Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net Income (Loss)	$ 84.0	$ (14.4)
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Amortization of Intangible Assets Acquired	3.9	4.5
Equity in Earnings of Equity Method Limited Liability Investments	(21.9)	(3.3)
Distribution of Accumulated Earnings of Equity Method Limited Liability Investments	15.9	10.3
Decrease (Increase) in Value of Fair Value Option Investments Reported in Investment Income	(0.9)	3.9
Amortization of Investment Securities and Depreciation of Investment Real Estate	12.8	11.7
Net Realized Gains on Sales of Investments	(45.0)	(24.0)
Net Impairment Losses Recognized in Earnings	10.5	24.0
Depreciation of Property and Equipment	9.8	10.5
Increase in Receivables	(27.2)	(23.8)
Increase in Deferred Policy Acquisition Costs	(29.6)	(11.8)
Increase in Insurance Reserves	71.4	177.6
Increase in Unearned Premiums	53.3	23.9
Change in Income Taxes	27.4	(30.2)
Change in Accrued Expenses and Other Liabilities	(1.5)	2.0
Other, Net	1.6	9.6
Net Cash Provided by Operating Activities	164.5	170.5
Investing Activities:
Sales, Paydowns and Maturities of Fixed Maturities	367.7	422.4
Purchases of Fixed Maturities	(401.8)	(539.8)
Sales of Equity Securities	230.3	107.2
Purchases of Equity Securities	(233.5)	(64.8)
Return of Investment of Equity Method Limited Liability Investments	36.3	22.6
Acquisitions of Equity Method Limited Liability Investments	(14.5)	(20.2)
Sales of Fair Value Option Investments	42.2	50.5
Purchases of Fair Value Option Investments	(7.0)	(16.0)
Decrease (Increase) in Short-term Investments	40.4	(68.5)
Improvements of Investment Real Estate	(1.3)	(1.8)
Sales of Investment Real Estate	26.2	7.5
Increase in Other Investments	(1.3)	(3.4)
Purchases of Corporate-owned Life Insurance	0.0	(7.5)
Acquisition and Development of Software	(28.8)	(8.8)
Other, Net	(4.4)	(2.0)
Net Cash Provided (Used) by Investing Activities	50.5	(122.6)
Financing Activities:
Net Proceeds from Issuance of Long-term Debt	200.2	0.0
Repayment of Long-term Debt	(360.0)	0.0
Common Stock Repurchases	0.0	(3.8)
Dividends and Dividend Equivalents Paid	(37.1)	(36.9)
Cash Exercise of Stock Options	3.7	1.2
Other, Net	0.1	1.0
Net Cash Used by Financing Activities	(193.1)	(38.5)
Increase in Cash	21.9	9.4
Cash, Beginning of Year	115.7	161.7
Cash, End of Period	$ 137.6	$ 171.1