CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash Flows from Operating Activities
Net Income	$ 475.0	$ 447.4
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Change in Receivables	94.8	48.1
Change in Deferred Acquisition Costs	(35.5)	(40.8)
Change in Insurance Reserves and Liabilities	244.1	211.0
Change in Income Taxes	55.7	44.5
Change in Other Accrued Liabilities	(12.6)	(37.6)
Non-cash Components of Net Investment Income	(213.4)	(190.5)
Net Realized Investment (Gain) Loss	(19.1)	15.2
Depreciation	53.4	50.6
Other, Net	(0.4)	13.5
Net Cash Provided by Operating Activities	642.0	561.4
Cash Flows from Investing Activities
Proceeds from Sales of Fixed Maturity Securities	272.2	674.7
Proceeds from Maturities of Fixed Maturity Securities	1,288.4	917.2
Proceeds from Sales and Maturities of Other Investments	106.8	166.7
Purchases of Fixed Maturity Securities	(1,384.6)	(1,741.1)
Purchases of Other Investments	(179.9)	(259.0)
Net Purchases of Short-term Investments	(330.3)	(604.2)
Net Increase (Decrease) in Payables for Collateral on Investments	(1.2)	34.8
Net Purchases of Property and Equipment	(47.8)	(41.6)
Net Cash Used by Investing Activities	(276.4)	(852.5)
Cash Flows from Financing Activities
Issuance of Long-term Debt	0.0	609.1
Long-term Debt Repayments	(33.5)	(24.0)
Issuance of Common Stock	1.5	2.7
Repurchase of Common Stock	(207.0)	(208.9)
Dividends Paid to Stockholders	(92.3)	(89.4)
Other, Net	(17.7)	(17.5)
Net Cash Provided (Used) by Financing Activities	(349.0)	272.0
Net Increase (Decrease) in Cash and Bank Deposits	16.6	(19.1)
Cash and Bank Deposits at Beginning of Year	100.4	112.9
Cash and Bank Deposits at End of Period	$ 117.0	$ 93.8