Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities:
Net Income	$ 183.6	$ 84.0
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Amortization of Intangible Assets Acquired	106.1	3.9
Equity in Earnings of Equity Method Limited Liability Investments	(8.1)	(21.9)
Distribution of Accumulated Earnings of Equity Method Limited Liability Investments	9.2	15.9
Decrease (Increase) in Value of Fair Value Option Investments Reported in Investment Income	0.0	(0.9)
Decrease (Increase) in Value of Equity Securities at Fair Value	(12.1)	0.0
Amortization of Investment Securities and Depreciation of Investment Real Estate	6.9	12.8
Net Realized Gains on Sales of Investments	(10.0)	(45.0)
Net Impairment Losses Recognized in Earnings	2.3	10.5
Depreciation of Property and Equipment	12.2	9.8
Increase in Receivables	(102.3)	(27.2)
Increase in Deferred Policy Acquisition Costs	(82.1)	(29.6)
Increase in Insurance Reserves	131.8	71.4
Increase in Unearned Premiums	102.3	53.3
Change in Income Taxes	4.6	27.4
Change in Accrued Expenses and Other Liabilities	(10.5)	(1.5)
Other, Net	11.4	1.6
Net Cash Provided by Operating Activities	345.3	164.5
Investing Activities:
Sales, Paydowns and Maturities of Fixed Maturities	2,133.7	367.7
Purchases of Fixed Maturities	(1,520.7)	(401.8)
Sales of Equity Securities	186.6	230.3
Purchases of Equity Securities	(344.3)	(233.5)
Return of Investment of Equity Method Limited Liability Investments	7.3	36.3
Acquisitions of Equity Method Limited Liability Investments	(17.4)	(14.5)
Sales of Fair Value Option Investments	0.0	42.2
Purchases of Fair Value Option Investments	0.0	7.0
Decrease (Increase) in Short-term Investments	(351.6)	40.4
Improvements of Investment Real Estate	(1.0)	(1.3)
Sales of Investment Real Estate	0.0	26.2
Increase (Decrease) in Other Investments	0.6	(1.3)
Acquisition and Development of Software	(53.9)	(28.8)
Other, Net	4.6	(4.4)
Acquisition of Business, Net of Cash Acquired	560.6	0.0
Net Cash Provided (Used) by Investing Activities	(516.7)	50.5
Financing Activities:
Net Proceeds from Issuance of Long-term Debt	249.0	200.2
Repayment of Long-term Debt	0.0	(360.0)
Dividends and Dividend Equivalents Paid	(40.7)	(37.1)
Proceeds from Advances from FHLB	10.0
Cash Exercise of Stock Options	0.7	3.7
Other, Net	(0.5)	0.1
Net Cash Provided (Used) by Financing Activities	218.5	(193.1)
Increase in Cash	47.1	21.9
Cash, Beginning of Year	45.7	115.7
Cash, End of Period	$ 92.8	$ 137.6