Capital Narrative (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Dec. 31, 2025
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Written Notice Period Required to Repurchase Excess Membership Capital Stock	15 days
Banking Regulation, Total Risk-Based Capital, Excess, Actual	$ 0	$ 0
Retained Earnings, Appropriated	$ 1,302	$ 1,254

Written Notice Period Required to Repurchase Excess Membership Capital Stock

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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
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- Definition

Amount of total risk-based capital exceeding minimum required for capital adequacy as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Amount of accumulated undistributed earnings (deficit) not available for dividend distribution. Includes, but is not limited to, retained earnings appropriated for specific business purpose.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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