Summary Of Significant Accounting Policies (Schedule Of Trust Assets And Reinsurance Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	$ 92.4		$ 104.7
Restricted securities available for sale	46.1		0.8
Accounts payable and accrued liabilities	105.8		95.8
Trust Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	2.2		42.1
Restricted securities available for sale	46.1
Unearned Premium [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts payable and accrued liabilities	35.7		32.3
Claims Reserve [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts payable and accrued liabilities	$ 1.4	[1]	$ 1.3	[1]

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