Dispositions - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022		Dec. 31, 2021	[2]	Dec. 01, 2022
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration	$ 90.0
Total impairment loss	49.6
Goodwill impairment	$ 49.6	$ 0.0	[1]	$ 0.0
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Reserve National Insurance Company
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal net of tax		$ 1.6
Total impairment loss						$ 11.4

[1] As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been recast to reflect application of the new guidance. See Note 2 to the Consolidated Financial Statements for additional information.

[2] As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been recast to reflect application of the new guidance. See Note 2 to the Consolidated Financial Statements for additional information.