Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Revenues
Premiums	$ 1,545.3	$ 1,473.2	$ 3,053.8	$ 2,921.8
Net investment income	105.5	90.4	211.6	180.1
Net realized and unrealized investment gains (losses):
Net realized losses from sales and other	(4.6)	(30.4)	(23.4)	(31.7)
Net change in fair value of equity securities and other	5.0	1.1	6.0	7.6
Impairments on investments:
Credit-related impairments	(2.5)	(3.5)	(2.5)	(3.2)
Losses on intent to sell securities	(0.4)	(1.7)	(0.4)	(1.7)
Total Impairments on investments	(2.9)	(5.2)	(2.9)	(4.9)
Total net realized and unrealized investment losses	(2.5)	(34.5)	(20.3)	(29.0)
Fees and other income	6.1	7.6	12.5	14.9
Total revenues	1,654.4	1,536.7	3,257.6	3,087.8
Losses and expenses
Losses and loss adjustment expenses	957.2	1,007.6	1,912.5	1,942.8
Amortization of deferred acquisition costs	319.0	303.5	632.9	602.5
Interest expense	8.6	8.6	17.1	17.1
Other operating expenses	170.8	165.7	336.2	328.8
Total losses and expenses	1,455.6	1,485.4	2,898.7	2,891.2
Income from continuing operations before income taxes	198.8	51.3	358.9	196.6
Income tax expense (benefit):
Current	46.4	17.0	76.4	45.7
Deferred	(4.5)	(6.1)	(2.6)	(5.0)
Total income tax expense	41.9	10.9	73.8	40.7
Income from continuing operations	156.9	40.4	285.1	155.9
Discontinued operations (net of taxes):
Income from discontinued life businesses	0.2	0.1	0.2	0.1
Net income	$ 157.1	$ 40.5	$ 285.3	$ 156.0
Basic:
Income from continuing operations	$ 4.37	$ 1.12	$ 7.93	$ 4.34
Income from discontinued life businesses	0	0.01	0.01	0.01
Net income per share	$ 4.37	$ 1.13	$ 7.94	$ 4.35
Weighted average shares outstanding	35.9	36.0	35.9	35.9
Diluted:
Income from continuing operations	$ 4.3	$ 1.11	$ 7.8	$ 4.3
Income from discontinued life businesses	0	0.01	0	0
Net income per share	$ 4.30	$ 1.12	$ 7.8	$ 4.3
Weighted average shares outstanding	36.5	36.3	36.6	36.3