 24,747 — — 24,747 Net actuarial loss (373 ) (373 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 857 — — 857 Amortization - hedging activities (2) — — 729 — 729 Amortization - pension and postretirement benefits (3) — — — 238 238 Other comprehensive income (loss) 29,671 25,604 (19,011 ) (135 ) 36,129 Balance, June 30, 2014 $ (72,094 ) $ (299,324 ) $ (70,605 ) $ (3,364 ) $ (445,387 ) Balance, December 31, 2014 $ (73,623 ) $ (275,942 ) $ (81,428 ) $ (5,993 ) $ (436,986 ) Other comprehensive income (loss) before reclassifications: Net unrealized gains (losses) 5,796 — 630 — 6,426 Accretion of noncredit loss — 23,453 — — 23,453 Net actuarial loss — — — (8 ) (8 ) Reclassifications from other comprehensive income to net income Noncredit other-than-temporary impairment losses reclassified to credit loss (1) — 1,195 — — 1,195 Amortization - hedging activities (4) — — 10,527 — 10,527 Amortization - pension and postretirement benefits (3) — — — 330 330 Other comprehensive income 5,796 24,648 11,157 322 41,923 Balance, June 30, 2015 $ (67,827 ) $ (251,294 ) $ (70,271 ) $ (5,671 ) $ (395,063 ) _______________________ (1) Recorded in net amount of impairment losses reclassified from accumulated other comprehensive loss in the statement of operations. (2) Amortization of hedging activities includes $720,000 recorded in CO bond interest expense and $9,000 recorded in net losses on derivatives and hedging activities in the statement of operations. (3) Recorded in other operating expenses in the statement of operations. (4) Amortization of hedging activities includes $10.5 million recorded in CO bond interest expense and $7,000 recorded in net losses on derivatives and hedging activities in the statement of operations.

Employee Retirement Plans (Tabl

Employee Retirement Plans (Tables)	6 Months Ended
	Jun. 30, 2015
Employee Retirement Plans [Line Items]
Net Periodic Benefit Cost [Table Text Block]	The following table presents the components of net periodic benefit cost for our nonqualified supplemental defined benefit retirement plan and postretirement benefits for the three and six months ended June 30, 2015 and 2014 (dollars in thousands): Nonqualified Supplemental Defined Benefit Retirement Plan For the Three Months Ended June 30, Postretirement Benefits For the Three Months Ended June 30, 2015 2014 2015 2014 Net Periodic Benefit Cost Service cost $ 172 $ 151 $ 12 $ 5 Interest cost 121 123 9 8 Amortization of net actuarial loss 97 125 3 1 Net periodic benefit cost $ 390 $ 399 $ 24 $ 14 Nonqualified Supplemental Defined Benefit Retirement Plan For the Six Months Ended June 30, Postretirement Benefits For the Six Months Ended June 30, 2015 2014 2015 2014 Net Periodic Benefit Cost Service cost $ 343 $ 276 $ 19 $ 12 Interest cost 242 231 16 16 Amortization of net actuarial loss 326 237 4 1 Net periodic benefit cost $ 911 $ 744 $ 39 $ 29
Pentegra Defined Contribution Plan and Thrift Benefit Equalization Plan [Member]
Employee Retirement Plans [Line Items]
Schedule of Costs of Retirement Plans [Table Text Block]	The following table sets forth our net pension costs under our defined benefit plan and expenses relating to our defined contribution plans (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2015 2014 2015 2014 Qualified Defined Benefit Multiemployer Plan - Pentegra Defined Benefit Plan $ 5,102 $ 763 $ 5,205 $ 1,526 Qualified Defined Contribution Plan - Pentegra Defined Contribution Plan 280 268 528 504 Nonqualified Defined Contribution Plan - Thrift Benefit Equalization Plan 9 7 119 106

Fair Values (Tables)

Fair Values (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments [Table Text Block]	The carrying values, fair values, and fair-value hierarchy of our financial instruments at June 30, 2015 , and December 31, 2014 , were as follows (dollars in thousands). These fair values do not represent an estimate of our overall market value as a going concern, which would take into account, among other things, our future business opportunities and the net profitability of our assets and liabilities. June 30, 2015 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral Financial instruments Assets: Cash and due from banks $ 844,228 $ 844,228 $ 844,228 $ — $ — $ — Interest-bearing deposits 267 267 267 — — — Securities purchased under agreements to resell 5,050,000 5,049,902 — 5,049,902 — — Federal funds sold 3,530,000 3,529,987 — 3,529,987 — — Trading securities (1) 237,414 237,414 — 237,414 — — Available-for-sale securities (1) 6,011,270 6,011,270 — 6,011,270 — — Held-to-maturity securities 2,939,093 3,260,144 — 1,798,553 1,461,591 — Advances 34,105,443 34,240,643 — 34,240,643 — — Mortgage loans, net 3,574,835 3,664,424 — 3,628,001 36,423 — Accrued interest receivable 77,828 77,828 — 77,828 — — Derivative assets (1) 28,443 28,443 — 36,609 — (8,166 ) Other assets (1) 15,312 15,312 6,965 8,347 — — Liabilities: Deposits (402,066 ) (402,066 ) — (402,066 ) — — COs: Bonds (26,075,429 ) (26,293,950 ) — (26,293,950 ) — — Discount notes (25,972,593 ) (25,973,298 ) — (25,973,298 ) — — Mandatorily redeemable capital stock (57,268 ) (57,268 ) (57,268 ) — — — Accrued interest payable (79,508 ) (79,508 ) — (79,508 ) — — Derivative liabilities (1) (476,415 ) (476,415 ) — (542,993 ) — 66,578 Other: Commitments to extend credit for advances — (157 ) — (157 ) — — Standby letters of credit (891 ) (891 ) — (891 ) — — _______________________ (1) Carried at fair value on a recurring basis. December 31, 2014 Carrying Value Total Fair Value Level 1 Level 2 Level 3 Netting Adjustments and Cash Collateral Financial instruments Assets: Cash and due from banks $ 1,124,536 $ 1,124,536 $ 1,124,536 $ — $ — $ — Interest-bearing deposits 163 163 163 — — — Securities purchased under agreements to resell 5,250,000 5,249,941 — 5,249,941 — — Federal funds sold 2,550,000 2,549,982 — 2,549,982 — — Trading securities (1) 244,969 244,969 — 244,969 — — Available-for-sale securities (1) 5,481,978 5,481,978 — 5,481,978 — — Held-to-maturity securities 3,352,189 3,710,815 — 2,176,268 1,534,547 — Advances 33,482,074 33,618,345 — 33,618,345 — — Mortgage loans, net 3,483,948 3,612,078 — 3,612,078 — — Accrued interest receivable 77,411 77,411 — 77,411 — — Derivative assets (1) 14,548 14,548 — 26,483 — (11,935 ) Other assets (1) 11,200 11,200 5,682 5,518 — — Liabilities: Deposits (369,331 ) (369,330 ) — (369,330 ) — — COs: Bonds (25,505,774 ) (25,741,697 ) — (25,741,697 ) — — Discount notes (25,309,608 ) (25,310,307 ) — (25,310,307 ) — — Mandatorily redeemable capital stock (298,599 ) (298,599 ) (298,599 ) — — — Accrued interest payable (91,225 ) (91,225 ) — (91,225 ) — — Derivative liabilities (1) (558,889 ) (558,889 ) — (616,033 ) — 57,144 Other: Commitments to extend credit for advances — 430 — 430 — — Standby letters of credit (745 ) (745 ) — (745 ) — — _______________________ (1) Carried at fair value on a recurring basis.
Fair Value Measured on Recurring Basis [Table Text Block]	The following tables present our assets and liabilities that are measured at fair value on the statement of condition, which are recorded on a recurring basis at June 30, 2015 , and December 31, 2014 , by fair-value hierarchy level (dollars in thousands): June 30, 2015 Level 1 Level 2 Level 3 Netting Adjustment (1) Total Assets: Trading securities: U.S. government-guaranteed – single-family MBS $ — $ 11,254 $ — $ — $ 11,254 GSEs – single-family MBS — 1,859 — — 1,859 GSEs – multifamily MBS — 224,301 — — 224,301 Total trading securities — 237,414 — — 237,414 Available-for-sale securities: Supranational institutions — 438,831 — — 438,831 U.S. government-owned corporations — 269,903 — — 269,903 GSEs — 117,706 — — 117,706 U.S. government guaranteed – single-family MBS — 178,910 — — 178,910 U.S. government guaranteed – multifamily MBS — 823,863 — — 823,863 GSEs – single-family MBS — 4,182,057 — — 4,182,057 Total available-for-sale securities — 6,011,270 — — 6,011,270 Derivative assets: Interest-rate-exchange agreements — 36,580 — (8,166 ) 28,414 Mortgage delivery commitments — 29 — — 29 Total derivative assets — 36,609 — (8,166 ) 28,443 Other assets 6,965 8,347 — — 15,312 Total assets at fair value $ 6,965 $ 6,293,640 $ — $ (8,166 ) $ 6,292,439 Liabilities: Derivative liabilities Interest-rate-exchange agreements $ — $ (542,908 ) $ — $ 66,578 $ (476,330 ) Mortgage delivery commitments — (85 ) — — (85 ) Total liabilities at fair value $ — $ (542,993 ) $ — $ 66,578 $ (476,415 ) _______________________ (1) These amounts represent the application of the netting requirements that 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. December 31, 2014 Level 1 Level 2 Level 3 Netting Adjustment (1) Total Assets: Trading securities: U.S. government-guaranteed – single-family MBS $ — $ 12,235 $ — $ — $ 12,235 GSEs – single-family MBS — 2,300 — — 2,300 GSEs – multifamily MBS — 230,434 — — 230,434 Total trading securities — 244,969 — — 244,969 Available-for-sale securities: Supranational institutions — 447,685 — — 447,685 U.S. government-owned corporations — 284,997 — — 284,997 GSEs — 123,453 — — 123,453 U.S. government guaranteed – single-family MBS — 206,028 — — 206,028 U.S. government guaranteed – multifamily MBS — 871,423 — — 871,423 GSEs – single-family MBS — 3,548,392 — — 3,548,392 Total available-for-sale securities — 5,481,978 — — 5,481,978 Derivative assets: Interest-rate-exchange agreements — 26,412 — (11,935 ) 14,477 Mortgage delivery commitments — 71 — — 71 Total derivative assets — 26,483 — (11,935 ) 14,548 Other assets 5,682 5,518 — — 11,200 Total assets at fair value $ 5,682 $ 5,758,948 $ — $ (11,935 ) $ 5,752,695 Liabilities: Derivative liabilities Interest-rate-exchange agreements $ — $ (616,025 ) $ — $ 57,144 $ (558,881 ) Mortgage delivery commitments — (8 ) — — (8 ) Total liabilities at fair value $ — $ (616,033 ) $ — $ 57,144 $ (558,889 ) _______________________ (1) These amounts represent the application of the netting requirements that 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 on a Nonrecurring Basis [Table Text Block]	The following tables present financial assets by level within the fair-value hierarchy which are recorded at fair value on a nonrecurring basis during the six months ended June 30, 2015 , and at December 31, 2014 (dollars in thousands). For the Six Months Ended June 30, 2015 Level 1 Level 2 Level 3 Total Held-to-maturity securities: Private-label residential MBS $ — $ — $ 10,724 $ 10,724 Mortgage loans held for portfolio — — 8,052 8,052 REO — — 1,637 1,637 Total assets recorded at fair value on a nonrecurring basis $ — $ — $ 20,413 $ 20,413 December 31, 2014 Level 1 Level 2 Level 3 Total Held-to-maturity securities: Private-label residential MBS $ — $ — $ 23,259 $ 23,259 REO — — 843 843 Total assets recorded at fair value on a nonrecurring basis $ — $ — $ 24,102 $ 24,102

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Off-Balance Sheet Commitments [Table Text Block]	The following table sets forth our off-balance-sheet commitments as of June 30, 2015 , and December 31, 2014 (dollars in thousands): June 30, 2015 December 31, 2014 Expire within one year Expire after one year Total Expire within one year Expire after one year Total Standby letters of credit outstanding (1) $ 4,454,029 $ 127,845 $ 4,581,874 $ 4,065,555 $ 125,381 $ 4,190,936 Commitments for unused lines of credit - advances (2) 1,262,441 — 1,262,441 1,255,445 — 1,255,445 Commitments to make additional advances 668,876 39,341 708,217 592,430 63,185 655,615 Commitments to invest in mortgage loans 26,986 — 26,986 26,927 — 26,927 Unsettled CO bonds, at par (3) 83,750 — 83,750 15,000 — 15,000 Unsettled CO discount notes, at par — — — 500,000 — 500,000 __________________________ (1) The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year. At June 30, 2015 , and December 31, 2014 , these amounts totaled $ 16.9 million and $26.2 million , respectively. Also excluded are commitments to issue standby letters of credit that expire after one year totaling $4.0 million at June 30, 2015 . (2) 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. (3) We had $70.0 million and $15.0 million in unsettled CO bonds that were hedged with associated interest-rate swaps at June 30, 2015 , and December 31, 2014 , respectively.

Transactions with Shareholders

Transactions with Shareholders (Tables)	6 Months Ended
	Jun. 30, 2015
Transactions with Shareholders [Abstract]
Schedule of Transactions with Shareholders [Table Text Block]	The following tables present transactions with shareholders whose holdings of capital stock exceed 10 percent or more of total capital stock outstanding at June 30, 2015 , and December 31, 2014 (dollars in thousands): Capital Stock Outstanding Percent of Total Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances As of June 30, 2015 Citizens Bank, N.A. $ 317,502 12.5 % $ 5,516,467 16.3 % $ 612 2.1 % As of December 31, 2014 Citizens Bank, N.A. $ 317,502 11.7 % $ 5,768,096 17.3 % $ 283 1.0 %
Schedule of Transactions with Shareholders, Interest and Fee Income [Table Text Block]	We recognized interest income on outstanding advances and fees on letters of credit from Citizens Bank, N.A. during the three and six months ended June 30, 2015 and 2014 as follows (dollars in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, Citizens Bank, N.A. 2015 2014 2015 2014 Interest income on advances $ 3,447 $ 3,592 $ 7,163 $ 5,750 Fees on letters of credit 1,050 868 2,039 1,658
Schedule of Transactions with Shareholders, Transactions with Directors' Financial Institutions [Table Text Block]	The following table presents the outstanding balances of capital stock, advances, and accrued interest receivable with members whose officers or directors serve on our board of directors, and those balances as a percentage of our total balance as reported on our statement of condition (dollars in thousands): Capital Stock Outstanding Percent of Total Par Value of Advances Percent of Total Par Value of Advances Total Accrued Interest Receivable Percent of Total Accrued Interest Receivable on Advances As of June 30, 2015 $ 88,897 3.5 % $ 1,198,088 3.5 % $ 1,244 4.2 % As of December 31, 2014 79,386 2.9 918,127 2.8 1,227 4.2

Trading Securities (Details)

Trading Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	$ 237,414	$ 244,969
U.S. government-guaranteed - single-family MBS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	11,254	12,235
GSEs - single-family [Member] | U.S. Government Sponsored Enterprises - MBS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	1,859	2,300
GSEs - multifamily [Member] | U.S. Government Sponsored Enterprises - MBS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities	$ 224,301	$ 230,434

Trading Securities - Net Unreal

Trading Securities - Net Unrealized (Losses) Gains (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Trading Securities [Abstract]
Net unrealized losses or gains on trading securities	$ (2,393)	$ 2,209	$ (1,112)	$ 2,963

Available-for-Sale Securities M

Available-for-Sale Securities Major Security Types (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	$ 6,079,097	$ 5,555,601
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		21,683	15,321
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(89,510)	(88,944)
Fair Value		6,011,270	5,481,978
Supranational institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	461,402	472,440
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		0	0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(22,571)	(24,755)
Fair Value		438,831	447,685
U.S. government-owned corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	311,311	322,436
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		0	0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(41,408)	(37,439)
Fair Value		269,903	284,997
GSEs [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	129,544	133,748
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		0	0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(11,838)	(10,295)
Fair Value		117,706	123,453
Other Than Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	902,257	928,624
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		0	0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(75,817)	(72,489)
Fair Value		826,440	856,135
U.S. government-guaranteed - single-family MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	180,356	207,090
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		246	375
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(1,692)	(1,437)
Fair Value		178,910	206,028
U.S. government guaranteed - multifamily MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	823,275	874,817
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		1,492	204
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(904)	(3,598)
Fair Value		823,863	871,423
MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1],[2]	5,176,840	4,626,977
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		21,683	15,321
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(13,693)	(16,455)
Fair Value	[2]	5,184,830	4,625,843
GSEs - single-family [Member] | GSEs - MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	4,173,209	3,545,070
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss		19,945	14,742
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss		(11,097)	(11,420)
Fair Value		$ 4,182,057	$ 3,548,392
[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.
[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.

Available-for-Sale Securities S

Available-for-Sale Securities Securities with Unrealized Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 1,433,008	$ 1,063,513
Less than 12 Months, Unrealized Losses	(5,305)	(4,385)
12 Months or More, Fair Value	1,577,108	1,949,721
12 Months or More, Unrealized Losses	(84,205)	(84,559)
Total Fair Value	3,010,116	3,013,234
Total Unrealized Losses	(89,510)	(88,944)
Supranational institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	438,831	447,685
12 Months or More, Unrealized Losses	(22,571)	(24,755)
Total Fair Value	438,831	447,685
Total Unrealized Losses	(22,571)	(24,755)
U.S. government-owned corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	269,903	284,997
12 Months or More, Unrealized Losses	(41,408)	(37,439)
Total Fair Value	269,903	284,997
Total Unrealized Losses	(41,408)	(37,439)
GSEs [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	117,706	123,453
12 Months or More, Unrealized Losses	(11,838)	(10,295)
Total Fair Value	117,706	123,453
Total Unrealized Losses	(11,838)	(10,295)
Other Than Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	826,440	856,135
12 Months or More, Unrealized Losses	(75,817)	(72,489)
Total Fair Value	826,440	856,135
Total Unrealized Losses	(75,817)	(72,489)
U.S. government-guaranteed - single-family MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	131,472	154,665
12 Months or More, Unrealized Losses	(1,692)	(1,437)
Total Fair Value	131,472	154,665
Total Unrealized Losses	(1,692)	(1,437)
U.S. government guaranteed - multifamily MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	155,776	610,470
Less than 12 Months, Unrealized Losses	(244)	(3,497)
12 Months or More, Fair Value	203,264	23,567
12 Months or More, Unrealized Losses	(660)	(101)
Total Fair Value	359,040	634,037
Total Unrealized Losses	(904)	(3,598)
MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	1,433,008	1,063,513
Less than 12 Months, Unrealized Losses	(5,305)	(4,385)
12 Months or More, Fair Value	750,668	1,093,586
12 Months or More, Unrealized Losses	(8,388)	(12,070)
Total Fair Value	2,183,676	2,157,099
Total Unrealized Losses	(13,693)	(16,455)
GSEs - single-family [Member] | GSEs - MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	1,277,232	453,043
Less than 12 Months, Unrealized Losses	(5,061)	(888)
12 Months or More, Fair Value	415,932	915,354
12 Months or More, Unrealized Losses	(6,036)	(10,532)
Total Fair Value	1,693,164	1,368,397
Total Unrealized Losses	$ (11,097)	$ (11,420)

Available-for-Sale Securities R

Available-for-Sale Securities Redemption Terms (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1]	$ 6,079,097	$ 5,555,601
Fair Value		6,011,270	5,481,978
Other Than Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Due in one year or less, amortized cost		0	0
Due in one year or less, fair value		0	0
Due after one year through five years, amortized cost		0	0
Due after one year through five years, fair value		0	0
Due after five years through 10 years, amortized cost		16,988	0
Due after five years through 10 years, fair value		16,378	0
Due after 10 years, amortized cost		885,269	928,624
Due after 10 years, fair value		810,062	856,135
Amortized Cost	[1]	902,257	928,624
Fair Value		826,440	856,135
MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	[1],[2]	5,176,840	4,626,977
Fair Value	[2]	$ 5,184,830	$ 4,625,843
[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.
[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.

Held-to-Maturity Securities Maj

Held-to-Maturity Securities Major Security Types (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		$ 3,190,387	$ 3,628,131
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		(251,294)	(275,942)
Carrying Value	[1],[2]	2,939,093	3,352,189
Gross Unrecognized Holding Gains		353,878	391,804
Gross Unrecognized Holding Losses		(32,827)	(33,178)
Fair Value		3,260,144	3,710,815
U.S. agency obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		4,739	5,777
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value		4,739	5,777
Gross Unrecognized Holding Gains		286	360
Gross Unrecognized Holding Losses		0	0
Fair Value		5,025	6,137
HFA securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		175,692	178,387
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value		175,692	178,387
Gross Unrecognized Holding Gains		30	30
Gross Unrecognized Holding Losses		(18,748)	(18,136)
Fair Value		156,974	160,281
Other Than Mortgage-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		180,431	184,164
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value	[1]	180,431	184,164
Gross Unrecognized Holding Gains		316	390
Gross Unrecognized Holding Losses		(18,748)	(18,136)
Fair Value		161,999	166,418
U.S. government-guaranteed - single-family MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		17,965	20,399
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value		17,965	20,399
Gross Unrecognized Holding Gains		413	487
Gross Unrecognized Holding Losses		0	0
Fair Value		18,378	20,886
U.S. government guaranteed - multifamily MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		39,755	115,712
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value		39,755	115,712
Gross Unrecognized Holding Gains		92	298
Gross Unrecognized Holding Losses		0	(6)
Fair Value		39,847	116,004
ABS backed by home equity loans [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		16,376	16,958
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		(719)	(784)
Carrying Value		15,657	16,174
Gross Unrecognized Holding Gains		775	856
Gross Unrecognized Holding Losses		(952)	(922)
Fair Value		15,480	16,108
MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[3]	3,009,956	3,443,967
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		(251,294)	(275,942)
Carrying Value	[1],[3]	2,758,662	3,168,025
Gross Unrecognized Holding Gains		353,562	391,414
Gross Unrecognized Holding Losses		(14,079)	(15,042)
Fair Value	[3]	3,098,145	3,544,397
GSEs - single-family [Member] | U.S. Government Sponsored Enterprises - MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		1,256,108	1,420,801
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value		1,256,108	1,420,801
Gross Unrecognized Holding Gains		36,320	40,518
Gross Unrecognized Holding Losses		(137)	(157)
Fair Value		1,292,291	1,461,162
GSEs - multifamily [Member] | U.S. Government Sponsored Enterprises - MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		418,302	542,130
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		0	0
Carrying Value		418,302	542,130
Gross Unrecognized Holding Gains		24,710	29,949
Gross Unrecognized Holding Losses		0	0
Fair Value		443,012	572,079
Residential Mortgage Backed Securities [Member] | Private-Label - Residential MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		1,261,450	1,327,967
Other-Than-Temporary Impairment Recognized in Accumulated Other Comprehensive Loss		(250,575)	(275,158)
Carrying Value		1,010,875	1,052,809
Gross Unrecognized Holding Gains		291,252	319,306
Gross Unrecognized Holding Losses		(12,990)	(13,957)
Fair Value		$ 1,289,137	$ 1,358,158
[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.
[2]	Fair values of held-to-maturity securities were $3,260,144 and $3,710,815 at June 30, 2015, and December 31, 2014, respectively.
[3]	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.

Held-to-Maturity Securities Fai

Held-to-Maturity Securities Fair Value and Unrealized Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	$ 102,839	$ 104,777
Less than 12 months, Unrealized Losses	(1,720)	(1,187)
12 Months or More, Fair Value	658,755	736,675
12 Months or More, Unrealized Losses	(61,900)	(64,321)
Total Fair Value	761,594	841,452
Total Unrealized Losses	(63,620)	(65,508)
HFA securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	14,916	14,850
Less than 12 months, Unrealized Losses	(84)	(150)
12 Months or More, Fair Value	136,316	139,544
12 Months or More, Unrealized Losses	(18,664)	(17,986)
Total Fair Value	151,232	154,394
Total Unrealized Losses	(18,748)	(18,136)
U.S. government guaranteed - multifamily MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value		9,282
Less than 12 months, Unrealized Losses		(6)
12 Months or More, Fair Value		0
12 Months or More, Unrealized Losses		0
Total Fair Value		9,282
Total Unrealized Losses		(6)
ABS backed by home equity loans [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	0	206
Less than 12 months, Unrealized Losses	0	(3)
12 Months or More, Fair Value	14,054	14,641
12 Months or More, Unrealized Losses	(1,107)	(1,074)
Total Fair Value	14,054	14,847
Total Unrealized Losses	(1,107)	(1,077)
MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	87,923	89,927
Less than 12 months, Unrealized Losses	(1,636)	(1,037)
12 Months or More, Fair Value	522,439	597,131
12 Months or More, Unrealized Losses	(43,236)	(46,335)
Total Fair Value	610,362	687,058
Total Unrealized Losses	(44,872)	(47,372)
GSEs - single-family [Member] | GSEs - MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 months, Unrealized Losses	0	0
12 Months or More, Fair Value	17,469	38,121
12 Months or More, Unrealized Losses	(137)	(157)
Total Fair Value	17,469	38,121
Total Unrealized Losses	(137)	(157)
Residential Mortgage Backed Securities [Member] | Private-Label - Residential MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	87,923	80,439
Less than 12 months, Unrealized Losses	(1,636)	(1,028)
12 Months or More, Fair Value	490,916	544,369
12 Months or More, Unrealized Losses	(41,992)	(45,104)
Total Fair Value	578,839	624,808
Total Unrealized Losses	$ (43,628)	$ (46,132)

Held-to-Maturity Securities Red

Held-to-Maturity Securities Redemption Terms (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		$ 3,190,387	$ 3,628,131
Carrying Value	[1],[2]	2,939,093	3,352,189
Fair Value		3,260,144	3,710,815
Other Than Mortgage-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Due in one year or less, Amortized Cost		100	150
Due in one year or less, Carrying Value	[1]	100	150
Due in one year or less, Fair Value		100	150
Due after one year through five years, Amortized Cost		8,331	9,369
Due after one year through five years, Carrying Value	[1]	8,331	9,369
Due after one year through five years, Fair Value		8,639	9,751
Due after five years through 10 years, Amortized Cost		17,020	17,115
Due after five years through 10 years, Carrying Value	[1]	17,020	17,115
Due after five years through 10 years, Fair Value		16,944	16,973
Due after 10 years, Amortized Cost		154,980	157,530
Due after 10 years, Carrying Value	[1]	154,980	157,530
Due after 10 years, Fair Value		136,316	139,544
Amortized Cost		180,431	184,164
Carrying Value	[1]	180,431	184,164
Fair Value		161,999	166,418
MBS [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	[3]	3,009,956	3,443,967
Carrying Value	[1],[3]	2,758,662	3,168,025
Fair Value	[3]	$ 3,098,145	$ 3,544,397
[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.
[2]	Fair values of held-to-maturity securities were $3,260,144 and $3,710,815 at June 30, 2015, and December 31, 2014, respectively.
[3]	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.

Other-Than-Temporary Impairme54

Other-Than-Temporary Impairment Projected Home Prices Recoveries (Details)	Jun. 30, 2015
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Governance Committee projected housing price decline rate over 12-month period	2.00%
OTTI Governance Committee projected housing price increase rate over 12-month period	8.00%
Minimum [Member]
Other than Temporary Impairment, Disclosure [Line Items]
Projected short-term house price change - increase rate for majority of markets	2.00%
Maximum [Member]
Other than Temporary Impairment, Disclosure [Line Items]
Projected short-term house price change - increase rate for majority of markets	5.00%

Other-Than-Temporary Impairme55

Other-Than-Temporary Impairment Significant Inputs (Details) - Jun. 30, 2015 - Alt-A [Member] - Private-Label Residential MBS[Member] - USD ($) $ in Thousands		Total
Other than Temporary Impairment, Disclosure [Line Items]
Par Value	[1]	$ 137,276
Project Prepayment Rates - Weighted Average Percent	[1]	8.30%
Projected Default Rates, Weighted Average Percent	[1]	33.40%
Projected Loss Severities, Weighted Average Percent	[1]	37.40%
Current Credit Enhancement, Weighted Average Percent	[1]	5.30%
Securitization in 2007 [Member]
Other than Temporary Impairment, Disclosure [Line Items]
Par Value	[1]	$ 50,731
Project Prepayment Rates - Weighted Average Percent	[1]	6.30%
Projected Default Rates, Weighted Average Percent	[1]	44.10%
Projected Loss Severities, Weighted Average Percent	[1]	37.50%
Current Credit Enhancement, Weighted Average Percent	[1]	0.00%
Securitization in 2006 [Member]
Other than Temporary Impairment, Disclosure [Line Items]
Par Value	[1]	$ 60,688
Project Prepayment Rates - Weighted Average Percent	[1]	10.30%
Projected Default Rates, Weighted Average Percent	[1]	27.80%
Projected Loss Severities, Weighted Average Percent	[1]	38.50%
Current Credit Enhancement, Weighted Average Percent	[1]	0.00%
Securitization in 2005 [Member]
Other than Temporary Impairment, Disclosure [Line Items]
Par Value	[1]	$ 23,273
Project Prepayment Rates - Weighted Average Percent	[1]	7.00%
Projected Default Rates, Weighted Average Percent	[1]	26.80%
Projected Loss Severities, Weighted Average Percent	[1]	38.00%
Current Credit Enhancement, Weighted Average Percent	[1]	30.60%
Securitization in 2004 and prior [Member]
Other than Temporary Impairment, Disclosure [Line Items]
Par Value	[1]	$ 2,584
Project Prepayment Rates - Weighted Average Percent	[1]	13.10%
Projected Default Rates, Weighted Average Percent	[1]	16.20%
Projected Loss Severities, Weighted Average Percent	[1]	5.00%
Current Credit Enhancement, Weighted Average Percent	[1]	3.80%
[1]	Securities are classified in the table above based upon the current performance characteristics of the underlying loan pool and therefore the manner in which the loan pool backing the security has been modeled (as prime, Alt-A, or subprime), rather than their classification of the security at the time of issuance.

Other-Than-Temporary Impairme56

Other-Than-Temporary Impairment OTTI Credit Losses Recognized During Life of Security (Details) $ in Thousands		Jun. 30, 2015USD ($)
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]
Par Value	[1]	$ 1,428,247
Amortized Cost	[1]	1,058,326
Carrying Value	[1]	807,032
Fair Value	[1]	1,098,987
Private-Label Residential MBS[Member] | Prime [Member]
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]
Par Value	[1]	54,384
Amortized Cost	[1]	46,936
Carrying Value	[1]	37,272
Fair Value	[1]	47,621
Private-Label Residential MBS[Member] | Alt-A [Member]
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]
Par Value	[1]	1,369,762
Amortized Cost	[1]	1,007,710
Carrying Value	[1]	766,799
Fair Value	[1]	1,047,631
ABS Backed by Home Equity Loans [Member] | Subprime [Member]
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]
Par Value	[1]	4,101
Amortized Cost	[1]	3,680
Carrying Value	[1]	2,961
Fair Value	[1]	$ 3,735
[1]	We have instituted litigation in relation to certain of the private-label MBS in which we invested. Our complaint asserts, among others, claims for untrue or misleading statements in the sale of securities. It is possible that classifications of private-label MBS as provided herein when based on classification at the time of issuance as disclosed by those securities' issuance documents, as well as other statements about the securities, are inaccurate.

Other-Than-Temporary Impairme57

Other-Than-Temporary Impairment Roll-forward of Amounts Related to Credit Losses Recognized in Earnings (Details) - Held-to-maturity Securities [Member] - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance at beginning of year		$ 559,725	$ 595,560	$ 568,652	$ 603,786
Additional credit losses for which an other-than-temporary impairment charge was previously recognized	[1]	1,429	399	1,775	857
Increase in cash flows expected to be collected which are recognized over the remaining life of the security	[2]	(9,813)	(8,625)	(19,086)	(17,309)
Balance at end of period		$ 551,341	$ 587,334	$ 551,341	$ 587,334
[1]	For the three months ended June 30, 2015 and 2014, additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to April 1, 2015 and 2014. For the six months ended June 30, 2015 and 2014, additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to January 1, 2015 and 2014
[2]	Represents amounts accreted as interest income during the current period.

Advances - Year of Contractual

Advances - Year of Contractual Maturity (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
Overdrawn demand-deposit accounts		$ 8,879	$ 19,863
Due in one year or less		21,799,346	20,561,912
Due after one year through two years		3,718,382	4,114,587
Due after two years through three years		3,327,720	3,564,747
Due after three years through four years		1,801,212	2,299,457
Due after four years through five years		1,555,863	1,087,673
Thereafter		1,721,263	1,626,475
Total par value		$ 33,932,665	$ 33,274,714
Federal Home Loan Bank, Advances, Weighted Average Interest Rate, Rolling Year [Abstract]
Overdrawn demand-deposit accounts, Weighted average rate		0.45%	0.44%
Due in one year or less, Weighted average rate		0.45%	0.41%
Due after one year through two years, Weighted average rate		2.17%	1.63%
Due after two years through three years, Weighted average rate		2.27%	2.68%
Due after three years through four years, Weighted average rate		2.09%	2.16%
Due after four years through five years, Weighted average rate		1.95%	2.11%
Thereafter, Weighted average rate		2.91%	2.98%
Total Weighted average rate		1.10%	1.11%
Premiums		$ 30,128	$ 32,887
Discounts		(17,980)	(18,549)
Market value of bifurcated derivatives	[1]	1,953	1,467
Hedging adjustments		158,677	191,555
Total		$ 34,105,443	$ 33,482,074
[1]	At June 30, 2015, and December 31, 2014, we had certain advances with embedded features that met the requirements to be separated from the host contract and designated as a stand-alone derivative.

Advances - Outstanding by the E

Advances - Outstanding by the Earlier of Contractual Maturity or Next Put Date (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Federal Home Loan Bank, Advances, Earlier of Contractual Maturity or Next Put or Convert Date, Rolling Year, Par Value [Abstract]
Overdrawn demand-deposit accounts	$ 8,879	$ 19,863
Due in one year or less	23,765,671	22,737,137
Due after one year through two years	2,883,357	3,767,187
Due after two years through three years	2,355,670	2,155,922
Due after three years through four years	1,661,962	1,931,707
Due after four years through five years	1,535,863	1,036,423
Thereafter	1,721,263	1,626,475
Total par value	$ 33,932,665	$ 33,274,714

Advances - Interest-Rate-Paymen

Advances - Interest-Rate-Payment Terms (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Federal Home Loan Bank, Advances, Fixed Rate [Abstract]
Fixed-rate	$ 28,097,886	$ 27,236,551
Federal Home Loan Bank, Advances, Floating Rate [Abstract]
Variable-rate	5,834,779	6,038,163
Total par value	$ 33,932,665	$ 33,274,714

Advances - Narratives (Details)

Advances - Narratives (Details) $ in Thousands	Jun. 30, 2015USD ($)Borrowers	Dec. 31, 2014USD ($)Borrowers
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, Advances, Outstanding, Greater than one billion dollars per borrower, Amount	$ 11,600,000	$ 10,700,000
Total par value	33,932,665	$ 33,274,714
Credit Risk Exposure and Security Terms [Abstract]
Minimum amount of advances outstanding per borrower	$ 1,000,000
Federal Home Loan Bank, Advances, Outstanding, Greater than one billion dollars per borrower, Number of borrowers | Borrowers	4	3
Total outstanding advances greater than $1.0 billion per borrower as a percentage of advances outstanding	34.10%	32.00%
Minimum [Member]
Federal Home Loan Bank, Advances [Line Items]
Interest rates of advances outstanding	(0.17%)	(0.22%)
Maximum [Member]
Federal Home Loan Bank, Advances [Line Items]
Interest rates of advances outstanding	7.72%	8.37%
Putable advances outstanding [Member]
Federal Home Loan Bank, Advances [Line Items]
Total par value	$ 2,200,000	$ 2,300,000
Callable advances outstanding [Member]
Federal Home Loan Bank, Advances [Line Items]
Total par value	$ 30,000	$ 30,000

Advances - Prepayment Fees (Det

Advances - Prepayment Fees (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Federal Home Loan Bank, Advances, Prepayment Fees [Abstract]
Prepayment fees received from borrowers	$ 279	$ 1,127	$ 3,896	$ 7,822
Less: hedging fair-value adjustments on prepaid advances	0	(359)	(2,731)	(552)
Less: net premiums associated with prepaid advances	0	0	0	(3,928)
Less: deferred recognition of prepayment fees received from borrowers on advance prepayments deemed to be loan modifications	0	0	(246)	(80)
Prepayment fees recognized in income on advance restructurings deemed to be extinguishments	0	0	3,102	0
Net prepayment fees recognized in income	$ 279	$ 768	$ 4,021	$ 3,262

Mortgage Loans Held for Portf63

Mortgage Loans Held for Portfolio (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]
Par Value	$ 3,511,983		$ 3,423,332
Premiums	63,971		62,554
Discounts	(2,442)		(2,761)
Deferred derivative gains, net	2,423		2,835
Total mortgage loans held for portfolio	3,575,935		3,485,960
Allowance for credit losses	(1,100)	$ (1,350)	(2,012)	$ (2,042)	$ (1,812)	$ (2,221)
Total mortgage loans, net of allowance for credit losses	$ 3,574,835		3,483,948
Fixed-rate 15-year single-family mortgages
Mortgage Loans on Real Estate [Line Items]
Original contractual terms	15 years
Par Value	$ 587,679		570,663
Fixed-rate 20- and 30-year single-family mortgages
Mortgage Loans on Real Estate [Line Items]
Par Value	2,924,304		2,852,669
Conventional mortgage loan [Member]
Mortgage Loans on Real Estate [Line Items]
Par Value	3,091,973		2,997,669
Government mortgage loan [Member]
Mortgage Loans on Real Estate [Line Items]
Par Value	$ 420,010		$ 425,663
Minimum [Member] | Fixed-rate 20- and 30-year single-family mortgages
Mortgage Loans on Real Estate [Line Items]
Original contractual terms	20 years
Maximum [Member] | Fixed-rate 20- and 30-year single-family mortgages
Mortgage Loans on Real Estate [Line Items]
Original contractual terms	30 years

Allowance for credit losses - C

Allowance for credit losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2015	Dec. 31, 2014
Mortgage Loans Past Due [Line Items]
Past due 30-59 days delinquent		$ 40,993	$ 51,879
Past due 60-89 days delinquent		13,877	14,425
Past due 90 days or more delinquent		33,779	45,394
Total past due		88,649	111,698
Total current loans		3,505,942	3,392,557
Total mortgage loans		3,594,591	3,504,255
In process of foreclosure, included above	[1]	$ 16,361	$ 16,495
Serious delinquency rate	[2]	0.98%	1.32%
Past due 90 days or more still accruing interest		$ 7,095	$ 7,467
Loans on nonaccrual status	[3]	$ 27,313	38,832
Number of days past due, loans at serious delinquent status		90 days
Recorded Investment in Conventional Mortgage Loans [Member]
Mortgage Loans Past Due [Line Items]
Past due 30-59 days delinquent		$ 23,477	32,068
Past due 60-89 days delinquent		9,177	9,834
Past due 90 days or more delinquent		26,684	37,927
Total past due		59,338	79,829
Total current loans		3,103,513	2,986,749
Total mortgage loans		3,162,851	3,066,578
In process of foreclosure, included above	[1]	$ 13,968	$ 13,709
Serious delinquency rate	[2]	0.89%	1.27%
Past due 90 days or more still accruing interest		$ 0	$ 0
Loans on nonaccrual status	[3]	27,313	38,832
Recorded Investment in Government Mortgage Loans [Member]
Mortgage Loans Past Due [Line Items]
Past due 30-59 days delinquent		17,516	19,811
Past due 60-89 days delinquent		4,700	4,591
Past due 90 days or more delinquent		7,095	7,467
Total past due		29,311	31,869
Total current loans		402,429	405,808
Total mortgage loans		431,740	437,677
In process of foreclosure, included above	[1]	$ 2,393	$ 2,786
Serious delinquency rate	[2]	1.64%	1.71%
Past due 90 days or more still accruing interest		$ 7,095	$ 7,467
Loans on nonaccrual status	[3]	$ 0	$ 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.

Allowance for credit losses - I

Allowance for credit losses - Individually Evaluated Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Allowance for Credit Losses [Abstract]
Individually evaluated impaired mortgage loans with no related allowance - Recorded Investment	$ 31,153		$ 31,153		$ 6,679
Individually evaluated impaired mortgage loans with no related allowance - Par Value	31,116		31,116		6,654
Individually evaluated impaired mortgage loans with a related allowance - Recorded Investment	0		0		3,097
Individually evaluated impaired mortgage loans with a related allowance - Par Value	0		0		3,073
Individually evaluated impaired mortgage loans - Related Allowance	0		0		544
Total individually evaluated impaired mortgage loans - Recorded Investment	31,153		31,153		9,776
Total individually evaluated impaired mortgage loans, Par Value	31,116		31,116		$ 9,727
Individually evaluated impaired mortgage loans with no related allowance - Average Recorded Investment	31,759	$ 3,637	32,557	$ 3,676
Individually evaluated impaired mortgage loans with no related allowance - Interest Income recognized	129	44	249	92
Individually evaluated impaired mortgage loans with a related allowance, Average Recorded Investment	0	2,538	0	2,839
Individually evaluated impaired mortgage loans with a related allowance, Interest Income recognized	0	2	0	13
Total individually evaluated impaired mortgage loans - Average Recorded Investment	31,759	6,175	32,557	6,515
Total individually evaluated impaired mortgage loans - Interest Income recognized	$ 129	$ 46	$ 249	$ 105

Allowance for credit losses - A

Allowance for credit losses - Allowance Rollforward (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period		$ 1,350	$ 1,812	$ 2,012	$ 2,221
Charge-offs, net of recoveries		(27)	(13)	(629)	(100)
(Reduction of) provision for credit losses		(223)	243	(283)	(79)
Balance, end of period		1,100	2,042	1,100	2,042
Ending balance, individually evaluated for impairment		0	605	0	605
Ending balance, collectively evaluated for impairment		1,100	1,437	1,100	1,437
Individually evaluated for impairment	[1]	31,153	6,142	31,153	6,142
Collectively evaluated for impairment	[1]	$ 3,131,698	$ 2,918,633	$ 3,131,698	$ 2,918,633
[1]	These amounts exclude government mortgage loans because we make no allowance for credit losses based on our investments in government mortgage loans, as discussed above under — Government Mortgage Loans Held for Portfolio.

Allowance for credit losses - N

Allowance for credit losses - Narratives (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Allowance for Credit Losses [Abstract]
REO	$ 4,100,000		$ 4,300,000
Carrying amount of REO sold	3,600,000	$ 4,400,000
Net gains (losses) on sale of REO assets	$ 321,000	$ (387,000)

Derivatives and Hedging Activ68

Derivatives and Hedging Activities Derivatives in Statement of Condition (Details) - USD ($)		Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		$ 16,068,427,000	$ 14,426,252,000
Derivative Asset, before netting and collateral adjustments		36,609,000	26,483,000
Derivative Liabilities, before netting and collateral adjustments		(542,993,000)	(616,033,000)
Derivative assets, netting adjustments and cash collateral including related accrued interest	[1],[2]	(8,166,000)	(11,935,000)
Derivative liabilities, netting adjustments and cash collateral including related accrued interest	[1],[2]	66,578,000	57,144,000
Derivative assets		28,443,000	14,548,000
Derivative liabilities		(476,415,000)	(558,889,000)
Derivatives designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		15,287,441,000	13,676,325,000
Derivative Asset, before netting and collateral adjustments		36,502,000	26,381,000
Derivative Liabilities, before netting and collateral adjustments		(523,255,000)	(596,176,000)
Derivatives not designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		780,986,000	749,927,000
Derivative Asset, before netting and collateral adjustments		107,000	102,000
Derivative Liabilities, before netting and collateral adjustments		(19,738,000)	(19,857,000)
Interest-rate swaps [Member] | Derivatives designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		14,534,641,000	12,579,525,000
Derivative Asset, before netting and collateral adjustments		36,333,000	26,381,000
Derivative Liabilities, before netting and collateral adjustments		(493,603,000)	(553,967,000)
Interest-rate swaps [Member] | Derivatives not designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		454,000,000	423,000,000
Derivative Asset, before netting and collateral adjustments		78,000	31,000
Derivative Liabilities, before netting and collateral adjustments		(19,653,000)	(19,849,000)
Forward-start interest-rate swaps | Derivatives designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		752,800,000	1,096,800,000
Derivative Asset, before netting and collateral adjustments		169,000	0
Derivative Liabilities, before netting and collateral adjustments		(29,652,000)	(42,209,000)
Interest-rate caps or floors [Member] | Derivatives not designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives		300,000,000	300,000,000
Derivative Asset, before netting and collateral adjustments		0	0
Derivative Liabilities, before netting and collateral adjustments		0	0
Mortgage-delivery commitment [Member] | Mortgages [Member]
Derivatives, Fair Value [Line Items]
Derivative assets		29,000	71,000
Derivative liabilities		(85,000)	(8,000)
Mortgage-delivery commitment [Member] | Derivatives not designated as hedging instruments [Member] | Mortgages [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives	[3]	26,986,000	26,927,000
Derivative Asset, before netting and collateral adjustments	[3]	29,000	71,000
Derivative Liabilities, before netting and collateral adjustments	[3]	(85,000)	(8,000)
Cleared derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, netting adjustments and cash collateral including related accrued interest		4,456,000	7,546,000
Derivative liabilities, netting adjustments and cash collateral including related accrued interest		35,675,000	37,953,000
Derivative assets		28,117,000	13,875,000
Derivative liabilities		0	1,000
Cash collateral and related accrued interest posted		60,700,000	45,500,000
Bilateral derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, netting adjustments and cash collateral including related accrued interest		(12,622,000)	(19,481,000)
Derivative liabilities, netting adjustments and cash collateral including related accrued interest		30,903,000	19,191,000
Derivative assets		297,000	602,000
Derivative liabilities		(476,330,000)	(558,882,000)
Cash collateral and related accrued interest received		$ 2,300,000	$ 290,000
[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 $60.7 million and $45.5 million at June 30, 2015, and December 31, 2014, 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 $2.3 million and $290,000 at June 30, 2015, and December 31, 2014, respectively.
[2]	Carried at fair value on a recurring basis.
[3]	Mortgage-delivery commitments are classified as derivatives with changes in fair value recorded in other income.

Derivatives and Hedging Activ69

Derivatives and Hedging Activities Derivatives in Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives and hedged items in fair-value hedging relationships	$ (1,087)	$ 965	$ (1,715)	$ 1,459
Cash flow hedge ineffectiveness	184	(35)	104	(170)
Total net (losses) gains related to derivatives designated as hedging instruments	(903)	930	(1,611)	1,289
Total net losses related to derivatives not designated as hedging instruments	(239)	(2,222)	(2,890)	(3,964)
Net losses on derivatives and hedging activities	(1,142)	(1,292)	(4,501)	(2,675)
Interest-rate swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives and hedged items in fair-value hedging relationships	(1,087)	965	(1,715)	1,459
Total net losses related to derivatives not designated as hedging instruments	403	(2,807)	(2,675)	(4,643)
Interest-rate caps or floors [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net losses related to derivatives not designated as hedging instruments	0	(25)	0	(42)
Mortgages [Member] | Mortgage-delivery commitment [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net losses related to derivatives not designated as hedging instruments	$ (642)	$ 610	$ (215)	$ 721

Derivatives and Hedging Activ70

Derivatives and Hedging Activities Derivatives in Statement of Income and Impact on Net Interest Income (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) on Derivative		$ 82,282	$ (1,107)	$ 64,825	$ (3,186)
Gain/(Loss) on Hedged Item		(83,369)	2,072	(66,540)	4,645
Net Fair-Value Hedge Ineffectiveness		(1,087)	965	(1,715)	1,459
Effect of Derivative on Net Interest Income	[1]	(26,785)	(28,990)	(52,468)	(60,861)
Advances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) on Derivative		39,168	8,124	33,311	30,109
Gain/(Loss) on Hedged Item		(38,764)	(8,040)	(32,878)	(29,881)
Net Fair-Value Hedge Ineffectiveness		404	84	433	228
Effect of Derivative on Net Interest Income	[1]	(32,611)	(33,019)	(64,510)	(66,430)
Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) on Derivative		54,244	(21,709)	27,245	(53,269)
Gain/(Loss) on Hedged Item		(53,694)	21,994	(26,368)	53,785
Net Fair-Value Hedge Ineffectiveness		550	285	877	516
Effect of Derivative on Net Interest Income	[1]	(9,439)	(9,504)	(18,921)	(18,998)
Deposits [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) on Derivative			(391)		(781)
Gain/(Loss) on Hedged Item			391		781
Net Fair-Value Hedge Ineffectiveness			0		0
Effect of Derivative on Net Interest Income	[1]		397		794
COs - bonds [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) on Derivative		(11,130)	12,869	4,269	20,755
Gain/(Loss) on Hedged Item		9,089	(12,273)	(7,294)	(20,040)
Net Fair-Value Hedge Ineffectiveness		(2,041)	596	(3,025)	715
Effect of Derivative on Net Interest Income	[1]	$ 15,265	$ 13,136	$ 30,963	$ 23,773
[1]	The net interest on derivatives in fair-value hedge relationships is presented in the statement of operations as interest income or interest expense of the respective hedged item.

Derivatives and Hedging Activ71

Derivatives and Hedging Activities Cash Flow Hedge Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative [Line Items]
Gains (Losses) Recognized in Net Losses on Derivatives and Hedging Activities (Ineffective Portion)	$ 184	$ (35)	$ 104	$ (170)
COs - bonds [Member] | Interest-rate swaps [Member]
Derivative [Line Items]
Gains (Losses) Recognized in Other Comprehensive Loss on Derivatives (Effective Portion)	12,773	(13,726)	630	(19,740)
(Losses) Gains Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion)	(5,628)	(720)	(10,520)	(720)
Gains (Losses) Recognized in Net Losses on Derivatives and Hedging Activities (Ineffective Portion)	$ 184	$ (35)	$ 104	$ (170)

Derivatives and Hedging Activ72

Derivatives and Hedging Activities Narratives (Details) - Jun. 30, 2015 - USD ($) $ in Thousands		Total
Derivative [Line Items]
Maximum length of time which we are hedging our exposure to the variability in future cash flows for forecasted transactions		9 years
Deferred net losses on derivative accumulated in other comprehensive loss expected to be reclassified to earnings during the next twelve months		$ 27,100
Aggregate fair value of all billateral derivative instruments with credit-risk-related contingent features that were in a net liability position		495,600
Post-haircut value of collateral already posted		403,800
Rating Downgrade from AA+ to AA or AA - [Member]
Derivative [Line Items]
Additional collateral	[1],[2]	30,282
Rating Downgrade From AA- to A+, A or A -[Member]
Derivative [Line Items]
Additional collateral	[1],[2]	35,320
Rating Downgrade From A- to below A- [Member]
Derivative [Line Items]
Additional collateral	[1],[2]	36,673
AA+ Rating [Member]
Derivative [Line Items]
Additional collateral		$ 1,100
[1]	Additional collateral of $1.1 million could be called by counterparties as of June 30, 2015, at our current credit rating of AA+ (based on the lower of our credit ratings from S&P and Moody's) and is not included in the table.
[2]	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.

Derivatives and Hedging Activ73

Derivatives and Hedging Activities Fair Value of Derivative Instruments With or Without Legal Rights of Offset (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative Assets, gross recognized amount		$ 36,580	$ 26,412
Derivative Liabilities gross recognized amount		(542,908)	(616,025)
Derivative assets, gross amounts of netting adjustments and cash collateral	[1],[2]	(8,166)	(11,935)
Derivative liabilities, gross amounts of netting adjustments and cash collateral	[1],[2]	66,578	57,144
Derivative Assets, net amounts after netting adjustments and cash collateral		28,414	14,477
Derivative Liabilities, net amounts after netting adjustments and cash collateral		(476,330)	(558,881)
Derivative assets		28,443	14,548
Derivative liabilities		(476,415)	(558,889)
Derivative Asset, Fair value, amount offset against collateral		28,443	14,548
Derivative Liability, Fair value, amount offset against collateral		(75,959)	(99,888)
Derivative Liabilities, additional net exposure, collateral pledged to counterparties in excess of net liabilities		2,900	4,000
Bilateral derivatives [Member]
Derivative [Line Items]
Derivative Assets, gross recognized amount		12,919	20,083
Derivative Liabilities gross recognized amount		(507,233)	(578,073)
Derivative assets, gross amounts of netting adjustments and cash collateral		(12,622)	(19,481)
Derivative liabilities, gross amounts of netting adjustments and cash collateral		30,903	19,191
Derivative Assets, net amounts after netting adjustments and cash collateral		297	602
Derivative Liabilities, net amounts after netting adjustments and cash collateral		(476,330)	(558,882)
Derivative assets		297	602
Derivative liabilities		(476,330)	(558,882)
Derivative Assets, fair value of securities pledged as collateral that can be sold or repledged	[3]	0	0
Derivative Liabilities, fair value of securities pledged as collateral that can be sold or repledged	[3]	86,821	66,056
Derivative Assets, fair value of securities pledged as collateral that cannot be sold or repledged	[3]	0	0
Derivative Liabilities, fair value of securities pledged as collateral that cannot be sold or repledged	[3]	313,635	392,944
Derivative Assets, Total non-cash collateral received or pledged, not offset	[3]	0	0
Derivative Liabilities, Total non-cash collateral received or pledged, not offset	[3]	400,456	459,000
Derivative Asset, Fair value, amount offset against collateral		297	602
Derivative Liability, Fair value, amount offset against collateral		(75,874)	(99,882)
Cleared derivatives [Member]
Derivative [Line Items]
Derivative Assets, gross recognized amount		23,661	6,329
Derivative Liabilities gross recognized amount		(35,675)	(37,952)
Derivative assets, gross amounts of netting adjustments and cash collateral		4,456	7,546
Derivative liabilities, gross amounts of netting adjustments and cash collateral		35,675	37,953
Derivative Assets, net amounts after netting adjustments and cash collateral		28,117	13,875
Derivative Liabilities, net amounts after netting adjustments and cash collateral		0	1
Derivative assets		28,117	13,875
Derivative liabilities		0	1
Derivative Asset, Fair value, amount offset against collateral		28,117	13,875
Derivative Liability, Fair value, amount offset against collateral		0	2
Mortgages [Member] | Mortgage-delivery commitment [Member]
Derivative [Line Items]
Derivative Asset, Mortgage delivery commitments		29	71
Derivative Liabilities, Mortgage delivery commitments		(85)	(8)
Derivative assets		29	71
Derivative liabilities		(85)	(8)
Derivative Asset, Fair value, amount offset against collateral		29	71
Derivative Liability, Fair value, amount offset against collateral		$ (85)	$ (8)
[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 $60.7 million and $45.5 million at June 30, 2015, and December 31, 2014, 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 $2.3 million and $290,000 at June 30, 2015, and December 31, 2014, respectively.
[2]	Carried at fair value on a recurring basis.
[3]	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net amount. At June 30, 2015, and December 31, 2014, we had additional net credit exposure of $2.9 million and $4.0 million, respectively, 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	Jun. 30, 2015	Dec. 31, 2014
Deposits [Abstract]
Interest-bearing deposit demand and overnight	$ 367,032	$ 340,441
Interest-bearing deposit other	4,584	5,120
Noninterest-bearing deposits other	30,450	23,770
Total deposits	$ 402,066	$ 369,331

Consolidated Obligations (Detai

Consolidated Obligations (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
CO Bonds [Abstract]
Total		$ 26,075,429	$ 25,505,774
COs – Discount Notes [Abstract]
Federal Home Loan Bank, Consolidated Obligations, Discount Notes		25,972,593	25,309,608
COs - Discount notes [Member]
COs – Discount Notes [Abstract]
Federal Home Loan Bank, Consolidated Obligations, Discount Notes		25,972,593	25,309,608
Par Value		$ 25,974,666	$ 25,312,040
Weighted Average Rate	[1]	0.08%	0.08%
COs - Bonds [Member]
CO Bonds [Abstract]
Due in one year or less		$ 7,751,955	$ 6,675,745
Due in one year or less, Weighted Average Rate	[2]	1.17%	1.41%
Due after one year through two years		$ 5,921,530	$ 5,573,745
Due after one year through two years, Weighted Average Rate	[2]	1.36%	1.46%
Due after two years through three years		$ 4,510,140	$ 4,842,570
Due after two years through three years, Weighted Average Rate	[2]	1.91%	1.91%
Due after three years through four years		$ 2,198,780	$ 2,392,380
Due after three years through four years, Weighted Average Rate	[2]	1.67%	1.77%
Due after four years through five years		$ 2,221,455	$ 2,244,815
Due after four years through five years, Weighted Average Rate	[2]	2.09%	1.95%
Thereafter		$ 3,305,000	$ 3,599,085
Thereafter, Weighted Average Rate	[2]	2.92%	2.79%
Par Value		$ 25,908,860	$ 25,328,340
Total, Weighted Average Rate	[2]	1.69%	1.79%
Premiums		$ 178,846	$ 199,628
Discounts		(16,763)	(19,386)
Hedging adjustments		4,486	(2,808)
Total		26,075,429	25,505,774
COs - Bonds [Member] | Fixed Interest Rate [Member]
CO Bonds [Abstract]
Par Value		22,911,860	22,513,340
COs - Bonds [Member] | Simple variable-rate [Member]
CO Bonds [Abstract]
Par Value		2,170,000	1,970,000
COs - Bonds [Member] | Step-up [Member]
CO Bonds [Abstract]
Par Value		827,000	845,000
COs - Bonds [Member] | Earlier of Contractual Maturity or Next Call Date [Member]
CO Bonds [Abstract]
Due in one year or less		12,043,955	10,805,745
Due after one year through two years		5,266,530	4,928,745
Due after two years through three years		3,440,140	4,252,570
Due after three years through four years		1,948,780	2,027,380
Due after four years through five years		1,646,455	1,619,815
Thereafter		1,563,000	1,694,085
COs - Bonds [Member] | Noncallable and nonputable [Member]
CO Bonds [Abstract]
Par Value		21,331,860	20,853,340
COs - Bonds [Member] | Callable [Member]
CO Bonds [Abstract]
Par Value		$ 4,577,000	$ 4,475,000
[1]	The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.
[2]	The CO bonds' weighted-average rate excludes concession fees.

Affordable Housing Program Narr

Affordable Housing Program Narratives (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Affordable Housing Program [Roll Forward]
Balance at beginning of year			$ 66,993	$ 62,591	$ 62,591
AHP expense for the period	$ 16,678	$ 3,778	20,445	8,184	17,623
AHP direct grant disbursements			(9,233)	$ (5,758)	(12,012)
AHP subsidy for AHP advance disbursements			(625)		(1,321)
Return of previously disbursed grants and subsidies			20		112
Balance at end of period	$ 77,600		$ 77,600		$ 66,993

Capital Requirements (Details)

Capital Requirements (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Capital [Abstract]
Capital-to-asset ratio, Required	4.00%	4.00%
Leverage capital-to-assets ratio, Required	5.00%	5.00%
Leverage capital-to-assets ratio, Actual	9.60%	9.80%
Multiplier for determining permanent capital in leverage capital calculation	1.5
Class B capital stock	$ 2,482,244	$ 2,413,114
Mandatorily redeemable capital stock	57,268	298,599
Retained earnings	1,063,854	901,658
Total permanent capital	3,603,366	3,613,371
Credit-risk capital	399,363	414,765
Market-risk capital	93,498	75,560
Operations-risk capital	147,858	147,097
Risk-based capital, Required	640,719	637,422
Excess of risk-based capital requirement	2,962,647	2,975,949
Regulatory capital, Required	2,257,995	2,204,267
Leverage capital, Required	2,822,493	2,755,334
Risk-based capital, Actual	3,603,366	3,613,371
Regulatory capital, Actual	$ 3,603,366	$ 3,613,371
Capital-to-asset ratio, Actual	6.40%	6.60%
Leverage capital, Actual	$ 5,405,049	$ 5,420,057

Accumulated Other Comprehensi78

Accumulated Other Comprehensive Loss (Details) - USD ($)		3 Months Ended				6 Months Ended
		Jun. 30, 2015		Jun. 30, 2014		Jun. 30, 2015		Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance						$ (436,986,000)
Accretion of noncredit loss		$ (11,990,000)		$ (12,612,000)		(23,453,000)		$ (24,747,000)
Amortization - hedging activities		5,631,000		724,000		10,527,000		729,000
Amortization - pension and postretirement benefits		92,000		(247,000)		322,000		(135,000)
Total other comprehensive income (loss)		16,766,000		24,604,000		41,923,000		36,129,000
Ending balance		(395,063,000)				(395,063,000)
Amortization of hedging activities recorded in interest expense CO bonds		5,600,000		720,000		10,500,000		720,000
Amortization of hedging activities recorded in net (losses) gains on derivatives and hedging activities		4,000		4,000		7,000		9,000
Net Unrealized Loss Relating to Hedging Activities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(88,675,000)		(57,603,000)		(81,428,000)		(51,594,000)
Net Unrealized gains (losses)		12,773,000		(13,726,000)		630,000		(19,740,000)
Amortization - hedging activities		5,631,000	[1]	724,000	[2]	10,527,000	[3]	729,000	[4]
Total other comprehensive income (loss)		18,404,000		(13,002,000)		11,157,000		(19,011,000)
Ending balance		(70,271,000)		(70,605,000)		(70,271,000)		(70,605,000)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(5,763,000)		(3,117,000)		(5,993,000)		(3,229,000)
Net actuarial loss		(8,000)		(373,000)		(8,000)		(373,000)
Amortization - pension and postretirement benefits	[5]	100,000		126,000		330,000		238,000
Total other comprehensive income (loss)		92,000		(247,000)		322,000		(135,000)
Ending balance		(5,671,000)		(3,364,000)		(5,671,000)		(3,364,000)
Total Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(411,829,000)		(469,991,000)		(436,986,000)		(481,516,000)
Net Unrealized gains (losses)		(2,020,000)		11,116,000		6,426,000		9,931,000
Accretion of noncredit loss		11,990,000		12,612,000		23,453,000		24,747,000
Net actuarial loss		(8,000)		(373,000)		(8,000)		(373,000)
Noncredit other-than-temporary impairment losses reclassified to credit loss	[6]	1,073,000		399,000		1,195,000		857,000
Amortization - hedging activities		5,631,000	[1]	724,000	[2]	10,527,000	[3]	729,000	[4]
Amortization - pension and postretirement benefits	[5]	100,000		126,000		330,000		238,000
Total other comprehensive income (loss)		16,766,000		24,604,000		41,923,000		36,129,000
Ending balance		(395,063,000)		(445,387,000)		(395,063,000)		(445,387,000)
Available-for-sale Securities [Member] | Net Unrealized Loss on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(53,034,000)		(96,936,000)		(73,623,000)		(101,765,000)
Net Unrealized gains (losses)		(14,793,000)		24,842,000		5,796,000		29,671,000
Total other comprehensive income (loss)		(14,793,000)		24,842,000		5,796,000		29,671,000
Ending balance		(67,827,000)		(72,094,000)		(67,827,000)		(72,094,000)
Held-to-maturity Securities [Member] | Noncredit Portion of Other-than-temporary Impairment Losses on Held-to-maturity Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(264,357,000)		(312,335,000)		(275,942,000)		(324,928,000)
Accretion of noncredit loss		11,990,000		12,612,000		23,453,000		24,747,000
Noncredit other-than-temporary impairment losses reclassified to credit loss	[6]	1,073,000		399,000		1,195,000		857,000
Total other comprehensive income (loss)		13,063,000		13,011,000		24,648,000		25,604,000
Ending balance		$ (251,294,000)		$ (299,324,000)		$ (251,294,000)		$ (299,324,000)
[1]	Amortization of hedging activities includes $5.6 million recorded in CO bond interest expense and $4,000 recorded in net losses on derivatives and hedging activities in the statement of operations.
[2]	Amortization of hedging activities includes $720,000 recorded in CO bond interest expense and $4,000 recorded in net losses on derivatives and hedging activities in the statement of operations.
[3]	Amortization of hedging activities includes $10.5 million recorded in CO bond interest expense and $7,000 recorded in net losses on derivatives and hedging activities in the statement of operations.
[4]	Amortization of hedging activities includes $720,000 recorded in CO bond interest expense and $9,000 recorded in net losses on derivatives and hedging activities in the statement of operations.
[5]	Recorded in other operating expenses in the statement of operations.
[6]	Recorded in net amount of impairment losses reclassified from accumulated other comprehensive loss in the statement of operations.

Employee Retirement Plans - Cos

Employee Retirement Plans - Costs of Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pentegra Defined Contribution Plan [Member]
Employee Retirement Plans [Line Items]
Pension expense	$ 280	$ 268	$ 528	$ 504
Thrift Benefit Equalization Plan [Member]
Employee Retirement Plans [Line Items]
Pension expense	9	7	119	106
Pentegra Defined Benefit Plan, Voluntary Contribution [Member]
Employee Retirement Plans [Line Items]
Net pension cost	5,000
Pentegra Defined Benefit Plan [Member]
Employee Retirement Plans [Line Items]
Net pension cost	$ 5,102	$ 763	$ 5,205	$ 1,526

Employees Retirement Plans - Co

Employees Retirement Plans - Components of net periodic benefit cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	$ 172	$ 151	$ 343	$ 276
Interest Cost	121	123	242	231
Amortization of net actuarial loss	97	125	326	237
Net periodic benefit cost	390	399	911	744
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	12	5	19	12
Interest Cost	9	8	16	16
Amortization of net actuarial loss	3	1	4	1
Net periodic benefit cost	$ 24	$ 14	$ 39	$ 29

Carrying Value and Fair Value o

Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities		$ 237,414	$ 244,969
Available-for-sale securities		6,011,270	5,481,978
Held-to-maturity Securities	[1],[2]	2,939,093	3,352,189
Held-to-maturity securities		3,260,144	3,710,815
Derivative assets		28,443	14,548
Derivative assets, netting adjustments and cash collateral	[3],[4]	(8,166)	(11,935)
Mandatorily redeemable capital stock		(57,268)	(298,599)
Derivative liabilities		(476,415)	(558,889)
Derivative liabilities, netting adjustments and cash collateral	[3],[4]	66,578	57,144
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		844,228	1,124,536
Interest-bearing deposits		267	163
Securities purchased under agreements to resell		0	0
Federal funds sold		0	0
Trading securities	[4]	0	0
Available-for-sale securities	[4]	0	0
Held-to-maturity securities		0	0
Advances		0	0
Mortgage loans, net		0	0
Accrued interest receivable		0	0
Derivative assets	[4]	0	0
Other assets	[4]	6,965	5,682
Deposits		0	0
Mandatorily redeemable capital stock		(57,268)	(298,599)
Accrued interest payable		0	0
Derivative liabilities	[4]	0	0
Level 1 [Member] | Commitments to extend credit for 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] | Consolidated Obligation 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		5,049,902	5,249,941
Federal funds sold		3,529,987	2,549,982
Trading securities	[4]	237,414	244,969
Available-for-sale securities	[4]	6,011,270	5,481,978
Held-to-maturity securities		1,798,553	2,176,268
Advances		34,240,643	33,618,345
Mortgage loans, net		3,628,001	3,612,078
Accrued interest receivable		77,828	77,411
Derivative assets	[4]	36,609	26,483
Other assets	[4]	8,347	5,518
Deposits		(402,066)	(369,330)
Mandatorily redeemable capital stock		0	0
Accrued interest payable		(79,508)	(91,225)
Derivative liabilities	[4]	(542,993)	(616,033)
Level 2 [Member] | Commitments to extend credit for advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(157)	430
Level 2 [Member] | Standby letters of credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(891)	(745)
Level 2 [Member] | Consolidated Obligation Discount Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount Notes		(25,973,298)	(25,310,307)
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	[4]	0	0
Available-for-sale securities	[4]	0	0
Held-to-maturity securities		1,461,591	1,534,547
Advances		0	0
Mortgage loans, net		36,423	0
Accrued interest receivable		0	0
Derivative assets	[4]	0	0
Other assets	[4]	0	0
Deposits		0	0
Mandatorily redeemable capital stock		0	0
Accrued interest payable		0	0
Derivative liabilities	[4]	0	0
Level 3 [Member] | Commitments to extend credit for 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] | Consolidated Obligation 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		844,228	1,124,536
Interest-bearing deposits		267	163
Securities purchased under agreements to resell		5,050,000	5,250,000
Federal funds sold		3,530,000	2,550,000
Trading securities	[4]	237,414	244,969
Available-for-sale securities	[4]	6,011,270	5,481,978
Held-to-maturity Securities		2,939,093	3,352,189
Advances		34,105,443	33,482,074
Mortgage loans, net		3,574,835	3,483,948
Accrued interest receivable		77,828	77,411
Derivative assets	[4]	28,443	14,548
Other assets	[4]	15,312	11,200
Deposits		(402,066)	(369,331)
Mandatorily redeemable capital stock		(57,268)	(298,599)
Accrued interest payable		(79,508)	(91,225)
Derivative liabilities	[4]	(476,415)	(558,889)
Carrying Value [Member] | Commitments to extend credit for 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		(891)	(745)
Carrying Value [Member] | Consolidated Obligation Discount Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount Notes		(25,972,593)	(25,309,608)
Total Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		844,228	1,124,536
Interest-bearing deposits		267	163
Securities purchased under agreements to resell		5,049,902	5,249,941
Federal funds sold		3,529,987	2,549,982
Trading securities	[4]	237,414	244,969
Available-for-sale securities	[4]	6,011,270	5,481,978
Held-to-maturity securities		3,260,144	3,710,815
Advances		34,240,643	33,618,345
Mortgage loans, net		3,664,424	3,612,078
Accrued interest receivable		77,828	77,411
Derivative assets	[4]	28,443	14,548
Other assets	[4]	15,312	11,200
Deposits		(402,066)	(369,330)
Mandatorily redeemable capital stock		(57,268)	(298,599)
Accrued interest payable		(79,508)	(91,225)
Derivative liabilities	[4]	(476,415)	(558,889)
Total Fair Value [Member] | Commitments to extend credit for advances [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(157)	430
Total Fair Value [Member] | Standby letters of credit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other		(891)	(745)
Total Fair Value [Member] | Consolidated Obligation Discount Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Discount Notes		(25,973,298)	(25,310,307)
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		(26,293,950)	(25,741,697)
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		(26,075,429)	(25,505,774)
COs - bonds [Member] | Total Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
CO Bonds		$ (26,293,950)	$ (25,741,697)
[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.
[2]	Fair values of held-to-maturity securities were $3,260,144 and $3,710,815 at June 30, 2015, and December 31, 2014, 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 $60.7 million and $45.5 million at June 30, 2015, and December 31, 2014, 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 $2.3 million and $290,000 at June 30, 2015, and December 31, 2014, respectively.
[4]	Carried at fair value on a recurring basis.

Fair Value Measured on Recurrin

Fair Value Measured on Recurring Basis (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		$ 237,414	$ 244,969
Available-for-sale securities		6,011,270	5,481,978
Derivative assets, netting adjustments and cash collateral	[1],[2]	(8,166)	(11,935)
Derivative assets		28,443	14,548
Derivative liabilities		(476,415)	(558,889)
Derivative liabilities, netting adjustments and cash collateral	[1],[2]	66,578	57,144
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	[2]	0	0
Available-for-sale securities	[2]	0	0
Derivative assets	[2]	0	0
Other assets	[2]	6,965	5,682
Derivative liabilities	[2]	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	[2]	237,414	244,969
Available-for-sale securities	[2]	6,011,270	5,481,978
Derivative assets	[2]	36,609	26,483
Other assets	[2]	8,347	5,518
Derivative liabilities	[2]	(542,993)	(616,033)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	[2]	0	0
Available-for-sale securities	[2]	0	0
Derivative assets	[2]	0	0
Other assets	[2]	0	0
Derivative liabilities	[2]	0	0
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, netting adjustments and cash collateral	[3]	(8,166)	(11,935)
Derivative liabilities, netting adjustments and cash collateral	[3]	66,578	57,144
Recurring [Member] | Interest-rate-exchange agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, netting adjustments and cash collateral	[3]	(8,166)	(11,935)
Derivative liabilities, netting adjustments and cash collateral	[3]	66,578	57,144
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Derivative assets		0	0
Other assets		6,965	5,682
Total assets at fair value		6,965	5,682
Total liabilities at fair value		0	0
Recurring [Member] | Level 1 [Member] | Interest-rate-exchange agreements [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]
Trading securities		237,414	244,969
Available-for-sale securities		6,011,270	5,481,978
Derivative assets		36,609	26,483
Other assets		8,347	5,518
Total assets at fair value		6,293,640	5,758,948
Total liabilities at fair value		(542,993)	(616,033)
Recurring [Member] | Level 2 [Member] | Interest-rate-exchange agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		36,580	26,412
Derivative liabilities		(542,908)	(616,025)
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
Derivative assets		0	0
Other assets		0	0
Total assets at fair value		0	0
Total liabilities at fair value		0	0
Recurring [Member] | Level 3 [Member] | Interest-rate-exchange agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Supranational institutions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		438,831	447,685
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		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		438,831	447,685
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		0	0
U.S. government-owned corporations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		269,903	284,997
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		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		269,903	284,997
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		0	0
GSEs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		117,706	123,453
GSEs [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
GSEs [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		117,706	123,453
GSEs [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
U.S. government guaranteed - single-family MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		11,254	12,235
Available-for-sale securities		178,910	206,028
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]
Trading securities		0	0
Available-for-sale securities		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]
Trading securities		11,254	12,235
Available-for-sale securities		178,910	206,028
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]
Trading securities		0	0
Available-for-sale securities		0	0
GSEs - MBS [Member] | Single Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		1,859	2,300
Available-for-sale securities		4,182,057	3,548,392
GSEs - MBS [Member] | Multi-Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		224,301	230,434
GSEs - MBS [Member] | Recurring [Member] | Level 1 [Member] | Single Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
GSEs - MBS [Member] | Recurring [Member] | Level 1 [Member] | Multi-Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
GSEs - MBS [Member] | Recurring [Member] | Level 2 [Member] | Single Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		1,859	2,300
Available-for-sale securities		4,182,057	3,548,392
GSEs - MBS [Member] | Recurring [Member] | Level 2 [Member] | Multi-Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		224,301	230,434
GSEs - MBS [Member] | Recurring [Member] | Level 3 [Member] | Single Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
Available-for-sale securities		0	0
GSEs - MBS [Member] | Recurring [Member] | Level 3 [Member] | Multi-Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
U.S. government guaranteed - multifamily MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		823,863	871,423
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		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		823,863	871,423
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		0	0
Total [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	[2]	237,414	244,969
Available-for-sale securities	[2]	6,011,270	5,481,978
Derivative assets	[2]	28,443	14,548
Other assets	[2]	15,312	11,200
Derivative liabilities	[2]	(476,415)	(558,889)
Total [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		237,414	244,969
Available-for-sale securities		6,011,270	5,481,978
Derivative assets		28,443	14,548
Other assets		15,312	11,200
Total assets at fair value		6,292,439	5,752,695
Total liabilities at fair value		(476,415)	(558,889)
Total [Member] | Recurring [Member] | Interest-rate-exchange agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		28,414	14,477
Derivative liabilities		(476,330)	(558,881)
Total [Member] | Supranational institutions [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		438,831	447,685
Total [Member] | U.S. government-owned corporations [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		269,903	284,997
Total [Member] | GSEs [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		117,706	123,453
Total [Member] | U.S. government guaranteed - single-family MBS [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		11,254	12,235
Available-for-sale securities		178,910	206,028
Total [Member] | GSEs - MBS [Member] | Recurring [Member] | Single Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		1,859	2,300
Available-for-sale securities		4,182,057	3,548,392
Total [Member] | GSEs - MBS [Member] | Recurring [Member] | Multi-Family Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		224,301	230,434
Total [Member] | U.S. government guaranteed - multifamily MBS [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		823,863	871,423
Mortgages [Member] | Mortgage-delivery commitment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		29	71
Derivative liabilities		(85)	(8)
Mortgages [Member] | Recurring [Member] | Level 1 [Member] | Mortgage-delivery commitment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Mortgages [Member] | Recurring [Member] | Level 2 [Member] | Mortgage-delivery commitment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		29	71
Derivative liabilities		(85)	(8)
Mortgages [Member] | Recurring [Member] | Level 3 [Member] | Mortgage-delivery commitment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Mortgages [Member] | Total [Member] | Recurring [Member] | Mortgage-delivery commitment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		29	71
Derivative liabilities		$ (85)	$ (8)
[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 $60.7 million and $45.5 million at June 30, 2015, and December 31, 2014, 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 $2.3 million and $290,000 at June 30, 2015, and December 31, 2014, respectively.
[2]	Carried at fair value on a recurring basis.
[3]	These amounts represent the application of the netting requirements that 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 Nonrecur

Fair Value Measured on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	$ 3,260,144	$ 3,710,815
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	0	0
Mortgage loans held for portfolio	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	1,798,553	2,176,268
Mortgage loans held for portfolio	3,628,001	3,612,078
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	1,461,591	1,534,547
Mortgage loans held for portfolio	36,423	0
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio	0
REO	0	0
Total assets recorded at fair value on a nonrecurring basis	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio	0
REO	0	0
Total assets recorded at fair value on a nonrecurring basis	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio	8,052
REO	1,637	843
Total assets recorded at fair value on a nonrecurring basis	20,413	24,102
Private-label residential MBS [Member] | Private-Label - Residential MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	1,289,137	1,358,158
Private-label residential MBS [Member] | Private-Label - Residential MBS [Member] | Fair Value, Measurements, 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	0	0
Private-label residential MBS [Member] | Private-Label - Residential MBS [Member] | Fair Value, Measurements, 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	0	0
Private-label residential MBS [Member] | Private-Label - Residential MBS [Member] | Fair Value, Measurements, 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	10,724	23,259
Total [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	3,260,144	3,710,815
Mortgage loans held for portfolio	3,664,424	3,612,078
Total [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio	8,052
REO	1,637	843
Total assets recorded at fair value on a nonrecurring basis	20,413	24,102
Total [Member] | Private-label residential MBS [Member] | Private-Label - Residential MBS [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of held-to-maturity securities	$ 10,724	$ 23,259

Commitments and Contingencies84

Commitments and Contingencies (Details) - USD ($)		6 Months Ended
		Jun. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Value of the guarantees related to standby letters of credit		$ 157,951,000	$ 28,472,000
Maximum term of commitments to invest in mortgage loans		45 days
Other FHLBanks [Member]
Loss Contingencies [Line Items]
Par value of other FHLBanks' outstanding COs for which we are jointly and severally liable		$ 800,900,000,000	796,400,000,000
Standby letters of credit issuance commitments [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year		16,900,000	26,200,000
Off-balance-sheet Commitments Expiring After One Year		$ 4,000,000
Minimum [Member]
Loss Contingencies [Line Items]
Term of standby letters of credit		20 days
Maximum [Member]
Loss Contingencies [Line Items]
Term of standby letters of credit		20 years
Standby letters of credit outstanding [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[1]	$ 4,454,029,000	4,065,555,000
Off-balance-sheet Commitments Expiring After One Year	[1]	127,845,000	125,381,000
Total Off-balance Sheet Commitments	[1]	4,581,874,000	4,190,936,000
Value of the guarantees related to standby letters of credit		891,000	745,000
Commitments for unused lines of credit - advances [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[2]	1,262,441,000	1,255,445,000
Off-balance-sheet Commitments Expiring After One Year	[2]	0	0
Total Off-balance Sheet Commitments	[2]	$ 1,262,441,000	1,255,445,000
Commitments for 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		$ 668,876,000	592,430,000
Off-balance-sheet Commitments Expiring After One Year		39,341,000	63,185,000
Total Off-balance Sheet Commitments		708,217,000	655,615,000
Commitments to invest in mortgage loans [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year		26,986,000	26,927,000
Off-balance-sheet Commitments Expiring After One Year		0	0
Total Off-balance Sheet Commitments		26,986,000	26,927,000
Unsettled CO bonds, at par [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year	[3]	83,750,000	15,000,000
Off-balance-sheet Commitments Expiring After One Year	[3]	0	0
Total Off-balance Sheet Commitments	[3]	83,750,000	15,000,000
Unsettled CO bonds, at par [Member] | Interest-rate swaps [Member]
Loss Contingencies [Line Items]
Total Off-balance Sheet Commitments		70,000,000	15,000,000
Unsettled CO discount notes, at par [Member]
Loss Contingencies [Line Items]
Off-balance-sheet Commitments Expiring Within One Year		0	500,000,000
Off-balance-sheet Commitments Expiring After One Year		0	0
Total Off-balance Sheet Commitments		$ 0	$ 500,000,000
[1]	The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year. At June 30, 2015, and December 31, 2014, these amounts totaled $16.9 million and $26.2 million, respectively. Also excluded are commitments to issue standby letters of credit that expire after one year totaling $4.0 million at June 30, 2015
[2]	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.
[3]	We had $70.0 million and $15.0 million in unsettled CO bonds that were hedged with associated interest-rate swaps at June 30, 2015, and December 31, 2014, respectively.

Transactions with Shareholder85

Transactions with Shareholders (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Transactions with Shareholders [Line Items]
Capital Stock Outstanding	$ 2,482,244		$ 2,482,244		$ 2,413,114
Par Value of Advances	33,932,665		33,932,665		33,274,714
Total Accrued Interest Receivable	77,828		77,828		77,411
Interest income on advances	58,441	$ 56,821	115,849	$ 112,692
Fees on letters of credit	2,089	1,615	4,008	3,285
Citizens Bank, N.A. [Member]
Transactions with Shareholders [Line Items]
Capital Stock Outstanding	$ 317,502		$ 317,502		$ 317,502
Percent of Total Capital Stock Outstanding	12.50%		12.50%		11.70%
Par Value of Advances	$ 5,516,467		$ 5,516,467		$ 5,768,096
Percentage of Total Par Value of Advances	16.30%		16.30%		17.30%
Total Accrued Interest Receivable	$ 612		$ 612		$ 283
Percent of Total Accrued Interest Receivable on Advances	2.10%		2.10%		1.00%
Interest income on advances	$ 3,447	3,592	$ 7,163	5,750
Directors' Financial Institutions [Member]
Transactions with Shareholders [Line Items]
Capital Stock Outstanding	$ 88,897		$ 88,897		$ 79,386
Percent of Total Capital Stock Outstanding	3.50%		3.50%		2.90%
Par Value of Advances	$ 1,198,088		$ 1,198,088		$ 918,127
Percentage of Total Par Value of Advances	3.50%		3.50%		2.80%
Total Accrued Interest Receivable	$ 1,244		$ 1,244		$ 1,227
Percent of Total Accrued Interest Receivable on Advances	4.20%		4.20%		4.20%
Minimum [Member]
Transactions with Shareholders [Line Items]
Definition of related party, minimum percent	10.00%		10.00%
Definition of shareholder concentration, minimum percent	10.00%		10.00%
Standby letters of credit [Member] | Citizens Bank, N.A. [Member]
Transactions with Shareholders [Line Items]
Fees on letters of credit	$ 1,050	$ 868	$ 2,039	$ 1,658

Subsequent Events (Details)

Subsequent Events (Details) - Common Class B [Member] - Subsequent Event [Member] - USD ($) $ in Millions	Aug. 04, 2015	Jul. 24, 2015
Subsequent Event [Line Items]
Annualized rate of cash dividend		3.28%
Dividend, including dividends on mandatorily redeemable capital stock	$ 20.6