Schedule II Condensed Financial Information of Registrant - Condensed Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues
Net investment income	$ 464.3	$ 445.7	$ 444.8
Realized investment gains	(13.0)	(17.3)	(24.0)
Total revenues	1,701.4	1,595.2	1,491.9
Expenses
Interest expense	36.4	34.6	29.7
Total benefits, losses and expenses	1,500.2	1,466.6	1,438.6
Income tax benefit	39.1	25.8	8.3
Net income	162.1	102.8	45.0
Parent company
Revenues
Net investment income	6.0	0.1	0.2
Realized investment gains	1.9	0.0	0.0
Total revenues	7.9	0.1	0.2
Expenses
Interest expense	36.4	34.6	29.7
Other	19.5	8.1	5.1
Total benefits, losses and expenses	55.9	42.7	34.8
Loss before income tax benefit and equity in net earnings of subsidiaries	(48.0)	(42.6)	(34.6)
Income tax benefit	(11.6)	(9.6)	(6.9)
Loss before equity in net earnings of subsidiaries	(36.4)	(33.0)	(27.7)
Equity in net earnings of subsidiaries	198.5	135.8	72.7
Net income	$ 162.1	$ 102.8	$ 45.0