CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Investment Securities:
Fixed maturity investments, at fair value	$ 1,886.2	$ 2,415.5
Short-term investments, at amortized cost (which approximates fair value)	320.0	300.0
Common equity securities, at fair value	266.5	285.3
Convertible fixed maturity investments, at fair value	79.8	93.8
Other investments	155.1	171.4
Total investments	2,707.6	3,266.0
Cash	54.9	33.6
Reinsurance recoverable on unpaid losses	2,167.5	1,893.2
Reinsurance recoverable on paid losses	16.5	44.5
Premiums receivable	230.9	275.0
Deferred acquisition costs	123.5	114.5
Ceded unearned premiums	10.7	113.9
Net deferred tax asset	93.6	101.2
Investment income accrued	14.1	19.4
Accounts receivable on unsettled investment sales	0.5	5.4
Other assets	269.2	300.0
Assets held for sale	132.6
Total assets	5,821.6	6,166.7
Liabilities
Loss and LAE reserves	3,358.6	3,295.5
Unearned premiums	528.0	627.5
Debt	269.7	419.6
Ceded reinsurance payable	23.4	149.3
Accounts payable on unsettled investment purchases	22.7	14.1
Other liabilities	397.7	411.8
Liabilities held for sale	107.6
Total liabilities	4,707.7	4,917.8
OneBeacon's common shareholders' equity and noncontrolling interests
Common shares and paid-in surplus (par value $0.01; authorized, 200,000,000 shares; issued and outstanding, 95,068,457 and 94,416,477 shares)	1,002.2	1,000.5
Retained earnings	108.5	228.2
Accumulated other comprehensive (loss) income, after tax:
Other comprehensive income and loss items	(10.9)	0.3
Total OneBeacon's common shareholders' equity	1,099.8	1,229.0
Total noncontrolling interests	14.1	19.9
Total OneBeacon's common shareholders' equity and noncontrolling interests	1,113.9	1,248.9
Total liabilities, OneBeacon's common shareholders' equity and noncontrolling interests	$ 5,821.6	$ 6,166.7