Earnings per share (Tables)

12 Months Ended

Dec. 31, 2012

Dilutive shares of consolidated condensed statements of operations

The following summarizes the shares included in the dilutive shares as disclosed in the statements of operations:

	Year ended December 31,
	2012		2011		2010
Weighted average number of shares for calculation of basic EPS — Common Stock		28,352,864		22,605,518		21,716,775
Stock options under Plans		509,599		849,104		779,472
Weighted average number of shares for calculation of diluted EPS — Common Stock		28,862,463		23,454,622		22,496,247

Common Stock issuable upon the exercise of certain stock options

The accompanying table represents Common Stock issuable upon the exercise of certain stock options and Series C Convertible Preferred Stock that have been excluded from the diluted earnings calculation because the effect of their inclusion would be anti-dilutive.

	Year ended December 31,
	2012		2011		2010
Stock options outstanding for the 1993, 1997, 2006 and 2011 Stock Options Plans		149,000		84,000		155,826
Series C Convertible Preferred Stock		1,531,891		3,714,518		—
		1,680,891		3,798,518		155,826