Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Fixed maturities, allowance for credit losses	$ 9.5	$ 8.2
Receivables from policyholders, allowance for credit losses	$ 3.6	$ 13.9
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	64,043,801	64,111,555
Common stock, shares outstanding (in shares)	64,043,801	64,111,555
Consolidated Entity, Excluding VIE
Fixed maturities, at amortized cost	$ 7,459.4	$ 7,565.8
Fixed maturities, allowance for credit losses	9.5	8.2
Equity securities, at cost	204.1	209.3
Receivables from policyholders, allowance for credit losses	3.6	13.9
Long-term Debt, Current, at Amortized Cost, Fair Value	448.0	0.0
Long-term Debt, Non-Current, at Amortized Cost, Fair Value	850.3	1,213.4
Variable Interest Entity, Primary Beneficiary
Fixed maturities, at amortized cost	1.7	1.7
Fixed maturities, allowance for credit losses	0.0	0.0
Receivables from policyholders, allowance for credit losses	$ 0.0	$ 0.0