Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Commitments and Contingencies (Textual) [Abstract]
Letters of credit issued and outstanding	$ 84.5
Irrevocable letters of credit [Member]
Commitments and Contingencies (Textual) [Abstract]
Letters of credit issued and outstanding	4.3
Letters of credit issued to other parties	0.8
Benefit of Vermont Department of Banking, Insurance, Securities and Health Care Administration	1.0
Contingent payment obligation	$ 2.5