Fair Value (Carrying Value and Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks		$ 118	$ 13
Trading securities		1,766	661
Available-for-sale (AFS) securities	[1]	15,495	6,931
HTM securities, Carrying Value	[2],[3]	7,545	11,089
HTM Securities, Fair Value		7,566	11,047
Accrued interest receivable		139	133
Derivative assets, net		33	185
Derivative Assets		44	86
Derivative Asset, Netting adjustments	[4]	11	(99)
Liabilities
Mandatorily redeemable capital stock		138	227		$ 309	$ 457
Borrowings from other FHLBanks		0	250
Accrued interest payable		164	155
Derivative liabilities, net		0	10
Derivative Liabilities		384	147
Derivative Liability, Netting adjustments	[4]	(384)	(137)
Carrying Value
Assets
Cash and due from banks		118	13
Interest-bearing deposits		2,269	2,555
Securities purchased under agreements to resell		7,000	7,300
Federal funds sold		3,562	3,845
Trading securities		1,766	661
Available-for-sale (AFS) securities		15,495	6,931
HTM securities, Carrying Value		7,545	11,089
Advances		65,374	73,434
Mortgage loans held for portfolio, net of allowance for credit losses on mortgage loans		3,314	3,066
Accrued interest receivable		139	133
Derivative assets, net	[5]	33	185
Other assets	[6]	19	16
Liabilities
Deposits		537	262
Total consolidated obligations		98,748	101,458
Mandatorily redeemable capital stock		138	227
Borrowings from other FHLBanks			250
Accrued interest payable		164	155
Derivative liabilities, net	[5]	0	10
Estimated Fair Value
Assets
Cash and due from banks		118	13
Interest-bearing deposits		2,269	2,555
Securities purchased under agreements to resell		7,000	7,299
Federal funds sold		3,562	3,846
Trading securities		1,766	661
Available-for-sale (AFS) securities		15,495	6,931
HTM Securities, Fair Value		7,566	11,047
Advances		65,492	73,462
Mortgage loans held for portfolio, net of allowance for credit losses on mortgage loans		3,332	2,975
Accrued interest receivable		139	133
Derivative assets, net	[5]	33	185
Other assets	[6]	19	16
Liabilities
Deposits		537	262
Total consolidated obligations		98,764	101,257
Mandatorily redeemable capital stock		138	227
Borrowings from other FHLBanks			250
Accrued interest payable		164	155
Derivative liabilities, net	[5]	0	10
Level 1
Assets
Cash and due from banks		118	13
Interest-bearing deposits		2,269	2,555
Securities purchased under agreements to resell		0	0
Federal funds sold		0	0
Trading securities		0	0
Available-for-sale (AFS) securities		0	0
HTM Securities, Fair Value		0	0
Advances		0	0
Mortgage loans held for portfolio, net of allowance for credit losses on mortgage loans		0	0
Accrued interest receivable		0	0
Derivative Assets		0	0	[5]
Other assets	[6]	19	16
Liabilities
Deposits		0	0
Total consolidated obligations		0	0
Mandatorily redeemable capital stock		138	227
Borrowings from other FHLBanks			0
Accrued interest payable		0	0
Derivative Liabilities		0	0	[5]
Level 2
Assets
Cash and due from banks		0	0
Interest-bearing deposits		0	0
Securities purchased under agreements to resell		7,000	7,299
Federal funds sold		3,562	3,846
Trading securities		1,766	661
Available-for-sale (AFS) securities		12,898	3,774
HTM Securities, Fair Value		7,181	10,362
Advances		65,492	73,462
Mortgage loans held for portfolio, net of allowance for credit losses on mortgage loans		3,332	2,975
Accrued interest receivable		139	133
Derivative Assets	[5]	44	86
Derivative Asset, Netting adjustments	[5]	(11)	99
Other assets	[6]	0	0
Liabilities
Deposits		537	262
Total consolidated obligations		98,764	101,257
Mandatorily redeemable capital stock		0	0
Borrowings from other FHLBanks			250
Accrued interest payable		164	155
Derivative Liabilities	[5]	384	147
Derivative Liability, Netting adjustments	[5]	(384)	(137)
Level 3
Assets
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	0
Available-for-sale (AFS) securities		2,597	3,157
HTM Securities, Fair Value		385	685
Advances		0	0
Mortgage loans held for portfolio, net of allowance for credit losses on mortgage loans		0	0
Accrued interest receivable		0	0
Derivative Assets		0	0	[5]
Other assets	[6]	0	0
Liabilities
Deposits		0	0
Total consolidated obligations		0	0
Mandatorily redeemable capital stock		0	0
Borrowings from other FHLBanks			0
Accrued interest payable		0	0
Derivative Liabilities		0	0	[5]
Standby letters of credit | Carrying Value
Other
Other commitments		32	27
Standby letters of credit | Estimated Fair Value
Other
Other commitments		32	27
Standby letters of credit | Level 1
Other
Other commitments		0	0
Standby letters of credit | Level 2
Other
Other commitments		32	27
Standby letters of credit | Level 3
Other
Other commitments		0	0
Discount notes | Carrying Value
Liabilities
Discount notes		27,376	29,182
Discount notes | Estimated Fair Value
Liabilities
Discount notes		27,378	29,178
Discount notes | Level 1
Liabilities
Discount notes		0	0
Discount notes | Level 2
Liabilities
Discount notes		27,378	29,178
Discount notes | Level 3
Liabilities
Discount notes		0	0
Bonds
Liabilities
Bonds		337	2,019
Bonds | Carrying Value
Liabilities
Bonds		71,372	72,276
Bonds | Estimated Fair Value
Liabilities
Bonds		71,386	72,079
Bonds | Level 1
Liabilities
Bonds		0	0
Bonds | Level 2
Liabilities
Bonds		71,386	72,079
Bonds | Level 3
Liabilities
Bonds		$ 0	$ 0

[1] At December 31, 2019, $381 of these securities were pledged as collateral that may be repledged. At December 31, 2018, none of these securities were pledged as collateral that may be repledged.

[2] Amortized cost includes unpaid principal balance, unamortized premiums and discounts, and previous OTTI recognized in earnings. The carrying value of HTM securities represents amortized cost after adjustment for non-credit-related OTTI recognized in AOCI.

[3] At December 31, 2019 and 2018, none of these securities were pledged as collateral that may be repledged.

[4] Amounts represent the application of the netting requirements that allow the Bank to settle positive and negative positions, and also cash collateral and related accrued interest held or placed with the same clearing agents and/or counterparty. Cash collateral posted and related accrued interest was $378 and $257 at December 31, 2019 and 2018, respectively. Cash collateral received and related accrued interest was $5 and $22 at December 31, 2019 and 2018, respectively.

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

[6] Represents publicly traded mutual funds held in a grantor trust.