Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Life insurance
Policyholder benefits net of remeasurement gain (losses)	$ 29.4	$ (47.4)	$ (11.1)
Health premium
Policyholder benefits net of remeasurement gain (losses)	$ 11.8	$ 15.6	$ (1.2)

Amount of remeasurement gain (loss) on liability for future policy benefit from application of revised benefit ratio as of contract issue. Includes, but is not limited to, remeasurement gain (loss) for annuitization insurance benefit, death and other insurance benefits, and traditional and limited-payment contracts.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480112/944-40-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480112/944-40-45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480112/944-40-45-4

Name:	us-gaap_LiabilityForFuturePolicyBenefitRemeasurementGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration