Fair Value (Fair Value Difference Between Fair Value and Remaining Contractual Principal Balance Outstanding) (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Fair Value Option, Principal Balance, Advances | $ 1,891 | $ 5,371 |
| Fair Value of advances under the fair value option | 1,879 | 5,441 |
| Fair Value Over/(Under) Principal Balance, Advances | (12) | 70 |
| Consolidated obligation bonds | ||
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Fair Value Option, Principal Balance, CO Bonds | 80 | 360 |
| Bonds, fair value under the fair value option | 80 | 357 |
| Fair Value Over/(Under) Principal Balance, CO Bonds | $ 0 | $ (3) |
| X | ||||||||||
- Definition Represents the outstanding amount of the unpaid principal balance of Federal Home Loan Bank Advances for which the fair value option has been elected. No definition available.
|
| X | ||||||||||
- Definition Represents the outstanding amount of the unpaid principal balance of consolidated obligation bonds for which the fair value option has been elected. No definition available.
|
| X | ||||||||||
- Definition Fair value of Federal Home Loan Bank (FHLBank) advances carried under the fair value option. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of long-term debt instruments that have contractual principal amounts and for which the fair value option has been elected. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- 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. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of accumulated increase (decrease) on advances made and reported by Federal Home Loan Bank (FHLBank) from fair value option adjustments. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Details
|