Stock-Based Compensation (Details 2) (Options, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Options
Unvested options, Number of Shares
Unvested at the beginning of the period (in shares)	204,225
Options granted (in shares)	128,700	132,900	123,600
Options cancelled (in shares)	(10,050)
Options vested (in shares)	(112,950)
Unvested at the end of the period (in shares)	209,925	204,225
Unvested options, Weighted Average Grant Date Value
Unvested at the beginning of the period (in dollars per share)	$ 4.00
Options granted (in dollars per share)	$ 4.18	$ 4.60	$ 3.73
Options cancelled (in dollars per share)	$ 4.26
Options vested (in dollars per share)	$ 4.11
Unvested at the end of the period (in dollars per share)	$ 1.04	$ 4.00
Additional disclosure
Total unrecognized compensation cost related to unvested stock-based compensation granted (in dollars)	$ 847,922
Weighted-average period over which unrecognized compensation expense is expected to be recognized	1 year 8 months 12 days
Fair value of option shares vested	$ 464,470	$ 388,904	$ 261,860