Investments (Securities Lending - Narrative) (Details) $ in Millions	Sep. 30, 2025 USD ($)
Investments, Debt and Equity Securities [Abstract]
Cash collateral on deposit from counterparties	$ 379
Percentage of reinvestment portfolio invested in liquid assets	50.00%

Amount of securities loaned to entities in exchange for collateral, not subject to a master netting arrangement.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Balance Type:	credit
Period Type:	instant