Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0001331463 (http://www.sec.gov/CIK)

Fair Value Disclosures [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
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 December 31, 2016 and 2015, were as follows (dollars in thousands). These fair values do not represent an estimate of our overall market value as a going concern, which would take into account, among other things, our future business opportunities and the net profitability of our assets and liabilities.   December 31, 2016   Carrying Value   Total Fair Value   Level 1   Level 2   Level 3   Netting Adjustments and Cash Collateral Financial instruments                       Assets:                       Cash and due from banks $ 520,031   $ 520,031   $ 520,031   $ —   $ —   $ — Interest-bearing deposits 278   278   278   —   —   — Securities purchased under agreements to resell 5,999,000   5,998,799   —   5,998,799   —   — Federal funds sold 2,700,000   2,699,949   —   2,699,949   —   — Trading securities(1) 612,622   612,622   —   612,622   —   — Available-for-sale securities(1) 6,588,664   6,588,664   —   6,580,518   8,146   — Held-to-maturity securities 2,130,767   2,372,290   —   1,176,269   1,196,021   — Advances 39,099,339   39,273,044   —   39,273,044   —   — Mortgage loans, net 3,693,894   3,736,548   —   3,708,123   28,425   — Accrued interest receivable 84,653   84,653   —   84,653   —   — Derivative assets(1) 61,598   61,598   —   55,078   —   6,520 Other assets (1) 17,779   17,779   8,394   9,385   —   — Liabilities:                     Deposits (482,163 )   (482,158 )   —   (482,158 )   —   — COs:                     Bonds (27,171,434 )   (27,298,499 )   —   (27,298,499 )   —   — Discount notes (30,053,964 )   (30,054,085 )   —   (30,054,085 )   —   — Mandatorily redeemable capital stock (32,687 )   (32,687 )   (32,687 )   —   —   — Accrued interest payable (80,822 )   (80,822 )   —   (80,822 )   —   — Derivative liabilities(1) (357,876 )   (357,876 )   —   (460,287 )   —   102,411 Other:                     Commitments to extend credit for advances —   (4,412 )   —   (4,412 )   —   — Standby letters of credit (1,064 )   (1,064 )   —   (1,064 )   —   — _______________________ (1) Carried at fair value on a recurring basis.   December 31, 2015   Carrying Value   Total Fair Value   Level 1   Level 2   Level 3   Netting Adjustments and Cash Collateral Financial instruments                       Assets:                       Cash and due from banks $ 254,218   $ 254,218   $ 254,218   $ —   $ —   $ — Interest-bearing deposits 197   197   197   —   —   — Securities purchased under agreements to resell 6,700,000   6,699,852   —   6,699,852   —   — Federal funds sold 2,120,000   2,119,962   —   2,119,962   —   — Trading securities(1) 230,134   230,134   —   230,134   —   — Available-for-sale securities(1) 6,314,285   6,314,285   —   6,314,285   —   — Held-to-maturity securities 2,654,565   2,923,124   —   1,562,243   1,360,881   — Advances 36,076,167   36,209,343   —   36,209,343   —   — Mortgage loans, net 3,581,788   3,666,146   —   3,635,073   31,073   — Accrued interest receivable 84,442   84,442   —   84,442   —   — Derivative assets(1) 40,117   40,117   —   27,138   —   12,979 Other assets(1) 15,292   15,292   6,373   8,919   —   — Liabilities:                       Deposits (482,602 )   (482,595 )   —   (482,595 )   —   — COs:                       Bonds (25,427,277 )   (25,578,547 )   —   (25,578,547 )   —   — Discount notes (28,479,097 )   (28,479,076 )   —   (28,479,076 )   —   — Mandatorily redeemable capital stock (41,989 )   (41,989 )   (41,989 )   —   —   — Accrued interest payable (81,268 )   (81,268 )   —   (81,268 )   —   — Derivative liabilities(1) (442,007 )   (442,007 )   —   (521,177 )   —   79,170 Other:                       Commitments to extend credit for advances —   (689 )   —   (689 )   —   — Standby letters of credit (831 )   (831 )   —   (831 )   —   — _______________________ (1) Carried at fair value on a recurring basis.
Fair Value Measured on Recurring Basis [Table Text Block]	The following tables present our assets and liabilities that are measured at fair value on the statement of condition, which are recorded on a recurring basis at December 31, 2016 and 2015, by fair-value hierarchy level (dollars in thousands):   December 31, 2016   Level 1   Level 2   Level 3   Netting Adjustment (1)   Total Assets:                   Trading securities:                   U.S. Treasury obligations $ —   $ 399,521   $ —   $ —   $ 399,521 U.S. government-guaranteed – single-family MBS —   8,494   —   —   8,494 GSEs – single-family MBS —   768   —   —   768 GSEs – multifamily MBS —   203,839   —   —   203,839 Total trading securities —   612,622   —   —   612,622 Available-for-sale securities:                   State or local HFA securities —   —   8,146   —   8,146 Supranational institutions —   422,620   —   —   422,620 U.S. government-owned corporations —   271,957   —   —   271,957 GSEs —   117,468   —   —   117,468 U.S. government guaranteed – single-family MBS —   124,727   —   —   124,727 U.S. government guaranteed – multifamily MBS —   563,361   —   —   563,361 GSEs – single-family MBS —   4,403,855   —   —   4,403,855 GSEs-multifamily —   676,530   —   —   676,530 Total available-for-sale securities —   6,580,518   8,146   —   6,588,664 Derivative assets:                   Interest-rate-exchange agreements —   55,008   —   6,520   61,528 Mortgage delivery commitments —   70   —   —   70 Total derivative assets —   55,078   —   6,520   61,598 Other assets 8,394   9,385   —   —   17,779 Total assets at fair value $ 8,394   $ 7,257,603   $ 8,146   $ 6,520   $ 7,280,663 Liabilities:                   Derivative liabilities                   Interest-rate-exchange agreements $ —   $ (460,116 )   $ —   $ 102,411   $ (357,705 ) Mortgage delivery commitments —   (171 )   —   —   (171 ) Total liabilities at fair value $ —   $ (460,287 )   $ —   $ 102,411   $ (357,876 ) _______________________ (1) These amounts represent the application of the netting requirements which allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.   December 31, 2015   Level 1   Level 2   Level 3   Netting Adjustment (1)   Total Assets:                   Trading securities:                   U.S. government-guaranteed – single-family MBS $ —   $ 10,296   $ —   $ —   $ 10,296 GSEs – single-family MBS —   1,449   —   —   1,449 GSEs – multifamily MBS —   218,389   —   —   218,389 Total trading securities —   230,134   —   —   230,134 Available-for-sale securities:                   Supranational institutions —   438,913   —   —   438,913 U.S. government-owned corporations —   265,968   —   —   265,968 GSEs —   117,792   —   —   117,792 U.S. government guaranteed – single-family MBS —   156,642   —   —   156,642 U.S. government guaranteed – multifamily MBS —   744,762   —   —   744,762 GSEs – single-family MBS —   4,590,208   —   —   4,590,208 Total available-for-sale securities —   6,314,285   —   —   6,314,285 Derivative assets:                   Interest-rate-exchange agreements —   27,120   —   12,979   40,099 Mortgage delivery commitments —   18   —   —   18 Total derivative assets —   27,138   —   12,979   40,117 Other assets 6,373   8,919   —   —   15,292 Total assets at fair value $ 6,373   $ 6,580,476   $ —   $ 12,979   $ 6,599,828 Liabilities:                   Derivative liabilities                   Interest-rate-exchange agreements $ —   $ (521,152 )   $ —   $ 79,170   $ (441,982 ) Mortgage delivery commitments —   (25 )   —   —   (25 ) Total liabilities at fair value $ —   $ (521,177 )   $ —   $ 79,170   $ (442,007 ) _______________________ (1) These amounts represent the application of the netting requirements which allow us to settle positive and negative positions and also cash collateral and related accrued interest held or placed with the same clearing member and/or counterparty.
Fair Value on a Nonrecurring Basis [Table Text Block]	The following tables present financial assets by level within the fair-value hierarchy which were recorded at fair value on a nonrecurring basis. The fair values presented are as of the date the fair value adjustment was recorded.   December 31, 2016   Level 1   Level 2   Level 3   Total Held-to-maturity securities:               Private-label residential MBS $ —   $ —   $ 8,498   $ 8,498 Mortgage loans held for portfolio —   —   5,618   5,618 REO —   —   786   786                 Total assets recorded at fair value on a nonrecurring basis $ —   $ —   $ 14,902   $ 14,902   December 31, 2015   Level 1   Level 2   Level 3   Total Held-to-maturity securities:               Private-label residential MBS $ —   $ —   $ 16,653   $ 16,653 Mortgage loans held for portfolio —   —   5,376   5,376 REO —   —   2,284   2,284                 Total assets recorded at fair value on a nonrecurring basis $ —   $ —   $ 24,313   $ 24,313
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table presents a reconciliation of available-for-sale securities that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the year ended December 31, 2016. There were no Level 3 available-for-sale securities during the years ended December 31, 2015 and 2014.     For the Year Ended December 31, 2016 Balance at beginning of year   $ — Purchases   9,350 Unrealized losses included in other comprehensive income   (1,204 ) Balance at end of year   $ 8,146