Condensed Consolidated Statements of (Loss) Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Premiums and other revenue:
Earned premiums	$ 435.0	$ 420.5
Net investment income	35.5	33.9
Fee and other income	2.1	2.3
Net realized investment (losses) gains:
Net realized investment gains (losses)	27.9	(1.7)
Change in fair value of equity securities	(39.3)	54.2
Credit losses on fixed maturity securities	(24.7)	0.0
Net realized investment (losses) gains	(36.1)	52.5
Total revenue	436.5	509.2
Expenses:
Losses and loss adjustment expenses	280.9	237.9
Underwriting, acquisition and insurance expenses	168.0	160.2
Other corporate expenses	3.3	0.5
Interest expense	7.7	8.5
Fee and other expense	1.2	1.3
Foreign currency exchange (gains) loss	(3.0)	0.7
Total expenses	458.1	409.1
(Loss) income before income taxes	(21.6)	100.1
Income tax (benefit) provision	(2.8)	8.9
Net (loss) income	$ (18.8)	$ 91.2
Net (loss) income per common share:
Basic (in dollars per share)	$ (0.55)	$ 2.68
Diluted (in dollars per share)	(0.55)	2.63
Dividends declared per common share (in dollars per share)	$ 0.31	$ 0.31
Weighted average common shares:
Basic (in shares)	34,469,516	33,984,329
Diluted (in shares)	34,469,516	34,737,939
Net realized investment (losses) gains before other-than-temporary impairment losses	$ (36.1)	$ 56.8
Other-than-temporary impairment losses recognized in earnings:
Other-than-temporary impairment losses on fixed maturities	0.0	(4.3)
Impairment losses recognized in earnings	0.0	(4.3)
Net realized investment (losses) gains	$ 27.9	$ (1.7)