Income Taxes - Schedule of Temporary Differences That Give Rise to Net Deferred Income Tax Assets (Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Income Tax Assets:
Insurance Reserves	$ 79.3	$ 76.8
Unearned Premium Reserves	44.1	45.0
Tax Capitalization of Policy Acquisition Costs	73.6	73.5
Net Operating Loss Carryforward	100.7	98.1
Payroll and Employee Benefit Accruals	79.9	67.8
Other	10.7	11.7
Total Deferred Income Tax Assets	388.3	372.9
Deferred Income Tax Liabilities:
Deferred Policy Acquisition Costs	104.1	102.9
Value of Insurance in Force Acquired	25.2	25.9
Investments	208.4	182.3
Depreciable Assets	29.3	22.5
Goodwill and Licenses	23.5	22.9
Other	6.3	5.7
Total Deferred Income Tax Liabilities	396.8	362.2
Valuation Allowance for State Income Taxes	6.6	6.8
Net Deferred Income Tax Liabilities	(15.1)	3.9
Federal [Member]
Deferred Income Tax Assets:
Net Operating Loss Carryforward	94.4	91.2
State [Member]
Deferred Income Tax Assets:
Net Operating Loss Carryforward	6.3	6.9
Fireside [Member] | State [Member]
Deferred Income Tax Liabilities:
Valuation Allowance for State Income Taxes	$ 6.6	$ 6.8