Stock-Based Compensation (Details 1) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Summary of all stock options outstanding
Balance at December 31, 2011, Shares subject to option	104,000
Balance at December 31, 2011, Weighted average exercise price per share	$ 28.57
Balance at December 31, 2011, Aggregate intrinsic value	$ 126,570
Balance at December 31, 2011, Weighted average contractual remaining life in years	6 years 2 months 12 days	6 years 2 months 12 days
Shares subject to option, Granted	16,000
Weighted average exercise price per share, Granted	$ 22.95
Shares subject to option, Exercised	(4,000)
Weighted average exercise price per share , Exercised	$ 15.04
Balance at September 30 2012, Shares subject to option	116,000	104,000
Balance at September 30 2012, Weighted average exercise price per share	$ 28.27	$ 28.57
Balance September 30 2012, Aggregate intrinsic value	$ 232,070
Balance at September 30 2012, Weighted average contractual remaining life in years	6 years 2 months 12 days	6 years 2 months 12 days