CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash Flows from Operating Activities
Net Income	$ 235.4	$ 886.1	$ 852.6
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Change in Receivables	37.0	1.7	113.9
Change in Deferred Acquisition Costs	(94.5)	(60.6)	(67.4)
Impairment of Deferred Acquisition Costs	289.8	0	0
Change in Insurance Reserves and Liabilities	1,113.9	537.8	441.2
Change in Income Taxes	(301.7)	164.3	59.2
Change in Other Accrued Liabilities	68.4	(95.5)	(18.4)
Non-cash Adjustments to Net Investment Income	(240.6)	(276.2)	(239.8)
Net Realized Investment (Gain) Loss	4.9	(24.7)	(11.7)
Depreciation	81.1	75.4	74.5
Other, Net	0	(11.5)	32.9
Net Cash Provided by Operating Activities	1,193.7	1,196.8	1,237.0
Cash Flows from Investing Activities
Proceeds from Sales of Fixed Maturity Securities	1,181.9	1,122.8	1,427.2
Proceeds from Maturities of Fixed Maturity Securities	1,692.7	2,192.8	1,132.5
Proceeds from Sales and Maturities of Other Investments	131.9	140.3	250.5
Purchase of Fixed Maturity Securities	(2,760.1)	(3,798.6)	(3,848.8)
Purchase of Other Investments	(304.1)	(332.8)	(267.7)
Net Sales (Purchases) of Short-term Investments	(254.6)	(288.1)	199.0
Other, Net	(98.0)	(110.1)	(106.6)
Net Cash Used by Investing Activities	(410.3)	(1,073.7)	(1,213.9)
Cash Flows from Financing Activities
Net Short-term Debt Borrowings (Repayments)	87.2	0	(190.5)
Issuance of Long-term Debt	0	396.9	346.8
Long-term Debt Repayments	(84.4)	(78.3)	(59.8)
Issuance of Common Stock	14.8	10.0	8.0
Repurchase of Common Stock	(619.9)	(356.0)	0
Dividends Paid to Stockholders	(121.0)	(114.8)	(104.5)
Treasury Stock Acquired, Shares		16.4
Other, Net	2.9	1.1	(1.5)
Net Cash Used by Financing Activities	(720.4)	(141.1)	(1.5)
Effect of Foreign Exchange Rate Changes on Cash	0	0	0.1
Net Increase (Decrease) in Cash and Bank Deposits	63.0	(18.0)	21.7
Cash and Bank Deposits at Beginning of Year	53.6	71.6	49.9
Cash and Bank Deposits at End of Period	$ 116.6	$ 53.6	$ 71.6