SCHEDULE IV -REINSURANCE (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Retrocessions associated with premiums assumed from other companies	$ 2,316	$ 1,913	$ 1,250
Property and Casualty Insurance [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums	287,982	270,002	245,912
Ceded to Other Companies	103,712	85,493	73,119
Assumed from Other Companies	53,191	60,061	41,945
Net Amount	$ 237,461	$ 244,570	$ 214,738
% of amount assumed to net (in hundredths)	21.40%	23.80%	19.00%