Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues
Premiums	$ 1,263.8	$ 1,161.8
Net investment income	76.9	76.8
Net realized and unrealized investment gains (losses):
Net realized gains (losses) from sales and other	3.0	(1.6)
Net change in fair value of equity securities	(18.0)	39.1
Impairment losses on investments	(0.9)	0.0
Total net realized and unrealized investment gains (losses)	(15.9)	37.5
Fees and other income	5.9	6.0
Total revenues	1,330.7	1,282.1
Losses and expenses
Losses and loss adjustment expenses	787.5	781.3
Amortization of deferred acquisition costs	262.9	240.3
Interest expense	8.5	8.5
Other operating expenses	141.8	137.9
Total losses and expenses	1,200.7	1,168.0
Income from continuing operations before income taxes	130.0	114.1
Income tax expense (benefit):
Current	30.2	8.9
Deferred	(5.5)	12.4
Total income tax expense	24.7	21.3
Income from continuing operations	105.3	92.8
Discontinued operations (net of taxes):
Net income	$ 104.8	$ 92.7
Basic:
Income from continuing operations	$ 2.96	$ 2.55
Net income per share	$ 2.95	$ 2.55
Weighted average shares outstanding	35.5	36.4
Diluted:
Income from continuing operations	$ 2.91	$ 2.52
Net income per share	$ 2.90	$ 2.51
Weighted average shares outstanding	36.1	36.9
Life [Member]
Discontinued operations (net of taxes):
Income (Loss) from discontinued operations	$ (0.5)	$ (0.1)
Basic:
Loss from discontinued operations	$ (0.01)
Diluted:
Income (Loss) from discontinued operations	$ (0.01)	$ (0.01)