Accounting Policies (Details 1)	Jul. 01, 2004 Standard Commercial Business Unit and Clarendon [Member]	Jul. 01, 2003 Standard Commercial Business Unit and Clarendon [Member]	Jul. 01, 2002 Standard Commercial Business Unit and Clarendon [Member]	Jul. 01, 2001 Standard Commercial Business Unit and Clarendon [Member]	Dec. 31, 2012 E&S Commercial Business Unit and Republic [Member]	Jan. 01, 2008 E&S Commercial Business Unit and Republic [Member]	Jan. 01, 2007 E&S Commercial Business Unit and Republic [Member]	Jan. 01, 2006 E&S Commercial Business Unit and Republic [Member]
Provisional loss ratio	64.20%	59.00%	59.00%	60.00%	62.50%	65.00%	65.00%	65.00%
Estimated ultimate loss ratio recorded to at December 31, 2012	61.80%	62.50%	64.50%	63.50%	50.70%	58.80%	62.40%	58.30%