Net Income Per Common Share (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2015 $ / shares shares	Jun. 30, 2014 $ / shares shares	Jun. 30, 2015 $ / shares shares	Jun. 30, 2014 item $ / shares shares
Net Income Per Common Share
Weighted average common basic shares outstanding	22,145,190	21,991,965	22,136,458	21,984,912
Effect of dilutive stock options and restricted stock units	376,642	406,921	368,945	390,465
Weighted average common diluted shares outstanding	22,521,832	22,398,886	22,505,403	22,375,377
Net income (loss) per share
Basic (in dollars per share) | $ / shares	$ 0.44	$ 0.24	$ 0.50	$ 0.44
Diluted (in dollars per share) | $ / shares	$ 0.43	$ 0.24	$ 0.49	$ 0.43
Performance-based incentive programs | item				0
Potential shares of common stock attributable to stock options excluded from net income per common share calculation			0