Federal Home Loan Bank of Boston 10-Q 12 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013	Oct. 31, 2013
		Common Class A [Member]	Common Class B [Member]
Entity Information [Line Items]	'	'	'
Document Type	'10-Q	'	'
Document Period End Date	30-Sep-13	'	'
Amendment Flag	'false	'	'
Entity Registrant Name	'Federal Home Loan Bank of Boston	'	'
Entity Central Index Key	'0001331463	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'Q3	'	'
Entity Common Stock, Shares Outstanding	'	0	34,266,181
Entity Well-known Seasoned Issuer	'No	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'

Statements_of_Condition_unaudi

Statements of Condition (unaudited) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS	'		'
Cash and due from banks	$3,172,772		$240,945
Interest-bearing deposits	219		192
Securities purchased under agreements to resell	1,500,000		4,015,000
Federal funds sold	500,000		600,000
Investment securities:	'		'
Trading securities	249,970		274,293
Available-for-sale securities - includes $4,101 and $8,582 pledged as collateral at September 30, 2013, and December 31, 2012, respectively that may be repledged	3,860,587		5,268,237
Held-to-maturity securities - includes $67,110 and $100,124 pledged as collateral at September 30, 2013, and December 31, 2012, respectively that may be repledged	4,361,134	[1],[2]	5,396,335	[1],[2]
Total investment securities	8,471,691		10,938,865
Advances	22,555,122		20,789,704
Mortgage loans held for portfolio, net of allowance for credit losses of $1,957 and $4,414 at September 30, 2013, and December 31, 2012, respectively	3,401,111		3,478,896
Accrued interest receivable	75,943		100,404
Premises, software, and equipment, net	3,634		4,382
Derivative assets, net	4,118		111
Other assets	36,050		40,518
Total Assets	39,720,660		40,209,017
Deposits:	'		'
Interest-bearing	553,807		557,440
Non-interest-bearing	16,549		37,528
Total Deposits	570,356		594,968
Consolidated obligations [Abstract]	'		'
Bonds	24,201,697		26,119,848
Discount notes	10,475,911		8,639,048
Total consolidated obligations	34,677,608		34,758,896
Mandatorily redeemable capital stock	977,390		215,863
Accrued interest payable	101,206		96,356
Affordable Housing Program (AHP) payable	55,761		50,545
Derivative liabilities, net	649,781		907,092
Other liabilities	23,870		19,198
Total liabilities	37,055,972		36,642,918
Commitments and contingencies (Note 18)	'		'
Capital	'		'
Capital stock b Class B b putable ($100 par value), 24,410 shares and 34,552 shares issued and outstanding at September 30, 2013, and December 31, 2012, respectively	2,441,028		3,455,165
Retained earnings:	'		'
Unrestricted	615,993		523,203
Restricted	89,752		64,351
Total retained earnings	705,745		587,554
Accumulated other comprehensive loss	-482,085		-476,620
Total capital	2,664,688		3,566,099
Total Liabilities and Capital	$39,720,660		$40,209,017
[1]	Fair values of held-to-maturity securities were $4,700,205 and $5,699,230 at SeptemberB 30, 2013, and DecemberB 31, 2012, respectively.
[2]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss.

Statements_of_Condition_Parent

Statements of Condition (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Per Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Available-for-sale securities pledged as collateral that may be repledged	$4,101	$8,582
Held-to-maturity securities pledged as collateral that may be repledged (a)	67,110	100,124
Allowance for credit losses	1,957	4,414
Common Stock, Class B, putable shares issued	24,410	34,552
Common Stock, Class B, putable, par value per share	$100	$100
Common Stock, Class B, putable shares outstanding	24,410	34,552
Fair value of held-to-maturity securities	$4,700,205	$5,699,230

Statements_of_Operations_unaud

Statements of Operations (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
INTEREST INCOME	'	'	'	'
Advances	$56,405	$72,551	$172,445	$225,037
Prepayment fees on advances, net	1,821	11,874	18,437	44,348
Securities purchased under agreements to resell	478	2,455	1,896	7,069
Federal funds sold	545	463	1,291	1,491
Trading securities	2,363	2,522	7,201	7,608
Available-for-sale securities	14,437	19,106	49,197	50,869
Held-to-maturity securities	30,750	35,057	93,761	111,445
Prepayment fees on investments	1,605	139	5,331	341
Mortgage loans held for portfolio	31,474	34,214	96,166	103,527
Other	1	2	4	3
Total interest income	139,879	178,383	445,729	551,738
INTEREST EXPENSE	'	'	'	'
Consolidated obligations - bonds	78,715	101,584	243,113	311,943
Consolidated obligations - discount notes	1,846	3,726	5,057	8,222
Deposits	3	11	12	42
Mandatorily redeemable capital stock	911	260	2,083	834
Other borrowings	1	1	3	2
Total interest expense	81,476	105,582	250,268	321,043
NET INTEREST INCOME	58,403	72,801	195,461	230,695
Reduction of provision for credit losses	'	-523	-2,194	-2,057
Provision for credit losses	83	'	'	'
NET INTEREST INCOME AFTER PROVISION FOR (REDUCTION OF) CREDIT LOSSES	58,320	73,324	197,655	232,752
OTHER INCOME (LOSS)	'	'	'	'
Total other-than-temporary impairment losses on investment securities	-80	-2,077	-180	-14,218
Net amount of impairment losses reclassified (from) to accumulated other comprehensive loss	-1,448	985	-2,163	8,674
Net other-than-temporary impairment losses on investment securities, credit portion	-1,528	-1,092	-2,343	-5,544
Loss on early extinguishment of debt	-568	-4,992	-4,956	-16,993
Service fees	1,797	1,483	4,909	4,474
Net unrealized gains (losses) on trading securities	726	4,669	-11,278	8,291
Net (losses) gains on derivatives and hedging activities	-1,070	-2,086	6,175	-8,509
Other	519	228	-2,188	2,753
Total other loss	-124	-1,790	-9,681	-15,528
OTHER EXPENSE	'	'	'	'
Compensation and benefits	9,162	8,405	25,983	25,723
Other operating expenses	4,693	4,380	14,082	13,442
Federal Housing Finance Agency (the FHFA)	666	1,073	2,373	3,472
Office of Finance	655	625	1,908	2,066
Other	608	556	2,283	1,753
Total other expense	15,784	15,039	46,629	46,456
INCOME BEFORE ASSESSMENTS	42,412	56,495	141,345	170,768
AHP	4,333	5,675	14,343	17,160
NET INCOME	$38,079	$50,820	$127,002	$153,608

Statements_of_Comprehensive_In

Statements of Comprehensive Income (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$38,079	$50,820	$127,002	$153,608
Other comprehensive income:	'	'	'	'
Net unrealized (losses) gains on available-for-sale securities	-17,195	17,525	-61,671	15,643
Net noncredit portion of other-than-temporary impairment losses on held-to-maturity securities	'	'	'	'
Noncredit portion	0	-2,013	-63	-10,931
Reclassification adjustment for noncredit portion of other-than-temporary impairment losses recognized as credit losses included in net income	1,448	1,028	2,226	2,257
Accretion of noncredit portion	14,256	17,838	44,000	56,131
Total net noncredit portion of other-than-temporary impairment losses on held-to-maturity securities	15,704	16,853	46,163	47,457
Net unrealized (losses) gains relating to hedging activities	'	'	'	'
Unrealized (losses) gains	-6,173	-10,448	11,001	-32,874
Reclassification adjustment for previously deferred hedging gains and losses included in net income	4	4	11	11
Total net unrealized (losses) gains relating to hedging activities	-6,169	-10,444	11,012	-32,863
Pension and postretirement benefits	-323	-166	-969	-500
Total other comprehensive (loss) income	-7,983	23,768	-5,465	29,737
Total comprehensive income	$30,096	$74,588	$121,537	$183,345

Statements_of_Capital_unaudite

Statements of Capital (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'
Beginning of period	'	'	$3,566,099	$3,489,034
Proceeds from sale of capital stock	'	'	120,396	46,094
Repurchase of capital stock	'	'	-275,011	-237,412
Shares Reclassified to Mandatorily Redeemable Capital Stock	'	'	-859,522	-1,014
Comprehensive income	30,096	74,588	121,537	183,345
Cash dividends on capital stock	'	'	-8,811	-13,471
Period end	2,664,688	3,466,576	2,664,688	3,466,576
Common Class B [Member]	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'
Beginning of period, shares	'	'	34,552	36,253
Beginning of period	'	'	3,455,165	3,625,348
Proceeds from sale of capital stock, shares	'	'	1,203	461
Proceeds from sale of capital stock	'	'	120,396	46,094
Repurchase of capital stock, shares	'	'	-2,750	-2,374
Repurchase of capital stock	'	'	-275,011	-237,412
Shares Reclassified to Mandatorily Redeemable Capital Stock, Shares	'	'	-8,595	-10
Shares Reclassified to Mandatorily Redeemable Capital Stock	'	'	-859,522	-1,014
Period end, shares	24,410	34,330	24,410	34,330
Period end	2,441,028	3,433,016	2,441,028	3,433,016
Retained Earnings, Unrestricted	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'
Beginning of period	'	'	523,203	375,158
Comprehensive income	'	'	101,601	122,887
Cash dividends on capital stock	'	'	-8,811	-13,471
Period end	615,993	484,574	615,993	484,574
Retained Earnings, Restricted	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'
Beginning of period	'	'	64,351	22,939
Comprehensive income	'	'	25,401	30,721
Period end	89,752	53,660	89,752	53,660
Retained Earnings, Total	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'
Beginning of period	'	'	587,554	398,097
Comprehensive income	'	'	127,002	153,608
Cash dividends on capital stock	'	'	-8,811	-13,471
Period end	705,745	538,234	705,745	538,234
Accumulated Other Comprehensive Loss	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'
Beginning of period	'	'	-476,620	-534,411
Comprehensive income	'	'	-5,465	29,737
Period end	($482,085)	($504,674)	($482,085)	($504,674)

Statements_of_Cash_Flows_unaud

Statements of Cash Flows (unaudited) (USD $)	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
OPERATING ACTIVITIES	'	'	'
Net income	$127,002	$153,608	'
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Depreciation and amortization	-36,170	-13,299	'
Reduction of provision for credit losses	-2,194	-2,057	'
Change in net fair-value adjustments on derivatives and hedging activities	-21,529	85,822	'
Net other-than-temporary impairment losses on investment securities, credit portion	2,343	5,544	'
Loss on early extinguishment of debt	4,956	16,993	'
Other adjustments	583	-312	'
Net change in:	'	'	'
Market value of trading securities	11,278	-8,291	'
Accrued interest receivable	24,461	20,567	'
Other assets	2,862	2,150	'
Accrued interest payable	4,850	18,181	'
Other liabilities	7,107	12,393	'
Total adjustments	-1,453	137,691	'
Net cash provided by operating activities	125,549	291,299	'
INVESTING ACTIVITIES	'	'	'
Interest-bearing deposits	-3,948	-84	'
Securities purchased under agreements to resell	2,515,000	1,775,000	'
Federal funds sold	100,000	1,170,000	'
Premises, software, and equipment	-671	-784	'
Trading securities:	'	'	'
Proceeds from long-term	13,045	3,035	'
Available-for-sale securities:	'	'	'
Proceeds from long-term	1,506,945	1,128,619	'
Purchases of long-term	-289,846	-1,615,479	'
Held-to-maturity securities:	'	'	'
Proceeds from long-term	1,089,923	1,016,930	'
Advances to members:	'	'	'
Proceeds	157,664,653	110,843,079	'
Disbursements	-159,602,066	-109,610,045	'
Mortgage loans held for portfolio:	'	'	'
Proceeds	595,488	610,854	'
Purchases	-535,022	-947,759	'
Proceeds from sale of foreclosed assets	9,454	7,904	'
Net cash provided by investing activities	3,062,955	4,381,270	'
FINANCING ACTIVITIES	'	'	'
Net change in deposits	-23,462	12,079	'
Net payments on derivatives with a financing element	-14,275	-27,101	'
Net proceeds from issuance of consolidated obligations:	'	'	'
Discount notes	40,911,806	101,912,981	'
Bonds	4,802,462	7,879,848	'
Bonds transferred from other Federal Home Loan Banks	80,135	130,276	'
Payments for maturing and retiring consolidated obligations:	'	'	'
Discount notes	-39,074,702	-104,572,190	'
Bonds	-6,677,223	-9,597,021	'
Proceeds from issuance of capital stock	120,396	46,094	'
Payments for redemption of mandatorily redeemable capital stock	-97,995	-12,580	'
Payments for repurchase of capital stock	-275,011	-237,412	'
Cash dividends paid	-8,808	-13,471	'
Net cash used in financing activities	-256,677	-4,478,497	'
Net increase in cash and due from banks	2,931,827	194,072	'
Cash and due from banks at beginning of the year	240,945	112,094	112,094
Cash and due from banks at end of the period	3,172,772	306,166	240,945
Supplemental disclosures:	'	'	'
Interest paid	309,767	357,257	'
AHP payments	8,842	4,313	5,415
Noncash transfers of mortgage loans held for portfolio to real-estaste-owned (REO)	$7,863	$10,435	'

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Basis of Presentation [Abstract]	'
Basis of Accounting [Text Block]	'
	Basis of Presentation
	The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information. 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, 2013. 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, 2012, filed with the Securities and Exchange Commission (the SEC) on March 26, 2013 (the 2012 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_Ac

Recently Issued and Adopted Accounting Guidance	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recently Issued Accounting Standards and Interpretations [Text Block]	'
	Recently Issued and Adopted Accounting Guidance
	Inclusion of the Overnight Index Swap Rate as a Benchmark Interest Rate for Hedge Accounting Purposes. On July 17, 2013, the Financial Accounting Standards Board (FASB) amended existing guidance to include the Fed Funds Effective Swap Rate (also referred to as Overnight Index Swap Rate (OIS)) as a U.S. benchmark interest rate for hedge accounting purposes. Including OIS as an acceptable U.S. benchmark interest rate, in addition to United States Treasuries and London Interbank Offered Rates (LIBOR), provides a more comprehensive spectrum of interest-rate resets to utilize as the designated benchmark interest-rate risk component under the hedge accounting guidance. The amendments also remove the restriction on using different benchmark interest rates for similar hedges. The amendments apply to all entities that elect to apply hedge accounting of the benchmark interest rate, and are effective prospectively for qualifying new or redesignated hedging relationships entered into on or after July 17, 2013. The adoption of this guidance did not affect our financial condition, results of operations, or cash flows.
	Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date. On February 28, 2013, the FASB issued guidance for the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation within the scope of this guidance is fixed at the reporting date. This guidance requires an entity to measure these obligations as the sum of (1) the amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and (2) any additional amount the reporting entity expects to pay on behalf of its co-obligors. In addition, this guidance requires an entity to disclose the nature and amount of the obligation as well as other information about those obligations. This guidance is effective for interim and annual periods beginning on or after December 15, 2013, and should be applied retrospectively to obligations with joint and several liability existing at the beginning of an entity's fiscal year of adoption.
	Upon adoption of this guidance on January 1, 2014, we will continue to recognize the COs for which we are the direct obligor as a liability, and will not recognize any amount for COs for which other FHLBanks are direct obligors, unless a default occurs and the FHFA mandates an allocation of a shortfall. Adoption of this guidance will have no impact on our financial condition, results of operations or cash flows.
	Disclosures about Offsetting Assets and Liabilities. On December 16, 2011, the FASB and the International Accounting Standards Board (the IASB) issued common disclosure requirements intended to help investors and other financial statement users better assess the effect or potential effect of offsetting arrangements on a company's financial position, whether a company's financial statements are prepared on the basis of GAAP or International Financial Reporting Standards (IFRS). This guidance was amended on January 31, 2013, to clarify that its scope includes only certain financial instruments that are either offset on the balance sheet or are subject to an enforceable master netting arrangement or similar agreement. We are required to disclose both gross and net information about derivative, repurchase, and security lending instruments that meet these criteria. This guidance, as amended, became effective for us for interim and annual periods beginning on January 1, 2013, and was applied retrospectively for all comparative periods presented. The adoption of this guidance has resulted in additional financial statement disclosures but did not affect our financial condition, results of operations, or cash flows. We do not have repurchase agreements and reverse repurchase agreements or securities borrowing and securities lending transactions that are subject to offset in our statement of condition. As a result, we are only providing the required disclosures related to derivative instruments. See Note 10 — Derivatives and Hedging Activities for disclosures related to this guidance.
	Presentation of Comprehensive Income. On February 5, 2013, the FASB issued guidance to improve the transparency of reporting reclassifications out of accumulated other comprehensive loss. This guidance does not change the current requirements for reporting net income or comprehensive income in financial statements. However, it does require that we provide information about the amounts reclassified out of accumulated other comprehensive loss by component. In addition, we are required to present significant amounts reclassified out of accumulated other comprehensive loss, either on the face of the financial statement where net income is presented or in the footnotes. These amounts are presented based on the respective lines of net income only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, we are required to cross-reference to other required disclosures that provide additional detail about these other amounts. This guidance became effective for interim and annual periods beginning after December 15, 2012, and has been applied prospectively. The adoption of this guidance resulted in additional financial statement disclosures but did not affect our financial condition, results of operations, or cash flows. See Note 15 — Accumulated Other Comprehensive Loss for disclosures related to this guidance.
	Regulatory Guidance
	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 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 in AB 2012-02 is generally consistent with the Uniform Retail Credit Classification and Account Management Policy issued by the federal banking regulators in June 2000. AB 2012-02 states that it was effective upon issuance. However, the FHFA issued additional guidance indicating that the asset classification provisions in AB 2012-02 should be implemented by January 1, 2014, and that the charge-off provisions in AB 2012-02 should be implemented no later than January 1, 2015. We are currently assessing the provisions of AB 2012-02 and have not yet determined its anticipated effect on our financial condition, results of operations, and cash flows.

Trading_Securities

Trading Securities	9 Months Ended
	Sep. 30, 2013
Trading Securities [Abstract]	'
Trading Securities (and Certain Trading Assets) Disclosure [Text Block]	'
	Trading Securities
	Major Security Types. Our trading securities as of September 30, 2013, and December 31, 2012, were (dollars in thousands):
		September 30, 2013		December 31, 2012
	Mortgage-backed securities (MBS)
	United States (U.S.) government-guaranteed – residential	$	14,962	$	16,876
	Government-sponsored enterprises (GSEs) – residential	3,803		4,946
	GSEs – commercial	231,205		252,471
	Total	$	249,970	$	274,293
	Net unrealized losses on trading securities held for the nine months ended September 30, 2013, amounted to $11.3 million and net unrealized gains on trading securities held for the nine months ended September 30, 2012, amounted to $8.3 million.
	We do not participate in speculative trading practices and typically hold these investments over a longer time horizon.

AvailableforSale_Securities

Available-for-Sale Securities	9 Months Ended
	Sep. 30, 2013
Available-for-sale Securities [Abstract]	'
Available-for-Sale Securities Disclosure [Text Block]	'
	Available-for-Sale Securities
	Major Security Types. Our available-for-sale securities as of September 30, 2013, were (dollars in thousands):
				Amounts Recorded in Accumulated Other Comprehensive Loss
		Amortized		Unrealized			Unrealized			Fair
		Cost (1)		Gains			Losses			Value
	Supranational institutions	$	453,905	$	—		$	(23,113	)	$	430,792
	U.S. government-owned corporations	286,097		—			(38,752		)	247,345
	GSEs	1,053,469		6,759			(11,471		)	1,048,757
		1,793,471		6,759			(73,336		)	1,726,894
	MBS
	U.S. government guaranteed – residential	294,051		453			(2,974		)	291,530
	GSEs – residential	1,857,379		5,180			(20,396		)	1,842,163
		2,151,430		5,633			(23,370		)	2,133,693
	Total	$	3,944,901	$	12,392		$	(96,706	)	$	3,860,587
	_______________________
	(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, 2012, were (dollars in thousands):
				Amounts Recorded in Accumulated Other Comprehensive Loss
		Amortized		Unrealized			Unrealized			Fair
		Cost (1)		Gains			Losses			Value
	Supranational institutions	$	502,177	$	—		$	(28,693	)	$	473,484
	U.S. government-owned corporations	330,106		—			(39,025		)	291,081
	GSEs	2,072,936		25,901			(13,753		)	2,085,084
		2,905,219		25,901			(81,471		)	2,849,649
	MBS
	U.S. government guaranteed – residential	72,862		497			—			73,359
	GSEs – residential	2,212,183		32,611			—			2,244,794
	GSEs – commercial	100,616		—			(181		)	100,435
		2,385,661		33,108			(181		)	2,418,588
	Total	$	5,290,880	$	59,009		$	(81,652	)	$	5,268,237
	_______________________
	(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.
	As of September 30, 2013, the amortized cost of our available-for-sale securities included net premiums of $66.5 million. Of that amount, $36.8 million of net premiums related to non-MBS and $29.7 million of net premiums related to MBS. As of December 31, 2012, the amortized cost of our available-for-sale securities included net premiums of $67.2 million. Of that amount, $50.2 million of net premiums related to non-MBS and $17.0 million of net premiums related to MBS.
	The following table summarizes our available-for-sale securities with unrealized losses as of September 30, 2013, 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		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Supranational institutions	$	—	$	—		$	430,792		$	(23,113	)	$	430,792	$	(23,113	)
	U.S. government-owned corporations	—		—			247,345			(38,752		)	247,345		(38,752		)
	GSEs	—		—			109,711			(11,471		)	109,711		(11,471		)
		—		—			787,848			(73,336		)	787,848		(73,336		)
	MBS
	U.S. government guaranteed – residential	228,122		(2,974		)	—			—			228,122		(2,974		)
	GSEs – residential	1,304,806		(20,396		)	—			—			1,304,806		(20,396		)
		1,532,928		(23,370		)	—			—			1,532,928		(23,370		)
	Total temporarily impaired	$	1,532,928	$	(23,370	)	$	787,848		$	(73,336	)	$	2,320,776	$	(96,706	)
	The following table summarizes our available-for-sale securities with unrealized losses as of December 31, 2012, 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		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Supranational institutions	$	—	$	—		$	473,484		$	(28,693	)	$	473,484	$	(28,693	)
	U.S. government-owned corporations	—		—			291,081			(39,025		)	291,081		(39,025		)
	GSEs	—		—			124,453			(13,753		)	124,453		(13,753		)
		—		—			889,018			(81,471		)	889,018		(81,471		)
	MBS
	GSEs – commercial	100,435		(181		)	—			—			100,435		(181		)
	Total temporarily impaired	$	100,435	$	(181	)	$	889,018		$	(81,471	)	$	989,453	$	(81,652	)
	Redemption Terms. The amortized cost and fair value of our available-for-sale securities by contractual maturity at September 30, 2013, and December 31, 2012, were (dollars in thousands):
		September 30, 2013					December 31, 2012
	Year of Maturity	Amortized		Fair			Amortized			Fair
		Cost		Value			Cost			Value
	Due in one year or less	$	932,287	$	939,046		$	1,147,950		$	1,156,133
	Due after one year through five years	—		—			786,779			804,498
Due after five years through 10 years	—		—			—			—
Due after 10 years	861,184		787,848			970,490			889,018
	1,793,471		1,726,894			2,905,219			2,849,649
MBS (1)	2,151,430		2,133,693			2,385,661			2,418,588
Total	$	3,944,901	$	3,860,587		$	5,290,880		$	5,268,237
_______________________
-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.

HeldtoMaturity_Securities

Held-to-Maturity Securities	9 Months Ended
	Sep. 30, 2013
Held-to-maturity Securities [Abstract]	'
Held-to-maturity Securities Disclosure [Text Block]	'
	Held-to-Maturity Securities
	Major Security Types. Our held-to-maturity securities as of September 30, 2013, 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	$	9,749	$	—		$	9,749	$	809		$	—		$	10,558
	State or local housing-finance-agency obligations (HFA securities)	185,156		—			185,156		48			(22,056		)	163,148
	GSEs	67,943		—			67,943		529			—			68,472
		262,848		—			262,848		1,386			(22,056		)	242,178
	MBS
	U.S. government guaranteed – residential	30,128		—			30,128		672			—			30,800
	U.S. government guaranteed – commercial	237,527		—			237,527		1,107			—			238,634
	GSEs – residential	1,879,733		—			1,879,733		49,546			(330		)	1,928,949
	GSEs – commercial	757,430		—			757,430		45,949			—			803,379
	Private-label – residential	1,506,605		(338,030		)	1,168,575		285,865			(22,128		)	1,432,312
	Private-label – commercial	1,621		—			1,621		8			—			1,629
	Asset-backed securities (ABS) backed by home equity loans	24,254		(982		)	23,272		893			(1,841		)	22,324
		4,437,298		(339,012		)	4,098,286		384,040			(24,299		)	4,458,027
	Total	$	4,700,146	$	(339,012	)	$	4,361,134	$	385,426		$	(46,355	)	$	4,700,205
	Our held-to-maturity securities as of December 31, 2012, 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	$	12,877	$	—		$	12,877	$	1,243		$	—		$	14,120
	HFA securities	189,719		—			189,719		44			(17,881		)	171,882
	GSEs	69,246		—			69,246		1,521			—			70,767
		271,842		—			271,842		2,808			(17,881		)	256,769
	MBS
	U.S. government guaranteed – residential	38,313		—			38,313		879			—			39,192
	U.S. government guaranteed – commercial	451,559		—			451,559		8,273			—			459,832
	GSEs – residential	2,357,479		—			2,357,479		78,105			(337		)	2,435,247
	GSEs – commercial	957,503		—			957,503		84,282			(2		)	1,041,783
	Private-label – residential	1,669,041		(384,051		)	1,284,990		183,581			(34,184		)	1,434,387
	Private-label – commercial	9,822		—			9,822		321			—			10,143
	ABS backed by home equity loans	25,951		(1,124		)	24,827		719			(3,669		)	21,877
		5,509,668		(385,175		)	5,124,493		356,160			(38,192		)	5,442,461
	Total	$	5,781,510	$	(385,175	)	$	5,396,335	$	358,968		$	(56,073	)	$	5,699,230
	As of September 30, 2013, the amortized cost of our held-to-maturity securities included net discounts of $457.5 million. Of that amount, net premiums of $626,000 related to non-MBS and net discounts of $458.1 million related to MBS. As of December 31, 2012, the amortized cost of our held-to-maturity securities included net discounts of $494.9 million. Of that amount, net premiums of $1.9 million related to non-MBS and net discounts of $496.8 million related to MBS.
	The following table summarizes our held-to-maturity securities with unrealized losses as of September 30, 2013, 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		Unrealized			Fair		Unrealized			Fair			Unrealized
		Value		Losses			Value		Losses			Value			Losses
	HFA securities	$	—	$	—		$	155,814	$	(22,056	)	$	155,814		$	(22,056	)
	MBS
	GSEs – residential	5,585		(6		)	45,424		(324		)	51,009			(330		)
	Private-label – residential	63,819		(1,434		)	966,325		(105,517		)	1,030,144			(106,951		)
	ABS backed by home equity loans	—		—			22,324		(2,108		)	22,324			(2,108		)
		69,404		(1,440		)	1,034,073		(107,949		)	1,103,477			(109,389		)
	Total	$	69,404	$	(1,440	)	$	1,189,887	$	(130,005	)	$	1,259,291		$	(131,445	)
	The following table summarizes our held-to-maturity securities with unrealized losses as of December 31, 2012, 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		Unrealized			Fair		Unrealized			Fair			Unrealized
		Value		Losses			Value		Losses			Value			Losses
	HFA securities	$	—	$	—		$	163,864	$	(17,881	)	$	163,864		$	(17,881	)
	MBS
	GSEs – residential	—		—			60,776		(337		)	60,776			(337		)
	GSEs – commercial	1,220		(2		)	—		—			1,220			(2		)
	Private-label – residential	—		—			1,325,876		(242,306		)	1,325,876			(242,306		)
	ABS backed by home equity loans	—		—			21,181		(4,114		)	21,181			(4,114		)
		1,220		(2		)	1,407,833		(246,757		)	1,409,053			(246,759		)
	Total	$	1,220	$	(2	)	$	1,571,697	$	(264,638	)	$	1,572,917		$	(264,640	)
	Redemption Terms. The amortized cost and fair value of our held-to-maturity securities by contractual maturity at September 30, 2013, and December 31, 2012, 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.
		September 30, 2013							December 31, 2012
	Year of Maturity	Amortized		Carrying			Fair		Amortized			Carrying			Fair
		Cost		Value (1)			Value		Cost			Value (1)			Value
	Due in one year or less	$	67,943	$	67,943		$	68,472	$	—		$	—		$	—
	Due after one year through five years	1,179		1,179			1,252		69,581			69,581			71,102
Due after five years through 10 years	30,091		30,091			30,587		32,562			32,562			33,604
Due after 10 years	163,635		163,635			141,867		169,699			169,699			152,063
	262,848		262,848			242,178		271,842			271,842			256,769
MBS (2)	4,437,298		4,098,286			4,458,027		5,509,668			5,124,493			5,442,461
Total	$	4,700,146	$	4,361,134		$	4,700,205	$	5,781,510		$	5,396,335		$	5,699,230
_______________________
(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.

OtherThanTemporary_Impairment

Other-Than-Temporary Impairment	9 Months Ended
	Sep. 30, 2013
Other-Than-Temporary Impairment Analysis [Abstract]	'
Other-than-Temporary Impairment [Text Block]	'
	Other-Than-Temporary Impairment
	We evaluate our individual available-for-sale and held-to-maturity securities for other-than-temporary impairment each quarter. As part of our evaluation of securities for other-than-temporary impairment, we consider whether we intend to sell each security for which fair value is less than amortized cost or whether it is more likely than not that we will be required to sell the security before the anticipated recovery of the remaining amortized cost. If either of these conditions is met, we recognize an other-than-temporary impairment charge in earnings equal to the entire difference between the security's amortized cost basis and its fair value at the statement of condition date. For securities in an unrealized loss position that meet neither of these conditions (excluding agency MBS) and for all residential private-label MBS, we perform a cash-flow analysis to determine whether the entire amortized cost basis of these impaired securities, including all previously other-than-temporarily impaired securities, will be recovered. If we do not expect to recover the entire amount, the unrealized loss position is considered to be other-than-temporarily impaired. We evaluate the security's other-than-temporary impairment to determine the amount of credit loss to be recognized in earnings, which is limited to the amount of that security's unrealized loss.
	Available-for-Sale Securities
	As a result of our evaluations, we determined that none of our available-for-sale securities were other-than-temporarily impaired at September 30, 2013. At September 30, 2013, 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. These unrealized losses are considered temporary as 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 September 30, 2013:
	•	Debentures issued by a supranational institution that were in an unrealized loss position as of September 30, 2013, are expected to return contractual principal and interest, based on our review and analysis of independent third-party credit reports on the supranational institution, and such supranational institution is rated triple-A (or equivalent) by each of the nationally recognized statistical rating organizations (NRSROs).
	•	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.
	•	We have concluded that 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.
	•	Agency MBS. For MBS issued by Fannie Mae and Freddie Mac, which we sometimes refer to as agency MBS in this report, 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.
	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 September 30, 2013, none of our held-to-maturity investments in HFA securities were rated below investment grade by an NRSRO. Because the decline in market value is attributable to changes in interest rates and credit spreads and to illiquidity in the credit markets 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 September 30, 2013.
	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 September 30, 2013, 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 September 30, 2013.
	Private-Label Residential MBS and ABS Backed by Home Equity Loans. Our evaluation includes estimating the projected cash flows that we are likely to collect based on an assessment of all available information, including the structure of the applicable security and certain assumptions to determine whether we will recover the entire amortized cost basis of the security, such as:
	•	the remaining payment terms for the security;
	•	prepayment speeds;
	•	default rates;
	•	loss severity on the collateral supporting each security based on underlying loan-level borrower and loan characteristics;
	•	expected housing price changes; and
	•	interest-rate assumptions.
	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, and loss severities. A significant input to the first model is the forecast of future housing-price changes for the relevant states and core-based statistical areas (CBSAs), based on an assessment of the individual housing markets. The term CBSA refers collectively to metropolitan and micropolitan statistical areas as defined by the United States Office of Management and Budget. As currently defined, a CBSA must contain at least one core urban area with a population of 10,000 or more people, plus adjacent territory that has a high degree of social and economic integration with the core as measured by commuting ties. The FHLBank System committee (OTTI Governance Committee) developed a short-term housing price forecast using whole percentages, with projected changes ranging from a decrease of 5.0 percent to an increase of 8.0 percent over the 12 month period beginning July 1, 2013. For the vast majority of markets, the short-term forecast has changes from a decrease of 1.0 percent to an increase of 7.0 percent. Thereafter home prices were projected to recover using one of five different recovery paths. Under those recovery paths, home prices were projected to increase as follows:
	Months		Recovery Range
	6-Jan		0	%	to	3.00%
	12-Jul		1	%	to	4.00%
	13-18		2	%	to	4.00%
	19-30		2	%	to	5.00%
	31-54		2	%	to	6.00%
	Thereafter		2.3	%	to	5.60%
	The month-by-month projections of future loan performance are derived from the first model to determine projected prepayments, defaults, and loss severities. These projections are then input into a second model that calculates the projected loan-level cash flows and then allocates those 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 September 30, 2013 (that is, a determination was made that less than the entire amortized cost basis is expected to be recovered), 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).
							Significant Inputs
							Projected		Projected			Projected			Current
							Prepayment Rates		Default Rates			Loss Severities			Credit Enhancement
	Private-label MBS by		Par Value				Weighted		Weighted			Weighted			Weighted
	Year of Securitization						Average		Average			Average			Average
							Percent		Percent			Percent			Percent
	Private-label residential MBS
	Alt-A (1)
	2007		$	65,490			5.3	%	58.2	%		45.1	%		25.5	%
	2005		9,797				6.1		45.5			41.5			22.3
	Total Alt-A		$	75,287			5.4	%	56.5	%		44.7	%		25.1	%
	ABS backed by home equity loans
	Subprime (1)
	2004 and prior		$	283			1.1	%	38.1	%		91.6	%		10.9	%
	_______________________
	(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 September 30, 2013 (dollars in thousands). Securities are classified in the table below based on their classifications at the time of issuance. We note that 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 per the following tables in this Note 6, for example) as disclosed by those securities' issuance documents, as well as other statements about the securities, are inaccurate.
		September 30, 2013
	Other-Than-Temporarily Impaired Investment	Par				Amortized			Carrying				Fair
		Value				Cost			Value				Value
	Private-label residential MBS – Prime	$	65,201			$	55,351		$	41,623			$	54,608
	Private-label residential MBS – Alt-A	1,603,544				1,159,835			835,533				1,108,360
	ABS backed by home equity loans – Subprime	5,066				4,504			3,522				4,415
	Total other-than-temporarily impaired securities	$	1,673,811			$	1,219,690		$	880,678			$	1,167,383
	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 September 30,							For the Nine Months Ended September 30,
		2013				2012			2013				2012
	Balance at beginning of period	$	472,243			$	520,654		$	497,102			$	544,833
	Additions:
	Credit losses for which other-than-temporary impairment was not previously recognized	—				—			—				—
	Additional credit losses for which an other-than-temporary impairment charge was previously recognized(1)	1,528				1,092			2,343				5,544
	Reductions:
	Securities matured or paid-down during the period	(10,427		)		(8,065		)	(28,793		)		(32,697		)
	Increase in cash flows expected to be collected which are recognized over the remaining life of the security	(5,864		)		(2,609		)	(13,172		)		(6,608		)
Balance at end of period	$	457,480			$	511,072		$	457,480			$	511,072
_______________________
-1	For the three months ended September 30, 2013 and 2012, additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to July 1, 2013 and 2012. For the nine months ended September 30, 2013 and 2012, 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, 2013 and 2012.

Advances

Advances	9 Months Ended
	Sep. 30, 2013
Advances [Abstract]	'
Federal Home Loan Bank, Advances [Text Block]	'
	Advances
	General Terms. At September 30, 2013, and December 31, 2012, we had advances outstanding with interest rates ranging from (0.20) percent to 8.37 percent and (0.15) 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.
		September 30, 2013							December 31, 2012
	Year of Contractual Maturity	Amount				Weighted			Amount				Weighted
						Average							Average
						Rate							Rate
	Overdrawn demand-deposit accounts	$	2,956			0.43	%		$	12,893			0.53	%
	Due in one year or less	10,214,001				0.65			8,273,972				1
	Due after one year through two years	2,106,545				2.28			2,198,709				2.61
	Due after two years through three years	2,400,698				2.26			1,921,353				2.57
	Due after three years through four years	3,220,895				2.82			2,347,511				2.56
	Due after four years through five years	2,235,554				2.45			3,033,895				3.04
	Thereafter	2,027,688				2.76			2,481,519				2.96
	Total par value	22,208,337				1.67	%		20,269,852				2.05	%
	Premiums	52,875							52,435
	Discounts	(20,298		)					(23,087		)
	Market value of embedded derivatives (1)	854							1,163
	Hedging adjustments	313,354							489,341
	Total	$	22,555,122						$	20,789,704
	_________________________
	-1	At September 30, 2013, and December 31, 2012, we had certain advances with embedded features that met the requirements to be separated from the host contract and designate the embedded features as a stand-alone derivative.
	We offer putable advances that provide us with the right to put the fixed-rate advance to the borrower (and thereby extinguish the advance) on predetermined exercise dates (put dates), and offer, subject to certain conditions, replacement funding at then-current advances rates. Generally, we would exercise the put options when interest rates increase. At September 30, 2013, and December 31, 2012, we had putable advances outstanding totaling $2.7 billion and $3.3 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):
		September 30, 2013							December 31, 2012
	Year of Contractual Maturity or Next Put Date	Par Value				Percentage			Par Value				Percentage
						of Total							of Total
	Overdrawn demand-deposit accounts	$	2,956			0	%		$	12,893			0.1	%
	Due in one year or less	12,648,176				57			11,218,147				55.3
	Due after one year through two years	1,959,795				8.8			1,919,209				9.5
	Due after two years through three years	2,153,298				9.7			1,779,103				8.8
	Due after three years through four years	1,763,370				7.9			1,906,611				9.4
	Due after four years through five years	1,704,304				7.7			1,441,870				7.1
	Thereafter	1,976,438				8.9			1,992,019				9.8
	Total par value	$	22,208,337			100	%		$	20,269,852			100	%
	We also offer callable advances that provide borrowers with the right to call, on predetermined option exercise dates, the advance prior to maturity without incurring prepayment or termination fees (callable advances). In exchange for receiving the right to call the advance on a predetermined call schedule, the borrower pays a higher fixed rate for the advance relative to an equivalent maturity, noncallable, fixed-rate advance. If the call option is exercised, replacement funding may be available. Other advances may only be prepaid by paying a fee (a prepayment fee) that makes us financially indifferent to the prepayment of the advance. At both September 30, 2013, and December 31, 2012, we had callable advances outstanding totaling $32.5 million.
	Interest-Rate-Payment Terms. The following table details interest-rate-payment types for our outstanding advances (dollars in thousands):
	Par value of advances	September 30, 2013				December 31, 2012
	Fixed-rate	$	21,789,381			$	19,179,459
	Variable-rate	418,956				1,090,393
	Total par value	$	22,208,337			$	20,269,852
	Credit Risk Exposure and Security Terms. Our potential credit risk from advances is principally concentrated in commercial banks, insurance companies, savings institutions, and credit unions. At September 30, 2013, and December 31, 2012, we had $3.7 billion and $1.8 billion, respectively, of advances issued to members with at least $1.0 billion of advances outstanding. These advances were made to two borrowers at September 30, 2013, and one borrower at December 31, 2012, representing 16.7 percent and 9.0 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. We record prepayment fees received from borrowers on prepaid advances net of any associated basis adjustments related to hedging activities on those advances and net of deferred prepayment fees on advance prepayments considered to be loan modifications. Additionally, for certain advances products, the prepayment-fee provisions of the advance agreement could result in either a payment from the borrower or to the borrower when such an advance is prepaid, based upon market conditions at the time of prepayment (referred to as a symmetrical prepayment fee). Advances with a symmetrical prepayment fee provision are hedged with derivatives containing offsetting terms, so that we are financially indifferent to the borrower's decision to prepay such advances. The net amount of prepayment fees is reflected as interest income in the statement of operations.
	For the three and nine months ended September 30, 2013 and 2012, net advance prepayment fees recognized in income are reflected in the following table (dollars in thousands):
			For the Three Months Ended September 30,								For the Nine Months Ended September 30,
			2013				2012				2013				2012
	Prepayment fees received from borrowers		$	12,270			$	23,247			$	40,644			$	91,471
	Less: hedging fair-value adjustments on prepaid advances		(6,123		)		(11,125		)		(19,330		)		(50,270		)
	Less: net premiums associated with prepaid advances		(430		)		(1,433		)		(4,424		)		(1,770		)
	Less: deferred recognition of prepayment fees received from borrowers on advance prepayments deemed to be loan modifications		(3,896		)		(2,893		)		(5,298		)		(4,580		)
	Prepayment fees recognized in income on advance restructurings deemed to be extinguishments		—				4,078				6,845				9,497
	Net prepayment fees recognized in income		$	1,821			$	11,874			$	18,437			$	44,348

Mortgage_Loans_Held_for_Portfo

Mortgage Loans Held for Portfolio	9 Months Ended
	Sep. 30, 2013
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 are either guaranteed or insured by federal agencies, as is the case with government mortgage loans, or are credit-enhanced by the related participating financial institution, as is the case with conventional mortgage loans. All such investments are held for portfolio. The mortgage loans are typically originated and credit-enhanced by the related participating financial institution. The majority of these loans are serviced by the originating institution or an affiliate thereof. However, a portion of these loans are sold servicing-released by the participating financial institution and serviced by a third-party servicer.
	The following table presents certain characteristics of the mortgage loans in which we have invested (dollars in thousands):
		September 30, 2013			December 31, 2012
	Real estate
	Fixed-rate 15-year single-family mortgages	$	614,920		$	679,153
	Fixed-rate 20- and 30-year single-family mortgages	2,730,363			2,743,955
	Premiums	59,679			60,573
	Discounts	(3,519		)	(4,021		)
	Deferred derivative gains, net	1,625			3,650
	Total mortgage loans held for portfolio	3,403,068			3,483,310
	Less: allowance for credit losses	(1,957		)	(4,414		)
	Total mortgage loans, net of allowance for credit losses	$	3,401,111		$	3,478,896
	The following table details the par value of mortgage loans held for portfolio (dollars in thousands):
		September 30, 2013			December 31, 2012
	Conventional mortgage loans	$	2,905,884		$	2,979,067
	Government mortgage loans	439,399			444,041
	Total par value	$	3,345,283		$	3,423,108
	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 FHLBank of Chicago.

Allowance_for_Credit_Losses

Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2013
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 2012 Annual Report.
	Secured Member Credit Products
	We manage our credit exposure to secured member credit products through an integrated approach that generally provides for a credit limit to be established for each borrower, includes an ongoing review of each borrower's financial condition, and is coupled with collateral and lending policies that are intended to limit risk of loss while balancing borrowers' needs for a reliable source of funding.
	We continue to evaluate and make changes to our collateral guidelines based on market conditions. At September 30, 2013, and December 31, 2012, we did not have any secured member credit products that were past due, on nonaccrual status, or considered impaired. In addition, there were no troubled debt restructurings related to credit products during the nine months ended September 30, 2013 and 2012.
	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 secured member credit products at September 30, 2013, and December 31, 2012. At September 30, 2013, and December 31, 2012, 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 on our secured member credit exposure to credit products, see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2012 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 September 30, 2013, and December 31, 2012. 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 on our government mortgage loans, see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2012 Annual Report.
	Conventional Mortgage Loans Held for Portfolio
	We periodically adjust the key inputs to our method for determining our allowance for credit losses based on our investments in conventional mortgage loans. These adjustments are intended to align our loss projections with the market conditions that are relevant to these loans. The key inputs to our method include past and current performance of these loans (including portfolio-delinquency and default-migration statistics), overall loan-portfolio-performance characteristics (including loss-mitigation features, especially credit enhancements, as discussed below under — Credit Enhancements), and loss-severity estimates for these loans. We update the following inputs at least once per quarter: current outstanding loan amounts, delinquency statistics of the portfolio, and related loss-mitigation features (including credit-enhancement and estimated credit-enhancement fee-recovery amounts) for all master commitments. A master commitment is a document which provides the general terms under which the participating financial institution will deliver mortgage loans, including a maximum loan delivery amount, maximum credit enhancement, if applicable, and expiration date. Additionally, we review our method's default migration factor on a quarterly basis to determine if the portfolio has exhibited any change in loans migrating from current to delinquent or from delinquent to default and make adjustments as appropriate.
	We use a third-party loan-loss projection model to determine our loss-severity estimates for our master commitments. The inputs to this model include loan-related characteristics (such as property types and locations), industry data (such as foreclosure timelines and associated costs), and current and projected housing prices. We update our loss-severity estimates each quarter.
	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 nine months ended September 30, 2013 and 2012, as well as the recorded investment in mortgage loans by impairment methodology at September 30, 2013 and 2012 (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 September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Allowance for credit losses
	Balance at beginning of period	$	1,999		$	6,114		$	4,414		$	7,800
	Charge-offs	(125		)	(77		)	(310		)	(229		)
	Recoveries	—			—			47			—
	Provision for (reduction of) credit losses	83			(523		)	(2,194		)	(2,057		)
	Balance at end of period	$	1,957		$	5,514		$	1,957		$	5,514
	Ending balance, individually evaluated for impairment	$	562		$	—		$	562		$	—
	Ending balance, collectively evaluated for impairment	$	1,395		$	5,514		$	1,395		$	5,514
	Recorded investment, end of period (1)
	Individually evaluated for impairment	$	6,743		$	2,256		$	6,743		$	2,256
	Collectively evaluated for impairment	$	2,961,768		$	3,041,201		$	2,961,768		$	3,041,201
	_________________________
	-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.
	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 September 30, 2013, and December 31, 2012 (dollars in thousands):
		September 30, 2013
		Recorded Investment in Conventional Mortgage Loans			Recorded Investment in Government Mortgage Loans			Total
	Past due 30-59 days delinquent	$	32,392		$	15,389		$	47,781
	Past due 60-89 days delinquent	13,091			3,618			16,709
	Past due 90 days or more delinquent	45,109			19,489			64,598
	Total past due	90,592			38,496			129,088
	Total current loans	2,877,919			413,215			3,291,134
	Total mortgage loans	$	2,968,511		$	451,711		$	3,420,222
	Other delinquency statistics
	In process of foreclosure, included above (1)	$	17,945		$	6,709		$	24,654
	Serious delinquency rate (2)	1.55		%	4.31		%	1.91		%
	Past due 90 days or more still accruing interest	$	—		$	19,489		$	19,489
	Loans on nonaccrual status (3)	$	45,409		$	—		$	45,409
	_______________________
	-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, 2012
		Recorded Investment in Conventional Mortgage Loans			Recorded Investment in Government Mortgage Loans			Total
	Past due 30-59 days delinquent	$	36,720		$	14,451		$	51,171
	Past due 60-89 days delinquent	12,339			4,459			16,798
	Past due 90 days or more delinquent	50,927			23,715			74,642
	Total past due	99,986			42,625			142,611
	Total current loans	2,944,184			414,400			3,358,584
	Total mortgage loans	$	3,044,170		$	457,025		$	3,501,195
	Other delinquency statistics
	In process of foreclosure, included above (1)	$	23,580		$	11,022		$	34,602
	Serious delinquency rate (2)	1.7		%	5.19		%	2.15		%
	Past due 90 days or more still accruing interest	$	—		$	23,715		$	23,715
	Loans on nonaccrual status (3)	$	51,609		$	—		$	51,609
	_______________________
	-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. The following tables present the recorded investment, par value and any related allowance for impaired loans individually assessed for impairment at September 30, 2013, and December 31, 2012, and the average recorded investment and interest income recognized on these loans during the three and nine months ended September 30, 2013 and 2012 (dollars in thousands).
		As of September 30, 2013									As of December 31, 2012
		Recorded Investment			Par Value			Related Allowance			Recorded Investment		Par Value		Related Allowance
Individually evaluated impaired mortgage loans with no related allowance		$	3,524		$	3,479		$	—		$	2,752	$	2,726	$	—
Individually evaluated impaired mortgage loans with a related allowance		3,219			3,197			562			—		—		—
Total individually evaluated impaired mortgage loans		$	6,743		$	6,676		$	562		$	2,752	$	2,726	$	—
		For the Three Months Ended September 30,
		2013						2012
		Average Recorded Investment			Interest Income Recognized			Average Recorded Investment			Interest Income Recognized
Individually evaluated impaired mortgage loans with no related allowance		$	3,516		$	31		$	2,282		$	27
Individually evaluated impaired mortgage loans with a related allowance		4,144			1			—			—
Total individually evaluated impaired mortgage loans		$	7,660		$	32		$	2,282		$	27
		For the Nine Months Ended September 30,
		2013						2012
		Average Recorded Investment			Interest Income Recognized			Average Recorded Investment			Interest Income Recognized
Individually evaluated impaired mortgage loans with no related allowance		$	3,315		$	140		$	1,513		$	54
Individually evaluated impaired mortgage loans with a related allowance		2,072			3			—			—
Total individually evaluated impaired mortgage loans		$	5,387		$	143		$	1,513		$	54
Credit Enhancements. Our allowance for credit losses factors in the credit enhancements associated with conventional mortgage loans under the MPF program. These credit enhancements apply after the homeowner's equity is exhausted and can include primary and/or supplemental mortgage insurance or other kinds of credit enhancement. The credit enhancement amounts needed to protect us against credit losses are determined through the use of a model. Any incurred losses that would be recovered from the credit enhancements are not reserved as part of our allowance for loan losses. In such cases, a receivable is generally established to reflect the expected recovery from credit-enhancement arrangements.
Conventional mortgage loans are required to be credit enhanced so that the risk of loss is limited to the losses equivalent to an investor in a double-A rated MBS at the time of purchase. We share the risk of credit losses on our investments in mortgage loans with the related participating financial institution by structuring potential losses on these investments into layers with respect to each master commitment. We analyze the risk characteristics of our mortgage loans using a third-party model to determine the credit enhancement amount. This credit-enhancement amount is broken into a first-loss account and a credit-enhancement obligation of each participating financial institution, which is calculated based on the risk analysis to equal the difference between the amounts needed for the master commitment to have a rating equivalent to a double-A rated MBS and our initial first-loss account exposure.
Participating financial institutions are paid a credit-enhancement fee for assuming credit risk and in some instances all or a portion of the credit-enhancement fee may be performance-based. For certain MPF products, our losses incurred under the first-loss account can be mitigated by withholding future performance-based credit-enhancement fees that would otherwise be payable to the participating financial institutions. We record credit-enhancement fees paid to participating financial institutions as a reduction to mortgage-loan-interest income. We incurred credit-enhancement fees of $773,000 and $782,000 during the three months ended September 30, 2013 and 2012, respectively. For the nine months ended September 30, 2013 and 2012, we incurred credit enhancement fees of $2.4 million and $2.3 million, respectively.
For additional information related to credit enhancements and the first-loss account, see Item 8 — Financial Statements and Supplementary Data — Note 10 — Allowance for Credit Losses in the 2012 Annual Report.
Withheld performance-based credit-enhancement fees can mitigate losses from our investments in mortgage loans and therefore we consider our expectations for each master commitment for such withheld fees in determining the allowance for loan losses. More specifically, we determine the amount of credit-enhancement fees available to mitigate losses as follows: accrued credit-enhancement fees to be paid to participating financial institutions; plus projected credit-enhancement fees to be paid to the participating financial institutions using the weighted average life of the loans within each relevant master commitment (the CE Fees Estimation Factor); minus any losses incurred or expected to be incurred. Previously, for the year ended December 31, 2012, and the quarter ended March 31, 2013, we had determined the CE Fees Estimation Factor using the projected credit-enhancement fees to be paid to the participating financial institutions over the next 12 months. We believe that our current approach is an improvement from our prior estimation method. Available credit-enhancement fees cannot be shared between master commitments and, as a result, some master commitments may have sufficient credit-enhancement fees to recover all losses while other master commitments may not.
The following table demonstrates the impact on our estimate of the allowance for credit losses resulting from the loss-mitigating features of conventional mortgage loans (dollars in thousands).
	September 30, 2013			December 31, 2012
Total estimated losses	$	3,902		$	10,053
Less: estimated losses in excess of the first-loss account, to be absorbed by participating financial institutions	(1,208		)	(5,010		)
Less: estimated performance-based credit-enhancement fees available for recapture	(737		)	(629		)
Net allowance for credit losses	$	1,957		$	4,414
Troubled Debt Restructurings. We consider a troubled debt restructuring of a financing receivable to have occurred when we grant a concession to a borrower that we would not otherwise consider for economic or legal reasons related to the borrower's financial difficulties. We classify troubled debt restructurings at the end of the three-month trial period for troubled debt restructurings involved in our modification program for conventional mortgage loans.
We also consider troubled debt restructurings to have occurred when a borrower has filed for bankruptcy under Chapter 7 of the U.S. Bankruptcy Code (Chapter 7 bankruptcy) pursuant to which the bankruptcy court has discharged the borrower's obligation to us and the borrower has not reaffirmed the debt.
A mortgage loan considered to be a troubled debt restructuring is individually evaluated for impairment when determining its related allowance for credit losses. Credit loss is measured by factoring in expected cash shortfalls (i.e., loss severity rate) incurred as of the reporting date as well as the economic loss attributable to delaying the original contractual principal and interest due dates, if applicable. During the three months ended September 30, 2013, we had one troubled debt restructuring. The recorded investment in the troubled debt restructuring post-modification was $121,000 as of the modification date. During the three months ended September 30, 2012, we had four troubled debt restructurings. The recorded investment in these troubled debt restructurings post-modification was $715,000 as of the modification date.
During the nine months ended September 30, 2013, we had four troubled debt restructurings. The recorded investment in these troubled debt restructurings post-modification was $880,000 as of the modification date.
During the nine months ended September 30, 2012, we had 10 troubled debt restructurings. The recorded investment in these troubled debt restructurings post-modification was $1.9 million as of the modification date.
As of September 30, 2013, we had mortgage loans with a recorded investment of $3.6 million that are considered troubled debt restructurings of which $2.9 million were performing and $661,000 were nonperforming. As of December 31, 2012, we had mortgage loans with a recorded investment of $2.8 million that are considered troubled debt restructurings, of which $1.9 million were performing and $912,000 were nonperforming.
As of September 30, 2013, we had two troubled debt restructurings with a recorded investment of $509,000 that resulted from borrowers that filed for Chapter 7 bankruptcy in which the bankruptcy court discharged the borrowers' obligations to us and the borrowers did not reaffirm the debt. We did not record an additional impairment charge or increase our allowance for credit losses since there are sufficient credit-enhancement fees remaining for the master commitment associated with these loans.
For the nine months ended September 30, 2013, none of our investments in conventional mortgage loans modified as troubled debt restructurings within the previous 12 months experienced a payment default. A loan modified as a troubled debt restructuring is considered to be in default if its contractual principal or interest is 60 days or more past due.
REO. At September 30, 2013, and December 31, 2012, we had $6.0 million and $8.7 million, respectively, in assets classified as REO. During the nine months ended September 30, 2013 and 2012, we sold REO assets with a recorded carrying value of $9.9 million and $8.2 million, respectively. Upon the sale of these properties, and inclusive of any proceeds received from primary mortgage-insurance coverage, we recognized net losses totaling $3.0 million and net gains totaling $308,000 during the nine months ended September 30, 2013 and 2012, respectively. Gains and losses on the sale of REO assets are recorded in other income.

Derivatives_and_Hedging_Activi

Derivatives and Hedging Activities	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivatives and Hedging Activities [Text Block]	'
	Derivatives and Hedging Activities
	We transact most of our derivatives with large banks and major broker-dealers. Some of these banks and broker-dealers or their affiliates buy, sell, and distribute COs. Derivative transactions may be either over-the-counter with a counterparty (bilateral derivatives) or cleared through a futures commission merchant (a clearing member) with a derivatives clearing organization (DCO) as the counterparty (cleared derivatives). We are not a derivative dealer and do not trade derivatives for short-term profit.
	Financial Statement Impact and Additional Financial Information. The notional amount of derivatives is a factor in determining periodic interest payments or cash flows received and paid. However, the notional amount of derivatives represents neither the actual amounts exchanged nor our overall exposure to credit and market risk. The risks of derivatives can be measured meaningfully on a portfolio basis that takes into account the counterparties, the types of derivatives, the items being hedged, and any offsets between the derivatives and the items being hedged.
	The following table presents the fair value of derivative instruments as of September 30, 2013 (dollars in thousands):
		Notional				Derivative				Derivative
		Amount of				Assets				Liabilities
		Derivatives
	Derivatives designated as hedging instruments
	Interest-rate swaps	$	12,359,840			$	45,740			$	(619,480	)
	Forward-start interest-rate swaps	1,250,000				—				(53,843		)
	Total derivatives designated as hedging instruments	13,609,840				45,740				(673,323		)
	Derivatives not designated as hedging instruments
	Interest-rate swaps	1,273,500				665				(22,934		)
	Interest-rate caps or floors	300,000				105				—
	Mortgage-delivery commitments (1)	18,107				164				—
	Total derivatives not designated as hedging instruments	1,591,607				934				(22,934		)
	Total notional amount of derivatives	$	15,201,447
	Total derivatives before netting adjustments					46,674				(696,257		)
	Netting adjustments (2)					(46,476		)		46,476
	Cash collateral and related accrued interest					3,920				—
	Derivative assets and derivative liabilities					$	4,118			$	(649,781	)
	_______________________
	(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.
	The following table presents the fair value of derivative instruments as of December 31, 2012 (dollars in thousands):
		Notional				Derivative				Derivative
		Amount of				Assets				Liabilities
		Derivatives
	Derivatives designated as hedging instruments
	Interest-rate swaps	$	14,595,750			$	87,463			$	(896,248	)
	Forward-start interest-rate swaps	1,250,000				—				(64,897		)
	Total derivatives designated as hedging instruments	15,845,750				87,463				(961,145		)
	Derivatives not designated as hedging instruments
	Interest-rate swaps	1,364,500				849				(34,217		)
	Interest-rate caps or floors	300,000				50				—
	Mortgage-delivery commitments (1)	30,938				35				(16		)
	Total derivatives not designated as hedging instruments	1,695,438				934				(34,233		)
	Total notional amount of derivatives	$	17,541,188
	Total derivatives before netting and collateral adjustments					88,397				(995,378		)
	Netting adjustments (2)					(88,286		)		88,286
	Derivative assets and derivative liabilities					$	111			$	(907,092	)
	_______________________
	-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.
	Net (losses) gains on derivatives and hedging activities recorded in Other Income (Loss) for the three and nine months ended September 30, 2013 and 2012, were as follows (dollars in thousands).
			For the Three Months Ended September 30,								For the Nine Months Ended September 30,
			2013				2012				2013				2012
	Derivatives and hedged items in fair-value hedging relationships:
	Interest-rate swaps		$	491			$	597			$	1,827			$	255
	Cash flow hedge ineffectiveness		13				—				53				—
	Derivatives not designated as hedging instruments:
	Economic hedges:
	Interest-rate swaps		(1,611		)		(3,243		)		5,720				(10,105		)
	Interest-rate caps or floors		(67		)		(207		)		55				(745		)
	Mortgage-delivery commitments		104				767				(1,480		)		2,086
	Total net gains related to derivatives not designated as hedging instruments		(1,574		)		(2,683		)		4,295				(8,764		)
	Net (losses) gains on derivatives and hedging activities		$	(1,070	)		$	(2,086	)		$	6,175			$	(8,509	)
	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 nine months ended September 30, 2013 and 2012 (dollars in thousands):
		For the Three Months Ended September 30, 2013
		Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
		Derivative				Hedged Item				Hedge				Derivatives on
										Ineffectiveness				Net Interest
														Income (1)
Hedged Item:
Advances	$	21,441			$	(21,300	)		$	141			$	(36,468	)
Investments	16,806				(16,418		)		388				(9,437		)
Deposits	(372		)		372				—				395
COs – bonds	3,407				(3,445		)		(38		)		13,640
Total	$	41,282			$	(40,791	)		$	491			$	(31,870	)
	For the Three Months Ended September 30, 2012
	Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
	Derivative				Hedged Item				Hedge				Derivatives on
									Ineffectiveness				Net Interest
													Income (1)
Hedged Item:
Advances	$	1,375			$	(1,116	)		$	259			$	(45,869	)
Investments	7,645				(7,183		)		462				(10,256		)
Deposits	(293		)		293				—				385
COs – bonds	(6,947		)		6,823				(124		)		21,003
Total	$	1,780			$	(1,183	)		$	597			$	(34,737	)
______________
(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.
	For the Nine Months Ended September 30, 2013
	Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
	Derivative				Hedged Item				Hedge				Derivatives on
									Ineffectiveness				Net Interest
													Income (1)
Hedged Item:
Advances	$	176,729			$	(175,986	)		$	743			$	(114,058	)
Investments	111,118				(109,922		)		1,196				(29,004		)
Deposits	(1,150		)		1,150				—				1,183
COs – bonds	(65,727		)		65,615				(112		)		52,616
Total	$	220,970			$	(219,143	)		$	1,827			$	(89,263	)
	For the Nine Months Ended September 30, 2012
	Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
	Derivative				Hedged Item				Hedge				Derivatives on
									Ineffectiveness				Net Interest
													Income (1)
Hedged Item:
Advances	$	55,505			$	(56,798	)		$	(1,293	)		$	(149,548	)
Investments	(5,066		)		6,321				1,255				(30,626		)
Deposits	(908		)		908				—				1,151
COs – bonds	(109,114		)		109,407				293				68,893
Total	$	(59,583	)		$	59,838			$	255			$	(110,130	)
______________
(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 gain or loss recognized in other comprehensive income for forward-start interest-rate swaps associated with CO bond hedged items in cash-flow hedging relationships was a loss of $6.2 million and a loss of $10.4 million for the three months ended September 30, 2013 and 2012, respectively, and was a gain of $11.0 million and a loss of $32.9 million for the nine months ended September 30, 2013 and 2012, respectively.
For the nine months ended September 30, 2013 and 2012, 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 September 30, 2013, the maximum length of time over which we are hedging our exposure to the variability in future cash flows for forecasted transactions is six years.
As of September 30, 2013, the amount of deferred net losses on derivative instruments accumulated in other comprehensive loss, related to cash flow hedges expected to be reclassified to earnings during the next 12 months is $3.3 million.
Managing Credit Risk on Derivatives. We are subject to credit risk on our hedging activities due to the risk of nonperformance by nonmember counterparties (including DCOs and their clearing members acting as agent to the DCOs as well as bilateral counterparties) to the derivative agreements. We manage credit risk through credit analysis, collateral requirements and adherence to the requirements set forth in our policies, U.S. Commodity Futures Trading Commission (the CFTC) regulations, and FHFA regulations. All counterparties must execute master-netting agreements prior to entering into any non-cleared derivative (bilateral derivative) with us.
Our master-netting agreements for bilateral derivatives contain bilateral-collateral exchange agreements that require that credit exposure beyond a defined threshold amount be secured by readily marketable, U.S. Treasury or GSE securities, or cash. The level of these collateral threshold amounts varies according to the counterparty's Standard & Poor's Ratings Services (S&P) or Moody's Investors Service (Moody's) long-term credit ratings. Credit exposures are then measured daily and adjustments to collateral positions are made in accordance with the terms of the master-netting agreements. These master-netting agreements also contain bilateral ratings-tied termination events permitting us to terminate all outstanding agreements with a counterparty in the event of a specified rating downgrade by Moody's or S&P. Based on credit analyses and collateral requirements, we do not anticipate any credit losses on our derivative agreements.
Certain 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 or S&P to a certain level, we are required to deliver additional collateral on derivative instruments 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 derivative instruments with these provisions that were in a net-liability position (before cash collateral and related accrued interest) at September 30, 2013, was $649.8 million for which we had delivered collateral with a post-haircut value of $502.8 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 derivatives counterparties could have required us to deliver based on incremental credit rating downgrades at September 30, 2013 (dollars in thousands).
Post-haircut Value of Incremental Collateral to be Delivered
as of September 30, 2013
Ratings Downgrade (1)
From		To		Incremental Collateral(2)
AA+		AA or AA-		$	39,587
AA-		A+, A or A-		53,117
A-		below A-		39,152
_______________________
-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 $14.4 million could be called by counterparties as of September 30, 2013, 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.
We execute bilateral derivatives with nonmember counterparties with long-term ratings of single-A (or equivalent) or better by the major NRSROs at the time of the transaction, although risk-reducing trades (trades that reduce our net credit exposure or exposure sensitivity to the counterparty) are permitted for counterparties whose ratings have fallen below these ratings. Some of these counterparties or their affiliates buy, sell, and distribute COs. See Note 12 — Consolidated Obligations for additional information. See also Note 18 — Commitments and Contingencies for a discussion of assets we have pledged to these counterparties.
For cleared derivatives, the DCO is our counterparty. We post initial margin and exchange variation margin through a clearing member who acts as our agent to the DCO and who guarantees our performance to the DCO, subject to the terms of relevant agreements. These arrangements expose us to institutional credit risk in the event that one of our agents (clearing members) or one of the DCOs fails to meet its obligations. The use of cleared derivatives is intended to mitigate credit risk exposure because the DCO, which is fully secured at all times through margin maintained with its clearing members, is substituted for the credit risk exposure of individual counterparties in bilateral derivatives and collateral is posted at least once daily for changes in the value of cleared derivatives through a clearing member. We have analyzed the rights, rules and regulations governing our cleared derivatives and determined that those rights, rules and regulations should result in a net claim through each of our clearing members with the related DCO upon an event of default including a bankruptcy, insolvency or similar proceeding involving the DCO or one of our clearing members, or both. For this purpose, net claim generally means a single net amount reflecting the aggregation of all amounts indirectly owed by us to the relevant DCO and indirectly payable to us from the relevant DCO. Based on this analysis, we are presenting a net derivative receivable or payable for all of our transactions through a particular clearing member with a particular DCO.
Offsetting of Certain Derivative Assets and Derivative Liabilities. We have certain derivative instruments that are subject to offset under master netting arrangements or by operation of law. We have elected to offset our derivative asset and liability positions, as well as cash collateral and associated accrued interest received or pledged, when we have the legal right of offset under these master agreements or by operation of law.
The following presents separately the fair value of derivative instruments 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 September 30, 2013, and December 31, 2012 (dollars in thousands).
		30-Sep-13
		Derivative Assets				Derivative Liabilities
Derivative instruments with legal right of offset
Gross recognized amount
Bilateral derivatives		$	43,620			$	(693,225	)
Cleared derivatives		2,890				(3,032		)
Total gross recognized amount		46,510				(696,257		)
Gross amounts of netting adjustments and cash collateral
Bilateral derivatives		(43,444		)		43,444
Cleared derivatives		888				3,032
Total gross amounts of netting adjustments and cash collateral		(42,556		)		46,476
Net amounts after netting adjustments and cash collateral
Bilateral derivatives		176				(649,781		)
Cleared derivatives		3,778				—
Total net amounts after netting adjustments and cash collateral		3,954				(649,781		)
Derivative instruments without legal right of offset
Bilateral derivatives (1)		164				—
Total derivative instruments without legal right of offset		164				—
Total derivative assets and total derivative liabilities
Bilateral derivatives		340				(649,781		)
Cleared derivatives		3,778				—
Total derivative assets and total derivative liabilities		4,118				(649,781		)
Non-cash collateral received or pledged not offset (2)
Can be sold or repledged
Bilateral derivatives		—				73,770
Total can be sold or repledged		—				73,770
Cannot be sold or repledged
Bilateral derivatives		—				448,670
Total cannot be sold or repledged		—				448,670
Net unsecured amount
Bilateral derivatives		340				(127,341		)
Cleared derivatives		3,778				—
Total net unsecured amount		$	4,118			$	(127,341	)
_______________________
-1	Consists of mortgage delivery commitments.
-2	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At September 30, 2013, we had additional net exposure of $6.8 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.
		31-Dec-12
		Derivative Assets				Derivative Liabilities
Derivative instruments with legal right of offset
Gross recognized amount		$	88,362			$	(995,362	)
Gross amounts of netting adjustments and cash collateral		(88,286		)		88,286
Total net amounts after netting adjustments and cash collateral		76				(907,076		)
Derivative instruments without legal right of offset (1)		35				(16		)
Total derivative assets and total derivative liabilities		111				(907,092		)
Non-cash collateral received or pledged not offset (2)
Collateral received or pledged - Can be sold or repledged		—				115,339
Collateral received or pledged - Cannot be sold or repledged		—				672,890
Net unsecured amount		$	111			$	(118,863	)
_______________________
-1	Consists of mortgage delivery commitments.
-2	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At December 31, 2012, we had additional net exposure of $18.0 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.

Deposits

Deposits	9 Months Ended
	Sep. 30, 2013
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.
	Deposits at September 30, 2013, and December 31, 2012, include hedging adjustments of $1.5 million and $2.7 million, respectively.
	The following table details interest-bearing and non-interest-bearing deposits (dollars in thousands):
		September 30, 2013		December 31, 2012
	Interest bearing
	Demand and overnight	$	529,641	$	530,887
	Term	20,919		21,638
	Other	3,247		4,915
	Non-interest bearing
	Other	16,549		37,528
	Total deposits	$	570,356	$	594,968
	The aggregate amount of time deposits with a denomination of $100,000 or more was $20.0 million as of September 30, 2013, and December 31, 2012.

Consolidated_Obligations

Consolidated Obligations	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Consolidated Obligations [Text Block]	'
	Consolidated Obligations
	COs consist of CO bonds and CO discount notes. CO bonds are issued primarily to raise intermediate- and long-term funds and are not subject to any statutory or regulatory limits on maturity. CO discount notes are issued to raise short-term funds and have original maturities of up to one year. These notes sell at less than their face amount and are redeemed at par value when they mature.
	COs - Bonds. The following table sets forth the outstanding CO bonds for which we were primarily liable at September 30, 2013, and December 31, 2012, by year of contractual maturity (dollars in thousands):
		September 30, 2013						December 31, 2012
	Year of Contractual Maturity	Amount			Weighted			Amount			Weighted
					Average						Average
					Rate (1)						Rate (1)
	Due in one year or less	$	8,452,690		1.08	%		$	8,344,355		1.67	%
	Due after one year through two years	3,738,790			2.1			5,447,000			1.36
	Due after two years through three years	3,426,190			2.24			3,482,025			2.44
	Due after three years through four years	2,508,440			1.92			1,975,360			2.34
	Due after four years through five years	1,983,770			2.31			3,122,805			2.22
	Thereafter	3,869,920			2.48			3,433,690			2.55
	Total par value	23,979,800			1.82	%		25,805,235			1.94	%
	Premiums	241,497						270,614
	Discounts	(20,826		)				(22,842		)
	Hedging adjustments	1,226						66,841
		$	24,201,697					$	26,119,848
	_______________________
	(1)          The CO bonds' weighted-average rate excludes concession fees.
	Our CO bonds outstanding at September 30, 2013, and December 31, 2012, included (dollars in thousands):
		September 30, 2013			December 31, 2012
	Par value of CO bonds
	Noncallable and non-putable	$	21,546,800		$	23,732,235
	Callable	2,433,000			2,073,000
	Total par value	$	23,979,800		$	25,805,235
	The following is a summary of the CO bonds for which we are primarily liable at September 30, 2013, and December 31, 2012, by year of contractual maturity or next call date for callable CO bonds (dollars in thousands):
	Year of Contractual Maturity or Next Call Date		September 30, 2013			December 31, 2012
	Due in one year or less		$	10,735,690		$	10,222,355
	Due after one year through two years		3,778,790			5,547,000
	Due after two years through three years		3,481,190			3,537,025
	Due after three years through four years		2,533,440			1,975,360
	Due after four years through five years		1,748,770			2,917,805
	Thereafter		1,701,920			1,605,690
	Total par value		$	23,979,800		$	25,805,235
	The following table sets forth the CO bonds for which we were primarily liable by interest-rate-payment type at September 30, 2013, and December 31, 2012 (dollars in thousands):
		September 30, 2013			December 31, 2012
	Par value of CO bonds
	Fixed-rate	$	20,124,800		$	21,385,235
	Simple variable-rate	2,970,000			3,570,000
	Step-up	885,000			850,000
	Total par value	$	23,979,800		$	25,805,235
	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)
	30-Sep-13	$	10,475,911		$	10,476,500			0.05	%
	31-Dec-12	$	8,639,048		$	8,640,000			0.09	%
	_______________________
	(1)          The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable_Housing_Program

Affordable Housing Program	9 Months Ended
	Sep. 30, 2013
Affordable Housing Program [Abstract]	'
Affordable Housing Program [Text Block]	'
	Affordable Housing Program
	We charge the amount set aside for the AHP to income and recognize it as a liability. We then reduce the AHP liability as the funds are disbursed. We had outstanding principal in AHP advances of $97.6 million and $99.9 million at September 30, 2013, and December 31, 2012, respectively.
	The following table presents a roll-forward of the AHP liability for the nine months ended September 30, 2013, and year ended December 31, 2012 (dollars in thousands):
		September 30, 2013			December 31, 2012
	Balance at beginning of year	$	50,545		$	34,241
	AHP expense for the period	14,343			23,122
	AHP direct grant disbursements	(8,842		)	(5,415		)
	AHP subsidy for AHP advance disbursements	(327		)	(1,477		)
	Return of previously disbursed grants and subsidies	42			74
	Balance at end of period	$	55,761		$	50,545

Capital

Capital	9 Months Ended
	Sep. 30, 2013
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, 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.
	3	Leverage capital. We are required to maintain at all times a leverage capital-to-assets ratio of at least five percent. A leverage capital-to-assets ratio is defined as permanent capital weighted 1.5 times divided by total assets.
	Mandatorily redeemable capital stock, which is classified as a liability under GAAP, is considered capital for determining our compliance with our regulatory capital requirements.
	The following tables demonstrate our compliance with our regulatory capital requirements at September 30, 2013, and December 31, 2012 (dollars in thousands):
	Risk-Based Capital Requirements	September 30,				December 31,
		2013				2012
	Permanent capital
	Class B capital stock	$	2,441,028			$	3,455,165
	Mandatorily redeemable capital stock	977,390				215,863
	Retained earnings	705,745				587,554
	Total permanent capital	$	4,124,163			$	4,258,582
	Risk-based capital requirement
	Credit-risk capital	$	419,065			$	473,233
	Market-risk capital	120,327				80,026
	Operations-risk capital	161,817				165,978
	Total risk-based capital requirement	$	701,209			$	719,237
	Permanent capital in excess of risk-based capital requirement	$	3,422,954			$	3,539,345
			September 30, 2013							December 31, 2012
			Required				Actual			Required			Actual
	Capital Ratio
	Risk-based capital		$	701,209			$	4,124,163		$	719,237		$	4,258,582
	Total regulatory capital		$	1,588,826			$	4,124,163		$	1,608,361		$	4,258,582
	Total capital-to-asset ratio		4		%		10.4		%	4		%	10.6		%
	Leverage Ratio
	Leverage capital		$	1,986,033			$	6,186,245		$	2,010,451		$	6,387,873
	Leverage capital-to-assets ratio		5		%		15.6		%	5		%	15.9		%
	Restricted Retained Earnings. Pursuant to a joint capital agreement among the FHLBanks, as amended (the Joint Capital Agreement), and our capital plan, we, together with the other FHLBanks, are required to contribute 20 percent of our quarterly net income to a restricted retained earnings account until the balance of that account equals at least one percent of the FHLBank's average balance of outstanding COs (excluding fair-value adjustments) for the calendar quarter. At September 30, 2013, our total contribution requirement totaled $358.1 million. As of September 30, 2013, and December 31, 2012, restricted retained earnings totaled $89.8 million and $64.4 million, respectively. These restricted retained earnings are not available to pay dividends.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2013
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 months ended September 30, 2013 and 2012 (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, June 30, 2012	$	(50,442	)	$	(420,392	)	$	(54,727	)	$	(2,881	)	$	(528,442	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized gains (losses)	17,525			—			(10,448		)	—			7,077
	Noncredit other-than-temporary impairment losses	—			(2,013		)	—			—			(2,013		)
	Accretion of noncredit loss	—			17,838			—			—			17,838
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			1,028			—			—			1,028
	Amortization - hedging activities (2)	—			—			4			—			4
	Amortization - pension and postretirement benefits (3)	—			—			—			(166		)	(166		)
	Other comprehensive income (loss)	17,525			16,853			(10,444		)	(166		)	23,768
	Balance, September 30, 2012	$	(32,917	)	$	(403,539	)	$	(65,171	)	$	(3,047	)	$	(504,674	)
	Balance, June 30, 2013	$	(67,119	)	$	(354,716	)	$	(47,846	)	$	(4,421	)	$	(474,102	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized losses	(17,195		)	—			(6,173		)	—			(23,368		)
	Noncredit other-than-temporary impairment losses	—			—			—			—			—
	Accretion of noncredit loss	—			14,256			—			—			14,256
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			1,448			—			—			1,448
	Amortization - hedging activities (2)	—			—			4			—			4
	Amortization - pension and postretirement benefits (3)	—			—			—			(323		)	(323		)
	Other comprehensive (loss)income	(17,195		)	15,704			(6,169		)	(323		)	(7,983		)
	Balance, September 30, 2013	$	(84,314	)	$	(339,012	)	$	(54,015	)	$	(4,744	)	$	(482,085	)
	_______________________
	(1) Recorded in net amount of impairment losses reclassified (from) to accumulated other comprehensive loss in the statement of operations.
	(2) Recorded in net gains on derivatives and hedging activities in the statement of operations.
	(3) Recorded in other operating expenses in the statement of operations.
	The following table presents a summary of changes in accumulated other comprehensive loss for the nine months ended September 30, 2013 and 2012 (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, December 31, 2011	$	(48,560	)	$	(450,996	)	$	(32,308	)	$	(2,547	)	$	(534,411	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized gains (losses)	15,643			—			(32,874		)	—			(17,231		)
	Noncredit other-than-temporary impairment losses	—			(10,931		)	—			—			(10,931		)
	Accretion of noncredit loss	—			56,131			—			—			56,131
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			2,257			—			—			2,257
	Amortization - hedging activities (2)	—			—			11			—			11
	Amortization - pension and postretirement benefits (3)	—			—			—			(500		)	(500		)
	Other comprehensive income (loss)	15,643			47,457			(32,863		)	(500		)	29,737
	Balance, September 30, 2012	$	(32,917	)	$	(403,539	)	$	(65,171	)	$	(3,047	)	$	(504,674	)
	Balance, December 31, 2012	$	(22,643	)	$	(385,175	)	$	(65,027	)	$	(3,775	)	$	(476,620	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized (losses) gains	(61,671		)	—			11,001			—			(50,670		)
	Noncredit other-than-temporary impairment losses	—			(63		)	—			—			(63		)
	Accretion of noncredit loss	—			44,000			—			—			44,000
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			2,226			—			—			2,226
	Amortization - hedging activities (2)	—			—			11			—			11
	Amortization - pension and postretirement benefits (3)	—			—			—			(969		)	(969		)
	Other comprehensive (loss)income	(61,671		)	46,163			11,012			(969		)	(5,465		)
	Balance, September 30, 2013	$	(84,314	)	$	(339,012	)	$	(54,015	)	$	(4,744	)	$	(482,085	)
	_______________________
	(1) Recorded in net amount of impairment losses reclassified (from) to accumulated other comprehensive loss in the statement of operations.
	(2) Recorded in net gains on derivatives and hedging activities in the statement of operations.
	(3) Recorded in other operating expenses in the statement of operations.

Employee_Retirement_Plans

Employee Retirement Plans	9 Months Ended
	Sep. 30, 2013
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, and the Internal Revenue Code. Accordingly, certain multiemployer plan disclosures, including the certified zone status, are not applicable to the Pentegra Defined Benefit Plan. Under the Pentegra Defined Benefit Plan, contributions made by a participating employer may be used to provide benefits to employees of other participating employers since assets contributed by an employer are not segregated in a separate account or restricted to provide benefits only to employees of that employer. Also, in the event a participating employer is unable to meet its contribution requirements, the required contributions for the other participating employers could increase proportionately. The plan covers substantially all of our officers and employees. The following table sets forth our net pension costs under the Pentegra Defined Benefit Plan (dollars in thousands):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Net pension cost	$	880		$	1,104		$	1,362		$	3,212
	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. Our obligation from this plan was $4.7 million and $3.6 million at September 30, 2013, and December 31, 2012, respectively. We maintain a rabbi trust intended to satisfy future benefit obligations.
	The following table sets forth expenses relating to our defined contribution plans (dollars in thousands):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Qualified Defined Contribution Plan - Pentegra Defined Contribution Plan	$	215		$	232		$	699		$	713
	Nonqualified Defined Contribution Plan - Thrift Benefit Equalization Plan	16			11			120			80
	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.
	In connection with the nonqualified supplemental defined benefit retirement plan and postretirement benefits, we recorded the following amounts as of September 30, 2013, and December 31, 2012 (dollars in thousands):
		Nonqualified Supplemental Defined Benefit Retirement Plan						Postretirement Benefits
		September 30, 2013			December 31, 2012			September 30, 2013			December 31, 2012
	Change in benefit obligation (1)
	Benefit obligation at beginning of year	$	7,969		$	5,901		$	721		$	634
	Service cost	419			418			24			32
	Interest cost	271			293			22			28
	Actuarial loss	1,570			1,657			(1		)	45
	Benefits paid	(254		)	(300		)	(14		)	(18		)
	Benefit obligation at end of period	9,975			7,969			752			721
	Change in plan assets
	Fair value of plan assets at beginning of year	—			—			—			—
	Employer contribution	254			300			14			18
	Benefits paid	(254		)	(300		)	(14		)	(18		)
	Fair value of plan assets at end of period	—			—			—			—
	Funded status at end of period	$	(9,975	)	$	(7,969	)	$	(752	)	$	(721	)
	______________________
	(1)      This represents projected benefit obligation for the nonqualified supplemental defined benefit retirement plan and accumulated postretirement benefit obligation for postretirement benefits.
	The following table presents the components of net periodic benefit cost and other amounts recognized in accumulated other comprehensive loss for our nonqualified supplemental defined benefit retirement plan and postretirement benefits for the three and nine months ended September 30, 2013 and 2012 (dollars in thousands):
			Nonqualified Supplemental Defined Benefit Retirement Plan For the Three Months Ended September 30,						Postretirement Benefits For the Three Months Ended September 30,
			2013			2012			2013			2012
	Net Periodic Benefit Cost
	Service cost		$	169		$	120		$	8		$	8
	Interest cost		109			83			7			7
	Amortization of net actuarial loss		197			116			3			3
	Net periodic benefit cost		$	475		$	319		$	18		$	18
			Nonqualified Supplemental Defined Benefit Retirement Plan For the Nine Months Ended September 30,						Postretirement Benefits For the Nine Months Ended September 30,
			2013			2012			2013			2012
	Net Periodic Benefit Cost
	Service cost		$	419		$	299		$	24		$	24
	Interest cost		271			209			22			21
	Amortization of net actuarial loss		591			349			9			7
	Net periodic benefit cost		$	1,281		$	857		$	55		$	52

Fair_Values

Fair Values	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value [Text Block]	'
	Fair Values
	A fair value hierarchy is used to prioritize the inputs of valuation techniques used to measure fair value. A description of the application of the fair value hierarchy, valuation techniques, and significant inputs is disclosed in Item 1 — Financial Statements and Supplementary Data — Note 19 — Fair Values in the 2012 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 nine month period ended September 30, 2013.
	The carrying values, fair values, and fair-value hierarchy of our financial instruments at September 30, 2013, and December 31, 2012, were as follows (dollars in thousands). These fair values do not represent an estimate of the Bank's 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.
		30-Sep-13
		Carrying			Total Fair Value			Level 1			Level 2			Level 3			Netting Adjustments and Cash Collateral
		Value
	Financial instruments
	Assets:
	Cash and due from banks	$	3,172,772		$	3,172,772		$	3,172,772		$	—		$	—		$	—
	Interest-bearing deposits	219			219			219			—			—			—
	Securities purchased under agreements to resell	1,500,000			1,499,980			—			1,499,980			—			—
	Federal funds sold	500,000			499,998			—			499,998			—			—
	Trading securities(1)	249,970			249,970			—			249,970			—			—
	Available-for-sale securities(1)	3,860,587			3,860,587			—			3,860,587			—			—
	Held-to-maturity securities(2)	4,361,134			4,700,205			—			3,080,792			1,619,413			—
	Advances	22,555,122			22,713,838			—			22,713,838			—			—
	Mortgage loans, net	3,401,111			3,457,996			—			3,457,996			—			—
	Accrued interest receivable	75,943			75,943			—			75,943			—			—
	Derivative assets(1)	4,118			4,118			—			46,674			—			(42,556		)
	Other assets (1)	9,595			9,595			4,768			4,827			—			—
	Liabilities:
	Deposits	(570,356		)	(569,439		)	—			(569,439		)	—			—
	COs:
	Bonds	(24,201,697		)	(24,384,324		)	—			(24,384,324		)	—			—
	Discount notes	(10,475,911		)	(10,476,247		)	—			(10,476,247		)	—			—
	Mandatorily redeemable capital stock	(977,390		)	(977,390		)	(977,390		)	—			—			—
	Accrued interest payable	(101,206		)	(101,206		)	—			(101,206		)	—			—
	Derivative liabilities(1)	(649,781		)	(649,781		)	—			(696,257		)	—			46,476
	Other:
	Commitments to extend credit for advances	—			(2,508		)	—			(2,508		)	—			—
	Standby letters of credit	(701		)	(701		)	—			(701		)	—			—
	_______________________
	-1	Carried at fair value on a recurring basis.
	-2	Private-label residential MBS and HFA securities are categorized as Level 3. Private-label residential MBS that have incurred other-than-temporary impairment losses are measured at fair value on a nonrecurring basis. See the recurring and nonrecurring tables below for more details.
		31-Dec-12
		Carrying			Total Fair			Level 1			Level 2			Level 3			Netting Adjustments and Cash Collateral
		Value			Value
	Financial instruments
	Assets:
	Cash and due from banks	$	240,945		$	240,945		$	240,945		$	—		$	—		$	—
	Interest-bearing deposits	192			192			192			—			—			—
	Securities purchased under agreements to resell	4,015,000			4,014,989			—			4,014,989			—			—
	Federal funds sold	600,000			599,994			—			599,994			—			—
	Trading securities(1)	274,293			274,293			—			274,293			—			—
	Available-for-sale securities(1)	5,268,237			5,268,237			—			5,268,237			—			—
	Held-to-maturity securities(2)	5,396,335			5,699,230			—			4,060,941			1,638,289			—
	Advances	20,789,704			21,168,928			—			21,168,928			—			—
	Mortgage loans, net	3,478,896			3,667,342			—			3,667,342			—			—
	Accrued interest receivable	100,404			100,404			—			100,404			—			—
	Derivative assets(1)	111			111			—			88,397			—			(88,286		)
	Other assets(1)	8,402			8,402			4,154			4,248			—			—
	Liabilities:
	Deposits	(594,968		)	(594,856		)	—			(594,856		)	—			—
	COs:
	Bonds	(26,119,848		)	(26,813,277		)	—			(26,813,277		)	—			—
	Discount notes	(8,639,048		)	(8,639,373		)	—			(8,639,373		)	—			—
	Mandatorily redeemable capital stock	(215,863		)	(215,863		)	(215,863		)	—			—			—
	Accrued interest payable	(96,356		)	(96,356		)	—			(96,356		)	—			—
	Derivative liabilities(1)	(907,092		)	(907,092		)	—			(995,378		)	—			88,286
	Other:
	Commitments to extend credit for advances	—			(229		)	—			(229		)	—			—
	Standby bond-purchase agreements	—			358			—			358			—			—
	Standby letters of credit	(523		)	(523		)	—			(523		)	—			—
_______________________
-1	Carried at fair value on a recurring basis.
-2	Private-label residential MBS and HFA securities are categorized as Level 3. Private-label residential MBS that have incurred other-than-temporary impairment losses are measured at fair value on a nonrecurring basis. See the recurring and nonrecurring tables below for more details.
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 September 30, 2013, and December 31, 2012, by fair-value hierarchy level (dollars in thousands):
	September 30, 2013
	Level 1			Level 2			Level 3			Netting			Total
										Adjustment (1)
Assets:
Trading securities:
U.S. government-guaranteed – residential MBS	$	—		$	14,962		$	—		$	—		$	14,962
GSEs – residential MBS	—			3,803			—			—			3,803
GSEs – commercial MBS	—			231,205			—			—			231,205
Total trading securities	—			249,970			—			—			249,970
Available-for-sale securities:
Supranational institutions	—			430,792			—			—			430,792
U.S. government-owned corporations	—			247,345			—			—			247,345
GSEs	—			1,048,757			—			—			1,048,757
U.S. government guaranteed – residential MBS	—			291,530			—			—			291,530
GSEs – residential MBS	—			1,842,163			—			—			1,842,163
Total available-for-sale securities	—			3,860,587			—			—			3,860,587
Derivative assets:
Interest-rate-exchange agreements	—			46,510			—			(42,556		)	3,954
Mortgage delivery commitments	—			164			—			—			164
Total derivative assets	—			46,674			—			(42,556		)	4,118
Other assets	4,768			4,827			—			—			9,595
Total assets at fair value	$	4,768		$	4,162,058		$	—		$	(42,556	)	$	4,124,270
Liabilities:
Derivative liabilities
Interest-rate-exchange agreements	$	—		$	(696,257	)	$	—		$	46,476		$	(649,781	)
Mortgage delivery commitments	—			—			—			—			—
Total liabilities at fair value	$	—		$	(696,257	)	$	—		$	46,476		$	(649,781	)
_______________________
(1)        These amounts represent the effect of master netting agreements which allow us to settle positive and negative positions and also cash collateral held or placed with the same clearing member and/or counterparty.
	December 31, 2012
	Level 1			Level 2			Level 3			Netting			Total
										Adjustment (1)
Assets:
Trading securities:
U.S. government-guaranteed – residential MBS	$	—		$	16,876		$	—		$	—		$	16,876
GSEs – residential MBS	—			4,946			—			—			4,946
GSEs – commercial MBS	—			252,471			—			—			252,471
Total trading securities	—			274,293			—			—			274,293
Available-for-sale securities:
Supranational institutions	—			473,484			—			—			473,484
U.S. government-owned corporations	—			291,081			—			—			291,081
GSEs	—			2,085,084			—			—			2,085,084
U.S. government guaranteed – residential MBS	—			73,359			—			—			73,359
GSEs – residential MBS	—			2,244,794			—			—			2,244,794
GSEs – commercial MBS	—			100,435			—			—			100,435
Total available-for-sale securities	—			5,268,237			—			—			5,268,237
Derivative assets:
Interest-rate-exchange agreements	—			88,362			—			(88,286		)	76
Mortgage delivery commitments	—			35			—			—			35
Total derivative assets	—			88,397			—			(88,286		)	111
Other assets	4,154			4,248			—			—			8,402
Total assets at fair value	$	4,154		$	5,635,175		$	—		$	(88,286	)	$	5,551,043
Liabilities:
Derivative liabilities
Interest-rate-exchange agreements	$	—		$	(995,362	)	$	—		$	88,286		$	(907,076	)
Mortgage delivery commitments	—			(16		)	—			—			(16		)
Total liabilities at fair value	$	—		$	(995,378	)	$	—		$	88,286		$	(907,092	)
_______________________
(1)         These amounts represent the effect of master netting agreements which allow us to settle positive and negative positions and also cash collateral held or placed with the same counterparty. We did not hold cash collateral, including accrued interest, associated with derivatives subject to master netting agreements as of December 31, 2012.
Fair Value on a Nonrecurring Basis
We measure certain held-to-maturity investment securities 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 at September 30, 2013, and December 31, 2012 (dollars in thousands).
	September 30, 2013
	Level 1			Level 2			Level 3			Total
REO	$	—		$	—		$	373		$	373
	31-Dec-12
	Level 1			Level 2			Level 3			Total
Held-to-maturity securities:
Private-label residential MBS	$	—		$	—		$	25		$	25
REO	—			—			195			195
Total assets recorded at fair value on a nonrecurring basis	$	—		$	—		$	220		$	220

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
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 September 30, 2013, and through the filing of this report, we do not believe that it is reasonably likely that we will be required to repay the principal or interest on any CO on behalf of another FHLBank.
	We have considered applicable FASB guidance and determined it is not necessary to recognize a liability for the fair value of our joint and several liability for all of the COs. The joint and several obligation is mandated by 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 September 30, 2013, and December 31, 2012. The par amounts of other FHLBanks' outstanding COs for which we are jointly and severally liable totaled $686.3 billion and $653.5 billion at September 30, 2013, and December 31, 2012, 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 September 30, 2013, and December 31, 2012 (dollars in thousands):
			September 30, 2013						December 31, 2012
			Expire within one year		Expire after one year		Total		Expire within one year		Expire after one year		Total
	Standby letters of credit outstanding (1)		$	2,852,332	$	235,116	$	3,087,448	$	870,905	$	343,744	$	1,214,649
	Commitments for standby bond purchases		—		—		—		158,960		—		158,960
	Commitments for unused lines of credit - advances (2)		1,287,377		—		1,287,377		1,290,776		—		1,290,776
	Commitments to make additional advances		18,713		49,124		67,837		22,985		72,036		95,021
	Commitments to invest in mortgage loans		18,107		—		18,107		30,938		—		30,938
	Unsettled CO bonds, at par (3)		45,000		—		45,000		124,100		—		124,100
	Unsettled CO discount notes, at par		—		—		—		1,405,000		—		1,405,000
	__________________________
	-1	The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year totaling $38.4 million as of September 30, 2013. Also excluded are commitments to issue standby letters of credit that expire within one year totaling $12.6 million at December 31, 2012.
	-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 no unsettled CO bonds that were hedged with associated interest-rate swaps at September 30, 2013. We had $100.0 million in unsettled CO bonds that were hedged with associated interest-rate swaps at December 31, 2012.
	Standby Letters of Credit. Standby letters of credit are executed with members or housing associates for a fee. A standby letter of credit is a financing arrangement between us and a member or housing associate pursuant to which we agree to fund the associated member's or housing associate's obligation to a third-party beneficiary should that member or housing associate 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 member or housing associate. The original terms of these standby letters of credit range from final expiries in 27 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 $701,000 and $523,000 at September 30, 2013, and December 31, 2012, respectively.
	We monitor the creditworthiness of our members and housing associates that have standby letter of credit agreements outstanding based on our evaluations of the financial condition of the member or housing associate. We review available financial data, which can include regulatory call reports filed by depository institution members, regulatory financial statements filed with the appropriate state insurance department by insurance company members, audited financial statements of housing associates, SEC filings, and rating-agency reports to ensure that potentially troubled members are identified as soon as possible. In addition, we have access to most members' regulatory examination reports. We analyze this information on a regular basis.
	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.
	Standby Bond-Purchase Agreements. We enter into standby bond-purchase agreements with state housing authorities from time to time whereby we, for a fee, agreed to purchase and hold the housing authority’s bonds until the designated remarketing agent can find an investor or the housing authority repurchases the bonds according to a schedule established by the standby bond-purchase agreement. Each standby bond-purchase agreement specifies the terms that would require us to purchase the bonds. The last standby bond-purchase commitment we had entered into expired in April 2013. At December 31, 2012, we had standby bond-purchase agreements with one state housing authority. During the three months ended September 30, 2012, we were not required to purchase any bonds under these agreements.
	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 execute new bilateral derivatives with counterparties with long-term ratings of single-A (or equivalent) or better by both S&P and Moody’s. All such derivatives are subject to master-netting agreements which include bilateral-collateral agreements. New derivatives with counterparties rated lower than single-A (or equivalent) are permitted only if they reduce exposure to that counterparty. As of September 30, 2013, and December 31, 2012, we had pledged as collateral securities that cannot be sold or repledged by the counterparty with a carrying value, including accrued interest, of $437.5 million and $650.9 million, respectively. As of September 30, 2013, and December 31, 2012, we had also pledged as collateral securities that can be sold or repledged with a carrying value, including accrued interest, of $71.4 million and $109.1 million, respectively.
	Legal Proceedings. We are subject to various legal proceedings arising in the normal course of business from time to time. 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	9 Months Ended
	Sep. 30, 2013
Transactions with Shareholders [Abstract]	'
Schedule of Transactions with Shareholders Disclosure [Text Block]	'
	Transactions with Shareholders
	Beginning in the second quarter of 2013, we defined related parties as members with more than 10 percent of the voting interests of our capital stock outstanding. In prior reports, we defined related parties as members whose capital stock holdings are in excess of 10 percent of total capital stock outstanding. The voting interest method of defining our related parties reflects a more narrow approach and is in agreement with accounting guidance. Shareholder concentrations, defined as members whose capital stock holdings are in excess of 10 percent of total capital stock outstanding, are disclosed in the shareholder concentration section below.
	Related Parties. 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 are 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 September 30, 2013, and December 31, 2012, 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 September 30, 2013, and December 31, 2012 (dollars in thousands):
	As of September 30, 2013	Capital Stock			Percent			Par				Percent of Total Par Value			Total Accrued		Percent of Total
		Outstanding			of Total			Value of				of Advances			Interest		Accrued Interest
								Advances							Receivable		Receivable on
																	Advances
	Bank of America, N.A.	$	857,835		25.1	%		$	99,221			0.4	%		$	398	1.2	%
	RBS Citizens N.A.	430,077			12.6			19,298				0.1			65		0.2
	As of December 31, 2012	Capital Stock			Percent			Par				Percent of Total Par Value			Total Accrued		Percent of Total
		Outstanding			of Total			Value of				of Advances			Interest		Accrued Interest
								Advances							Receivable		Receivable on
																	Advances
	Bank of America Rhode Island, N.A.(1)	$	978,084		26.6	%		$	101,795			0.5	%		$	437	1.2	%
	RBS Citizens N.A.	484,517			13.2			519,808				2.6			109		0.3
	__________________________
	-1	Capital stock outstanding at December 31, 2012 included $1.9 million held by CW Reinsurance Company, a subsidiary of Bank of America Corporation (BANA). Bank of America Rhode Island, N.A. (BANA RI) merged into BANA, its parent, during the quarter ended June 30, 2013. BANA is ineligible for membership.
	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 from the above shareholders during the three and nine months ended September 30, 2013 and 2012 as follows (dollars in thousands):
			For the Three Months Ended September 30,							For the Nine Months Ended September 30,
			2013			2012				2013				2012
	Bank of America, N.A. (1)		$	1,295		$	2,137			$	3,984			$	5,114
	RBS Citizens N.A.		210			3,155				977				8,367
	__________________________
	-1	Includes interest income from advances outstanding to BANA RI through the date of its merger with BANA in April 2013.
	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.
		Capital Stock			Percent			Par				Percent of Total Par Value			Total Accrued		Percent of Total
		Outstanding			of Total			Value of				of Advances			Interest		Accrued Interest
								Advances							Receivable		Receivable on
																	Advances
	As of September 30, 2013	$	127,020		3.7	%		$	655,493			3	%		$	1,668	5.1	%
	As of December 31, 2012	143,165			3.9			792,839				3.9			2,138		6.1

Transactions_with_Other_FHLBan

Transactions with Other FHLBanks	9 Months Ended
	Sep. 30, 2013
Transactions with Other FHLBanks [Abstract]	'
Transactions with Other FHLBanks [Text Block]	'
	Transactions with Other FHLBanks
	We may occasionally enter into transactions with other FHLBanks. These transactions are summarized below.
	Overnight Funds. We may borrow or lend unsecured overnight funds from or to other FHLBanks. All such transactions are at current market rates. Interest income and interest expense related to these transactions with other FHLBanks are included within other interest income and interest expense from other borrowings in the statement of operations.
	MPF Mortgage Loans. We pay a transaction-services fee to the FHLBank of Chicago for our participation in the MPF program. This fee is assessed monthly, and is based upon the amount of mortgage loans which we invested in after January 1, 2004, and which remain outstanding on our statement of condition. We recorded $387,000 and $347,000 for the three months ended September 30, 2013 and 2012, in MPF transaction-services fee expense to the FHLBank of Chicago which has been recorded in the statement of operations as other expense. We recorded $1.2 million and $966,000 for the nine months ended September 30, 2013 and 2012, in MPF transaction-services fee expense to the FHLBank of Chicago.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	Subsequent Events
	On October 25, 2013, the board of directors declared a cash dividend at an annualized rate of 0.37 percent based on capital stock balances outstanding during the third quarter of 2013. The dividend, including dividends on mandatorily redeemable capital stock, amounted to $3.2 million and was paid on November 4, 2013.

Summary_of_Significant_Account

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Investment, Policy [Policy Text Block]	'
	We evaluate our individual available-for-sale and held-to-maturity securities for other-than-temporary impairment each quarter. As part of our evaluation of securities for other-than-temporary impairment, we consider whether we intend to sell each security for which fair value is less than amortized cost or whether it is more likely than not that we will be required to sell the security before the anticipated recovery of the remaining amortized cost. If either of these conditions is met, we recognize an other-than-temporary impairment charge in earnings equal to the entire difference between the security's amortized cost basis and its fair value at the statement of condition date. For securities in an unrealized loss position that meet neither of these conditions (excluding agency MBS) and for all residential private-label MBS, we perform a cash-flow analysis to determine whether the entire amortized cost basis of these impaired securities, including all previously other-than-temporarily impaired securities, will be recovered. If we do not expect to recover the entire amount, the unrealized loss position is considered to be other-than-temporarily impaired. We evaluate the security's other-than-temporary impairment to determine the amount of credit loss to be recognized in earnings, which is limited to the amount of that security's unrealized loss.
Federal Home Loan Bank Advances, Prepayment Fees, Policy	'
	Prepayment Fees. We record prepayment fees received from borrowers on prepaid advances net of any associated basis adjustments related to hedging activities on those advances and net of deferred prepayment fees on advance prepayments considered to be loan modifications. Additionally, for certain advances products, the prepayment-fee provisions of the advance agreement could result in either a payment from the borrower or to the borrower when such an advance is prepaid, based upon market conditions at the time of prepayment (referred to as a symmetrical prepayment fee). Advances with a symmetrical prepayment fee provision are hedged with derivatives containing offsetting terms, so that we are financially indifferent to the borrower's decision to prepay such advances. The net amount of prepayment fees is reflected as interest income in the statement of operations.
Loans and Leases Receivable, Allowance for Loan Losses, Policy	'
	We periodically adjust the key inputs to our method for determining our allowance for credit losses based on our investments in conventional mortgage loans. These adjustments are intended to align our loss projections with the market conditions that are relevant to these loans. The key inputs to our method include past and current performance of these loans (including portfolio-delinquency and default-migration statistics), overall loan-portfolio-performance characteristics (including loss-mitigation features, especially credit enhancements, as discussed below under — Credit Enhancements), and loss-severity estimates for these loans. We update the following inputs at least once per quarter: current outstanding loan amounts, delinquency statistics of the portfolio, and related loss-mitigation features (including credit-enhancement and estimated credit-enhancement fee-recovery amounts) for all master commitments. A master commitment is a document which provides the general terms under which the participating financial institution will deliver mortgage loans, including a maximum loan delivery amount, maximum credit enhancement, if applicable, and expiration date. Additionally, we review our method's default migration factor on a quarterly basis to determine if the portfolio has exhibited any change in loans migrating from current to delinquent or from delinquent to default and make adjustments as appropriate.
	We use a third-party loan-loss projection model to determine our loss-severity estimates for our master commitments. The inputs to this model include loan-related characteristics (such as property types and locations), industry data (such as foreclosure timelines and associated costs), and current and projected housing prices. We update our loss-severity estimates each quarter.
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	'
	Troubled Debt Restructurings. We consider a troubled debt restructuring of a financing receivable to have occurred when we grant a concession to a borrower that we would not otherwise consider for economic or legal reasons related to the borrower's financial difficulties. We classify troubled debt restructurings at the end of the three-month trial period for troubled debt restructurings involved in our modification program for conventional mortgage loans.
	We also consider troubled debt restructurings to have occurred when a borrower has filed for bankruptcy under Chapter 7 of the U.S. Bankruptcy Code (Chapter 7 bankruptcy) pursuant to which the bankruptcy court has discharged the borrower's obligation to us and the borrower has not reaffirmed the debt.
Derivatives, Policy [Policy Text Block]	'
	Managing Credit Risk on Derivatives. We are subject to credit risk on our hedging activities due to the risk of nonperformance by nonmember counterparties (including DCOs and their clearing members acting as agent to the DCOs as well as bilateral counterparties) to the derivative agreements. We manage credit risk through credit analysis, collateral requirements and adherence to the requirements set forth in our policies, U.S. Commodity Futures Trading Commission (the CFTC) regulations, and FHFA regulations. All counterparties must execute master-netting agreements prior to entering into any non-cleared derivative (bilateral derivative) with us.
	Our master-netting agreements for bilateral derivatives contain bilateral-collateral exchange agreements that require that credit exposure beyond a defined threshold amount be secured by readily marketable, U.S. Treasury or GSE securities, or cash. The level of these collateral threshold amounts varies according to the counterparty's Standard & Poor's Ratings Services (S&P) or Moody's Investors Service (Moody's) long-term credit ratings. Credit exposures are then measured daily and adjustments to collateral positions are made in accordance with the terms of the master-netting agreements. These master-netting agreements also contain bilateral ratings-tied termination events permitting us to terminate all outstanding agreements with a counterparty in the event of a specified rating downgrade by Moody's or S&P. Based on credit analyses and collateral requirements, we do not anticipate any credit losses on our derivative agreements.
Joint and Several Liability, Policy	'
	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_Trading_Sec

Trading Securities Trading Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Trading Securities [Abstract]	'
Trading Securities by Major Security Type [Table Text Block]	'
	Our trading securities as of September 30, 2013, and December 31, 2012, were (dollars in thousands):
		September 30, 2013		December 31, 2012
	Mortgage-backed securities (MBS)
	United States (U.S.) government-guaranteed – residential	$	14,962	$	16,876
	Government-sponsored enterprises (GSEs) – residential	3,803		4,946
	GSEs – commercial	231,205		252,471
	Total	$	249,970	$	274,293

AvailableforSale_Securities_Ta

Available-for-Sale Securities (Tables)	9 Months Ended
	Sep. 30, 2013
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 September 30, 2013, were (dollars in thousands):
				Amounts Recorded in Accumulated Other Comprehensive Loss
		Amortized		Unrealized			Unrealized			Fair
		Cost (1)		Gains			Losses			Value
	Supranational institutions	$	453,905	$	—		$	(23,113	)	$	430,792
	U.S. government-owned corporations	286,097		—			(38,752		)	247,345
	GSEs	1,053,469		6,759			(11,471		)	1,048,757
		1,793,471		6,759			(73,336		)	1,726,894
	MBS
	U.S. government guaranteed – residential	294,051		453			(2,974		)	291,530
	GSEs – residential	1,857,379		5,180			(20,396		)	1,842,163
		2,151,430		5,633			(23,370		)	2,133,693
	Total	$	3,944,901	$	12,392		$	(96,706	)	$	3,860,587
	_______________________
	(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, 2012, were (dollars in thousands):
				Amounts Recorded in Accumulated Other Comprehensive Loss
		Amortized		Unrealized			Unrealized			Fair
		Cost (1)		Gains			Losses			Value
	Supranational institutions	$	502,177	$	—		$	(28,693	)	$	473,484
	U.S. government-owned corporations	330,106		—			(39,025		)	291,081
	GSEs	2,072,936		25,901			(13,753		)	2,085,084
		2,905,219		25,901			(81,471		)	2,849,649
	MBS
	U.S. government guaranteed – residential	72,862		497			—			73,359
	GSEs – residential	2,212,183		32,611			—			2,244,794
	GSEs – commercial	100,616		—			(181		)	100,435
		2,385,661		33,108			(181		)	2,418,588
	Total	$	5,290,880	$	59,009		$	(81,652	)	$	5,268,237
	_______________________
	(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 September 30, 2013, 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		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Supranational institutions	$	—	$	—		$	430,792		$	(23,113	)	$	430,792	$	(23,113	)
	U.S. government-owned corporations	—		—			247,345			(38,752		)	247,345		(38,752		)
	GSEs	—		—			109,711			(11,471		)	109,711		(11,471		)
		—		—			787,848			(73,336		)	787,848		(73,336		)
	MBS
	U.S. government guaranteed – residential	228,122		(2,974		)	—			—			228,122		(2,974		)
	GSEs – residential	1,304,806		(20,396		)	—			—			1,304,806		(20,396		)
		1,532,928		(23,370		)	—			—			1,532,928		(23,370		)
	Total temporarily impaired	$	1,532,928	$	(23,370	)	$	787,848		$	(73,336	)	$	2,320,776	$	(96,706	)
	The following table summarizes our available-for-sale securities with unrealized losses as of December 31, 2012, 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		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Supranational institutions	$	—	$	—		$	473,484		$	(28,693	)	$	473,484	$	(28,693	)
	U.S. government-owned corporations	—		—			291,081			(39,025		)	291,081		(39,025		)
	GSEs	—		—			124,453			(13,753		)	124,453		(13,753		)
		—		—			889,018			(81,471		)	889,018		(81,471		)
	MBS
	GSEs – commercial	100,435		(181		)	—			—			100,435		(181		)
	Total temporarily impaired	$	100,435	$	(181	)	$	889,018		$	(81,471	)	$	989,453	$	(81,652	)
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 September 30, 2013, and December 31, 2012, were (dollars in thousands):
		September 30, 2013					December 31, 2012
	Year of Maturity	Amortized		Fair			Amortized			Fair
		Cost		Value			Cost			Value
	Due in one year or less	$	932,287	$	939,046		$	1,147,950		$	1,156,133
	Due after one year through five years	—		—			786,779			804,498
	Due after five years through 10 years	—		—			—			—
	Due after 10 years	861,184		787,848			970,490			889,018
		1,793,471		1,726,894			2,905,219			2,849,649
	MBS (1)	2,151,430		2,133,693			2,385,661			2,418,588
	Total	$	3,944,901	$	3,860,587		$	5,290,880		$	5,268,237
	_______________________
	-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.

HeldtoMaturity_Securities_Tabl

Held-to-Maturity Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Held-to-maturity Securities [Line Items]	'
HTM Securities by Major Security Type [Table Text Block]	'
	Our held-to-maturity securities as of September 30, 2013, 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	$	9,749	$	—		$	9,749	$	809		$	—		$	10,558
	State or local housing-finance-agency obligations (HFA securities)	185,156		—			185,156		48			(22,056		)	163,148
	GSEs	67,943		—			67,943		529			—			68,472
		262,848		—			262,848		1,386			(22,056		)	242,178
	MBS
	U.S. government guaranteed – residential	30,128		—			30,128		672			—			30,800
	U.S. government guaranteed – commercial	237,527		—			237,527		1,107			—			238,634
	GSEs – residential	1,879,733		—			1,879,733		49,546			(330		)	1,928,949
	GSEs – commercial	757,430		—			757,430		45,949			—			803,379
	Private-label – residential	1,506,605		(338,030		)	1,168,575		285,865			(22,128		)	1,432,312
	Private-label – commercial	1,621		—			1,621		8			—			1,629
	Asset-backed securities (ABS) backed by home equity loans	24,254		(982		)	23,272		893			(1,841		)	22,324
		4,437,298		(339,012		)	4,098,286		384,040			(24,299		)	4,458,027
	Total	$	4,700,146	$	(339,012	)	$	4,361,134	$	385,426		$	(46,355	)	$	4,700,205
	Our held-to-maturity securities as of December 31, 2012, 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	$	12,877	$	—		$	12,877	$	1,243		$	—		$	14,120
	HFA securities	189,719		—			189,719		44			(17,881		)	171,882
	GSEs	69,246		—			69,246		1,521			—			70,767
		271,842		—			271,842		2,808			(17,881		)	256,769
	MBS
	U.S. government guaranteed – residential	38,313		—			38,313		879			—			39,192
	U.S. government guaranteed – commercial	451,559		—			451,559		8,273			—			459,832
	GSEs – residential	2,357,479		—			2,357,479		78,105			(337		)	2,435,247
	GSEs – commercial	957,503		—			957,503		84,282			(2		)	1,041,783
	Private-label – residential	1,669,041		(384,051		)	1,284,990		183,581			(34,184		)	1,434,387
	Private-label – commercial	9,822		—			9,822		321			—			10,143
	ABS backed by home equity loans	25,951		(1,124		)	24,827		719			(3,669		)	21,877
		5,509,668		(385,175		)	5,124,493		356,160			(38,192		)	5,442,461
	Total	$	5,781,510	$	(385,175	)	$	5,396,335	$	358,968		$	(56,073	)	$	5,699,230
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 September 30, 2013, 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		Unrealized			Fair		Unrealized			Fair			Unrealized
		Value		Losses			Value		Losses			Value			Losses
	HFA securities	$	—	$	—		$	155,814	$	(22,056	)	$	155,814		$	(22,056	)
	MBS
	GSEs – residential	5,585		(6		)	45,424		(324		)	51,009			(330		)
	Private-label – residential	63,819		(1,434		)	966,325		(105,517		)	1,030,144			(106,951		)
	ABS backed by home equity loans	—		—			22,324		(2,108		)	22,324			(2,108		)
		69,404		(1,440		)	1,034,073		(107,949		)	1,103,477			(109,389		)
	Total	$	69,404	$	(1,440	)	$	1,189,887	$	(130,005	)	$	1,259,291		$	(131,445	)
	The following table summarizes our held-to-maturity securities with unrealized losses as of December 31, 2012, 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		Unrealized			Fair		Unrealized			Fair			Unrealized
		Value		Losses			Value		Losses			Value			Losses
	HFA securities	$	—	$	—		$	163,864	$	(17,881	)	$	163,864		$	(17,881	)
	MBS
	GSEs – residential	—		—			60,776		(337		)	60,776			(337		)
	GSEs – commercial	1,220		(2		)	—		—			1,220			(2		)
	Private-label – residential	—		—			1,325,876		(242,306		)	1,325,876			(242,306		)
	ABS backed by home equity loans	—		—			21,181		(4,114		)	21,181			(4,114		)
		1,220		(2		)	1,407,833		(246,757		)	1,409,053			(246,759		)
	Total	$	1,220	$	(2	)	$	1,571,697	$	(264,638	)	$	1,572,917		$	(264,640	)
HTM Securities by Contractual Maturity [Table Text Block]	'
	The amortized cost and fair value of our held-to-maturity securities by contractual maturity at September 30, 2013, and December 31, 2012, 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.
		September 30, 2013							December 31, 2012
	Year of Maturity	Amortized		Carrying			Fair		Amortized			Carrying			Fair
		Cost		Value (1)			Value		Cost			Value (1)			Value
	Due in one year or less	$	67,943	$	67,943		$	68,472	$	—		$	—		$	—
	Due after one year through five years	1,179		1,179			1,252		69,581			69,581			71,102
	Due after five years through 10 years	30,091		30,091			30,587		32,562			32,562			33,604
	Due after 10 years	163,635		163,635			141,867		169,699			169,699			152,063
		262,848		262,848			242,178		271,842			271,842			256,769
	MBS (2)	4,437,298		4,098,286			4,458,027		5,509,668			5,124,493			5,442,461
	Total	$	4,700,146	$	4,361,134		$	4,700,205	$	5,781,510		$	5,396,335		$	5,699,230
	_______________________
	(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.

OtherThanTemporary_Impairment_

Other-Than-Temporary Impairment (Tables)	9 Months Ended
	Sep. 30, 2013
Other-Than-Temporary Impairment Analysis [Abstract]	'
Recovery Ranges of Housing Price Change [Table Text Block]	'
	Under those recovery paths, home prices were projected to increase as follows:
	Months		Recovery Range
	6-Jan		0	%	to	3.00%
	12-Jul		1	%	to	4.00%
	13-18		2	%	to	4.00%
	19-30		2	%	to	5.00%
	31-54		2	%	to	6.00%
	Thereafter		2.3	%	to	5.60%
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 September 30, 2013 (that is, a determination was made that less than the entire amortized cost basis is expected to be recovered), 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).
							Significant Inputs
							Projected		Projected			Projected			Current
							Prepayment Rates		Default Rates			Loss Severities			Credit Enhancement
	Private-label MBS by		Par Value				Weighted		Weighted			Weighted			Weighted
	Year of Securitization						Average		Average			Average			Average
							Percent		Percent			Percent			Percent
	Private-label residential MBS
	Alt-A (1)
	2007		$	65,490			5.3	%	58.2	%		45.1	%		25.5	%
	2005		9,797				6.1		45.5			41.5			22.3
	Total Alt-A		$	75,287			5.4	%	56.5	%		44.7	%		25.1	%
	ABS backed by home equity loans
	Subprime (1)
	2004 and prior		$	283			1.1	%	38.1	%		91.6	%		10.9	%
	_______________________
	(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 September 30, 2013 (dollars in thousands). Securities are classified in the table below based on their classifications at the time of issuance. We note that 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 per the following tables in this Note 6, for example) as disclosed by those securities' issuance documents, as well as other statements about the securities, are inaccurate.
		September 30, 2013
	Other-Than-Temporarily Impaired Investment	Par				Amortized			Carrying				Fair
		Value				Cost			Value				Value
	Private-label residential MBS – Prime	$	65,201			$	55,351		$	41,623			$	54,608
	Private-label residential MBS – Alt-A	1,603,544				1,159,835			835,533				1,108,360
	ABS backed by home equity loans – Subprime	5,066				4,504			3,522				4,415
	Total other-than-temporarily impaired securities	$	1,673,811			$	1,219,690		$	880,678			$	1,167,383
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 September 30,							For the Nine Months Ended September 30,
		2013				2012			2013				2012
	Balance at beginning of period	$	472,243			$	520,654		$	497,102			$	544,833
	Additions:
	Credit losses for which other-than-temporary impairment was not previously recognized	—				—			—				—
	Additional credit losses for which an other-than-temporary impairment charge was previously recognized(1)	1,528				1,092			2,343				5,544
	Reductions:
	Securities matured or paid-down during the period	(10,427		)		(8,065		)	(28,793		)		(32,697		)
	Increase in cash flows expected to be collected which are recognized over the remaining life of the security	(5,864		)		(2,609		)	(13,172		)		(6,608		)
	Balance at end of period	$	457,480			$	511,072		$	457,480			$	511,072
	_______________________
	-1	For the three months ended September 30, 2013 and 2012, additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to July 1, 2013 and 2012. For the nine months ended September 30, 2013 and 2012, 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, 2013 and 2012.

Advances_Tables

Advances (Tables)	9 Months Ended
	Sep. 30, 2013
Advances [Abstract]	'
Advances Redemption Terms [Table Text Block]	'
	At September 30, 2013, and December 31, 2012, we had advances outstanding with interest rates ranging from (0.20) percent to 8.37 percent and (0.15) 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.
		September 30, 2013							December 31, 2012
	Year of Contractual Maturity	Amount				Weighted			Amount				Weighted
						Average							Average
						Rate							Rate
	Overdrawn demand-deposit accounts	$	2,956			0.43	%		$	12,893			0.53	%
	Due in one year or less	10,214,001				0.65			8,273,972				1
	Due after one year through two years	2,106,545				2.28			2,198,709				2.61
	Due after two years through three years	2,400,698				2.26			1,921,353				2.57
	Due after three years through four years	3,220,895				2.82			2,347,511				2.56
	Due after four years through five years	2,235,554				2.45			3,033,895				3.04
	Thereafter	2,027,688				2.76			2,481,519				2.96
	Total par value	22,208,337				1.67	%		20,269,852				2.05	%
	Premiums	52,875							52,435
	Discounts	(20,298		)					(23,087		)
	Market value of embedded derivatives (1)	854							1,163
	Hedging adjustments	313,354							489,341
	Total	$	22,555,122						$	20,789,704
	_________________________
	-1	At September 30, 2013, and December 31, 2012, we had certain advances with embedded features that met the requirements to be separated from the host contract and designate the embedded features as a stand-alone derivative.
Advances by Year of the Earlier of Contractual Maturity or Next Put Date [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):
		September 30, 2013							December 31, 2012
	Year of Contractual Maturity or Next Put Date	Par Value				Percentage			Par Value				Percentage
						of Total							of Total
	Overdrawn demand-deposit accounts	$	2,956			0	%		$	12,893			0.1	%
	Due in one year or less	12,648,176				57			11,218,147				55.3
	Due after one year through two years	1,959,795				8.8			1,919,209				9.5
	Due after two years through three years	2,153,298				9.7			1,779,103				8.8
	Due after three years through four years	1,763,370				7.9			1,906,611				9.4
	Due after four years through five years	1,704,304				7.7			1,441,870				7.1
	Thereafter	1,976,438				8.9			1,992,019				9.8
	Total par value	$	22,208,337			100	%		$	20,269,852			100	%
Advances by Interest Rate Payment Terms [Table Text Block]	'
	The following table details interest-rate-payment types for our outstanding advances (dollars in thousands):
	Par value of advances	September 30, 2013				December 31, 2012
	Fixed-rate	$	21,789,381			$	19,179,459
	Variable-rate	418,956				1,090,393
	Total par value	$	22,208,337			$	20,269,852
Schedule of Prepayment Fees on Advances [Table Text Block]	'
	For the three and nine months ended September 30, 2013 and 2012, net advance prepayment fees recognized in income are reflected in the following table (dollars in thousands):
			For the Three Months Ended September 30,								For the Nine Months Ended September 30,
			2013				2012				2013				2012
	Prepayment fees received from borrowers		$	12,270			$	23,247			$	40,644			$	91,471
	Less: hedging fair-value adjustments on prepaid advances		(6,123		)		(11,125		)		(19,330		)		(50,270		)
	Less: net premiums associated with prepaid advances		(430		)		(1,433		)		(4,424		)		(1,770		)
	Less: deferred recognition of prepayment fees received from borrowers on advance prepayments deemed to be loan modifications		(3,896		)		(2,893		)		(5,298		)		(4,580		)
	Prepayment fees recognized in income on advance restructurings deemed to be extinguishments		—				4,078				6,845				9,497
	Net prepayment fees recognized in income		$	1,821			$	11,874			$	18,437			$	44,348

Mortgage_Loans_Held_for_Portfo1

Mortgage Loans Held for Portfolio (Tables)	9 Months Ended
	Sep. 30, 2013
Mortgage Loans on Real Estate [Abstract]	'
Mortgage Loans Held for Portfolio [Table Text Block]	'
	The following table presents certain characteristics of the mortgage loans in which we have invested (dollars in thousands):
		September 30, 2013			December 31, 2012
	Real estate
	Fixed-rate 15-year single-family mortgages	$	614,920		$	679,153
	Fixed-rate 20- and 30-year single-family mortgages	2,730,363			2,743,955
	Premiums	59,679			60,573
	Discounts	(3,519		)	(4,021		)
	Deferred derivative gains, net	1,625			3,650
	Total mortgage loans held for portfolio	3,403,068			3,483,310
	Less: allowance for credit losses	(1,957		)	(4,414		)
	Total mortgage loans, net of allowance for credit losses	$	3,401,111		$	3,478,896
Mortgage Loans Held for Portfolio by Collateral/Guarantee Type [Table Text Block]	'
	The following table details the par value of mortgage loans held for portfolio (dollars in thousands):
		September 30, 2013			December 31, 2012
	Conventional mortgage loans	$	2,905,884		$	2,979,067
	Government mortgage loans	439,399			444,041
	Total par value	$	3,345,283		$	3,423,108

Allowance_for_Credit_Losses_Ta

Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2013
Allowance for Credit Losses [Abstract]	'
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 nine months ended September 30, 2013 and 2012, as well as the recorded investment in mortgage loans by impairment methodology at September 30, 2013 and 2012 (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 September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Allowance for credit losses
	Balance at beginning of period	$	1,999		$	6,114		$	4,414		$	7,800
	Charge-offs	(125		)	(77		)	(310		)	(229		)
	Recoveries	—			—			47			—
	Provision for (reduction of) credit losses	83			(523		)	(2,194		)	(2,057		)
	Balance at end of period	$	1,957		$	5,514		$	1,957		$	5,514
	Ending balance, individually evaluated for impairment	$	562		$	—		$	562		$	—
	Ending balance, collectively evaluated for impairment	$	1,395		$	5,514		$	1,395		$	5,514
	Recorded investment, end of period (1)
	Individually evaluated for impairment	$	6,743		$	2,256		$	6,743		$	2,256
	Collectively evaluated for impairment	$	2,961,768		$	3,041,201		$	2,961,768		$	3,041,201
	_________________________
	-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.
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 September 30, 2013, and December 31, 2012 (dollars in thousands):
		September 30, 2013
		Recorded Investment in Conventional Mortgage Loans			Recorded Investment in Government Mortgage Loans			Total
	Past due 30-59 days delinquent	$	32,392		$	15,389		$	47,781
	Past due 60-89 days delinquent	13,091			3,618			16,709
	Past due 90 days or more delinquent	45,109			19,489			64,598
	Total past due	90,592			38,496			129,088
	Total current loans	2,877,919			413,215			3,291,134
	Total mortgage loans	$	2,968,511		$	451,711		$	3,420,222
	Other delinquency statistics
	In process of foreclosure, included above (1)	$	17,945		$	6,709		$	24,654
	Serious delinquency rate (2)	1.55		%	4.31		%	1.91		%
	Past due 90 days or more still accruing interest	$	—		$	19,489		$	19,489
	Loans on nonaccrual status (3)	$	45,409		$	—		$	45,409
	_______________________
	-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, 2012
		Recorded Investment in Conventional Mortgage Loans			Recorded Investment in Government Mortgage Loans			Total
	Past due 30-59 days delinquent	$	36,720		$	14,451		$	51,171
	Past due 60-89 days delinquent	12,339			4,459			16,798
	Past due 90 days or more delinquent	50,927			23,715			74,642
	Total past due	99,986			42,625			142,611
	Total current loans	2,944,184			414,400			3,358,584
	Total mortgage loans	$	3,044,170		$	457,025		$	3,501,195
	Other delinquency statistics
	In process of foreclosure, included above (1)	$	23,580		$	11,022		$	34,602
	Serious delinquency rate (2)	1.7		%	5.19		%	2.15		%
	Past due 90 days or more still accruing interest	$	—		$	23,715		$	23,715
	Loans on nonaccrual status (3)	$	51,609		$	—		$	51,609
	_______________________
	-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.
Impaired Financing Receivables [Table Text Block]	'
	The following tables present the recorded investment, par value and any related allowance for impaired loans individually assessed for impairment at September 30, 2013, and December 31, 2012, and the average recorded investment and interest income recognized on these loans during the three and nine months ended September 30, 2013 and 2012 (dollars in thousands).
			As of September 30, 2013									As of December 31, 2012
			Recorded Investment			Par Value			Related Allowance			Recorded Investment		Par Value		Related Allowance
	Individually evaluated impaired mortgage loans with no related allowance		$	3,524		$	3,479		$	—		$	2,752	$	2,726	$	—
	Individually evaluated impaired mortgage loans with a related allowance		3,219			3,197			562			—		—		—
	Total individually evaluated impaired mortgage loans		$	6,743		$	6,676		$	562		$	2,752	$	2,726	$	—
			For the Three Months Ended September 30,
			2013						2012
			Average Recorded Investment			Interest Income Recognized			Average Recorded Investment			Interest Income Recognized
	Individually evaluated impaired mortgage loans with no related allowance		$	3,516		$	31		$	2,282		$	27
	Individually evaluated impaired mortgage loans with a related allowance		4,144			1			—			—
	Total individually evaluated impaired mortgage loans		$	7,660		$	32		$	2,282		$	27
			For the Nine Months Ended September 30,
			2013						2012
			Average Recorded Investment			Interest Income Recognized			Average Recorded Investment			Interest Income Recognized
	Individually evaluated impaired mortgage loans with no related allowance		$	3,315		$	140		$	1,513		$	54
	Individually evaluated impaired mortgage loans with a related allowance		2,072			3			—			—
	Total individually evaluated impaired mortgage loans		$	5,387		$	143		$	1,513		$	54
Impact of Loss Mitigating Features of Conventional Mortgage Loans [Table Text Block]	'
	The following table demonstrates the impact on our estimate of the allowance for credit losses resulting from the loss-mitigating features of conventional mortgage loans (dollars in thousands).
		September 30, 2013			December 31, 2012
	Total estimated losses	$	3,902		$	10,053
	Less: estimated losses in excess of the first-loss account, to be absorbed by participating financial institutions	(1,208		)	(5,010		)
	Less: estimated performance-based credit-enhancement fees available for recapture	(737		)	(629		)
	Net allowance for credit losses	$	1,957		$	4,414

Derivatives_and_Hedging_Activi1

Derivatives and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair Value of Derivative Instruments [Table Text Block]	'
	The following table presents the fair value of derivative instruments as of September 30, 2013 (dollars in thousands):
		Notional				Derivative				Derivative
		Amount of				Assets				Liabilities
		Derivatives
	Derivatives designated as hedging instruments
	Interest-rate swaps	$	12,359,840			$	45,740			$	(619,480	)
	Forward-start interest-rate swaps	1,250,000				—				(53,843		)
	Total derivatives designated as hedging instruments	13,609,840				45,740				(673,323		)
	Derivatives not designated as hedging instruments
	Interest-rate swaps	1,273,500				665				(22,934		)
	Interest-rate caps or floors	300,000				105				—
	Mortgage-delivery commitments (1)	18,107				164				—
	Total derivatives not designated as hedging instruments	1,591,607				934				(22,934		)
	Total notional amount of derivatives	$	15,201,447
	Total derivatives before netting adjustments					46,674				(696,257		)
	Netting adjustments (2)					(46,476		)		46,476
	Cash collateral and related accrued interest					3,920				—
	Derivative assets and derivative liabilities					$	4,118			$	(649,781	)
	_______________________
	(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.
	The following table presents the fair value of derivative instruments as of December 31, 2012 (dollars in thousands):
		Notional				Derivative				Derivative
		Amount of				Assets				Liabilities
		Derivatives
	Derivatives designated as hedging instruments
	Interest-rate swaps	$	14,595,750			$	87,463			$	(896,248	)
	Forward-start interest-rate swaps	1,250,000				—				(64,897		)
	Total derivatives designated as hedging instruments	15,845,750				87,463				(961,145		)
	Derivatives not designated as hedging instruments
	Interest-rate swaps	1,364,500				849				(34,217		)
	Interest-rate caps or floors	300,000				50				—
	Mortgage-delivery commitments (1)	30,938				35				(16		)
	Total derivatives not designated as hedging instruments	1,695,438				934				(34,233		)
	Total notional amount of derivatives	$	17,541,188
	Total derivatives before netting and collateral adjustments					88,397				(995,378		)
	Netting adjustments (2)					(88,286		)		88,286
	Derivative assets and derivative liabilities					$	111			$	(907,092	)
	_______________________
	-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.
Net (Losses) Gains on Derivatives and Hedging Activities [Table Text Block]	'
	Net (losses) gains on derivatives and hedging activities recorded in Other Income (Loss) for the three and nine months ended September 30, 2013 and 2012, were as follows (dollars in thousands).
			For the Three Months Ended September 30,								For the Nine Months Ended September 30,
			2013				2012				2013				2012
	Derivatives and hedged items in fair-value hedging relationships:
	Interest-rate swaps		$	491			$	597			$	1,827			$	255
	Cash flow hedge ineffectiveness		13				—				53				—
	Derivatives not designated as hedging instruments:
	Economic hedges:
	Interest-rate swaps		(1,611		)		(3,243		)		5,720				(10,105		)
	Interest-rate caps or floors		(67		)		(207		)		55				(745		)
	Mortgage-delivery commitments		104				767				(1,480		)		2,086
	Total net gains related to derivatives not designated as hedging instruments		(1,574		)		(2,683		)		4,295				(8,764		)
	Net (losses) gains on derivatives and hedging activities		$	(1,070	)		$	(2,086	)		$	6,175			$	(8,509	)
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 nine months ended September 30, 2013 and 2012 (dollars in thousands):
		For the Three Months Ended September 30, 2013
		Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
		Derivative				Hedged Item				Hedge				Derivatives on
										Ineffectiveness				Net Interest
														Income (1)
	Hedged Item:
	Advances	$	21,441			$	(21,300	)		$	141			$	(36,468	)
	Investments	16,806				(16,418		)		388				(9,437		)
	Deposits	(372		)		372				—				395
	COs – bonds	3,407				(3,445		)		(38		)		13,640
	Total	$	41,282			$	(40,791	)		$	491			$	(31,870	)
		For the Three Months Ended September 30, 2012
		Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
		Derivative				Hedged Item				Hedge				Derivatives on
										Ineffectiveness				Net Interest
														Income (1)
	Hedged Item:
	Advances	$	1,375			$	(1,116	)		$	259			$	(45,869	)
	Investments	7,645				(7,183		)		462				(10,256		)
	Deposits	(293		)		293				—				385
	COs – bonds	(6,947		)		6,823				(124		)		21,003
	Total	$	1,780			$	(1,183	)		$	597			$	(34,737	)
	______________
	(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.
		For the Nine Months Ended September 30, 2013
		Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
		Derivative				Hedged Item				Hedge				Derivatives on
										Ineffectiveness				Net Interest
														Income (1)
	Hedged Item:
	Advances	$	176,729			$	(175,986	)		$	743			$	(114,058	)
	Investments	111,118				(109,922		)		1,196				(29,004		)
	Deposits	(1,150		)		1,150				—				1,183
	COs – bonds	(65,727		)		65,615				(112		)		52,616
	Total	$	220,970			$	(219,143	)		$	1,827			$	(89,263	)
		For the Nine Months Ended September 30, 2012
		Gain/(Loss) on				Gain/(Loss) on				Net Fair-Value				Effect of
		Derivative				Hedged Item				Hedge				Derivatives on
										Ineffectiveness				Net Interest
														Income (1)
	Hedged Item:
	Advances	$	55,505			$	(56,798	)		$	(1,293	)		$	(149,548	)
	Investments	(5,066		)		6,321				1,255				(30,626		)
	Deposits	(908		)		908				—				1,151
	COs – bonds	(109,114		)		109,407				293				68,893
	Total	$	(59,583	)		$	59,838			$	255			$	(110,130	)
	______________
	(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.
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 derivatives counterparties could have required us to deliver based on incremental credit rating downgrades at September 30, 2013 (dollars in thousands).
	Post-haircut Value of Incremental Collateral to be Delivered
	as of September 30, 2013
	Ratings Downgrade (1)
	From		To		Incremental Collateral(2)
	AA+		AA or AA-		$	39,587
	AA-		A+, A or A-		53,117
	A-		below A-		39,152
	_______________________
	-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 $14.4 million could be called by counterparties as of September 30, 2013, 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 presents separately the fair value of derivative instruments 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 September 30, 2013, and December 31, 2012 (dollars in thousands).
			30-Sep-13
			Derivative Assets				Derivative Liabilities
	Derivative instruments with legal right of offset
	Gross recognized amount
	Bilateral derivatives		$	43,620			$	(693,225	)
	Cleared derivatives		2,890				(3,032		)
	Total gross recognized amount		46,510				(696,257		)
	Gross amounts of netting adjustments and cash collateral
	Bilateral derivatives		(43,444		)		43,444
	Cleared derivatives		888				3,032
	Total gross amounts of netting adjustments and cash collateral		(42,556		)		46,476
	Net amounts after netting adjustments and cash collateral
	Bilateral derivatives		176				(649,781		)
	Cleared derivatives		3,778				—
	Total net amounts after netting adjustments and cash collateral		3,954				(649,781		)
	Derivative instruments without legal right of offset
	Bilateral derivatives (1)		164				—
	Total derivative instruments without legal right of offset		164				—
	Total derivative assets and total derivative liabilities
	Bilateral derivatives		340				(649,781		)
	Cleared derivatives		3,778				—
	Total derivative assets and total derivative liabilities		4,118				(649,781		)
	Non-cash collateral received or pledged not offset (2)
	Can be sold or repledged
	Bilateral derivatives		—				73,770
	Total can be sold or repledged		—				73,770
	Cannot be sold or repledged
	Bilateral derivatives		—				448,670
	Total cannot be sold or repledged		—				448,670
	Net unsecured amount
	Bilateral derivatives		340				(127,341		)
	Cleared derivatives		3,778				—
	Total net unsecured amount		$	4,118			$	(127,341	)
	_______________________
	-1	Consists of mortgage delivery commitments.
	-2	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At September 30, 2013, we had additional net exposure of $6.8 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.
			31-Dec-12
			Derivative Assets				Derivative Liabilities
	Derivative instruments with legal right of offset
	Gross recognized amount		$	88,362			$	(995,362	)
	Gross amounts of netting adjustments and cash collateral		(88,286		)		88,286
	Total net amounts after netting adjustments and cash collateral		76				(907,076		)
	Derivative instruments without legal right of offset (1)		35				(16		)
	Total derivative assets and total derivative liabilities		111				(907,092		)
	Non-cash collateral received or pledged not offset (2)
	Collateral received or pledged - Can be sold or repledged		—				115,339
	Collateral received or pledged - Cannot be sold or repledged		—				672,890
	Net unsecured amount		$	111			$	(118,863	)
	_______________________
	-1	Consists of mortgage delivery commitments.
	-2	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At December 31, 2012, we had additional net exposure of $18.0 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.
	For additional information on our derivatives and hedging activities, see Item 8 — Financial Statements and Supplementary Data — Note 11 — Derivatives and Note 1 — Summary of Significant Accounting Policies in the 2012 Annual Report.

Deposits_Tables

Deposits (Tables)	9 Months Ended
	Sep. 30, 2013
Deposits [Abstract]	'
Interest-bearing and Non-interest-bearing Deposits [Table Text Block]	'
	The following table details interest-bearing and non-interest-bearing deposits (dollars in thousands):
		September 30, 2013		December 31, 2012
	Interest bearing
	Demand and overnight	$	529,641	$	530,887
	Term	20,919		21,638
	Other	3,247		4,915
	Non-interest bearing
	Other	16,549		37,528
	Total deposits	$	570,356	$	594,968

Consolidated_Obligations_Table

Consolidated Obligations (Tables)	9 Months Ended
	Sep. 30, 2013
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 September 30, 2013, and December 31, 2012, by year of contractual maturity (dollars in thousands):
		September 30, 2013						December 31, 2012
	Year of Contractual Maturity	Amount			Weighted			Amount			Weighted
					Average						Average
					Rate (1)						Rate (1)
	Due in one year or less	$	8,452,690		1.08	%		$	8,344,355		1.67	%
	Due after one year through two years	3,738,790			2.1			5,447,000			1.36
	Due after two years through three years	3,426,190			2.24			3,482,025			2.44
	Due after three years through four years	2,508,440			1.92			1,975,360			2.34
	Due after four years through five years	1,983,770			2.31			3,122,805			2.22
	Thereafter	3,869,920			2.48			3,433,690			2.55
	Total par value	23,979,800			1.82	%		25,805,235			1.94	%
	Premiums	241,497						270,614
	Discounts	(20,826		)				(22,842		)
	Hedging adjustments	1,226						66,841
		$	24,201,697					$	26,119,848
	_______________________
	(1)          The CO bonds' weighted-average rate excludes concession fees.
CO Bonds by Call Feature [Table Text Block]	'
	Our CO bonds outstanding at September 30, 2013, and December 31, 2012, included (dollars in thousands):
		September 30, 2013			December 31, 2012
	Par value of CO bonds
	Noncallable and non-putable	$	21,546,800		$	23,732,235
	Callable	2,433,000			2,073,000
	Total par value	$	23,979,800		$	25,805,235
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 are primarily liable at September 30, 2013, and December 31, 2012, by year of contractual maturity or next call date for callable CO bonds (dollars in thousands):
	Year of Contractual Maturity or Next Call Date		September 30, 2013			December 31, 2012
	Due in one year or less		$	10,735,690		$	10,222,355
	Due after one year through two years		3,778,790			5,547,000
	Due after two years through three years		3,481,190			3,537,025
	Due after three years through four years		2,533,440			1,975,360
	Due after four years through five years		1,748,770			2,917,805
	Thereafter		1,701,920			1,605,690
	Total par value		$	23,979,800		$	25,805,235
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 September 30, 2013, and December 31, 2012 (dollars in thousands):
		September 30, 2013			December 31, 2012
	Par value of CO bonds
	Fixed-rate	$	20,124,800		$	21,385,235
	Simple variable-rate	2,970,000			3,570,000
	Step-up	885,000			850,000
	Total par value	$	23,979,800		$	25,805,235
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)
	30-Sep-13	$	10,475,911		$	10,476,500			0.05	%
	31-Dec-12	$	8,639,048		$	8,640,000			0.09	%
	_______________________
	(1)          The CO discount notes' weighted-average rate represents a yield to maturity excluding concession fees.

Affordable_Housing_Program_Tab

Affordable Housing Program (Tables)	9 Months Ended
	Sep. 30, 2013
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 nine months ended September 30, 2013, and year ended December 31, 2012 (dollars in thousands):
		September 30, 2013			December 31, 2012
	Balance at beginning of year	$	50,545		$	34,241
	AHP expense for the period	14,343			23,122
	AHP direct grant disbursements	(8,842		)	(5,415		)
	AHP subsidy for AHP advance disbursements	(327		)	(1,477		)
	Return of previously disbursed grants and subsidies	42			74
	Balance at end of period	$	55,761		$	50,545

Capital_Tables

Capital (Tables)	9 Months Ended
	Sep. 30, 2013
Capital [Abstract]	'
Compliance with Regulatory Capital Requirements [Table Text Block]	'
	The following tables demonstrate our compliance with our regulatory capital requirements at September 30, 2013, and December 31, 2012 (dollars in thousands):
	Risk-Based Capital Requirements	September 30,				December 31,
		2013				2012
	Permanent capital
	Class B capital stock	$	2,441,028			$	3,455,165
	Mandatorily redeemable capital stock	977,390				215,863
	Retained earnings	705,745				587,554
	Total permanent capital	$	4,124,163			$	4,258,582
	Risk-based capital requirement
	Credit-risk capital	$	419,065			$	473,233
	Market-risk capital	120,327				80,026
	Operations-risk capital	161,817				165,978
	Total risk-based capital requirement	$	701,209			$	719,237
	Permanent capital in excess of risk-based capital requirement	$	3,422,954			$	3,539,345
			September 30, 2013							December 31, 2012
			Required				Actual			Required			Actual
	Capital Ratio
	Risk-based capital		$	701,209			$	4,124,163		$	719,237		$	4,258,582
	Total regulatory capital		$	1,588,826			$	4,124,163		$	1,608,361		$	4,258,582
	Total capital-to-asset ratio		4		%		10.4		%	4		%	10.6		%
	Leverage Ratio
	Leverage capital		$	1,986,033			$	6,186,245		$	2,010,451		$	6,387,873
	Leverage capital-to-assets ratio		5		%		15.6		%	5		%	15.9		%

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2013
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 months ended September 30, 2013 and 2012 (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, June 30, 2012	$	(50,442	)	$	(420,392	)	$	(54,727	)	$	(2,881	)	$	(528,442	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized gains (losses)	17,525			—			(10,448		)	—			7,077
	Noncredit other-than-temporary impairment losses	—			(2,013		)	—			—			(2,013		)
	Accretion of noncredit loss	—			17,838			—			—			17,838
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			1,028			—			—			1,028
	Amortization - hedging activities (2)	—			—			4			—			4
	Amortization - pension and postretirement benefits (3)	—			—			—			(166		)	(166		)
	Other comprehensive income (loss)	17,525			16,853			(10,444		)	(166		)	23,768
	Balance, September 30, 2012	$	(32,917	)	$	(403,539	)	$	(65,171	)	$	(3,047	)	$	(504,674	)
	Balance, June 30, 2013	$	(67,119	)	$	(354,716	)	$	(47,846	)	$	(4,421	)	$	(474,102	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized losses	(17,195		)	—			(6,173		)	—			(23,368		)
	Noncredit other-than-temporary impairment losses	—			—			—			—			—
	Accretion of noncredit loss	—			14,256			—			—			14,256
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			1,448			—			—			1,448
	Amortization - hedging activities (2)	—			—			4			—			4
	Amortization - pension and postretirement benefits (3)	—			—			—			(323		)	(323		)
	Other comprehensive (loss)income	(17,195		)	15,704			(6,169		)	(323		)	(7,983		)
	Balance, September 30, 2013	$	(84,314	)	$	(339,012	)	$	(54,015	)	$	(4,744	)	$	(482,085	)
	_______________________
	(1) Recorded in net amount of impairment losses reclassified (from) to accumulated other comprehensive loss in the statement of operations.
	(2) Recorded in net gains on derivatives and hedging activities in the statement of operations.
	(3) Recorded in other operating expenses in the statement of operations.
	The following table presents a summary of changes in accumulated other comprehensive loss for the nine months ended September 30, 2013 and 2012 (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, December 31, 2011	$	(48,560	)	$	(450,996	)	$	(32,308	)	$	(2,547	)	$	(534,411	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized gains (losses)	15,643			—			(32,874		)	—			(17,231		)
	Noncredit other-than-temporary impairment losses	—			(10,931		)	—			—			(10,931		)
	Accretion of noncredit loss	—			56,131			—			—			56,131
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			2,257			—			—			2,257
	Amortization - hedging activities (2)	—			—			11			—			11
	Amortization - pension and postretirement benefits (3)	—			—			—			(500		)	(500		)
	Other comprehensive income (loss)	15,643			47,457			(32,863		)	(500		)	29,737
	Balance, September 30, 2012	$	(32,917	)	$	(403,539	)	$	(65,171	)	$	(3,047	)	$	(504,674	)
	Balance, December 31, 2012	$	(22,643	)	$	(385,175	)	$	(65,027	)	$	(3,775	)	$	(476,620	)
	Other comprehensive income (loss) before reclassifications:
	Net unrealized (losses) gains	(61,671		)	—			11,001			—			(50,670		)
	Noncredit other-than-temporary impairment losses	—			(63		)	—			—			(63		)
	Accretion of noncredit loss	—			44,000			—			—			44,000
	Reclassifications from other comprehensive income to net income
	Noncredit other-than-temporary impairment losses reclassified to credit loss (1)	—			2,226			—			—			2,226
	Amortization - hedging activities (2)	—			—			11			—			11
	Amortization - pension and postretirement benefits (3)	—			—			—			(969		)	(969		)
	Other comprehensive (loss)income	(61,671		)	46,163			11,012			(969		)	(5,465		)
	Balance, September 30, 2013	$	(84,314	)	$	(339,012	)	$	(54,015	)	$	(4,744	)	$	(482,085	)
	_______________________
	(1) Recorded in net amount of impairment losses reclassified (from) to accumulated other comprehensive loss in the statement of operations.
	(2) Recorded in net gains on derivatives and hedging activities in the statement of operations.
	(3) Recorded in other operating expenses in the statement of operations.

Employee_Retirement_Plans_Tabl

Employee Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Employee Retirement Plans [Line Items]	'
Schedule of Net Funded Status [Table Text Block]	'
	The following table sets forth our net pension costs under the Pentegra Defined Benefit Plan (dollars in thousands):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Net pension cost	$	880		$	1,104		$	1,362		$	3,212
Change in Benefit Obligation [Table Text Block]	'
	In connection with the nonqualified supplemental defined benefit retirement plan and postretirement benefits, we recorded the following amounts as of September 30, 2013, and December 31, 2012 (dollars in thousands):
		Nonqualified Supplemental Defined Benefit Retirement Plan						Postretirement Benefits
		September 30, 2013			December 31, 2012			September 30, 2013			December 31, 2012
	Change in benefit obligation (1)
	Benefit obligation at beginning of year	$	7,969		$	5,901		$	721		$	634
	Service cost	419			418			24			32
	Interest cost	271			293			22			28
	Actuarial loss	1,570			1,657			(1		)	45
	Benefits paid	(254		)	(300		)	(14		)	(18		)
	Benefit obligation at end of period	9,975			7,969			752			721
	Change in plan assets
	Fair value of plan assets at beginning of year	—			—			—			—
	Employer contribution	254			300			14			18
	Benefits paid	(254		)	(300		)	(14		)	(18		)
	Fair value of plan assets at end of period	—			—			—			—
	Funded status at end of period	$	(9,975	)	$	(7,969	)	$	(752	)	$	(721	)
	______________________
	(1)      This represents projected benefit obligation for the nonqualified supplemental defined benefit retirement plan and accumulated postretirement benefit obligation for postretirement benefits.
Net Periodic Benefit Cost [Table Text Block]	'
	The following table presents the components of net periodic benefit cost and other amounts recognized in accumulated other comprehensive loss for our nonqualified supplemental defined benefit retirement plan and postretirement benefits for the three and nine months ended September 30, 2013 and 2012 (dollars in thousands):
			Nonqualified Supplemental Defined Benefit Retirement Plan For the Three Months Ended September 30,						Postretirement Benefits For the Three Months Ended September 30,
			2013			2012			2013			2012
	Net Periodic Benefit Cost
	Service cost		$	169		$	120		$	8		$	8
	Interest cost		109			83			7			7
	Amortization of net actuarial loss		197			116			3			3
	Net periodic benefit cost		$	475		$	319		$	18		$	18
			Nonqualified Supplemental Defined Benefit Retirement Plan For the Nine Months Ended September 30,						Postretirement Benefits For the Nine Months Ended September 30,
			2013			2012			2013			2012
	Net Periodic Benefit Cost
	Service cost		$	419		$	299		$	24		$	24
	Interest cost		271			209			22			21
	Amortization of net actuarial loss		591			349			9			7
	Net periodic benefit cost		$	1,281		$	857		$	55		$	52
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 expenses relating to our defined contribution plans (dollars in thousands):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Qualified Defined Contribution Plan - Pentegra Defined Contribution Plan	$	215		$	232		$	699		$	713
	Nonqualified Defined Contribution Plan - Thrift Benefit Equalization Plan	16			11			120			80

Fair_Values_Tables

Fair Values (Tables)	9 Months Ended
	Sep. 30, 2013
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 September 30, 2013, and December 31, 2012, were as follows (dollars in thousands). These fair values do not represent an estimate of the Bank's 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.
		30-Sep-13
		Carrying			Total Fair Value			Level 1			Level 2			Level 3			Netting Adjustments and Cash Collateral
		Value
	Financial instruments
	Assets:
	Cash and due from banks	$	3,172,772		$	3,172,772		$	3,172,772		$	—		$	—		$	—
	Interest-bearing deposits	219			219			219			—			—			—
	Securities purchased under agreements to resell	1,500,000			1,499,980			—			1,499,980			—			—
	Federal funds sold	500,000			499,998			—			499,998			—			—
	Trading securities(1)	249,970			249,970			—			249,970			—			—
	Available-for-sale securities(1)	3,860,587			3,860,587			—			3,860,587			—			—
	Held-to-maturity securities(2)	4,361,134			4,700,205			—			3,080,792			1,619,413			—
	Advances	22,555,122			22,713,838			—			22,713,838			—			—
	Mortgage loans, net	3,401,111			3,457,996			—			3,457,996			—			—
	Accrued interest receivable	75,943			75,943			—			75,943			—			—
	Derivative assets(1)	4,118			4,118			—			46,674			—			(42,556		)
	Other assets (1)	9,595			9,595			4,768			4,827			—			—
	Liabilities:
	Deposits	(570,356		)	(569,439		)	—			(569,439		)	—			—
	COs:
	Bonds	(24,201,697		)	(24,384,324		)	—			(24,384,324		)	—			—
	Discount notes	(10,475,911		)	(10,476,247		)	—			(10,476,247		)	—			—
	Mandatorily redeemable capital stock	(977,390		)	(977,390		)	(977,390		)	—			—			—
	Accrued interest payable	(101,206		)	(101,206		)	—			(101,206		)	—			—
	Derivative liabilities(1)	(649,781		)	(649,781		)	—			(696,257		)	—			46,476
	Other:
	Commitments to extend credit for advances	—			(2,508		)	—			(2,508		)	—			—
	Standby letters of credit	(701		)	(701		)	—			(701		)	—			—
	_______________________
	-1	Carried at fair value on a recurring basis.
	-2	Private-label residential MBS and HFA securities are categorized as Level 3. Private-label residential MBS that have incurred other-than-temporary impairment losses are measured at fair value on a nonrecurring basis. See the recurring and nonrecurring tables below for more details.
		31-Dec-12
		Carrying			Total Fair			Level 1			Level 2			Level 3			Netting Adjustments and Cash Collateral
		Value			Value
	Financial instruments
	Assets:
	Cash and due from banks	$	240,945		$	240,945		$	240,945		$	—		$	—		$	—
	Interest-bearing deposits	192			192			192			—			—			—
	Securities purchased under agreements to resell	4,015,000			4,014,989			—			4,014,989			—			—
	Federal funds sold	600,000			599,994			—			599,994			—			—
	Trading securities(1)	274,293			274,293			—			274,293			—			—
	Available-for-sale securities(1)	5,268,237			5,268,237			—			5,268,237			—			—
	Held-to-maturity securities(2)	5,396,335			5,699,230			—			4,060,941			1,638,289			—
	Advances	20,789,704			21,168,928			—			21,168,928			—			—
	Mortgage loans, net	3,478,896			3,667,342			—			3,667,342			—			—
	Accrued interest receivable	100,404			100,404			—			100,404			—			—
	Derivative assets(1)	111			111			—			88,397			—			(88,286		)
	Other assets(1)	8,402			8,402			4,154			4,248			—			—
	Liabilities:
	Deposits	(594,968		)	(594,856		)	—			(594,856		)	—			—
	COs:
	Bonds	(26,119,848		)	(26,813,277		)	—			(26,813,277		)	—			—
	Discount notes	(8,639,048		)	(8,639,373		)	—			(8,639,373		)	—			—
	Mandatorily redeemable capital stock	(215,863		)	(215,863		)	(215,863		)	—			—			—
	Accrued interest payable	(96,356		)	(96,356		)	—			(96,356		)	—			—
	Derivative liabilities(1)	(907,092		)	(907,092		)	—			(995,378		)	—			88,286
	Other:
	Commitments to extend credit for advances	—			(229		)	—			(229		)	—			—
	Standby bond-purchase agreements	—			358			—			358			—			—
	Standby letters of credit	(523		)	(523		)	—			(523		)	—			—
	_______________________
	-1	Carried at fair value on a recurring basis.
-2	Private-label residential MBS and HFA securities are categorized as Level 3. Private-label residential MBS that have incurred other-than-temporary impairment losses are measured at fair value on a nonrecurring basis. See the recurring and nonrecurring tables below for more details.
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 September 30, 2013, and December 31, 2012, by fair-value hierarchy level (dollars in thousands):
		September 30, 2013
		Level 1			Level 2			Level 3			Netting			Total
											Adjustment (1)
	Assets:
	Trading securities:
	U.S. government-guaranteed – residential MBS	$	—		$	14,962		$	—		$	—		$	14,962
	GSEs – residential MBS	—			3,803			—			—			3,803
	GSEs – commercial MBS	—			231,205			—			—			231,205
	Total trading securities	—			249,970			—			—			249,970
	Available-for-sale securities:
	Supranational institutions	—			430,792			—			—			430,792
	U.S. government-owned corporations	—			247,345			—			—			247,345
	GSEs	—			1,048,757			—			—			1,048,757
	U.S. government guaranteed – residential MBS	—			291,530			—			—			291,530
	GSEs – residential MBS	—			1,842,163			—			—			1,842,163
	Total available-for-sale securities	—			3,860,587			—			—			3,860,587
	Derivative assets:
	Interest-rate-exchange agreements	—			46,510			—			(42,556		)	3,954
	Mortgage delivery commitments	—			164			—			—			164
	Total derivative assets	—			46,674			—			(42,556		)	4,118
	Other assets	4,768			4,827			—			—			9,595
	Total assets at fair value	$	4,768		$	4,162,058		$	—		$	(42,556	)	$	4,124,270
	Liabilities:
	Derivative liabilities
	Interest-rate-exchange agreements	$	—		$	(696,257	)	$	—		$	46,476		$	(649,781	)
	Mortgage delivery commitments	—			—			—			—			—
	Total liabilities at fair value	$	—		$	(696,257	)	$	—		$	46,476		$	(649,781	)
	_______________________
	(1)        These amounts represent the effect of master netting agreements which allow us to settle positive and negative positions and also cash collateral held or placed with the same clearing member and/or counterparty.
		December 31, 2012
		Level 1			Level 2			Level 3			Netting			Total
											Adjustment (1)
	Assets:
	Trading securities:
	U.S. government-guaranteed – residential MBS	$	—		$	16,876		$	—		$	—		$	16,876
	GSEs – residential MBS	—			4,946			—			—			4,946
	GSEs – commercial MBS	—			252,471			—			—			252,471
	Total trading securities	—			274,293			—			—			274,293
	Available-for-sale securities:
	Supranational institutions	—			473,484			—			—			473,484
	U.S. government-owned corporations	—			291,081			—			—			291,081
	GSEs	—			2,085,084			—			—			2,085,084
	U.S. government guaranteed – residential MBS	—			73,359			—			—			73,359
	GSEs – residential MBS	—			2,244,794			—			—			2,244,794
	GSEs – commercial MBS	—			100,435			—			—			100,435
	Total available-for-sale securities	—			5,268,237			—			—			5,268,237
	Derivative assets:
	Interest-rate-exchange agreements	—			88,362			—			(88,286		)	76
	Mortgage delivery commitments	—			35			—			—			35
	Total derivative assets	—			88,397			—			(88,286		)	111
	Other assets	4,154			4,248			—			—			8,402
	Total assets at fair value	$	4,154		$	5,635,175		$	—		$	(88,286	)	$	5,551,043
	Liabilities:
	Derivative liabilities
	Interest-rate-exchange agreements	$	—		$	(995,362	)	$	—		$	88,286		$	(907,076	)
	Mortgage delivery commitments	—			(16		)	—			—			(16		)
	Total liabilities at fair value	$	—		$	(995,378	)	$	—		$	88,286		$	(907,092	)
	_______________________
	(1)         These amounts represent the effect of master netting agreements which allow us to settle positive and negative positions and also cash collateral held or placed with the same counterparty. We did not hold cash collateral, including accrued interest, associated with derivatives subject to master netting agreements as of December 31, 2012.
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 at September 30, 2013, and December 31, 2012 (dollars in thousands).
		September 30, 2013
		Level 1			Level 2			Level 3			Total
	REO	$	—		$	—		$	373		$	373
		31-Dec-12
		Level 1			Level 2			Level 3			Total
	Held-to-maturity securities:
	Private-label residential MBS	$	—		$	—		$	25		$	25
	REO	—			—			195			195
	Total assets recorded at fair value on a nonrecurring basis	$	—		$	—		$	220		$	220

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Off-Balance Sheet Commitments [Table Text Block]	'
	The following table sets forth our off-balance-sheet commitments as of September 30, 2013, and December 31, 2012 (dollars in thousands):
			September 30, 2013						December 31, 2012
			Expire within one year		Expire after one year		Total		Expire within one year		Expire after one year		Total
	Standby letters of credit outstanding (1)		$	2,852,332	$	235,116	$	3,087,448	$	870,905	$	343,744	$	1,214,649
	Commitments for standby bond purchases		—		—		—		158,960		—		158,960
	Commitments for unused lines of credit - advances (2)		1,287,377		—		1,287,377		1,290,776		—		1,290,776
	Commitments to make additional advances		18,713		49,124		67,837		22,985		72,036		95,021
	Commitments to invest in mortgage loans		18,107		—		18,107		30,938		—		30,938
	Unsettled CO bonds, at par (3)		45,000		—		45,000		124,100		—		124,100
	Unsettled CO discount notes, at par		—		—		—		1,405,000		—		1,405,000
	__________________________
	-1	The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year totaling $38.4 million as of September 30, 2013. Also excluded are commitments to issue standby letters of credit that expire within one year totaling $12.6 million at December 31, 2012.
	-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 no unsettled CO bonds that were hedged with associated interest-rate swaps at September 30, 2013. We had $100.0 million in unsettled CO bonds that were hedged with associated interest-rate swaps at December 31, 2012.

Transactions_with_Shareholders1

Transactions with Shareholders (Tables)	9 Months Ended
	Sep. 30, 2013
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 September 30, 2013, and December 31, 2012 (dollars in thousands):
	As of September 30, 2013	Capital Stock			Percent			Par				Percent of Total Par Value			Total Accrued		Percent of Total
		Outstanding			of Total			Value of				of Advances			Interest		Accrued Interest
								Advances							Receivable		Receivable on
																	Advances
	Bank of America, N.A.	$	857,835		25.1	%		$	99,221			0.4	%		$	398	1.2	%
	RBS Citizens N.A.	430,077			12.6			19,298				0.1			65		0.2
	As of December 31, 2012	Capital Stock			Percent			Par				Percent of Total Par Value			Total Accrued		Percent of Total
		Outstanding			of Total			Value of				of Advances			Interest		Accrued Interest
								Advances							Receivable		Receivable on
																	Advances
	Bank of America Rhode Island, N.A.(1)	$	978,084		26.6	%		$	101,795			0.5	%		$	437	1.2	%
	RBS Citizens N.A.	484,517			13.2			519,808				2.6			109		0.3
	__________________________
	-1	Capital stock outstanding at December 31, 2012 included $1.9 million held by CW Reinsurance Company, a subsidiary of Bank of America Corporation (BANA). Bank of America Rhode Island, N.A. (BANA RI) merged into BANA, its parent, during the quarter ended June 30, 2013. BANA is ineligible for membership.
Schedule of Transactions with Shareholders, Interest Income [Table Text Block]	'
	We recognized interest income on outstanding advances from the above shareholders during the three and nine months ended September 30, 2013 and 2012 as follows (dollars in thousands):
			For the Three Months Ended September 30,							For the Nine Months Ended September 30,
			2013			2012				2013				2012
	Bank of America, N.A. (1)		$	1,295		$	2,137			$	3,984			$	5,114
	RBS Citizens N.A.		210			3,155				977				8,367
	__________________________
	-1	Includes interest income from advances outstanding to BANA RI through the date of its merger with BANA in April 2013.
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.
		Capital Stock			Percent			Par				Percent of Total Par Value			Total Accrued		Percent of Total
		Outstanding			of Total			Value of				of Advances			Interest		Accrued Interest
								Advances							Receivable		Receivable on
																	Advances
	As of September 30, 2013	$	127,020		3.7	%		$	655,493			3	%		$	1,668	5.1	%
	As of December 31, 2012	143,165			3.9			792,839				3.9			2,138		6.1

Trading_Securities_Details

Trading Securities (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'	'	'
Trading securities	$249,970	'	$249,970	'	$274,293
Net Realized and Unrealized Gain (Loss) on Trading Securities	726	4,669	-11,278	8,291	'
U.S. Government Guaranteed - Residential MBS [Member]	'	'	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'	'	'
Trading securities	14,962	'	14,962	'	16,876
GSEs b Residential MBS [Member]	'	'	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'	'	'
Trading securities	3,803	'	3,803	'	4,946
GSEs b Commercial MBS [Member]	'	'	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'	'	'
Trading securities	$231,205	'	$231,205	'	$252,471

AvailableforSale_Securities_Ma

Available-for-Sale Securities (Major Security Types) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	$3,944,901	[1]	$5,290,880	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	12,392		59,009
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-96,706		-81,652
Fair Value	3,860,587		5,268,237
Supranational institutions [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	453,905	[1]	502,177	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	0		0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-23,113		-28,693
Fair Value	430,792		473,484
U.S. government-owned corporations	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	286,097	[1]	330,106	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	0		0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-38,752		-39,025
Fair Value	247,345		291,081
GSEs [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	1,053,469	[1]	2,072,936	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	6,759		25,901
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-11,471		-13,753
Fair Value	1,048,757		2,085,084
Other Than Mortgage-backed Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	1,793,471	[1]	2,905,219	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	6,759		25,901
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-73,336		-81,471
Fair Value	1,726,894		2,849,649
U.S. Government Guaranteed - Residential MBS [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	294,051	[1]	72,862	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	453		497
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-2,974		0
Fair Value	291,530		73,359
GSEs b Residential MBS [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	1,857,379	[1]	2,212,183	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	5,180		32,611
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-20,396		0
Fair Value	1,842,163		2,244,794
GSEs b Commercial MBS [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	'		100,616	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	'		0
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	'		-181
Fair Value	'		100,435
MBS [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	2,151,430	[1]	2,385,661	[1]
Unrealized Gains Amounts Recorded in Accumulated Other Comprehensive Loss	5,633		33,108
Unrealized Losses Amounts Recorded in Accumulated Other Comprehensive Loss	-23,370		-181
Fair Value	$2,133,693	[2]	$2,418,588	[2]
[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.

AvailableforSale_Securities_Na

Available-for-Sale Securities (Narratives) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities, Unamortized Premium (Discount), Net	$66.50	$67.20
Other Than Mortgage-backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities, Unamortized Premium (Discount), Net	36.8	50.2
MBS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities, Unamortized Premium (Discount), Net	$29.70	$17

AvailableforSale_Securities_Se

Available-for-Sale Securities (Securities with Unrealized Losses) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	$1,532,928	$100,435
Less than 12 Months, Unrealized Losses	-23,370	-181
12 Months or More, Fair Value	787,848	889,018
12 Months or More, Unrealized Losses	-73,336	-81,471
Total Fair Value	2,320,776	989,453
Total Unrealized Losses	-96,706	-81,652
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	430,792	473,484
12 Months or More, Unrealized Losses	-23,113	-28,693
Total Fair Value	430,792	473,484
Total Unrealized Losses	-23,113	-28,693
U.S. government-owned corporations	'	'
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	247,345	291,081
12 Months or More, Unrealized Losses	-38,752	-39,025
Total Fair Value	247,345	291,081
Total Unrealized Losses	-38,752	-39,025
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	109,711	124,453
12 Months or More, Unrealized Losses	-11,471	-13,753
Total Fair Value	109,711	124,453
Total Unrealized Losses	-11,471	-13,753
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	787,848	889,018
12 Months or More, Unrealized Losses	-73,336	-81,471
Total Fair Value	787,848	889,018
Total Unrealized Losses	-73,336	-81,471
Residential Mortgage Backed Securities, US Government Guaranteed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	228,122	'
Less than 12 Months, Unrealized Losses	-2,974	'
12 Months or More, Fair Value	0	'
12 Months or More, Unrealized Losses	0	'
Total Fair Value	228,122	'
Total Unrealized Losses	-2,974	'
GSEs b Residential MBS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	1,304,806	'
Less than 12 Months, Unrealized Losses	-20,396	'
12 Months or More, Fair Value	0	'
12 Months or More, Unrealized Losses	0	'
Total Fair Value	1,304,806	'
Total Unrealized Losses	-20,396	'
GSEs b Commercial MBS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	'	100,435
Less than 12 Months, Unrealized Losses	'	-181
12 Months or More, Fair Value	'	0
12 Months or More, Unrealized Losses	'	0
Total Fair Value	'	100,435
Total Unrealized Losses	'	-181
MBS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	1,532,928	'
Less than 12 Months, Unrealized Losses	-23,370	'
12 Months or More, Fair Value	0	'
12 Months or More, Unrealized Losses	0	'
Total Fair Value	1,532,928	'
Total Unrealized Losses	($23,370)	'

AvailableforSale_Securities_Re

Available-for-Sale Securities (Redemption Terms) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	$3,944,901		$5,290,880
Fair Value	3,860,587		5,268,237
Other Than Mortgage-backed Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Due in One Year or Less, Amortized Cost	932,287		1,147,950
Due in One Year or Less, Fair Value	939,046		1,156,133
Due after One Year Through Five Years, Amortized Cost	0		786,779
Due after One Year Through Five Years, Fair Value	0		804,498
Due after Five Years Through Ten Years, Amortized Cost	0		0
Due after Five Years Through Ten Years, Fair Value	0		0
Due after Ten Years, Amortized Cost	861,184		970,490
Due after Ten Years, Fair Value	787,848		889,018
Amortized Cost	1,793,471		2,905,219
Fair Value	1,726,894		2,849,649
MBS [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Amortized Cost	2,151,430	[1]	2,385,661	[1]
Fair Value	$2,133,693	[1]	$2,418,588	[1]
[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.

HeldtoMaturity_Securities_Majo

Held-to-Maturity Securities Major Security Types (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	$4,700,146		$5,781,510
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	-339,012		-385,175
Carrying Value	4,361,134	[1],[2]	5,396,335	[1],[2]
Held to Maturity Securities Accumulated Unrecognized Holding Gains	385,426		358,968
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-46,355		-56,073
Fair Value	4,700,205		5,699,230
U.S. Agency Obligations [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	9,749		12,877
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	9,749		12,877
Held to Maturity Securities Accumulated Unrecognized Holding Gains	809		1,243
Held to Maturity Securities Accumulated Unrecognized Holding Losses	0		0
Fair Value	10,558		14,120
HFA Securities [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	185,156		189,719
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	185,156		189,719
Held to Maturity Securities Accumulated Unrecognized Holding Gains	48		44
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-22,056		-17,881
Fair Value	163,148		171,882
GSEs [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	67,943		69,246
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	67,943		69,246
Held to Maturity Securities Accumulated Unrecognized Holding Gains	529		1,521
Held to Maturity Securities Accumulated Unrecognized Holding Losses	0		0
Fair Value	68,472		70,767
Other Than Mortgage-backed Securities [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	262,848		271,842
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	262,848	[2]	271,842	[2]
Held to Maturity Securities Accumulated Unrecognized Holding Gains	1,386		2,808
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-22,056		-17,881
Fair Value	242,178		256,769
U.S. Government Guaranteed - Residential MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	30,128		38,313
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	30,128		38,313
Held to Maturity Securities Accumulated Unrecognized Holding Gains	672		879
Held to Maturity Securities Accumulated Unrecognized Holding Losses	0		0
Fair Value	30,800		39,192
U.S. Government Guaranteed - Commercial MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	237,527		451,559
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	237,527		451,559
Held to Maturity Securities Accumulated Unrecognized Holding Gains	1,107		8,273
Held to Maturity Securities Accumulated Unrecognized Holding Losses	0		0
Fair Value	238,634		459,832
GSEs b Residential MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	1,879,733		2,357,479
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	1,879,733		2,357,479
Held to Maturity Securities Accumulated Unrecognized Holding Gains	49,546		78,105
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-330		-337
Fair Value	1,928,949		2,435,247
GSEs b Commercial MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	757,430		957,503
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	757,430		957,503
Held to Maturity Securities Accumulated Unrecognized Holding Gains	45,949		84,282
Held to Maturity Securities Accumulated Unrecognized Holding Losses	0		-2
Fair Value	803,379		1,041,783
Private-Label Residential MBS[Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	1,506,605		1,669,041
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	-338,030		-384,051
Carrying Value	1,168,575		1,284,990
Held to Maturity Securities Accumulated Unrecognized Holding Gains	285,865		183,581
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-22,128		-34,184
Fair Value	1,432,312		1,434,387
Private-Label b Commercial MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	1,621		9,822
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	0		0
Carrying Value	1,621		9,822
Held to Maturity Securities Accumulated Unrecognized Holding Gains	8		321
Held to Maturity Securities Accumulated Unrecognized Holding Losses	0		0
Fair Value	1,629		10,143
ABS Backed by Home Equity Loans [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	24,254		25,951
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	-982		-1,124
Carrying Value	23,272		24,827
Held to Maturity Securities Accumulated Unrecognized Holding Gains	893		719
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-1,841		-3,669
Fair Value	22,324		21,877
MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	4,437,298	[3]	5,509,668	[3]
Other Than Temporary Impairment Recognized in Accumulated Other Comprehensive Loss	-339,012		-385,175
Carrying Value	4,098,286	[2],[3]	5,124,493	[2],[3]
Held to Maturity Securities Accumulated Unrecognized Holding Gains	384,040		356,160
Held to Maturity Securities Accumulated Unrecognized Holding Losses	-24,299		-38,192
Fair Value	$4,458,027	[3]	$5,442,461	[3]
[1]	Fair values of held-to-maturity securities were $4,700,205 and $5,699,230 at SeptemberB 30, 2013, and DecemberB 31, 2012, respectively.
[2]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss.
[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.

HeldtoMaturity_Securities_Narr

Held-to-Maturity Securities (Narratives) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]	'	'
Net premium (discounts) of held-to-maturity securities	($457.50)	($494.90)
Other Than Mortgage-backed Securities [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Net premium (discounts) of held-to-maturity securities	0.6	1.9
MBS [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Net premium (discounts) of held-to-maturity securities	($458.10)	($496.80)

HeldtoMaturity_Securities_Fair

Held-to-Maturity Securities Fair Value and Unrealized Losses (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]	'	'
Less than 12 Months, Fair Value	$69,404	$1,220
Less than 12 Months, Unrealized Losses	-1,440	-2
12 Months or More, Fair Value	1,189,887	1,571,697
12 Months or More, Unrealized Losses	-130,005	-264,638
Total Fair Value	1,259,291	1,572,917
Total Unrealized Losses	-131,445	-264,640
HFA Securities [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	155,814	163,864
12 Months or More, Unrealized Losses	-22,056	-17,881
Total Fair Value	155,814	163,864
Total Unrealized Losses	-22,056	-17,881
GSEs b Residential MBS [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Less than 12 Months, Fair Value	5,585	0
Less than 12 Months, Unrealized Losses	-6	0
12 Months or More, Fair Value	45,424	60,776
12 Months or More, Unrealized Losses	-324	-337
Total Fair Value	51,009	60,776
Total Unrealized Losses	-330	-337
GSEs b Commercial MBS [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Less than 12 Months, Fair Value	'	1,220
Less than 12 Months, Unrealized Losses	'	-2
12 Months or More, Fair Value	'	0
12 Months or More, Unrealized Losses	'	0
Total Fair Value	'	1,220
Total Unrealized Losses	'	-2
Private-Label Residential MBS[Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Less than 12 Months, Fair Value	63,819	0
Less than 12 Months, Unrealized Losses	-1,434	0
12 Months or More, Fair Value	966,325	1,325,876
12 Months or More, Unrealized Losses	-105,517	-242,306
Total Fair Value	1,030,144	1,325,876
Total Unrealized Losses	-106,951	-242,306
ABS Backed by Home Equity Loans [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	22,324	21,181
12 Months or More, Unrealized Losses	-2,108	-4,114
Total Fair Value	22,324	21,181
Total Unrealized Losses	-2,108	-4,114
MBS [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Less than 12 Months, Fair Value	69,404	1,220
Less than 12 Months, Unrealized Losses	-1,440	-2
12 Months or More, Fair Value	1,034,073	1,407,833
12 Months or More, Unrealized Losses	-107,949	-246,757
Total Fair Value	1,103,477	1,409,053
Total Unrealized Losses	($109,389)	($246,759)

HeldtoMaturity_Securities_Rede

Held-to-Maturity Securities Redemption Terms (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	$4,700,146		$5,781,510
Carrying Value	4,361,134	[1],[2]	5,396,335	[1],[2]
Fair Value	4,700,205		5,699,230
Other Than Mortgage-backed Securities [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Due in one year or less, Amortized Cost	67,943		0
Due in one year or less, Carrying Amount	67,943	[1]	0	[1]
Due in one year or less, Fair Value	68,472		0
Due after one year through five years, Amortized Cost	1,179		69,581
Due after one year through five years, Carrying Amount	1,179	[1]	69,581	[1]
Due after one year through five years, Fair Value	1,252		71,102
Due after five years through 10 years, Amortized Cost	30,091		32,562
Due after five years through 10 years, Carrying Amount	30,091	[1]	32,562	[1]
Due after five years through 10 years, Fair Value	30,587		33,604
Due after 10 years, Amortized Cost	163,635		169,699
Due after 10 years, Carrying Amount	163,635	[1]	169,699	[1]
Due after 10 years, Fair Value	141,867		152,063
Amortized Cost	262,848		271,842
Carrying Value	262,848	[1]	271,842	[1]
Fair Value	242,178		256,769
MBS [Member]	'		'
Schedule of Held-to-maturity Securities [Line Items]	'		'
Amortized Cost	4,437,298	[3]	5,509,668	[3]
Carrying Value	4,098,286	[1],[3]	5,124,493	[1],[3]
Fair Value	$4,458,027	[3]	$5,442,461	[3]
[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 $4,700,205 and $5,699,230 at SeptemberB 30, 2013, and DecemberB 31, 2012, 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.

OtherThanTemporary_Impairment_1

Other-Than-Temporary Impairment Projected Home Prices Recoveries (Details)	Sep. 30, 2013
Recovery Range Annualized % [Line Items]	'
OTTI Governance Committee projected housing price decline rate	5.00%
OTTI Governance Committee projected housing price increase rate	8.00%
Projected house price decline rate	1.00%
Projected house price increase rate	7.00%
Minimum [Member]	'
Recovery Range Annualized % [Line Items]	'
1-6 months	0.00%
7-12 months	1.00%
13-18 months	2.00%
19-30 months	2.00%
31-54 months	2.00%
Thereafter	2.30%
Maximum [Member]	'
Recovery Range Annualized % [Line Items]	'
1-6 months	3.00%
7-12 months	4.00%
13-18 months	4.00%
19-30 months	5.00%
31-54 months	6.00%
Thereafter	5.60%

OtherThanTemporary_Impairment_2

Other-Than-Temporary Impairment Significant Inputs (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Alt-A [Member] | Private-Label Residential MBS[Member]	'
Other than Temporary Impairment, Disclosure [Line Items]	'
Par Value	$75,287	[1]
Project Prepayment Rates - Weighted Average Percent	5.40%	[1]
Projected Default Rates, Weighted Average Percent	56.50%	[1]
Projected Loss Severities, Weighted Average Percent	44.70%	[1]
Current Credit Enhancement, Weighted Average Percent	25.10%	[1]
Alt-A [Member] | Securitization in 2007 [Member] | Private-Label Residential MBS[Member]	'
Other than Temporary Impairment, Disclosure [Line Items]	'
Par Value	65,490	[1]
Project Prepayment Rates - Weighted Average Percent	5.30%	[1]
Projected Default Rates, Weighted Average Percent	58.20%	[1]
Projected Loss Severities, Weighted Average Percent	45.10%	[1]
Current Credit Enhancement, Weighted Average Percent	25.50%	[1]
Alt-A [Member] | Securitization in 2005 [Member] | Private-Label Residential MBS[Member]	'
Other than Temporary Impairment, Disclosure [Line Items]	'
Par Value	9,797	[1]
Project Prepayment Rates - Weighted Average Percent	6.10%	[1]
Projected Default Rates, Weighted Average Percent	45.50%	[1]
Projected Loss Severities, Weighted Average Percent	41.50%	[1]
Current Credit Enhancement, Weighted Average Percent	22.30%	[1]
Subprime [Member] | Securitization in 2004 and Earlier [Member] | ABS Backed by Home Equity Loans [Member]	'
Other than Temporary Impairment, Disclosure [Line Items]	'
Par Value	$283	[1]
Project Prepayment Rates - Weighted Average Percent	1.10%	[1]
Projected Default Rates, Weighted Average Percent	38.09%	[1]
Projected Loss Severities, Weighted Average Percent	91.60%	[1]
Current Credit Enhancement, Weighted Average Percent	10.90%	[1]
[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.

OtherThanTemporary_Impairment_3

Other-Than-Temporary Impairment OTTI Credit Losses Recognized During Life of Security (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]	'
Par Value	$1,673,811
Amortized Cost	1,219,690
Carrying Value	880,678
Fair Value	1,167,383
Private-Label Residential MBS[Member] | Prime [Member]	'
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]	'
Par Value	65,201
Amortized Cost	55,351
Carrying Value	41,623
Fair Value	54,608
Private-Label Residential MBS[Member] | Alt-A [Member]	'
Other-than-temporary Impairment Credit Losses Recognized During the Life of the Security [Abstract]	'
Par Value	1,603,544
Amortized Cost	1,159,835
Carrying Value	835,533
Fair Value	1,108,360
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	5,066
Amortized Cost	4,504
Carrying Value	3,522
Fair Value	$4,415

OtherThanTemporary_Impairment_4

Other-Than-Temporary Impairment Roll-forward of Amounts Related to Credit Losses Recognized in Earnings (Details) (Held-to-maturity Securities [Member], USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Held-to-maturity Securities [Member]	'		'		'		'
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]	'		'		'		'
Balance at beginning of period	$472,243		$520,654		$497,102		$544,833
Credit losses for which other-than-temporary impairment was not previously recognized	0		0		0		0
Additional credit losses for which an other-than-temporary impairment charge was previously recognized	1,528	[1]	1,092	[1]	2,343	[1]	5,544	[1]
Securities matured during the period	-10,427		-8,065		-28,793		-32,697
Increase in cash flows expected to be collected which are recognized over the remaining life of the security	-5,864		-2,609		-13,172		-6,608
Balance at end of period	$457,480		$511,072		$457,480		$511,072
[1]	For the three months ended SeptemberB 30, 2013 and 2012, additional credit losses for which an other-than-temporary impairment charge was previously recognized relate to securities that were also previously impaired prior to July 1, 2013 and 2012. For the nine months ended SeptemberB 30, 2013 and 2012, 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, 2013 and 2012.

Advances_Year_of_Contractual_M

Advances - Year of Contractual Maturity (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Advances [Abstract]	'		'
Overdrawn demand-deposit accounts	$2,956		$12,893
Due in one year or less	10,214,001		8,273,972
Due after one year through two years	2,106,545		2,198,709
Due after two years through three years	2,400,698		1,921,353
Due after three years through four years	3,220,895		2,347,511
Due after four years through five years	2,235,554		3,033,895
Thereafter	2,027,688		2,481,519
Total par value	22,208,337		20,269,852
Overdrawn demand-deposit accounts, Weighted average rate	0.43%		0.53%
Due in one year or less, Weighted average rate	0.65%		1.00%
Due after one year through two years, Weighted average rate	2.28%		2.61%
Due after two years through three years, Weighted average rate	2.26%		2.57%
Due after three years through four years, Weighted average rate	2.82%		2.56%
Due after four years through five years, Weighted average rate	2.45%		3.04%
Thereafter, Weighted average rate	2.76%		2.96%
Total Weighted average rate	1.67%		2.05%
Premiums	52,875		52,435
Discounts	-20,298		-23,087
Market value of embedded derivatives	854	[1]	1,163	[1]
Hedging adjustments	313,354		489,341
Total Advances	$22,555,122		$20,789,704
[1]	At SeptemberB 30, 2013, and DecemberB 31, 2012, we had certain advances with embedded features that met the requirements to be separated from the host contract and designate the embedded features as a stand-alone derivative.

Advances_Outstanding_by_the_Ea

Advances - Outstanding by the Earlier of Contractual Maturity or Next Put Date (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Advances [Abstract]	'	'
Overdrawn demand-deposit accounts	$2,956	$12,893
Due in one year or less	12,648,176	11,218,147
Due after one year through two years	1,959,795	1,919,209
Due after two years through three years	2,153,298	1,779,103
Due after three years through four years	1,763,370	1,906,611
Due after four years through five years	1,704,304	1,441,870
Thereafter	1,976,438	1,992,019
Total par value	$22,208,337	$20,269,852
Overdrawn demand-deposit accounts, Percentage of Total	0.00%	0.10%
Due in one year or less, Percentage of total	57.00%	55.30%
Due after one year through two years, Percentage of total	8.80%	9.50%
Due after two years through three years, Percentage of total	9.70%	8.80%
Due after three years through four years, Percentage of total	7.90%	9.40%
Due after four years through five years, Percentage of total	7.70%	7.10%
Thereafter, Percentage of total	8.90%	9.80%
Total Percentage	100.00%	100.00%

Advances_InterestRatePayment_T

Advances - Interest-Rate-Payment Terms (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Advances [Abstract]	'	'
Fixed-rate	$21,789,381	$19,179,459
Variable-rate	418,956	1,090,393
Total par value	$22,208,337	$20,269,852

Advances_Narratives_Details

Advances - Narratives (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Federal Home Loan Bank, Advances [Line Items]	'	'
Putable Federal Home Loan Bank Advances	$2,700,000,000	$3,300,000,000
Callable Federal Home Loan Bank Advances	32,500,000	32,500,000
Federal Home Loan Bank Advances [Member]	'	'
Credit Risk Exposure and Security Terms [Abstract]	'	'
Total outstanding advances greater than $1.0 billion per borrower, amount	3,700,000,000	1,800,000,000
Minimum amount of advances outstanding per borrower disclosed herein	$1,000,000,000	'
Number of financial institutions with more than $1.0 billion advances borrowing	2	1
Total outstanding advances greater than $1.0 billion per borrower as a percentage of advances outstanding	16.70%	9.00%
Minimum [Member]	'	'
Federal Home Loan Bank, Advances [Line Items]	'	'
Interest rates of advances outstanding	-0.20%	-0.15%
Maximum [Member]	'	'
Federal Home Loan Bank, Advances [Line Items]	'	'
Interest rates of advances outstanding	8.37%	8.37%

Advances_Advances_Prepayment_F

Advances Advances - Prepayment Fees (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Advances [Abstract]	'	'	'	'
Prepayment fees received from borrowers	$12,270	$23,247	$40,644	$91,471
Less: hedging fair-value adjustments on prepaid advances	-6,123	-11,125	-19,330	-50,270
Less: net premiums associated with prepaid advances	-430	-1,433	-4,424	-1,770
Less: deferred recognition of prepayment fees received from borrowers on advance prepayments deemed to be loan modifications	-3,896	-2,893	-5,298	-4,580
Prepayment fees recognized in income on advance restructurings deemed to be extinguishments	0	4,078	6,845	9,497
Net prepayment fees recognized in income	$1,821	$11,874	$18,437	$44,348

Mortgage_Loans_Held_for_Portfo2

Mortgage Loans Held for Portfolio (Details) (USD $)

Sep. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Dec. 31, 2011

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

In Thousands, unless otherwise specified

Fixed-rate 15-year single-family mortgages

Fixed-rate 15-year single-family mortgages

Fixed-rate 20- and 30-year single-family mortgages

Fixed-rate 20- and 30-year single-family mortgages

Conventional Mortgage Loan [Member]

Conventional Mortgage Loan [Member]

Government Loan Member [Member]

Government Loan Member [Member]

Minimum [Member]

Maximum [Member]

Fixed-rate 20- and 30-year single-family mortgages

Fixed-rate 20- and 30-year single-family mortgages

Mortgage Loans on Real Estate [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Original contractual terms

'

'

'

'

'

'

'15 years

'

'

'

'

'

'

'

'20 years

'30 years

Par Value

$3,345,283

'

$3,423,108

'

'

'

$614,920

$679,153

$2,730,363

$2,743,955

$2,905,884

$2,979,067

$439,399

$444,041

'

'

Premiums

59,679

'

60,573

'

'

'

'

'

'

'

'

'

'

'

'

'

Discounts

-3,519

'

-4,021

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred derivative gains, net

1,625

'

3,650

'

'

'

'

'

'

'

'

'

'

'

'

'

Total mortgage loans held for portfolio

3,403,068

'

3,483,310

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for credit losses

-1,957

-1,999

-4,414

-5,514

-6,114

-7,800

'

'

'

'

'

'

'

'

'

'

Total mortgage loans, net of allowance for credit losses

$3,401,111

'

$3,478,896

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance_for_credit_losses_Na

Allowance for credit losses - Narratives (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
	Contracts	Contracts	Contracts	Contracts
Allowance for Credit Losses [Abstract]	'	'	'	'	'
Credit enhancement fees	$773,000	$782,000	$2,400,000	$2,300,000	'
Number of troubled debt restructurings	1	4	4	10	'
Post-modification recorded investment in the troubled debt restructurings	121,000	715,000	880,000	1,900,000	'
Recorded investment of trouble debt restructuring	3,600,000	'	3,600,000	'	2,800,000
Troubled debt restructurings - performing	2,900,000	'	2,900,000	'	1,900,000
Troubled debt restructurings - nonperforming	661,000	'	661,000	'	912,000
Number of troubled debt restructurings due to Chapter 7 bankruptcy	'	'	2	'	'
Troubled debt restructurings recorded investment due to Chapter 7 bankruptcy	'	'	509,000	'	'
Troubled debt restructuring default term	'	'	'60 days	'	'
REO	6,000,000	'	6,000,000	'	8,700,000
Carrying amount of REO sold	'	'	9,900,000	8,200,000	'
Net gain (loss) on sale of REO assets	'	'	($3,000,000)	$308,000	'

Allowance_for_credit_losses_Al

Allowance for credit losses - Allowance Rollforward (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]	'		'		'		'
Balance at beginning of period	$1,999		$6,114		$4,414		$7,800
Charge-offs	-125		-77		-310		-229
Recoveries	0		0		47		0
Provision for credit losses	83		'		'		'
Reduction of provision for credit losses	'		-523		-2,194		-2,057
Balance at end of period	1,957		5,514		1,957		5,514
Ending balance, individually evaluated for impairment	562		0		562		0
Ending balance, collectively evaluated for impairment	1,395		5,514		1,395		5,514
Individually evaluated for impairment	6,743	[1]	2,256	[1]	6,743	[1]	2,256	[1]
Collectively evaluated for impairment	$2,961,768	[1]	$3,041,201	[1]	$2,961,768	[1]	$3,041,201	[1]
[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 b Government Mortgage Loans Held for Portfolio.

Allowance_for_credit_losses_Cr

Allowance for credit losses - Credit Quality Indicators (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Mortgage Loans Past Due [Line Items]	'		'
Past due 30-59 days delinquent	$47,781		$51,171
Past due 60-89 days delinquent	16,709		16,798
Past due 90 days or more delinquent	64,598		74,642
Total past due	129,088		142,611
Total current loans	3,291,134		3,358,584
Total mortgage loans	3,420,222		3,501,195
In process of foreclosure, included above	24,654	[1]	34,602	[1]
Serious delinquency rate	1.91%	[2]	2.15%	[2]
Past due 90 days or more still accruing interest	19,489		23,715
Loans on nonaccrual status	45,409	[3]	51,609	[3]
Number of days past due, loans at serious delinquent status	'90 days		'
Conventional Mortgage Loan [Member]	'		'
Mortgage Loans Past Due [Line Items]	'		'
Past due 30-59 days delinquent	32,392		36,720
Past due 60-89 days delinquent	13,091		12,339
Past due 90 days or more delinquent	45,109		50,927
Total past due	90,592		99,986
Total current loans	2,877,919		2,944,184
Total mortgage loans	2,968,511		3,044,170
In process of foreclosure, included above	17,945	[1]	23,580	[1]
Serious delinquency rate	1.55%	[2]	1.70%	[2]
Past due 90 days or more still accruing interest	0		0
Loans on nonaccrual status	45,409	[3]	51,609	[3]
Government Loan Member [Member]	'		'
Mortgage Loans Past Due [Line Items]	'		'
Past due 30-59 days delinquent	15,389		14,451
Past due 60-89 days delinquent	3,618		4,459
Past due 90 days or more delinquent	19,489		23,715
Total past due	38,496		42,625
Total current loans	413,215		414,400
Total mortgage loans	451,711		457,025
In process of foreclosure, included above	6,709	[1]	11,022	[1]
Serious delinquency rate	4.31%	[2]	5.19%	[2]
Past due 90 days or more still accruing interest	19,489		23,715
Loans on nonaccrual status	$0	[3]	$0	[3]
[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_In

Allowance for credit losses - Individually Evaluated Impaired Loans (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Allowance for Credit Losses [Abstract]	'	'	'	'	'
Individually evaluated impaired mortgage loans with no related allowance - recorded investment	$3,524	'	$3,524	'	$2,752
Individually evaluated impaired mortgage loans with no related allowance - par value	3,479	'	3,479	'	2,726
Individually evaluated impaired mortgage loans with related allowance - recorded Investment	3,219	'	3,219	'	0
Individually evaluated impaired mortgage loans with related allowance - par value	3,197	'	3,197	'	0
Individually evaluated impaired mortgage loans - related allowance	562	'	562	'	0
Individually evaluated impaired mortgage loans - recorded investment	6,743	'	6,743	'	2,752
Individually evaluated impaired mortgage loans, par value	6,676	'	6,676	'	2,726
Individually evaluated impaired mortgage loans with no related allowance - average recorded investment	3,516	2,282	3,315	1,513	'
Individually evaluated impaired mortgage loans with no related Allowance - interest income, accrual method	31	27	140	54	'
Individually evaluated impaired mortgage loans with related allowance, average recorded investment	4,144	0	2,072	0	'
Individually evaluated impaired mortgage loans with related allowance, interest income, accrual method	1	0	3	0	'
Individually evaluated impaired mortgage loans - average recorded investment	7,660	2,282	5,387	1,513	'
Individually evaluated impaired mortgage loans - interest income, accrual method	$32	$27	$143	$54	'

Allowance_for_credit_losses_Im

Allowance for credit losses - Impact of Loss Mitigation Features (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Allowance for Credit Losses [Abstract]	'	'	'	'	'	'
Total estimated losses	$3,902	'	$10,053	'	'	'
Less: estimated losses in excess of the first-loss account, to be absorbed by participating financial institutions	-1,208	'	-5,010	'	'	'
Less: estimated performance-based credit-enhancement fees available for recapture	-737	'	-629	'	'	'
Net allowance for credit losses	$1,957	$1,999	$4,414	$5,514	$6,114	$7,800

Derivatives_and_Hedging_Activi2

Derivatives and Hedging Activities Derivatives in Statement of Condition (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'		'
Notional Amount of Derivatives Designated as Hedging Instruments	$13,609,840		$15,845,750
Derivative Assets Designated as Hedging Instruments	45,740		87,463	[1]
Derivative Liabilities Designated as Hedging Instruments	-673,323		-961,145
Notional Amount of Derivatives Not Designated as Hedging Instruments	1,591,607		1,695,438
Derivatives Assets Not Designated as Hedging Instruments	934		934
Derivatives Liabilities Not Designated as Hedging Instruments	-22,934		-34,233
Notional Amount of Derivatives	15,201,447		17,541,188
Derivative Assets, Before Netting and Collateral Adjustments	46,674		88,397
Derivative Liabilities, Before Netting and Collateral Adjustments	-696,257		-995,378
Derivative Assets	4,118		111
Derivative Liabilities	-649,781		-907,092
Netting Adjustments [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Derivative Asset, Amount Offset Against Collateral	-46,476	[2]	-88,286	[2]
Derivative Liability, Amount Offset Against Collateral	46,476	[2]	88,286	[2]
Derivative Assets	-42,556	[3]	-88,286
Derivative Liabilities	46,476	[3]	88,286
Interest-Rate Swaps [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Notional Amount of Derivatives Designated as Hedging Instruments	12,359,840		14,595,750
Derivative Assets Designated as Hedging Instruments	45,740		87,463
Derivative Liabilities Designated as Hedging Instruments	-619,480		-896,248
Notional Amount of Derivatives Not Designated as Hedging Instruments	1,273,500		1,364,500
Derivatives Assets Not Designated as Hedging Instruments	665		849
Derivatives Liabilities Not Designated as Hedging Instruments	-22,934		-34,217
Forward-start interest-rate swaps	'		'
Derivatives, Fair Value [Line Items]	'		'
Notional Amount of Derivatives Designated as Hedging Instruments	1,250,000		1,250,000
Derivative Assets Designated as Hedging Instruments	0		0
Derivative Liabilities Designated as Hedging Instruments	-53,843		-64,897
Interest-Rate Caps or Floors [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Notional Amount of Derivatives Not Designated as Hedging Instruments	300,000		300,000
Derivatives Assets Not Designated as Hedging Instruments	105		50
Derivatives Liabilities Not Designated as Hedging Instruments	0		0
Mortgage-Delivery Commmitment [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Notional Amount of Derivatives Not Designated as Hedging Instruments	18,107	[4]	30,938	[4]
Derivatives Assets Not Designated as Hedging Instruments	164	[4]	35	[4]
Derivatives Liabilities Not Designated as Hedging Instruments	0	[4]	-16	[4]
Cash Collateral And Related Accrued Interest [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Derivative Asset, Amount Offset Against Collateral	3,920		'
Derivative Liability, Amount Offset Against Collateral	$0		'
[1]	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At DecemberB 31, 2012, we had additional net exposure of $18.0 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.
[2]	Amounts represent the effect of master-netting agreements intended to allow us to settle positive and negative positions with the same counterparty.
[3]	Carried at fair value on a recurring basis.
[4]	Mortgage-delivery commitments are classified as derivatives with changes in fair value recorded in other income.

Derivatives_and_Hedging_Activi3

Derivatives and Hedging Activities Derivatives in Statement of Income (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Gain on Cash Flow Hedge Ineffectiveness	$13	$0	$53	$0
Derivatives not designated as hedging instruments	-1,574	-2,683	4,295	-8,764
Net (losses) gains on derivatives and hedging activities	-1,070	-2,086	6,175	-8,509
Interest-Rate Swaps [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivatives and hedged items in fair-value hedging relationships	491	597	1,827	255
Derivatives not designated as hedging instruments	-1,611	-3,243	5,720	-10,105
Interest-Rate Caps or Floors [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivatives not designated as hedging instruments	-67	-207	55	-745
Mortgage-Delivery Commmitment [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivatives not designated as hedging instruments	$104	$767	($1,480)	$2,086

Derivatives_and_Hedging_Activi4

Derivatives and Hedging Activities Derivatives in Statement of Income and Impact on Interest (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Gain/(Loss) on Derivative	$41,282		$1,780		$220,970		($59,583)
Gain/(Loss) on Hedged Item	-40,791		-1,183		-219,143		59,838
Net Fair-Value Hedge Ineffectiveness	491		597		1,827		255
Effect of Derivatives on Net Interest Income	-31,870	[1]	-34,737	[1]	-89,263	[1]	-110,130	[1]
Advances [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Gain/(Loss) on Derivative	21,441		1,375		176,729		55,505
Gain/(Loss) on Hedged Item	-21,300		-1,116		-175,986		-56,798
Net Fair-Value Hedge Ineffectiveness	141		259		743		-1,293
Effect of Derivatives on Net Interest Income	-36,468	[1]	-45,869	[1]	-114,058	[1]	-149,548	[1]
Investments [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Gain/(Loss) on Derivative	16,806		7,645		111,118		-5,066
Gain/(Loss) on Hedged Item	-16,418		-7,183		-109,922		6,321
Net Fair-Value Hedge Ineffectiveness	388		462		1,196		1,255
Effect of Derivatives on Net Interest Income	-9,437	[1]	-10,256	[1]	-29,004	[1]	-30,626	[1]
Deposits [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Gain/(Loss) on Derivative	-372		-293		-1,150		-908
Gain/(Loss) on Hedged Item	372		293		1,150		908
Net Fair-Value Hedge Ineffectiveness	0		0		0		0
Effect of Derivatives on Net Interest Income	395	[1]	385	[1]	1,183	[1]	1,151	[1]
COs - Bonds [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Gain/(Loss) on Derivative	3,407		-6,947		-65,727		-109,114
Gain/(Loss) on Hedged Item	-3,445		6,823		65,615		109,407
Net Fair-Value Hedge Ineffectiveness	-38		-124		-112		293
Effect of Derivatives on Net Interest Income	$13,640	[1]	$21,003	[1]	$52,616	[1]	$68,893	[1]
[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_Activi5

Derivatives and Hedging Activities Narratives (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Derivative [Line Items]	'		'	'		'
Gain (Loss) recognized in other comprehensive income for hedged items in cash-flow hedging relationships	($6,173,000)		($10,448,000)	$11,001,000		($32,874,000)
Maximum length of time which we are hedging our exposure to the variability in future cash flows for forecasted transactions	'		'	'6 years		'
Deferred net losses on derivative instruments accumulated in other comprehensive loss	3,300,000		'	3,300,000		'
Aggregate fair value of all derivative instruments with credit-risk-related contingent features that were in a net liability position	649,800,000		'	649,800,000		'
Post-haircut value of collateral already posted	502,800,000		'	502,800,000		'
Rating Downgrade from AA+ to AA or AA - [Member]	'		'	'		'
Derivative [Line Items]	'		'	'		'
Additional collateral	39,587,000	[1],[2]	'	39,587,000	[1],[2]	'
Rating Downgrade From AA- to A+, A or A -[Member]	'		'	'		'
Derivative [Line Items]	'		'	'		'
Additional collateral	53,117,000	[1],[2]	'	53,117,000	[1],[2]	'
Rating Downgrade From A- to below A- [Member]	'		'	'		'
Derivative [Line Items]	'		'	'		'
Additional collateral	39,152,000	[1],[2]	'	39,152,000	[1],[2]	'
AA+ Rating [Member]	'		'	'		'
Derivative [Line Items]	'		'	'		'
Additional collateral	$14,400,000		'	$14,400,000		'
[1]	Ratings are expressed in this table according to S&P's conventions but include the equivalent of such rating by Moody's. If there is a split rating, the lower rating is used.
[2]	Additional collateral of $14.4 million could be called by counterparties as of SeptemberB 30, 2013, 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.

Derivatives_and_Hedging_Activi6

Derivatives and Hedging Activities Fair Value of Derivative Instruments With or Without Legal Rights of Offset (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Derivative [Line Items]	'		'
Derivative Assets, Gross recognized amount	$46,510,000		$88,362,000
Derivative Liabilities, Gross recognized amount	-696,257,000		-995,362,000
Derivative Assets, Gross amounts of netting adjustments and cash collateral	-42,556,000		-88,286,000
Derivative Liabilities, Gross amounts of netting adjustments and cash collateral	46,476,000		88,286,000
Derivative Assets, Net amounts after netting adjustments and cash collateral	3,954,000		76,000
Derivative Liabilities, Net amounts after netting adjustments and cash collateral	-649,781,000		-907,076,000
Derivative Assets, Derivative instruments without legal right of offset	164,000	[1]	35,000	[1]
Derivative Liabilities, Derivative instruments without legal right of offset	0	[1]	-16,000	[1]
Derivative Assets	4,118,000		111,000
Derivative Liabilities	-649,781,000		-907,092,000
Derivative Assets, Fair Value of Securities Pledged as Collateral that May Be Sold or Repledged	0	[2]	0
Derivative Liabilities, Fair value of securities pledged as collateral that may be sold or repledged	73,770,000	[2]	115,339,000	[3]
Derivative Liabilities, Fair value of securities pledged as collateral that may not be sold or repledged	448,670,000	[2]	672,890,000	[3]
Net unsecured amount of derivative assets after related delivery of collateral	4,118,000		111,000
Net unsecured amount of derivative liabilities after related delivery of collateral	-127,341,000		-118,863,000
Derivative Liabilities, additional net exposure, collateral pledged to counterparties in excess of net liabilities	6,800,000		18,000,000
Over the Counter [Member]	'		'
Derivative [Line Items]	'		'
Derivative Assets, Gross recognized amount	43,620,000		'
Derivative Liabilities, Gross recognized amount	-693,225,000		'
Derivative Assets, Gross amounts of netting adjustments and cash collateral	-43,444,000		'
Derivative Liabilities, Gross amounts of netting adjustments and cash collateral	43,444,000		'
Derivative Assets, Net amounts after netting adjustments and cash collateral	176,000		'
Derivative Liabilities, Net amounts after netting adjustments and cash collateral	-649,781,000		'
Derivative Assets, Derivative instruments without legal right of offset	164,000		'
Derivative Liabilities, Derivative instruments without legal right of offset	0		'
Derivative Assets	340,000		'
Derivative Liabilities	-649,781,000		'
Derivative Assets, Fair Value of Securities Pledged as Collateral that May Be Sold or Repledged	0		'
Derivative Liabilities, Fair value of securities pledged as collateral that may be sold or repledged	73,770,000		'
Derivative Liabilities, Fair value of securities pledged as collateral that may not be sold or repledged	448,670,000		'
Net unsecured amount of derivative assets after related delivery of collateral	340,000		'
Net unsecured amount of derivative liabilities after related delivery of collateral	-127,341,000		'
Exchange Cleared [Member]	'		'
Derivative [Line Items]	'		'
Derivative Assets, Gross recognized amount	2,890,000		'
Derivative Liabilities, Gross recognized amount	-3,032,000		'
Derivative Assets, Gross amounts of netting adjustments and cash collateral	888,000		'
Derivative Liabilities, Gross amounts of netting adjustments and cash collateral	3,032,000		'
Derivative Assets, Net amounts after netting adjustments and cash collateral	3,778,000		'
Derivative Liabilities, Net amounts after netting adjustments and cash collateral	0		'
Derivative Assets	3,778,000		'
Derivative Liabilities	0		'
Net unsecured amount of derivative assets after related delivery of collateral	3,778,000		'
Net unsecured amount of derivative liabilities after related delivery of collateral	$0		'
[1]	Consists of mortgage delivery commitments.
[2]	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At SeptemberB 30, 2013, we had additional net exposure of $6.8 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.
[3]	Includes non-cash collateral at fair value. Any overcollateralization with a counterparty is not included in the determination of the net unsecured amount. At DecemberB 31, 2012, we had additional net exposure of $18.0 million due to instances where our collateral pledged to a counterparty exceeded our net liability position.

Deposits_Details

Deposits (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Deposits [Abstract]	'	'
Hedging adjustment	$1,500,000	$2,700,000
Interest bearing deposit demand and overnight	529,641,000	530,887,000
Interest bearing deposit term	20,919,000	21,638,000
Interest bearing deposit other	3,247,000	4,915,000
Non-interest Bearing Deposits Other	16,549,000	37,528,000
Total Deposits	570,356,000	594,968,000
Aggregate amount of time deposits with a denomination of $100,000 or more	$20,000,000	$20,000,000

Consolidated_Obligations_Detai

Consolidated Obligations (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
CO Bonds [Abstract]	'		'
Total	$24,201,697		$26,119,848
COs b Discount Notes [Abstract]	'		'
Federal Home Loan Bank, Consolidated Obligations, Discount Notes	10,475,911		8,639,048
COs - Discount notes [Member]	'		'
COs b Discount Notes [Abstract]	'		'
Federal Home Loan Bank, Consolidated Obligations, Discount Notes	10,475,911		8,639,048
Par Value	10,476,500		8,640,000
Weighted Average Rate	0.05%	[1]	0.09%	[1]
COs - Bonds [Member]	'		'
CO Bonds [Abstract]	'		'
Due in one year or less	8,452,690		8,344,355
Due in one year or less, Weighted average rate	1.08%	[2]	1.67%	[2]
Due after one year through two years	3,738,790		5,447,000
Due after one year through two years, Weighted average rate	2.10%	[2]	1.36%	[2]
Due after two years through three years	3,426,190		3,482,025
Due after two years through three years, Weighted average rate	2.24%	[2]	2.44%	[2]
Due after three years through four years	2,508,440		1,975,360
Due after three years through four years, Weighted average rate	1.92%	[2]	2.34%	[2]
Due after four years through five years	1,983,770		3,122,805
Due after four years through five years, Weighted average rate	2.31%	[2]	2.22%	[2]
Thereafter	3,869,920		3,433,690
Thereafter, Weighted average rate	2.48%	[2]	2.55%	[2]
Par Value	23,979,800		25,805,235
Total, Weighted average rate	1.82%	[2]	1.94%	[2]
Premiums	241,497		270,614
Discounts	-20,826		-22,842
Hedging adjustment	1,226		66,841
Total	24,201,697		26,119,848
COs - Bonds [Member] | Fixed Interest Rate [Member]	'		'
CO Bonds [Abstract]	'		'
Par Value	20,124,800		21,385,235
COs - Bonds [Member] | Simple variable rate [Member]	'		'
CO Bonds [Abstract]	'		'
Par Value	2,970,000		3,570,000
COs - Bonds [Member] | Step-up [Member]	'		'
CO Bonds [Abstract]	'		'
Par Value	885,000		850,000
COs - Bonds [Member] | Earlier of Contractual Maturity or Next Call Date [Member]	'		'
CO Bonds [Abstract]	'		'
Due in one year or less	10,735,690		10,222,355
Due after one year through two years	3,778,790		5,547,000
Due after two years through three years	3,481,190		3,537,025
Due after three years through four years	2,533,440		1,975,360
Due after four years through five years	1,748,770		2,917,805
Thereafter	1,701,920		1,605,690
COs - Bonds [Member] | Noncallable and non-putable [Member]	'		'
CO Bonds [Abstract]	'		'
Par Value	21,546,800		23,732,235
COs - Bonds [Member] | Callable [Member]	'		'
CO Bonds [Abstract]	'		'
Par Value	$2,433,000		$2,073,000
[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_Det

Affordable Housing Program (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Affordable Housing Program [Abstract]	'	'	'	'	'
Principal outstanding in AHP advances	$97,600,000	'	$97,600,000	'	$99,900,000
Affordable Housing Program [Roll Forward]	'	'	'	'	'
Balance at beginning of year	'	'	50,545,000	34,241,000	34,241,000
AHP expense for the period	4,333,000	5,675,000	14,343,000	17,160,000	23,122,000
AHP direct grant disbursements	'	'	-8,842,000	-4,313,000	-5,415,000
AHP subsidy for AHP advance disbursements	'	'	-327,000	'	-1,477,000
Return of previously disbursed grants and subsidies	'	'	42,000	'	74,000
Balance at end of period	$55,761,000	'	$55,761,000	'	$50,545,000

Capital_Details

Capital (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
			FHLBanks [Member]
Capital [Line Items]	'	'	'
Multiplier for Determining Permanent Capital in Leverage Capital Calculation	1.5	'	'
Class B capital stock	$2,441,028,000	$3,455,165,000	'
Mandatorily redeemable capital stock	977,390,000	215,863,000	'
Retained earnings	705,745,000	587,554,000	'
Total permanent capital	4,124,163,000	4,258,582,000	'
Credit-risk capital	419,065,000	473,233,000	'
Market-risk capital	120,327,000	80,026,000	'
Operations-risk capital	161,817,000	165,978,000	'
Risk-based capital required	701,209,000	719,237,000	'
Excess of risk-based capital requirement	3,422,954,000	3,539,345,000	'
Regulatory Capital, Required	1,588,826,000	1,608,361,000	'
Capital-to-asset ratio required	4.00%	4.00%	'
Leverage capital required	1,986,033,000	2,010,451,000	'
Leverage capital-to-assets ratio required	5.00%	5.00%	'
Actual risk-based capital	4,124,163,000	4,258,582,000	'
Actual regulatory capital	4,124,163,000	4,258,582,000	'
Actual capital-to-asset ratio	10.40%	10.60%	'
Actual leverage capital	6,186,245,000	6,387,873,000	'
Actual leverage capital-to-assets ratio	15.60%	15.90%	'
Quarterly percentage of net income contributed to restricted retained earnings per the Joint Capital Enhancement Agreement	'	'	20.00%
Percent of average balance of outstanding consolidated obligations required per Joint Capital Enhancement Agreement for each previous quarter	'	'	1.00%
Contribution requirement - Restricted Retained Earnings	358,100,000	'	'
Restricted retained earnings	$89,752,000	$64,351,000	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Noncredit other-than-temporary impairment losses	$0	($2,013)	($63)	($10,931)
Amortization - hedging activities	4	4	11	11
Amortization - pension and postretirement benefits	-323	-166	-969	-500
Net Unrealized Loss Relating to Hedging Activities [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	-47,846	-54,727	-65,027	-32,308
Net Unrealized (losses) gains	-6,173	-10,448	11,001	-32,874
Amortization - hedging activities	4	4	11	11
Other comprehensive (loss) income	-6,169	-10,444	11,012	-32,863
Ending balance	-54,015	-65,171	-54,015	-65,171
Pension and Postretirement Benefits [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	-4,421	-2,881	-3,775	-2,547
Amortization - pension and postretirement benefits	-323	-166	-969	-500
Other comprehensive (loss) income	-323	-166	-969	-500
Ending balance	-4,744	-3,047	-4,744	-3,047
Accumulated Other Comprehensive Income (Loss) [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	-474,102	-528,442	-476,620	-534,411
Net Unrealized (losses) gains	-23,368	7,077	-50,670	-17,231
Noncredit other-than-temporary impairment losses	0	-2,013	-63	-10,931
Accretion of noncredit loss	14,256	17,838	44,000	56,131
Noncredit other-than-temporary impairment losses reclassified to credit loss	1,448	1,028	2,226	2,257
Amortization - hedging activities	4	4	11	11
Amortization - pension and postretirement benefits	-323	-166	-969	-500
Other comprehensive (loss) income	-7,983	23,768	-5,465	29,737
Ending balance	-482,085	-504,674	-482,085	-504,674
Available-for-sale Securities [Member] | Net Unrealized Loss on Available-for-Sale Securities [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	-67,119	-50,442	-22,643	-48,560
Net Unrealized (losses) gains	-17,195	17,525	-61,671	15,643
Other comprehensive (loss) income	-17,195	17,525	-61,671	15,643
Ending balance	-84,314	-32,917	-84,314	-32,917
Held-to-maturity Securities [Member] | Net Noncredit Portion of Other-Than-Temporary Impairment Losses on Held-to-Maturity Securities [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	-354,716	-420,392	-385,175	-450,996
Noncredit other-than-temporary impairment losses	0	-2,013	-63	-10,931
Accretion of noncredit loss	14,256	17,838	44,000	56,131
Noncredit other-than-temporary impairment losses reclassified to credit loss	1,448	1,028	2,226	2,257
Other comprehensive (loss) income	15,704	16,853	46,163	47,457
Ending balance	($339,012)	($403,539)	($339,012)	($403,539)

Employee_Retirement_Plans_Net_

Employee Retirement Plans - Net Pension Costs (Details) (Pentegra Defined Benefit Plan [Member], USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pentegra Defined Benefit Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Multiemployer Plan, Period Contributions	$880	$1,104	$1,362	$3,212

Employee_Retirement_Plans_Cost

Employee Retirement Plans - Costs of Retirement Plans (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Pentegra Defined Contribution Plan [Member]	'	'	'	'	'
Employee Retirement Plans [Line Items]	'	'	'	'	'
Pension and Other Postretirement Benefit Expense	$215,000	$232,000	$699,000	$713,000	'
Thrift Benefit Equalization Plan [Member]	'	'	'	'	'
Employee Retirement Plans [Line Items]	'	'	'	'	'
Pension and Other Postretirement Benefit Expense	16,000	11,000	120,000	80,000	'
Nonqualified defined contribution plan obligation	$4,700,000	'	$4,700,000	'	$3,600,000

Employee_Retirement_Plans_Nonq

Employee Retirement Plans - Nonqualified Supplemental Defined Benefit and Postretirement Benefits (Details) (USD $)	3 Months Ended			9 Months Ended				12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Supplemental Employee Retirement Plans, Defined Benefit [Member]	'		'	'		'		'
Change in benefit obligation [Roll Forward]	'		'	'		'		'
Benefit obligation at beginning of year	'		'	$7,969	[1]	$5,901	[1]	$5,901	[1]
Service Cost	169		120	419	[1]	299		418	[1]
Interest Cost	109		83	271	[1]	209		293	[1]
Actuarial loss	'		'	1,570	[1]	'		1,657	[1]
Benefits paid	'		'	-254	[1]	'		-300	[1]
Benefit obligation at end of period	9,975	[1]	'	9,975	[1]	'		7,969	[1]
Change in plan assets [Roll Forward]	'		'	'		'		'
Fair value of plan assets at beginning of year	'		'	0		0		0
Employer contribution	'		'	254		'		300
Benefits paid	'		'	-254	[1]	'		-300	[1]
Fair value of plan assets at end of period	0		'	0		'		0
Funded status at end of period	-9,975		'	-9,975		'		-7,969
Other Postretirement Benefit Plans, Defined Benefit [Member]	'		'	'		'		'
Change in benefit obligation [Roll Forward]	'		'	'		'		'
Benefit obligation at beginning of year	'		'	721	[1]	634	[1]	634	[1]
Service Cost	8		8	24	[1]	24		32	[1]
Interest Cost	7		7	22	[1]	21		28	[1]
Actuarial loss	'		'	-1	[1]	'		45	[1]
Benefits paid	'		'	-14	[1]	'		-18	[1]
Benefit obligation at end of period	752	[1]	'	752	[1]	'		721	[1]
Change in plan assets [Roll Forward]	'		'	'		'		'
Fair value of plan assets at beginning of year	'		'	0		0		0
Employer contribution	'		'	14		'		18
Benefits paid	'		'	-14	[1]	'		-18	[1]
Fair value of plan assets at end of period	0		'	0		'		0
Funded status at end of period	($752)		'	($752)		'		($721)
[1]	This represents projected benefit obligation for the nonqualified supplemental defined benefit retirement plan and accumulated postretirement benefit obligation for postretirement benefits.

Employee_Retirement_Plans_Comp

Employee Retirement Plans Components of net periodic benefit cost and other amounts recognized in AOCL (Details) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Supplemental Employee Retirement Plans, Defined Benefit [Member]	'	'	'		'	'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'	'	'		'	'
Service Cost	$169	$120	$419	[1]	$299	$418	[1]
Interest Cost	109	83	271	[1]	209	293	[1]
Amortization of net actuarial loss	197	116	591		349	'
Net periodic benefit cost	475	319	1,281		857	'
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'		'	'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'	'	'		'	'
Service Cost	8	8	24	[1]	24	32	[1]
Interest Cost	7	7	22	[1]	21	28	[1]
Amortization of net actuarial loss	3	3	9		7	'
Net periodic benefit cost	$18	$18	$55		$52	'
[1]	This represents projected benefit obligation for the nonqualified supplemental defined benefit retirement plan and accumulated postretirement benefit obligation for postretirement benefits.

Fair_Values_Carrying_Value_and

Fair Values (Carrying Value and Fair Value of Financial Instruments) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Trading securities	$249,970		$274,293
Available-for-sale securities	3,860,587		5,268,237
Held-to-maturity Securities	4,361,134	[1],[2]	5,396,335	[1],[2]
Held-to-maturity securities	4,700,205		5,699,230
Derivative Asset	4,118		111
Mandatorily redeemable capital stock	-977,390		-215,863
Derivative Liabilities	-649,781		-907,092
Level 1 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Cash and due from banks	3,172,772		240,945
Interest-bearing deposits	219		192
Securities purchased under agreements to resell	0		0
Federal funds sold	0		0
Trading securities	0	[3]	0
Available-for-sale securities	0	[3]	0
Held-to-maturity securities	0	[4]	0
Advances	0		0
Mortgage loans, net	0		0
Accrued interest receivable	0		0
Derivative Asset	0	[3]	0
Other Assets	4,768	[3]	4,154
Deposits	0		0
Mandatorily redeemable capital stock	-977,390		-215,863
Accrued interest payable	0		0
Derivative Liabilities	0	[3]	0
Level 2 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Cash and due from banks	0		0
Interest-bearing deposits	0		0
Securities purchased under agreements to resell	1,499,980		4,014,989
Federal funds sold	499,998		599,994
Trading securities	249,970	[3]	274,293
Available-for-sale securities	3,860,587	[3]	5,268,237
Held-to-maturity securities	3,080,792	[4]	4,060,941
Advances	22,713,838		21,168,928
Mortgage loans, net	3,457,996		3,667,342
Accrued interest receivable	75,943		100,404
Derivative Asset	46,674	[3]	88,397
Other Assets	4,827	[3]	4,248
Deposits	-569,439		-594,856
Mandatorily redeemable capital stock	0		0
Accrued interest payable	-101,206		-96,356
Derivative Liabilities	-696,257	[3]	-995,378
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	0	[3]	0
Available-for-sale securities	0	[3]	0
Held-to-maturity securities	1,619,413	[4]	1,638,289
Advances	0		0
Mortgage loans, net	0		0
Accrued interest receivable	0		0
Derivative Asset	0	[3]	0
Other Assets	0	[3]	0
Deposits	0		0
Mandatorily redeemable capital stock	0		0
Accrued interest payable	0		0
Derivative Liabilities	0	[3]	0
Netting Adjustments and Cash Collateral [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	0	[3]	0
Available-for-sale securities	0	[3]	0
Held-to-maturity securities	0	[4]	0
Advances	0		0
Mortgage loans, net	0		0
Accrued interest receivable	0		0
Derivative Asset	-42,556	[3]	-88,286
Other Assets	0	[3]	0
Deposits	0		0
Mandatorily redeemable capital stock	0		0
Accrued interest payable	0		0
Derivative Liabilities	46,476	[3]	88,286
Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Cash and due from banks	3,172,772		240,945
Interest-bearing deposits	219		192
Securities purchased under agreements to resell	1,500,000		4,015,000
Federal funds sold	500,000		600,000
Trading securities	249,970	[3]	274,293
Available-for-sale securities	3,860,587	[3]	5,268,237
Held-to-maturity Securities	4,361,134	[4]	5,396,335
Advances	22,555,122		20,789,704
Mortgage loans, net	3,401,111		3,478,896
Accrued interest receivable	75,943		100,404
Derivative Asset	4,118	[3]	111
Other Assets	9,595	[3]	8,402
Deposits	-570,356		-594,968
Mandatorily redeemable capital stock	-977,390		-215,863
Accrued interest payable	-101,206		-96,356
Derivative Liabilities	-649,781	[3]	-907,092
Total Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Cash and due from banks	3,172,772		240,945
Interest-bearing deposits	219		192
Securities purchased under agreements to resell	1,499,980		4,014,989
Federal funds sold	499,998		599,994
Trading securities	249,970	[3]	274,293
Available-for-sale securities	3,860,587	[3]	5,268,237
Held-to-maturity securities	4,700,205	[4]	5,699,230
Advances	22,713,838		21,168,928
Mortgage loans, net	3,457,996		3,667,342
Accrued interest receivable	75,943		100,404
Derivative Asset	4,118	[3]	111
Other Assets	9,595	[3]	8,402
Deposits	-569,439		-594,856
Mandatorily redeemable capital stock	-977,390		-215,863
Accrued interest payable	-101,206		-96,356
Derivative Liabilities	-649,781	[3]	-907,092
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	-24,384,324		-26,813,277
COs - Bonds [Member] | Level 3 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Bonds	0		0
COs - Bonds [Member] | Netting Adjustments and Cash Collateral [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Bonds	0		0
COs - Bonds [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Bonds	-24,201,697		-26,119,848
COs - Bonds [Member] | Total Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Bonds	-24,384,324		-26,813,277
COs - Discount notes [Member] | Level 1 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Discount Notes	0		0
COs - Discount notes [Member] | Level 2 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Discount Notes	-10,476,247		-8,639,373
COs - Discount notes [Member] | Level 3 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Discount Notes	0		0
COs - Discount notes [Member] | Netting Adjustments and Cash Collateral [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Discount Notes	0		0
COs - Discount notes [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Discount Notes	-10,475,911		-8,639,048
COs - Discount notes [Member] | Total Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
CO Discount Notes	-10,476,247		-8,639,373
Commitments to Extend Credit for Advances [Member] | Level 1 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Commitments to Extend Credit for Advances [Member] | Level 2 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	-2,508		-229
Commitments to Extend Credit for Advances [Member] | Level 3 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Commitments to Extend Credit for Advances [Member] | Netting Adjustments and Cash Collateral [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Commitments to Extend Credit for Advances [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Commitments to Extend Credit for Advances [Member] | Total Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	-2,508		-229
Standby Bond-Purchase Agreements [Member] | Level 1 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	'		0
Standby Bond-Purchase Agreements [Member] | Level 2 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	'		358
Standby Bond-Purchase Agreements [Member] | Level 3 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	'		0
Standby Bond-Purchase Agreements [Member] | Netting Adjustments and Cash Collateral [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	'		0
Standby Bond-Purchase Agreements [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	'		0
Standby Bond-Purchase Agreements [Member] | Total Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	'		358
Standby Letters of Credit [Member] | Level 1 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Standby Letters of Credit [Member] | Level 2 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	-701		-523
Standby Letters of Credit [Member] | Level 3 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Standby Letters of Credit [Member] | Netting Adjustments and Cash Collateral [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	0		0
Standby Letters of Credit [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	-701		-523
Standby Letters of Credit [Member] | Total Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Other	($701)		($523)
[1]	Fair values of held-to-maturity securities were $4,700,205 and $5,699,230 at SeptemberB 30, 2013, and DecemberB 31, 2012, respectively.
[2]	Carrying value of held-to-maturity securities represents the sum of amortized cost and the amount of noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive loss.
[3]	Carried at fair value on a recurring basis.
[4]	Private-label residential MBS and HFA securities are categorized as Level 3. Private-label residential MBS that have incurred other-than-temporary impairment losses are measured at fair value on a nonrecurring basis. See the recurring and nonrecurring tables below for more details.

Fair_Values_Fair_Value_Measure

Fair Values (Fair Value Measured on Recurring Basis) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	$249,970		$274,293
Available-for-sale securities	3,860,587		5,268,237
Derivatives Assets Not Designated as Hedging Instruments	934		934
Derivative Assets	4,118		111
Derivatives Liabilities Not Designated as Hedging Instruments	-22,934		-34,233
Mortgage-Delivery Commmitment [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivatives Assets Not Designated as Hedging Instruments	164	[1]	35	[1]
Derivatives Liabilities Not Designated as Hedging Instruments	0	[1]	-16	[1]
Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[2]	0
Available-for-sale securities	0	[2]	0
Derivative Assets	0	[2]	0
Other Assets	4,768	[2]	4,154
Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	249,970	[2]	274,293
Available-for-sale securities	3,860,587	[2]	5,268,237
Derivative Assets	46,674	[2]	88,397
Other Assets	4,827	[2]	4,248
Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[2]	0
Available-for-sale securities	0	[2]	0
Derivative Assets	0	[2]	0
Other Assets	0	[2]	0
Netting Adjustments [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[2]	0
Available-for-sale securities	0	[2]	0
Derivative Assets	-42,556	[2]	-88,286
Other Assets	0	[2]	0
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
Interest-rate-exchange Agreements Derivative Assets	0		0
Derivative Assets	0		0
Other Assets	4,768		4,154
Total assets at fair value	4,768		4,154
Interest-rate-exchange Agreements Derivative Liabilities	0		0
Derivatives Liabilities Not Designated as Hedging Instruments	0		0
Total liabilities at fair value	0		0
Recurring [Member] | Level 1 [Member] | Mortgage-Delivery Commmitment [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivatives Assets Not Designated as Hedging Instruments	0		0
Recurring [Member] | Level 1 [Member] | Supranational institutions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring [Member] | Level 1 [Member] | U.S. government-owned corporations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring [Member] | Level 1 [Member] | GSEs [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring [Member] | Level 1 [Member] | U.S. Government Guaranteed - Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0		0
Available-for-sale securities	0		0
Recurring [Member] | Level 1 [Member] | GSEs b Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0		0
Available-for-sale securities	0		0
Recurring [Member] | Level 1 [Member] | GSEs b Commercial MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0		0
Available-for-sale securities	'		0
Recurring [Member] | Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	249,970		274,293
Available-for-sale securities	3,860,587		5,268,237
Interest-rate-exchange Agreements Derivative Assets	46,510		88,362
Derivative Assets	46,674		88,397
Other Assets	4,827		4,248
Total assets at fair value	4,162,058		5,635,175
Interest-rate-exchange Agreements Derivative Liabilities	-696,257		-995,362
Derivatives Liabilities Not Designated as Hedging Instruments	0		-16
Total liabilities at fair value	-696,257		-995,378
Recurring [Member] | Level 2 [Member] | Mortgage-Delivery Commmitment [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivatives Assets Not Designated as Hedging Instruments	164		35
Recurring [Member] | Level 2 [Member] | Supranational institutions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	430,792		473,484
Recurring [Member] | Level 2 [Member] | U.S. government-owned corporations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	247,345		291,081
Recurring [Member] | Level 2 [Member] | GSEs [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,048,757		2,085,084
Recurring [Member] | Level 2 [Member] | U.S. Government Guaranteed - Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	14,962		16,876
Available-for-sale securities	291,530		73,359
Recurring [Member] | Level 2 [Member] | GSEs b Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	3,803		4,946
Available-for-sale securities	1,842,163		2,244,794
Recurring [Member] | Level 2 [Member] | GSEs b Commercial MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	231,205		252,471
Available-for-sale securities	'		100,435
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
Interest-rate-exchange Agreements Derivative Assets	0		0
Derivative Assets	0		0
Other Assets	0		0
Total assets at fair value	0		0
Interest-rate-exchange Agreements Derivative Liabilities	0		0
Derivatives Liabilities Not Designated as Hedging Instruments	0		0
Total liabilities at fair value	0		0
Recurring [Member] | Level 3 [Member] | Mortgage-Delivery Commmitment [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivatives Assets Not Designated as Hedging Instruments	0		0
Recurring [Member] | Level 3 [Member] | Supranational institutions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring [Member] | Level 3 [Member] | U.S. government-owned corporations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring [Member] | Level 3 [Member] | GSEs [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring [Member] | Level 3 [Member] | U.S. Government Guaranteed - Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0		0
Available-for-sale securities	0		0
Recurring [Member] | Level 3 [Member] | GSEs b Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0		0
Available-for-sale securities	0		0
Recurring [Member] | Level 3 [Member] | GSEs b Commercial MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0		0
Available-for-sale securities	'		0
Recurring [Member] | Netting Adjustments [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[3]	0
Available-for-sale securities	0	[3]	0
Interest-rate-exchange Agreements Derivative Assets	-42,556	[3]	-88,286
Derivative Assets	-42,556	[3]	-88,286
Other Assets	0		0
Total assets at fair value	-42,556	[3]	-88,286
Interest-rate-exchange Agreements Derivative Liabilities	46,476	[3]	88,286
Derivatives Liabilities Not Designated as Hedging Instruments	0		0
Total liabilities at fair value	46,476	[3]	88,286
Recurring [Member] | Netting Adjustments [Member] | Mortgage-Delivery Commmitment [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivatives Assets Not Designated as Hedging Instruments	0	[3]	0
Recurring [Member] | Netting Adjustments [Member] | Supranational institutions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0	[3]	0
Recurring [Member] | Netting Adjustments [Member] | U.S. government-owned corporations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0	[3]	0
Recurring [Member] | Netting Adjustments [Member] | GSEs [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0	[3]	0
Recurring [Member] | Netting Adjustments [Member] | U.S. Government Guaranteed - Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[3]	0
Available-for-sale securities	0	[3]	0
Recurring [Member] | Netting Adjustments [Member] | GSEs b Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[3]	0
Available-for-sale securities	0	[3]	0
Recurring [Member] | Netting Adjustments [Member] | GSEs b Commercial MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	0	[3]	0
Available-for-sale securities	'		0
Recurring [Member] | Total Fair Value [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	249,970		274,293
Available-for-sale securities	3,860,587		5,268,237
Interest-rate-exchange Agreements Derivative Assets	3,954		76
Derivative Assets	4,118		111
Other Assets	9,595		8,402
Total assets at fair value	4,124,270		5,551,043
Interest-rate-exchange Agreements Derivative Liabilities	-649,781		-907,076
Derivatives Liabilities Not Designated as Hedging Instruments	0		-16
Total liabilities at fair value	-649,781		-907,092
Recurring [Member] | Total Fair Value [Member] | Mortgage-Delivery Commmitment [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivatives Assets Not Designated as Hedging Instruments	164		35
Recurring [Member] | Total Fair Value [Member] | Supranational institutions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	430,792		473,484
Recurring [Member] | Total Fair Value [Member] | U.S. government-owned corporations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	247,345		291,081
Recurring [Member] | Total Fair Value [Member] | GSEs [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,048,757		2,085,084
Recurring [Member] | Total Fair Value [Member] | U.S. Government Guaranteed - Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	14,962		16,876
Available-for-sale securities	291,530		73,359
Recurring [Member] | Total Fair Value [Member] | GSEs b Residential MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	3,803		4,946
Available-for-sale securities	1,842,163		2,244,794
Recurring [Member] | Total Fair Value [Member] | GSEs b Commercial MBS [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading securities	231,205		252,471
Available-for-sale securities	'		$100,435
[1]	Mortgage-delivery commitments are classified as derivatives with changes in fair value recorded in other income.
[2]	Carried at fair value on a recurring basis.
[3]	These amounts represent the effect of master netting agreements which allow us to settle positive and negative positions and also cash collateral held or placed with the same clearing member and/or counterparty.

Fair_Values_Fair_Value_Measure1

Fair Values (Fair Value Measured on Nonrecurring Basis) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value of held-to-maturity securities	$4,700,205		$5,699,230
Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value of held-to-maturity securities	0	[1]	0
Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value of held-to-maturity securities	3,080,792	[1]	4,060,941
Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value of held-to-maturity securities	1,619,413	[1]	1,638,289
Fair Value, Measurements, Nonrecurring [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
REO	373		195
Total assets recorded at fair value on a nonrecurring basis	'		220
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
REO	0		0
Total assets recorded at fair value on a nonrecurring basis	'		0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
REO	0		0
Total assets recorded at fair value on a nonrecurring basis	'		0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
REO	373		195
Total assets recorded at fair value on a nonrecurring basis	'		220
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	1,432,312		1,434,387
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	'		25
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
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
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	'		$25
[1]	Private-label residential MBS and HFA securities are categorized as Level 3. Private-label residential MBS that have incurred other-than-temporary impairment losses are measured at fair value on a nonrecurring basis. See the recurring and nonrecurring tables below for more details.

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	9 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
			Housing_Authorities
Loss Contingencies [Line Items]	'		'
Value of the guarantees related to standby letters of credit	$23,870,000		$19,198,000
Number of State Housing Authorities Standby Bond Purchase Agreements	'		1
Maximum term of commitments to invest in mortgage loans	'45 days		'
Carrying value, including accrued interest, of securities pledged as collateral that cannot be sold or repledged	437,500,000		650,900,000
Carrying value, including accrued interest, of securities pledged as collateral that can be sold or repledged	71,400,000		109,100,000
Other FHLBanks [Member]	'		'
Loss Contingencies [Line Items]	'		'
Par value of other FHLBanks' outstanding COs for which we are jointly and severally liable	686,300,000,000		653,500,000,000
Minimum [Member]	'		'
Loss Contingencies [Line Items]	'		'
Term of standby letters of credit	'27 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	2,852,332,000	[1]	870,905,000	[1]
Off-balance-sheet Commitments Expiring After One Year	235,116,000	[1]	343,744,000	[1]
Total Off-balance Sheet Commitments	3,087,448,000	[1]	1,214,649,000	[1]
Value of the guarantees related to standby letters of credit	701,000		523,000
Commitments for Standby Bond Purchases [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	0		158,960,000
Off-balance-sheet Commitments Expiring After One Year	0		0
Total Off-balance Sheet Commitments	0		158,960,000
Commitments for Unused Lines of Credit - Advances [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	1,287,377,000	[2]	1,290,776,000	[2]
Off-balance-sheet Commitments Expiring After One Year	0	[2]	0	[2]
Total Off-balance Sheet Commitments	1,287,377,000	[2]	1,290,776,000	[2]
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 Aditional Advances [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	18,713,000		22,985,000
Off-balance-sheet Commitments Expiring After One Year	49,124,000		72,036,000
Total Off-balance Sheet Commitments	67,837,000		95,021,000
Commitments to Invest in Mortgage Loans [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	18,107,000		30,938,000
Off-balance-sheet Commitments Expiring After One Year	0		0
Total Off-balance Sheet Commitments	18,107,000		30,938,000
Unsettled CO Bonds, at Par [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	45,000,000	[3]	124,100,000	[3]
Off-balance-sheet Commitments Expiring After One Year	0	[3]	0	[3]
Total Off-balance Sheet Commitments	45,000,000	[3]	124,100,000	[3]
Unsettled CO Bonds, at Par [Member] | Interest-Rate Swaps [Member]	'		'
Loss Contingencies [Line Items]	'		'
Total Off-balance Sheet Commitments	'		100,000,000
Unsettled CO Discount Notes, at Par [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	0		1,405,000,000
Off-balance-sheet Commitments Expiring After One Year	0		0
Total Off-balance Sheet Commitments	0		1,405,000,000
Standby Letters of Credit Issuance Commitments [Member]	'		'
Loss Contingencies [Line Items]	'		'
Off-balance-sheet Commitments Expiring Within One Year	$38,400,000		$12,600,000
[1]	The amount of standby letters of credit outstanding excludes commitments to issue standby letters of credit that expire within one year totaling $38.4 million as of SeptemberB 30, 2013. Also excluded are commitments to issue standby letters of credit that expire within one year totaling $12.6 million at DecemberB 31, 2012.
[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 no unsettled CO bonds that were hedged with associated interest-rate swaps at SeptemberB 30, 2013. We had $100.0 million in unsettled CO bonds that were hedged with associated interest-rate swaps at DecemberB 31, 2012.

Transactions_with_Shareholders2

Transactions with Shareholders (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Transactions with Shareholders [Line Items]	'		'		'		'		'
Capital Stock Outstanding	$2,441,028		'		$2,441,028		'		$3,455,165
Par Value of Advances	22,208,337		'		22,208,337		'		20,269,852
Total Accrued Interest Receivable	75,943		'		75,943		'		100,404
Interest income on outstanding advances	56,405		72,551		172,445		225,037		'
Bank of America , N.A. [Member]	'		'		'		'		'
Transactions with Shareholders [Line Items]	'		'		'		'		'
Capital Stock Outstanding	857,835		'		857,835		'		'
Percent of Total	25.10%		'		25.10%		'		'
Par Value of Advances	99,221		'		99,221		'		'
Percentage of Total Par Value of Advances	0.40%		'		0.40%		'		'
Total Accrued Interest Receivable	398		'		398		'		'
Percent of Total Accrued Interest Receivable on Advances	1.20%		'		1.20%		'		'
Interest income on outstanding advances	1,295	[1]	2,137	[1]	3,984	[1]	5,114	[1]	'
Bank of America Rhode Island, N.A. [Member]	'		'		'		'		'
Transactions with Shareholders [Line Items]	'		'		'		'		'
Capital Stock Outstanding	'		'		'		'		978,084	[2]
Percent of Total	'		'		'		'		26.60%	[2]
Par Value of Advances	'		'		'		'		101,795	[2]
Percentage of Total Par Value of Advances	'		'		'		'		0.50%	[2]
Total Accrued Interest Receivable	'		'		'		'		437	[2]
Percent of Total Accrued Interest Receivable on Advances	'		'		'		'		1.20%	[2]
RBS Citizens N.A. [Member]	'		'		'		'		'
Transactions with Shareholders [Line Items]	'		'		'		'		'
Capital Stock Outstanding	430,077		'		430,077		'		484,517
Percent of Total	12.60%		'		12.60%		'		13.20%
Par Value of Advances	19,298		'		19,298		'		519,808
Percentage of Total Par Value of Advances	0.10%		'		0.10%		'		2.60%
Total Accrued Interest Receivable	65		'		65		'		109
Percent of Total Accrued Interest Receivable on Advances	0.20%		'		0.20%		'		0.30%
Interest income on outstanding advances	210		3,155		977		8,367		'
CW Reinsurance Company [Member]	'		'		'		'		'
Transactions with Shareholders [Line Items]	'		'		'		'		'
Capital Stock Outstanding	'		'		'		'		1,900
Directors' Financial Institutions [Member]	'		'		'		'		'
Transactions with Shareholders [Line Items]	'		'		'		'		'
Capital Stock Outstanding	127,020		'		127,020		'		143,165
Percent of Total	3.70%		'		3.70%		'		3.90%
Par Value of Advances	655,493		'		655,493		'		792,839
Percentage of Total Par Value of Advances	3.00%		'		3.00%		'		3.90%
Total Accrued Interest Receivable	$1,668		'		$1,668		'		$2,138
Percent of Total Accrued Interest Receivable on Advances	5.10%		'		5.10%		'		6.10%
Minimum [Member]	'		'		'		'		'
Transactions with Shareholders [Line Items]	'		'		'		'		'
Related Party Transaction, Definiton of Related Party Voting Interests, Percent	10.00%		'		10.00%		'		'
Related Party Transaction, Definiton of Related Party Capital Stock, Percent	10.00%		'		10.00%		'		'
Transactions with Shareholders, Definition of Shareholder Concentrations Capital Stock, Percent	10.00%		'		10.00%		'		'
[1]	Includes interest income from advances outstanding to BANA RI through the date of its merger with BANA in April 2013.
[2]	Capital stock outstanding at DecemberB 31, 2012 included $1.9 million held by CW Reinsurance Company, a subsidiary of Bank of America Corporation (BANA). Bank of America Rhode Island, N.A. (BANA RI) merged into BANA, its parent, during the quarter ended June 30, 2013. BANA is ineligible for membership.

Transactions_with_Other_FHLBan1

Transactions with Other FHLBanks (Details) (FHLBank of Chicago [Member], USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
FHLBank of Chicago [Member]	'	'	'	'
Transactions with Other FHLBanks [Line Items]	'	'	'	'
MPF transaction-services fee expense	$387,000	$347,000	$1,156,000	$966,000

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent Event [Member], USD $)	Oct. 25, 2013	Nov. 04, 2013
In Millions, unless otherwise specified	Dividend Declared [Member]	Dividend Paid [Member]
Subsequent Event [Line Items]	'	'
Annualized rate of cash dividend	0.37%	'
Dividend, including dividends on mandatorily redeemable capital stock	'	$3.20