Net Income Per Comon Share Data (Details 1) (Stock options [Member])
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Stock options [Member]
       
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive equity awards 86,500 267 86,500 58,767