Net Income Per Common Share (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net Income Per Common Share
Weighted average common basic shares outstanding	15,665,263	15,834,622	15,614,868	15,812,910
Effect of dilutive stock options and restricted stock units (in shares)	235,396	329,492	245,800	342,362
Weighted average common diluted shares outstanding	15,900,659	16,164,114	15,860,668	16,155,272
Net income per share:
Basic (in dollars per share)	$ 0.27	$ 0.29	$ 0.41	$ 0.53
Diluted (in dollars per share)	$ 0.26	$ 0.28	$ 0.40	$ 0.52
Anti dilutive securities excluded in computation of diluted earnings per share
Anti-dilutive options (in shares)		9,534		9,534