CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash Flows from Operating Activities
Net Income	$ 210.6	$ 212.9
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Change in Receivables	(27.3)	49.2
Change in Deferred Acquisition Costs	(20.3)	(10.7)
Change in Insurance Reserves and Liabilities	113.0	98.4
Change in Income Taxes	83.0	161.4
Change in Other Accrued Liabilities	(30.8)	(69.0)
Non-cash Components of Net Investment Income	(86.9)	(90.5)
Net Realized Investment Loss	20.5	15.3
Depreciation	25.4	23.5
Other, Net	6.1	9.6
Net Cash Provided by Operating Activities	293.3	400.1
Cash Flows from Investing Activities
Proceeds from Sales of Fixed Maturity Securities	364.8	108.5
Proceeds from Maturities of Fixed Maturity Securities	348.7	468.0
Proceeds from Sales and Maturities of Other Investments	78.5	42.5
Purchases of Fixed Maturity Securities	(882.7)	(959.5)
Purchases of Other Investments	(84.0)	(127.6)
Net Sales of Short-term Investments	70.9	259.8
Net Increase in Payables for Collateral on Investments	10.5	6.1
Net Purchases of Property and Equipment	(17.2)	(31.4)
Net Cash Used by Investing Activities	(110.5)	(233.6)
Cash Flows from Financing Activities
Long-term Debt Repayments	(13.2)	(29.1)
Issuance of Common Stock	1.7	0.8
Repurchase of Common Stock	(108.8)	(108.1)
Dividends Paid to Stockholders	(45.2)	(42.3)
Other, Net	(9.5)	(6.2)
Net Cash Used by Financing Activities	(175.0)	(184.9)
Net Increase (Decrease) in Cash and Bank Deposits	7.8	(18.4)
Cash and Bank Deposits at Beginning of Year	112.9	102.5
Cash and Bank Deposits at End of Period	$ 120.7	$ 84.1