CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues
Earned insurance and reinsurance premiums	$ 1,927.8	$ 2,251.8	$ 2,717.6
Net investment income	184.5	208.9	250.1
Net realized and unrealized investment gains	122.8	82.6	361.7
Other revenue	(57.0)	23.4	113.9
Total revenues	2,178.1	2,566.7	3,443.3
Expenses
Loss and loss adjustment expenses	1,206.9	1,389.2	1,424.1
Insurance and reinsurance acquisition expenses	400.0	479.1	547.2
Other underwriting expenses	279.1	332.9	406.6
General and administrative expenses	175.3	155.1	197.4
Interest expense on debt	55.2	57.3	70.8
Total expenses	2,116.5	2,413.6	2,646.1
Pre-tax income	61.6	153.1	797.2
Income tax benefit (expense)	122.7	(16.9)	(214.2)
Net income from continuing operations	184.3	136.2	583.0
Gain on sale of Esurance and AFI, net of tax	677.5
Loss on sale of AutoOne, net of tax	(19.2)
Net loss from discontinued operations, net of tax	(13.0)	(6.6)	(27.8)
Income before equity in earnings of unconsolidated affiliates	829.6	129.6	555.2
Equity in (losses) earnings of unconsolidated affiliates	(20.2)	9.9	24.3
Net income	809.4	139.5	579.5
Net income attributable to noncontrolling interests	(41.5)	(53.0)	(109.5)
Net income attributable to White Mountains' common shareholders	767.9	86.5	470.0
Change in equity in net unrealized (losses) gains from investments in unconsolidated affiliates, net of tax	(58.5)	73.5	192.4
Change in foreign currency translation, net of tax	(15.2)	49.8	73.0
Net change in pension liability and other, net of tax	(10.8)	6.3	19.1
Comprehensive income	683.4	216.1	754.5
Comprehensive loss (income) attributable to noncontrolling interests	2.8	(1.7)	(3.7)
Comprehensive income attributable to White Mountains' common shareholders	$ 686.2	$ 214.4	$ 750.8
Basic earnings (loss) per share
Continuing operations (in dollars per share)	$ 15.56	$ 10.89	$ 56.25
Discontinued operations (in dollars per share)	$ 81.88	$ (0.77)	$ (3.14)
Total consolidated operations (in dollars per share)	$ 97.44	$ 10.12	$ 53.11
Diluted earnings (loss) per share
Continuing operations (in dollars per share)	$ 15.56	$ 10.89	$ 56.24
Discontinued operations (in dollars per share)	$ 81.88	$ (0.77)	$ (3.14)
Total consolidated operations (in dollars per share)	$ 97.44	$ 10.12	$ 53.10
Dividends declared and paid per White Mountains' common share (in dollars per share)	$ 1.00	$ 1.00	$ 1.00