Goodwill and Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended			0 Months Ended	3 Months Ended	0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 01, 2011	Sep. 30, 2012	Aug. 29, 2008	Sep. 30, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 44,695,000	$ 44,695,000
Impairment of goodwill	0	0	0
Weighted average period to amortize acquired intangible assets	13 years
Standard Commercial P & C Business Unit [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	2,100,000
TBIC Holding Corporation Inc [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Business acquisition, cash paid				1,600,000	350,000
Business acquisition, bargain purchase gain recorded				165,000
TBIC Holding Corporation Inc [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Potential cash payment following 16 full calendar quarters				3,000,000
E & S Commercial Business Unit [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	19,800,000
Hallmark Select Business Unit [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	17,400,000
Excess and Umbrella Business Unit [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Business acquisition, percentage of voting interests acquired						80.00%
Business acquisition, total consideration						15,000,000
Goodwill	7,700,000
Excess and Umbrella Business Unit [Member] | Put or Call Option [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Business acquisition, percentage of voting interests acquired					20.00%		20.00%
Business acquisition, total consideration							1,700,000
General Aviation and Satellite Component [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	9,700,000
Personal Lines Business Unit [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 5,400,000