CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operations:
Net income	$ 102.2	$ 96.6
Charges (credits) to reconcile net income to net cash and cash equivalents provided from operations:
Net realized and unrealized investment (gains) losses	(22.7)	0.7
Net realized and unrealized (gains) losses on investment-related derivative instruments	(0.1)	(4.3)
Net amortization and depreciation of assets and liabilities	2.9	3.9
Expense recognized for RSUs	3.0	3.3
Net change in:
Loss and loss adjustment expense reserves	(44.6)	(52.5)
Reinsurance recoverable on paid and unpaid losses	9.4	0.4
Unearned insurance and reinsurance premiums	95.8	80.8
Insurance and reinsurance balances payable	18.2	18.3
Unearned reinsurance premiums ceded	(15.5)	(14.5)
Deferred insurance and reinsurance acquisition costs	(9.7)	(6.1)
Insurance and reinsurance premiums receivable	(69.7)	(66.5)
Other assets	(0.3)	(1.9)
Accounts payable, accrued expenses and other liabilities	(14.5)	1.3
Other	0.7	(11.5)
Net cash and cash equivalents provided from operations	55.1	48.0
Cash flows from investing activities:
Purchases of fixed maturity investments	(1,722.7)	(1,351.2)
Purchases of equity securities	(228.6)	(26.5)
Purchases of other investments	(325.0)
Sales, maturities, calls and pay downs of fixed maturity investments	1,739.6	1,502.4
Sales of equity securities	171.9	28.9
Sales and redemptions of other investments	253.6	42.3
Settlements of investment-related derivative instruments	(3.9)	(3.0)
Net investments in reverse repurchase agreements	(39.6)	(144.3)
Net change in restricted cash	59.3	2.5
Payment of accrued investment performance fees	(4.1)	(6.4)
Acquisitions of capitalized assets	(0.3)	(0.4)
Net cash and cash equivalents (used for) provided from investing activities	(99.8)	44.3
Cash flows from financing activities:
Repurchases of Common Shares	(66.2)	(38.7)
Net investment in non-controlling interests		31.4
Net proceeds from repurchase agreements	397.4
Dividends paid - Common Shares	(6.2)	(6.3)
Dividends paid - Preferred Shares	(3.3)	(3.3)
Net cash and cash equivalents provided from (used for) financing activities	321.7	(16.9)
Effect of foreign currency exchange rate fluctuations on cash and cash equivalents	2.0	(6.0)
Net increase in cash and cash equivalents during the period	279.0	69.4
Cash and cash equivalents - beginning of year	468.4	283.4
Cash and cash equivalents - end of period	$ 747.4	$ 352.8