Investments - Other (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Debt securities
Debt Securities, Available-for-sale [Line Items]
Assets held by insurance regulators	$ 15	$ 14

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/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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+ Details