Significant Accounting Policies (Details 4) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Liability Policies [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Self-Insured Retention, Maximum Per Incident	$ 0.5
Property Policies [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Self-Insured Retention, Maximum Per Incident	$ 1.0