Business Combinations (Details Textual) (USD $)	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 30, 2010	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Nov. 30, 2010
Restructuring Cost and Reserve [Line Items]
Stockholders' equity		$ 400,034,094				$ 383,451,592				$ 400,034,094	$ 383,451,592	$ 380,102,810	$ 385,505,699
Total assets		1,336,889,187				1,290,793,478				1,336,889,187	1,290,793,478
Business Combinations (Textual) [Abstract]
Stockholders' equity price												122.00%
Stockholders' equity price in cash															42,300,000
Equity Amount paid to MICO's stockholders												35,100,000
Additional amount payable												7,200,000
Property and casualty insurance premiums												105,400,000	106,600,000
Net premiums earned/Premiums earned		121,824,349	120,916,960	117,569,122	114,691,791	114,176,695	108,506,809	104,991,401	103,795,279	475,002,222	431,470,184	378,030,129	27,000,000
Goodwill		4,700,000								4,700,000
Other intangible assets		958,000								958,000
Losses and loss expenses															1,000,000
Business combinations redundancy reserves description										less than 1.0
Return of any redundancy in excess												50.00%
Final actuarial review of the development of such reserves												3 years
Reinsurance agreements												75.00%		80.00%
Obligations of West Bend		5,000,000								5,000,000
Obligations under the reinsurance agreements		22,600,000								22,600,000
Fair value of assets		26,300,000								26,300,000
Reinsurance agreement with third-party reinsurers												50.00%
Reinsurance agreement with Donegal Mutual												25.00%
Total revenues related to the operations of MICO and Atlantic States	2,400,000
Pro forma income statement adjustments													3,800,000
MICO [Member]
Restructuring Cost and Reserve [Line Items]
Stockholders' equity													32,000,000
Total assets													224,500,000
Business Combinations (Textual) [Abstract]
Goodwill		4,703,000								4,703,000
Other intangible assets		$ 958,000								$ 958,000