Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Net earned insurance and reinsurance premiums	$ 370.7	$ 308.9	$ 682.6	$ 593.4
Net investment income	24.4	19.2	44.5	30.0
Net realized investment gains	15.6	7.8	24.6	4.1
Net unrealized investment gains	15.5	24.7	89.5	40.7
Net foreign exchange (losses) gains	(0.6)	25.6	4.5	22.1
Other revenue	15.4	55.6	35.0	79.0
Total revenues	441.0	441.8	880.7	769.3
Expenses
Loss and loss adjustment expenses	278.0	151.4	461.9	292.4
Insurance and reinsurance acquisition expenses	77.0	66.8	140.3	129.8
Other underwriting expenses	35.5	38.2	70.8	81.4
General and administrative expenses	28.2	24.2	52.6	38.5
Intangible asset amortization expenses	4.0	4.0	7.9	7.9
Interest expense on debt	8.0	7.8	15.6	15.5
Total expenses	430.7	292.4	749.1	565.5
Pre-tax income	10.3	149.4	131.6	203.8
Income tax expense	(2.1)	(51.2)	(19.3)	(62.3)
Net income	8.2	98.2	112.3	141.5
Income attributable to non-controlling interests	(0.8)	(0.4)	(1.2)	(0.6)
Income attributable to Sirius Group	7.4	97.8	111.1	140.9
Change in carrying value of Series B preference shares	(0.8)		(9.2)
Accrued dividends on Series A redeemable preference shares				(2.6)
Net income attributable to Sirius Group's common shareholders	$ 6.6	$ 97.8	$ 101.9	$ 138.3
Net income per common share and common share equivalent
Basic earnings per common share and common share equivalent	$ 0.05	$ 0.78	$ 0.80	$ 1.11
Diluted earnings per common share and common share equivalent	$ 0.05	$ 0.78	$ 0.80	$ 1.11
Weighted average number of common shares and common share equivalents outstanding:
Basic weighted average number of common shares and common share equivalents outstanding	115,243,685	120,000,000	115,212,772	120,000,000
Diluted weighted average number of common shares and common share equivalents outstanding	115,796,367	120,000,000	127,542,402	120,000,000