Activities with Other FHLBanks (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Other Transactions [Line Items]
Payments for FHLBank Advance, Investing Activities	$ 264,580	$ 305,197	$ 266,362
Loans to Other Federal Home Loan Banks	0	0	0	$ 200
Payments for Federal Home Loan Bank Loans	1,265	1,600	50
Proceeds from Federal Home Loan Bank Loans	(1,265)	(1,600)	(250)
Loans from Other Federal Home Loan Banks	0	500	600	0
Proceeds from FHLBank Borrowings, Financing Activities		1,000	600
Payments of FHLBank Borrowings, Financing Activities		(1,100)	0
Federal Home Loan Bank, Advances, Premium	25	38
Federal Home Loan Bank of Topeka [Member]
Schedule of Other Transactions [Line Items]
Loans to Other Federal Home Loan Banks	0	0	0	0
Payments for Federal Home Loan Bank Loans	150		50
Proceeds from Federal Home Loan Bank Loans	(150)		(50)
Federal Home Loan Bank of Dallas [Member]
Schedule of Other Transactions [Line Items]
Loans to Other Federal Home Loan Banks		0	0
Payments for Federal Home Loan Bank Loans		500
Proceeds from Federal Home Loan Bank Loans		(500)
Federal Home Loan Bank of Atlanta [Member]
Schedule of Other Transactions [Line Items]
Loans to Other Federal Home Loan Banks	0	0
Payments for Federal Home Loan Bank Loans	565
Proceeds from Federal Home Loan Bank Loans	(565)
Loans from Other Federal Home Loan Banks	0	500	200	0
Proceeds from FHLBank Borrowings, Financing Activities	400	500	200
Payments of FHLBank Borrowings, Financing Activities	(900)	(200)	0
Federal Home Loan Bank of Chicago [Member]
Schedule of Other Transactions [Line Items]
Payments for FHLBank Advance, Investing Activities	37
Federal Home Loan Bank, Advances, Premium	1
Federal Home Loan Bank of Indianapolis [Member]
Schedule of Other Transactions [Line Items]
Loans to Other Federal Home Loan Banks	0	0
Payments for Federal Home Loan Bank Loans	550
Proceeds from Federal Home Loan Bank Loans	$ (550)
Federal Home Loan Bank of San Francisco [Member]
Schedule of Other Transactions [Line Items]
Loans to Other Federal Home Loan Banks		0	0	200
Payments for Federal Home Loan Bank Loans		300	0
Proceeds from Federal Home Loan Bank Loans		(300)	(200)
Loans from Other Federal Home Loan Banks		0	0
Proceeds from FHLBank Borrowings, Financing Activities		500
Payments of FHLBank Borrowings, Financing Activities		(500)
Federal Home Loan Bank of Boston [Member]
Schedule of Other Transactions [Line Items]
Loans to Other Federal Home Loan Banks		0	0
Payments for Federal Home Loan Bank Loans		800
Proceeds from Federal Home Loan Bank Loans		(800)
Loans from Other Federal Home Loan Banks		0	400	$ 0
Proceeds from FHLBank Borrowings, Financing Activities		0	400
Payments of FHLBank Borrowings, Financing Activities		$ (400)	$ 0

Amounts for the payment of Federal Home Loan Bank loans.

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Proceeds from Federal Home Loan Bank Loans

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Schedule of Other Transactions [Line Items]

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Amount of unearned premiums on outstanding advances made and reported by Federal Home Loan Bank (FHLBank).

+ References

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Amount of Federal Home Loan Bank (FHLBank) loans from another FHLBank.

+ References

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Amount of Federal Home Loan Bank (FHLBank) loans to another FHLBank.

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Amount of cash outflow for disbursement to borrower related to advance, made by Federal Home Loan Bank (FHLBank), classified as investing activity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

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Amount of cash inflow from Federal Home Loan Bank (FHLBank) borrowing, classified as financing activity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

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Amount of cash outflow for repayment of Federal Home Loan Bank (FHLBank) borrowing, classified as financing activity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

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