Long-Duration Insurance Contracts - Reconciliation of LFPB to Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	$ 1,586.5	$ 1,611.5
Whole life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	280.3	278.8
Term life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	148.4	144.1
Experience life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	718.0	740.8
Limited-Pay Whole Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	56.0	54.6
Supplemental health
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	188.9	191.8
SPIA (life contingent)
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	91.6	96.0
Limited-pay whole life DPL
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	6.6	6.2
SPIA (life contingent) DPL
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	1.2	1.5
Reconciling items
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net liability for future policy benefits	$ 95.4	$ 97.7