Advances (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank, Advances [Line Items]
Advances	$ 80,360	$ 106,323
Advances, Par Value	80,185	106,413
Deposit Liabilities Reclassified as Loans Receivable	$ 1	2
Minimum [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, Advances, Maturity Period, Fixed Rate	1 day
Federal Home Loan Bank, Advances, Maturity Period, Variable Rate	1 year
Maximum [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, Advances, Maturity Period, Fixed Rate	30 years
Federal Home Loan Bank, Advances, Maturity Period, Variable Rate	20 years
Federal Home Loan Bank, Advances, Callable Option [Member]
Federal Home Loan Bank, Advances [Line Items]
Advances, Par Value	$ 25,500	35,600
Federal Home Loan Bank, Advances, Putable Option [Member]
Federal Home Loan Bank, Advances [Line Items]
Advances, Par Value	1,400	283
Wells Fargo Bank N.A. [Member]
Federal Home Loan Bank, Advances [Line Items]
Advances	$ 25,450	$ 49,575
Federal Home Loan Bank Advances, Percent	32.00%	47.00%

The aggregate carrying amount of all Federal Home Loan Bank loans (advances) expressed as a percent.

No definition available.

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- Definition

Amount of deposits held by the entity that have been reclassified as loan balances receivable, for example, but not limited to, overdrafts receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=116652737&loc=d3e64164-112818

+ Details

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- Definition

Amount of Federal Home Loan Bank (FHLBank) advances to member financial institutions.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Maturity period on fixed rate advances made and reported by Federal Home Loan Bank (FHLBank), in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Maturity period on variable rate advances made and reported by Federal Home Loan Bank (FHLBank), in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank).

+ References

No definition available.

+ Details

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