Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities:
Net Income	$ 85.7	$ 114.5	$ 217.7
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Decrease (Increase) in Deferred Policy Acquisition Costs	(13.1)	(0.4)	0.5
Amortization of Intangible Assets Acquired	15.4	7.2	8.3
Equity in Earnings of Equity Method Limited Liability Investments	(19.0)	(9.0)	(26.4)
Distribution of Accumulated Earnings of Equity Method Limited Liability Investments	8.6	21.7	15.4
Decrease (Increase) in Value of Fair Value Option Investments reported in Investment Income	(0.3)	0.7	0.0
Amortization of Investment Securities and Depreciation of Investment Real Estate	16.1	15.4	16.2
Net Realized Gains on Sales of Investments	52.1	39.1	99.1
Net Impairment Losses Recognized in Earnings	27.2	15.2	13.9
Loss from Early Extinguishment of Debt	9.1	0.0	0.0
Depreciation of Property and Equipment	13.5	16.0	17.4
Write-off of Long-lived Assets	11.1	54.6	0.0
Decrease in Other Receivables	49.6	46.2	43.5
Increase (Decrease) in Insurance Reserves	39.6	(54.7)	(72.5)
Decrease in Unearned Premiums	(9.4)	(62.0)	(52.0)
Change in Income Taxes	(21.8)	11.2	57.9
Increase (Decrease) in Accrued Expenses and Other Liabilities	22.6	(20.3)	(54.8)
Other, Net	32.2	16.4	36.1
Net Cash Provided by Operating Activities	215.0	133.6	122.1
Investing Activities:
Sales, Paydowns and Maturities of Fixed Maturities	627.8	573.7	664.4
Purchases of Fixed Maturities	(681.3)	(553.0)	(744.5)
Sales of Equity Securities	238.4	245.3	182.1
Purchases of Equity Securities	(134.0)	(235.2)	(213.4)
Acquisition and Improvements of Investment Real Estate	(1.8)	(2.1)	(5.4)
Sales of Investment Real Estate	7.7	0.9	102.7
Sales of and Return of Investment of Equity Method Limited Liability Investments	32.9	55.2	31.3
Acquisitions of Equity Method Limited Liability Investments	(32.4)	(21.4)	(20.5)
Sales of Fair Value Option Investments	0.0	6.9	0.0
Purchases of Fair Value Option Investments	(111.0)	(60.9)	0.0
Decrease (Increase) in Short-term Investments	104.9	(63.9)	41.8
Acquisition of Businesses, Net of Cash Acquired	57.6	0.0	0.0
Disposition of Business, Net of Cash Disposed	0.0	8.9	3.8
Increase in Other Investments	(3.2)	(8.0)	(9.1)
Purchase of Corporate-owned Life Insurance	(7.5)	(33.5)	0.0
Acquisition of Software	(8.9)	(11.3)	(15.2)
Other, Net	(2.6)	(5.9)	(13.2)
Net Cash Provided (Used) by Investing Activities	(28.6)	(104.3)	4.8
Financing Activities:
Net Proceeds from Issuances of Debt	345.8	144.0	0.0
Repayments of Debt	(357.3)	0.0	(5.5)
Common Stock Repurchases	(45.0)	(114.0)	(100.4)
Dividends and Dividend Equivalents Paid	(49.7)	(51.8)	(54.9)
Cash Exercise of Stock Options	3.9	0.5	1.7
Other, Net	1.5	1.6	2.4
Net Cash Used by Financing Activities	(100.8)	(19.7)	(156.7)
Increase (Decrease) in Cash	85.6	9.6	(29.8)
Cash, Beginning of Year	76.1	66.5	96.3
Cash, End of Year	$ 161.7	$ 76.1	$ 66.5