CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Earned insurance premiums	$ 264.8	$ 282.1
Net investment income	26.1	17.9
Net realized and unrealized investment gains	51.3	29.5
Other revenue	43.7	39.8
Total revenues	385.9	369.3
Expenses:
Loss and loss adjustment expenses	151.7	161.1
Insurance Acquisition Expenses	46.6	52.7
Other Underwriting Expense	51.8	55.4
General and administrative expenses	94.2	87.1
Interest expense	3.7	4.5
Total expenses	348.0	360.8
Pre-tax income from continuing operations	37.9	8.5
Income tax (expense) benefit	(3.9)	9.7
Net income from continuing operations	34.0	18.2
Net (loss) gain on sale of discontinued operations, net of tax	(1.0)	0.0
Net income from discontinued operations, net of tax	0.0	1.1
Net income	33.0	19.3
Net loss (income) attributable to non-controlling interests	1.3	(6.3)
Net income attributable to White Mountains’s common shareholders	34.3	13.0
Other comprehensive income, net of tax:
Change in foreign currency translation, pension liability and other, net of tax	0.9	0.1
Comprehensive income attributable to White Mountains’s common shareholders	$ 35.2	$ 50.3
Basic income (loss) per share
Continuing operations	$ 7.72	$ 2.14
Discontinued operations	(0.22)	0.20
Total consolidated operations	7.50	2.34
Diluted income (loss) per share
Continuing operations	7.72	2.14
Discontinued operations	(0.22)	0.20
Total consolidated operations	7.50	2.34
Dividends declared per White Mountains’s common share	$ 1.00	$ 1.00
Sale of Tranzact [Member]
Expenses:
Net (loss) gain on sale of discontinued operations, net of tax	$ (1.0)	$ 0.0
Sirius Group
Revenues:
Net realized and unrealized investment gains		4.1
Other comprehensive income, net of tax:
Change in foreign currency translation, pension liability and other, net of tax	$ 0.0	$ 37.2