CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Assets
Fixed maturity investments, at fair value	$ 5,030.5	$ 5,196.2
Short-term investments, at amortized cost (which approximates fair value)	635.9	630.6
Common equity securities, at fair value	1,156.8	1,029.7
Convertible fixed maturity investments, at fair value	80.5	127.4
Other long-term investments	288.9	294.2
Total investments	7,192.6	7,278.1
Cash (restricted $56.1 and $249.8)	382.8	462.4
Reinsurance recoverable on unpaid losses	428.1	429.1
Reinsurance recoverable on paid losses	25.4	17.9
Insurance and reinsurance premiums receivable	518.9	556.3
Funds held by ceding companies	106.3	127.4
Investments in unconsolidated affiliates	321.4	387.9
Deferred acquisition costs	174.7	195.3
Deferred tax asset	512.1	569.6
Ceded unearned insurance and reinsurance premiums	92.4	91.8
Accrued investment income	39.3	45.9
Accounts receivable on unsettled investment sales	12.1	3.9
Other assets	458.1	503.0
Assets held for sale	1,880.1	2,226.8
Total assets	12,144.3	12,895.4
Liabilities
Loss and loss adjustment expense reserves	3,079.3	3,168.9
Unearned insurance and reinsurance premiums	901.4	924.1
Variable annuity benefit guarantee	52.8	441.5
Debt	676.4	751.2
Deferred tax liability	356.2	341.3
Accrued incentive compensation	218.3	159.0
Ceded reinsurance payable	71.9	116.5
Funds held under insurance and reinsurance contracts	127.1	43.7
Accounts payable on unsettled investment purchases	20.5	11.4
Other liabilities	362.9	452.8
Liabilities held for sale	1,880.1	2,226.8
Total liabilities	7,746.9	8,637.2
White Mountains’ common shareholders’ equity
White Mountains’ common shares at $1 par value per share—authorized 50,000,000 shares; issued and outstanding 6,176,739 and 6,290,964 shares	6.2	6.3
Paid-in surplus	1,044.9	1,050.9
Retained earnings	2,802.3	2,542.7
Accumulated other comprehensive income (loss), after-tax:
Equity in net unrealized (losses) gains from investments in Symetra common shares	(40.4)	57.7
Net unrealized foreign currency translation gains	88.4	85.7
Pension liability and other	4.1	(11.5)
Total White Mountains’ common shareholders’ equity	3,905.5	3,731.8
Non-controlling interests
Total non-controlling interests	491.9	526.4
Total equity	4,397.4	4,258.2
Total liabilities and equity	12,144.3	12,895.4
OneBeacon
Non-controlling interests
Total non-controlling interests	273.7	251.4
Sirius Group
Non-controlling interests
Total non-controlling interests	250.0	250.0
HG Global
Non-controlling interests
Total non-controlling interests	16.6	16.6
BAM
Non-controlling interests
Total non-controlling interests	(97.6)	(36.0)
Other Noncontrolling Interest
Non-controlling interests
Total non-controlling interests	$ 49.2	$ 44.4