Earnings per share (Tables)

12 Months Ended

Dec. 31, 2012

Earnings Per Share [Abstract]

Schedule of Reconciliation of Weighted Average Shares Used in Calculation of Basic and Diluted Earnings Per Share

The following is a reconciliation of the weighted average shares used in the basic and diluted net income (loss) per common share computations.

	Year Ended December 31,
	2012		2011		2010
Weighted average common shares-basic		18,977,263		18,219,343		17,601,956
Effect of diluted securities:
Unexercised stock options net of treasury share repurchase		413,150		—		311,589
Weighted average common share-diluted		19,390,413		18,219,343		17,913,545