Commitments and Contingencies (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 sqft
Loss Contingencies [Line Items]
Letters of credit issued and outstanding	$ 81.4
Commitments and Contingencies (Textual) [Abstract]
Pledged investment assets	90.1
Rentable square feet for primary operations	47,000
Term of lease	86 months
Irrevocable letters of credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued and outstanding	5.3
Letters of credit issued to other parties	0.8
Benefit of Vermont Department of Banking, Insurance, Securities and Health Care Administration	2.0
Contingent payment obligation	$ 2.5