CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash Flows From Operating Activities
Net income	$ 66.2	$ 49.7
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment gains	(8.1)	(2.3)
Net amortization and depreciation	8.4	9.1
Stock-based compensation expense	3.6	4.1
Amortization of defined benefit plan costs	2.9	2.3
Deferred income taxes expense (benefit)	18.4	(18.9)
Change in deferred acquisition costs	(5.2)	(9.4)
Change in premiums receivable, net of reinsurance premiums payable	0.3	49.3
Change in loss, loss adjustment expense and unearned premium reserves	(24.3)	109.9
Change in reinsurance recoverable	19.6	(158.4)
Change in expenses and taxes payable	(101.4)	(28.2)
Other, net	2.1	5.5
Net cash provided by (used in) operating activities	(17.5)	12.7
Cash Flows From Investing Activities
Proceeds from disposals and maturities of fixed maturities	400.2	550.9
Proceeds from disposals of equity securities and other investments	36.7	2.6
Purchase of fixed maturities	(223.9)	(663.0)
Purchase of equity securities and other investments	(123.8)	(98.4)
Capital expenditures	(5.7)	(3.2)
Net cash provided by (used in) investing activities	83.5	(211.1)
Cash Flows From Financing Activities
Proceeds from exercise of employee stock options	4.5	1.1
Proceeds from debt borrowings, net	169.5	7.4
Decrease in cash collateral related to securities lending program	(19.8)	(7.8)
Dividends paid to shareholders	(14.8)	(13.5)
Repurchases of debt	(46.3)	(0.8)
Repurchases of common stock	(25.2)
Other financing activities	(1.0)	(0.2)
Net cash provided by (used in) financing activities	66.9	(13.8)
Effect of exchange rate changes on cash	(6.2)	20.1
Net change in cash and cash equivalents	126.7	(192.1)
Net change in cash related to discontinued operations	(0.5)
Cash and cash equivalents, beginning of period	564.8	820.4
Cash and cash equivalents, end of period	$ 691.0	$ 628.3