Fair Value Disclosures Fair Value Summary (Details) - USD ($)		Jun. 30, 2017		Dec. 31, 2016
Assets
Cash and Due from Banks		$ 370,216,000		$ 8,737,000
Trading securities		882,000		970,000
Available-for-sale securities		350,004,000		1,300,023,000
Held-to-maturity Securities	[1]	14,687,378,000		14,546,979,000
Held-to-maturity Securities, Fair Value		14,634,113,000		14,413,231,000
Accrued interest receivable		118,472,000		109,886,000
Derivative assets		78,149,000		104,753,000
Derivative Asset, Netting Adjustments And Cash Collateral	[2],[4]	38,483,000	[3]	50,904,000	[5]
Advances, Fair Value Disclosure	[6]	15,063,000		15,093,000
Liabilities
Mandatorily redeemable capital stock		35,969,000		34,782,000
Accrued Interest Payable, Fair Value Disclosure		127,328,000		119,322,000
Derivative liabilities		5,942,000		17,874,000
Derivative Liability, Netting Adjustments And Cash Collateral	[2],[4]	(69,862,000)	[3]	(84,191,000)	[5]
Variation Margin for Daily Settled Contracts, Net		54,630,000		0
Consolidated Obligation Bonds [Member]
Liabilities
Consolidated Obligations, Bonds		5,605,291,000		7,895,510,000
Fair Value, Inputs, Level 1 [Member]
Assets
Cash and Due from Banks		370,216,000		8,737,000
Interest-bearing deposits		0		0
Securities purchased under resale agreements		0		0
Federal funds sold		0		0
Trading securities		0		0
Available-for-sale securities		0		0
Held-to-maturity Securities, Fair Value		0		0
Advances		0	[7]	0	[8]
Mortgage loans held for portfolio, net		0		0
Accrued interest receivable		0		0
Derivative assets		0		0
Liabilities
Deposits		0		0
Mandatorily redeemable capital stock		35,969,000		34,782,000
Accrued Interest Payable, Fair Value Disclosure		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 1 [Member] | Financial Standby Letter of Credit [Member]
Other [Abstract]
Commitments, Fair Value Disclosure		0		0
Fair Value, Inputs, Level 1 [Member] | Consolidated Obligation Bonds [Member]
Liabilities
Consolidated Obligations, Bonds		0	[9]	0	[10]
Fair Value, Inputs, Level 1 [Member] | Discount Notes [Member]
Liabilities
Consolidated Obligations, Discount Notes		0		0
Fair Value, Inputs, Level 2 [Member]
Assets
Cash and Due from Banks		0		0
Interest-bearing deposits		190,000		129,000
Securities purchased under resale agreements		5,865,703,000		5,229,487,000
Federal funds sold		7,030,000,000		4,257,000,000
Trading securities		882,000		970,000
Available-for-sale securities		350,004,000		1,300,023,000
Held-to-maturity Securities, Fair Value		14,634,113,000		14,413,231,000
Advances		71,146,618,000	[7]	69,842,730,000	[8]
Mortgage loans held for portfolio, net		9,468,253,000		9,152,186,000
Accrued interest receivable		118,472,000		109,886,000
Derivative assets		39,666,000		53,849,000
Liabilities
Deposits		712,986,000		765,628,000
Mandatorily redeemable capital stock		0		0
Accrued Interest Payable, Fair Value Disclosure		127,328,000		119,322,000
Derivative liabilities		75,804,000		102,065,000
Fair Value, Inputs, Level 2 [Member] | Financial Standby Letter of Credit [Member]
Other [Abstract]
Commitments, Fair Value Disclosure		725,000		708,000
Fair Value, Inputs, Level 2 [Member] | Consolidated Obligation Bonds [Member]
Liabilities
Consolidated Obligations, Bonds		53,513,451,000	[9]	53,278,571,000	[10]
Fair Value, Inputs, Level 2 [Member] | Discount Notes [Member]
Liabilities
Consolidated Obligations, Discount Notes		49,359,067,000		44,689,594,000
Fair Value, Inputs, Level 3 [Member]
Assets
Cash and Due from Banks		0		0
Interest-bearing deposits		0		0
Securities purchased under resale agreements		0		0
Federal funds sold		0		0
Trading securities		0		0
Available-for-sale securities		0		0
Held-to-maturity Securities, Fair Value		0		0
Advances		0	[7]	0	[8]
Mortgage loans held for portfolio, net		19,196,000		22,604,000
Accrued interest receivable		0		0
Derivative assets		0		0
Liabilities
Deposits		0		0
Mandatorily redeemable capital stock		0		0
Accrued Interest Payable, Fair Value Disclosure		0		0
Derivative liabilities		0		0
Fair Value, Inputs, Level 3 [Member] | Financial Standby Letter of Credit [Member]
Other [Abstract]
Commitments, Fair Value Disclosure		0		0
Fair Value, Inputs, Level 3 [Member] | Consolidated Obligation Bonds [Member]
Liabilities
Consolidated Obligations, Bonds		0	[9]	0	[10]
Fair Value, Inputs, Level 3 [Member] | Discount Notes [Member]
Liabilities
Consolidated Obligations, Discount Notes		0		0
Carrying Value
Assets
Cash and Due from Banks		370,216,000		8,737,000
Interest-bearing deposits		190,000		129,000
Securities purchased under resale agreements		5,865,699,000		5,229,487,000
Federal funds sold		7,030,000,000		4,257,000,000
Trading securities		882,000		970,000
Available-for-sale securities		350,004,000		1,300,023,000
Held-to-maturity Securities		14,687,378,000		14,546,979,000
Advances		71,088,071,000	[7]	69,882,074,000	[8]
Mortgage loans held for portfolio, net		9,447,220,000		9,148,718,000
Accrued interest receivable		118,472,000		109,886,000
Derivative assets		78,149,000		104,753,000
Liabilities
Deposits		713,124,000		765,879,000
Mandatorily redeemable capital stock		35,969,000		34,782,000
Accrued Interest Payable, Fair Value Disclosure		127,328,000		119,322,000
Derivative liabilities		5,942,000		17,874,000
Carrying Value | Financial Standby Letter of Credit [Member]
Other [Abstract]
Commitments, Fair Value Disclosure		0		0
Carrying Value | Consolidated Obligation Bonds [Member]
Liabilities
Consolidated Obligations, Bonds		53,359,309,000	[9]	53,190,866,000	[10]
Carrying Value | Discount Notes [Member]
Liabilities
Consolidated Obligations, Discount Notes		49,359,582,000		44,689,662,000
Fair Value
Assets
Cash and Due from Banks		370,216,000		8,737,000
Interest-bearing deposits		190,000		129,000
Securities purchased under resale agreements		5,865,703,000		5,229,487,000
Federal funds sold		7,030,000,000		4,257,000,000
Trading securities		882,000		970,000
Available-for-sale securities		350,004,000		1,300,023,000
Held-to-maturity Securities, Fair Value		14,634,113,000		14,413,231,000
Advances		71,146,618,000	[7]	69,842,730,000	[8]
Mortgage loans held for portfolio, net		9,487,449,000		9,174,790,000
Accrued interest receivable		118,472,000		109,886,000
Derivative assets		78,149,000		104,753,000
Liabilities
Deposits		712,986,000		765,628,000
Mandatorily redeemable capital stock		35,969,000		34,782,000
Accrued Interest Payable, Fair Value Disclosure		127,328,000		119,322,000
Derivative liabilities		5,942,000		17,874,000
Fair Value | Financial Standby Letter of Credit [Member]
Other [Abstract]
Commitments, Fair Value Disclosure		725,000		708,000
Fair Value | Consolidated Obligation Bonds [Member]
Liabilities
Consolidated Obligations, Bonds		53,513,451,000	[9]	53,278,571,000	[10]
Fair Value | Discount Notes [Member]
Liabilities
Consolidated Obligations, Discount Notes		$ 49,359,067,000		$ 44,689,594,000

[1] Fair values: $14,634,113 and $14,413,231 at June 30, 2017 and December 31, 2016, respectively.

[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] 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.

[7] Includes (in thousands) $15,063 of Advances recorded under the fair value option at June 30, 2017.

[8] Includes (in thousands) $15,093 of Advances recorded under the fair value option at December 31, 2016.

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

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