Fair Value Disclosures Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Thousands		Jun. 30, 2017		Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		$ 882		$ 970
Available-for-sale securities		350,004		1,300,023
Advances, Fair Value Disclosure	[1]	15,063		15,093
Derivative assets		78,149		104,753
Derivative Asset, Netting Adjustments And Cash Collateral	[2],[4]	38,483	[3]	50,904	[5]
Derivative liabilities		5,942		17,874
Derivative Liability, Netting Adjustments And Cash Collateral	[2],[4]	(69,862)	[3]	(84,191)	[5]
Variation Margin for Daily Settled Contracts, Net		54,630		0
Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		5,605,291		7,895,510
Single Family, Mortgage-backed Securities, Other US Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		882		970
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		350,004		1,300,023
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Advances, Fair Value Disclosure		15,063		15,093
Derivative Asset, Netting Adjustments And Cash Collateral		38,483	[6]	50,904	[7]
Derivative Liability, Netting Adjustments And Cash Collateral		(69,862)	[6]	(84,191)	[7]
Fair Value, Measurements, Recurring [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		5,605,291		7,895,510
Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Netting Adjustments And Cash Collateral		38,483	[6]	50,904	[7]
Derivative Liability, Netting Adjustments And Cash Collateral		(69,862)	[6]	(84,191)	[7]
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0		0
Available-for-sale securities		0		0
Derivative assets		0		0
Derivative liabilities		0		0
Mortgage loans held for portfolio, net		0		0
Fair Value, Inputs, Level 1 [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		0	[8]	0	[9]
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Advances, Fair Value Disclosure		0		0
Derivative assets		0		0
Total assests at fair value		0		0
Derivative liabilities		0		0
Total liabilities at fair value		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Single Family, Mortgage-backed Securities, Other US Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		0	[10]	0	[11]
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		882		970
Available-for-sale securities		350,004		1,300,023
Derivative assets		39,666		53,849
Derivative liabilities		75,804		102,065
Mortgage loans held for portfolio, net		9,468,253		9,152,186
Fair Value, Inputs, Level 2 [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		53,513,451	[8]	53,278,571	[9]
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Advances, Fair Value Disclosure		15,063		15,093
Derivative assets		39,666		53,849
Total assests at fair value		405,615		1,369,935
Derivative liabilities		75,804		102,065
Total liabilities at fair value		5,681,095		7,997,575
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		5,605,291		7,895,510
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		39,055		52,849
Derivative liabilities		74,666		91,271
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		374		319
Derivative liabilities		572		10,628
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		237		681
Derivative liabilities		566		166
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Single Family, Mortgage-backed Securities, Other US Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		882		970
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		350,004		1,300,023
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		0	[10]	0	[11]
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0		0
Available-for-sale securities		0		0
Derivative assets		0		0
Derivative liabilities		0		0
Mortgage loans held for portfolio, net		19,196		22,604
Fair Value, Inputs, Level 3 [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		0	[8]	0	[9]
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Advances, Fair Value Disclosure		0		0
Derivative assets		0		0
Total assests at fair value		0		0
Derivative liabilities		0		0
Total liabilities at fair value		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Single Family, Mortgage-backed Securities, Other US Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		409	[10]	1,388	[11]
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		882		970
Available-for-sale securities		350,004		1,300,023
Derivative assets		78,149		104,753
Derivative liabilities		5,942		17,874
Mortgage loans held for portfolio, net		9,487,449		9,174,790
Fair Value | Consolidated Obligation Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Consolidated Obligations, Bonds		53,513,451	[8]	53,278,571	[9]
Fair Value | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		78,149		104,753
Total assests at fair value		444,098		1,420,839
Derivative liabilities		5,942		17,874
Total liabilities at fair value		5,611,233		7,913,384
Fair Value | Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		77,538		103,753
Derivative liabilities		4,804		7,080
Fair Value | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		374		319
Derivative liabilities		572		10,628
Fair Value | Fair Value, Measurements, Recurring [Member] | Forward Contracts [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		237		681
Derivative liabilities		566		166
Fair Value | Fair Value, Measurements, Recurring [Member] | Single Family, Mortgage-backed Securities, Other US Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		882		970
Fair Value | Fair Value, Measurements, Recurring [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		350,004		1,300,023
Fair Value | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for portfolio, net		$ 409	[10]	$ 1,388	[11]

[1] At June 30, 2017 and December 31, 2016, none of the Advances were 90 days or more past due or had been placed on non-accrual status.

[2] Amounts represent the application of the netting requirements that allow the FHLB to settle positive and negative positions, cash collateral and related accrued interest held or placed by the FHLB with the same clearing agent and/or counterparty, and effective January 3, 2017, includes fair value adjustments on derivatives for which variation margin is characterized as a daily settled contract. Cash collateral posted and related accrued interest was (in thousands) $79,634 and $180,169 at June 30, 2017 and December 31, 2016. Cash collateral received and related accrued interest was (in thousands) $25,919 and $45,074 at June 30, 2017 and December 31, 2016. Variation margin for daily settled contracts was (in thousands) $54,630 at June 30, 2017 and $0 at December 31, 2016.

[3] Amounts represent the application of the netting requirements that allow the FHLB to settle positive and negative positions, cash collateral and related accrued interest held or placed by the FHLB with the same counterparty, and effective January 3, 2017, includes fair value adjustments on derivatives for which variation margin is characterized as a daily settled contract. Variation margin for daily settled contracts was (in thousands) $54,630 at June 30, 2017.

[4] Variation margin for daily settled contracts was (in thousands) $54,630 at June 30, 2017.

[5] Amounts represent the application of the netting requirements that allow the FHLB to settle positive and negative positions and also cash collateral and related accrued interest held or placed by the FHLB with the same counterparty.

[6] Amounts represent the application of the netting requirements that allow the FHLB to settle positive and negative positions, cash collateral and related accrued interest held or placed by the FHLB with the same counterparty, and effective January 3, 2017, includes fair value adjustments on derivatives for which variation margin is characterized as a daily settled contract. Variation margin for daily settled contracts was (in thousands) $54,630 at June 30, 2017.

[7] Amounts represent the application of the netting requirements that allow the FHLB to settle positive and negative positions and also cash collateral and related accrued interest held or placed by the FHLB with the same counterparty.

[8] Includes (in thousands) $5,605,291 of Consolidated Obligation Bonds recorded under the fair value option at June 30, 2017.

[9] Includes (in thousands) $7,895,510 of Consolidated Obligation Bonds recorded under the fair value option at December 31, 2016.

[10] The fair value information presented is as of the date the fair value adjustment was recorded during the six months ended June 30, 2017.

[11] The fair value information presented is as of the date the fair value adjustment was recorded during the year ended December 31, 2016.