CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Cash flows from operations:
Net income	$ 33.0	$ 19.3
Charges (credits) to reconcile net income to net cash used for operations:
Net realized and unrealized investment (gains) losses	(51.3)	(29.5)
Deferred income tax (benefit) expense	(1.1)	5.0
Net (loss) income from discontinued operations	0.0	(1.1)
Net loss on sale of discontinued operations	1.0	0.0
Amortization and depreciation	14.6	11.4
Other operating items:
Net change in loss and loss adjustment expense reserves	2.9	(46.2)
Net change in reinsurance recoverable on paid and unpaid losses	1.4	26.5
Net change in unearned insurance premiums	20.7	13.9
Net change in deferred acquisition costs	(3.5)	(2.2)
Net change in ceded unearned premiums	(8.2)	(6.8)
Net change in funds held under insurance treaties	(4.3)	(2.8)
Net change in insurance premiums receivable	2.7	(11.0)
Net change in restricted cash	0.0	(2.6)
Net change in other assets and liabilities, net	(64.0)	(19.8)
Net cash used for operations - continuing operations	(56.1)	(45.9)
Net cash used for operations	(56.1)	(86.6)
Cash flows from investing activities:
Net change in short-term investments	55.6	(50.4)
Sales of fixed maturity and convertible investments	868.5	202.3
Maturities, calls and paydowns of fixed maturity and convertible investments	175.8	155.9
Sales of common equity securities	17.7	767.5
Distributions and redemptions of other long-term investments	16.5	3.0
Net settlement of investment cash flows and contributions with discontinued operations	0.0	(559.8)
Purchases of other long-term investments	(22.4)	(10.9)
Purchases of common equity securities	(113.4)	(86.1)
Purchases of fixed maturity and convertible investments	(957.6)	(315.2)
Purchases of unconsolidated affiliates and consolidated subsidiaries, net of cash acquired	0.0	(8.1)
Net change in unsettled investment purchases and sales	(1.0)	44.3
Net acquisitions of property and equipment	(0.4)	(1.3)
Net cash provided from investing activities - continuing operations	39.3	141.2
Net cash provided from investing activities	39.3	174.8
Cash flows from financing activities:
Draw down of debt and revolving line of credit	0.0	102.5
Repayment of debt and revolving line of credit	(1.2)	0.0
Cash dividends paid to the Company’s common shareholders	(4.6)	(5.4)
Common shares repurchased	0.0	(166.8)
OneBeacon Ltd. common shares repurchased and retired	0.0	(10.6)
Distribution to non-controlling interest shareholders	(5.1)	(4.7)
Contributions to discontinued operations	0.0	(3.0)
Payments of contingent consideration related to purchases of consolidated subsidiaries	0.0	(7.8)
Capital contributions from BAM members	9.6	6.7
Other Financing Activities, Net	(7.6)	(7.2)
Net cash used for financing activities - continuing operations	(8.9)	(96.3)
Net cash used for financing activities	(8.9)	(104.6)
Effect of Exchange Rate on Cash and Cash Equivalents	0.0	0.0
Net change in cash during the period - continuing operations	(25.7)	(1.0)
Cash balances at beginning of period	149.8	167.2	$ 167.2
Add: cash held for sale at the beginning of period	0.9	1.2	1.2
Less: cash held for sale at the end of period	0.0	2.1	0.9
Cash balances at end of period	125.0	165.3	149.8
Supplemental cash flows information:
Interest paid	(0.2)	(0.2)
Net income tax refund from national governments	0.0	13.5
Discontinued Operations [Member]
Charges (credits) to reconcile net income to net cash used for operations:
Net realized and unrealized investment (gains) losses	0.0	8.8
Net (loss) income from discontinued operations	0.0	(1.1)
Other operating items:
Net cash used for operations - discontinued operations	0.0	(40.7)
Cash flows from investing activities:
Net cash provided from investing activities - discontinued operations	0.0	33.6
Cash flows from financing activities:
Net cash used for financing activities - discontinued operations	0.0	(8.3)
Cash balances at beginning of period	0.0	150.2	150.2
Cash balances at end of period	0.0	139.9	$ 0.0
Supplemental cash flows information:
Net income tax refund from national governments	$ 0.0	$ 36.4