Consolidated Statements of (Loss) Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues
Net earned insurance and reinsurance premiums	$ 369.8	$ 370.7	$ 804.5	$ 682.6
Net investment income	14.8	24.4	28.3	44.5
Net realized investment gains	7.1	15.6	27.4	24.6
Net unrealized investment gains (losses)	8.7	15.5	(35.1)	89.5
Net foreign exchange (losses) gains	(16.1)	(0.6)	2.4	4.5
Other revenue	10.2	15.4	14.5	35.0
Total revenues	394.5	441.0	842.0	880.7
Expenses
Loss and loss adjustment expenses	240.3	278.0	667.4	461.9
Insurance and reinsurance acquisition expenses	78.1	77.0	152.8	140.3
Other underwriting expenses	36.3	35.5	74.3	70.8
General and administrative expenses	23.9	28.2	56.0	52.6
Intangible asset amortization expenses	4.0	4.0	7.9	7.9
Interest expense on debt	7.9	8.0	15.7	15.6
Total expenses	390.5	430.7	974.1	749.1
Pre-tax income (loss)	4.0	10.3	(132.1)	131.6
Income tax (expense) benefit	(11.2)	(2.1)	3.6	(19.3)
Net (loss) income	(7.2)	8.2	(128.5)	112.3
Loss (income) attributable to non-controlling interests	0.2	(0.8)	0.0	(1.2)
(Loss) income attributable to Sirius Group	(7.0)	7.4	(128.5)	111.1
Change in carrying value of Series B preference shares	(6.6)	(0.8)	16.8	(9.2)
Net (loss) income attributable to Sirius Group's common shareholders	$ (13.6)	$ 6.6	$ (111.7)	$ 101.9
Net (loss) income per common share and common share equivalent
Basic earnings per common share and common share equivalent (in dollars per share)	$ (0.12)	$ 0.05	$ (0.97)	$ 0.80
Diluted earnings per common share and common share equivalent (in dollars per share)	$ (0.12)	$ 0.05	$ (1.01)	$ 0.80
Weighted average number of common shares and common share equivalents outstanding:
Basic weighted average number of common shares and common share equivalents outstanding (in shares)	115,278,176	115,243,685	115,269,720	115,212,772
Diluted weighted average number of common shares and common share equivalents outstanding (in shares)	115,278,176	115,796,367	127,171,390	127,542,402