Investments - Credit Loss Allowance (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Investments [Abstract]
Agent loans, allowance for credit loss	$ 1.0	$ 1.0
Available-for-sale securities, allowance for credit loss	$ 0.4	$ 0.2

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant