CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities
Net Income	$ 727.3	$ 683.4
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Change in Receivables	(119.0)	(65.7)
Change in Deferred Acquisition Costs	(66.6)	(69.8)
Change in Insurance Reserves and Liabilities	348.1	274.1
Change in Income Taxes	81.4	(0.8)
Change in Other Accrued Liabilities	(6.6)	(37.6)
Non-cash Components of Net Investment Income	(145.7)	(135.0)
Net Realized Investment (Gain) Loss	(28.9)	4.2
Depreciation	78.4	75.9
Other, Net	(2.4)	26.2
Net Cash Provided by Operating Activities	866.0	754.9
Cash Flows from Investing Activities
Proceeds from Sales of Fixed Maturity Securities	303.2	726.6
Proceeds from Maturities of Fixed Maturity Securities	1,848.5	1,504.1
Proceeds from Sales and Maturities of Other Investments	172.3	257.7
Purchases of Fixed Maturity Securities	(2,063.4)	(2,452.3)
Purchases of Other Investments	(313.5)	(431.4)
Net Sales (Purchases) of Short-term Investments	(252.6)	38.6
Net Increase (Decrease) in Payables for Collateral on Investments	(7.7)	24.7
Acquisition of Business, Net of Cash Acquired	0.0	128.5
Net Purchases of Property and Equipment	(64.7)	(60.1)
Net Cash Used by Investing Activities	(377.9)	(520.6)
Cash Flows from Financing Activities
Issuance of Long-term Debt	0.0	609.1
Long-term Debt Repayments	(48.5)	(399.0)
Issuance of Common Stock	9.5	3.6
Repurchase of Common Stock	(307.2)	(309.1)
Dividends Paid to Stockholders	(144.1)	(136.2)
Other, Net	(28.1)	(27.7)
Net Cash Used by Financing Activities	(518.4)	(259.3)
Net Decrease in Cash and Bank Deposits	(30.3)	(25.0)
Cash and Bank Deposits at Beginning of Year	100.4	112.9
Cash and Bank Deposits at End of Period	$ 70.1	$ 87.9