Quarterly report pursuant to sections 13 or 15(d)

Summary of Stock Option Activity (Detail)

v2.4.0.8
Summary of Stock Option Activity (Detail) (USD $)
 6 Months Ended 12 Months Ended
Jun. 30, 2013
Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares Available for Future Grant, Beginning Balance 381,170 353,953
Shares Available for Future Grant, Options granted   (54,250)
Shares Available for Future Grant, Options exercised 96,146  
Shares Available for Future Grant, Options forfeited or expired 163,637 81,467
Shares Available for Future Grant, Ending Balance 640,953 381,170
Number of Shares Outstanding Under Option, Beginning Balance 706,803 737,020
Number of Shares Outstanding Under Option, Options granted 0 54,250
Number of Shares Outstanding Under Option, Options exercised (96,146)  
Number of Shares Outstanding Under Option, Options forfeited or expired (163,637) (84,467)
Number of Shares Outstanding Under Option, Ending Balance 447,020 706,803
Weighted Average Exercise Price, Beginning Balance $ 4.27 $ 4.26
Weighted Average Exercise Price , Options granted   $ 0.54
Weighted Average Exercise Price, Options exercised $ 2.27  
Weighted Average Exercise Price, Options forfeited or expired $ 4.83 $ 1.83
Weighted Average Exercise Price, Ending Balance $ 4.51 $ 4.27