Investments (Details 1) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Held to Maturity
Due in one year or less, Amortized Cost	$ 1,500,000
Due after one year through five years, Amortized Cost	33,069,000
Due after five years through ten years, Amortized Cost	9,118,000
Due after ten years, Amortized Cost
Residential mortgage-backed securities, Amortized Cost	201,000
Total held to maturity, Amortized Cost	43,888,265	58,489,619
Due in one year or less, Estimated Fair Value	1,524,000
Due after one year through five years, Estimated Fair Value	34,535,000
Due after five years through ten years, Estimated Fair Value	9,672,000
Due after ten years, Estimated Fair Value
Residential mortgage-backed securities, Estimated Fair Value	217,000
Total Held to Maturity, Estimated Fair Value	45,948,000	61,422,000
Available for sale
Due in one year or less, Amortized Cost	15,257,000
Due after one year through five years, Amortized Cost	62,479,000
Due after five years through ten years, Amortized Cost	190,144,000
Due after ten years, Amortized Cost	256,563,000
Residential mortgage-backed securities, Amortized Cost	119,445,000
Total available for sale securities, Amortized Cost	643,888,000
Due in one year or less, Estimated Fair Value	15,390,000
Due after one year through five years, Estimated Fair Value	64,884,000
Due after five years through ten years, Estimated Fair Value	203,214,000
Due after ten years, Estimated Fair Value	280,309,000
Residential mortgage-backed securities, Estimated Fair Value	123,682,000
Total available for sale, Estimated Fair Value	$ 687,478,911	$ 646,598,178