Annual report pursuant to section 13 and 15(d)

Summary of Stock Option Activity (Detail)

v2.4.0.6
Summary of Stock Option Activity (Detail) (USD $)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares Available for Future Grant, Beginning Balance 353,953 423,618
Shares Available for Future Grant, Options granted at market (54,250) (224,250)
Shares Available for Future Grant, Options exercised      
Shares Available for Future Grant, Options forfeited or expired 81,467 154,585
Shares Available for Future Grant, Ending Balance 381,170 353,953
Beginning Balance 737,020 670,355
Number of Shares Outstanding Under Option, Options granted at market 54,250 224,250
Number of Shares Outstanding Under Option, Options exercised      
Number of Shares Outstanding Under Option, Options forfeited or expired (84,467) (157,585)
Ending Balance 706,803 737,020
Weighted Average Exercise Price, Beginning Balance $ 4.26 $ 4.60
Weighted Average Exercise Price , Options granted at market $ 0.54 $ 2.32
Weighted Average Exercise Price, Options exercised      
Weighted Average Exercise Price, Options forfeited or expired $ 1.83 $ 2.95
Weighted Average Exercise Price, Ending Balance $ 4.27 $ 4.26