Summary of Significant Accounting Policies (Schedule of Trust Assets and Reinsurance Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	$ 205.4		$ 111.3
Restricted securities available for sale	51.4		53.6
Accounts payable and accrued liabilities	111.4		113.8
Trust Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	1.5		1.2
Restricted securities available for sale	51.4		53.6
Unearned Premium [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts payable and accrued liabilities	39.2		42.4
Claims Reserve [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts payable and accrued liabilities	$ 1.6	[1]	$ 1.7	[1]

[1] The claims reserve is estimated based on historical claims experience.