Quarterly report pursuant to Section 13 or 15(d)

Summary of Warrant Activity (Detail)

v3.5.0.2
Summary of Warrant Activity (Detail) - Warrants
6 Months Ended
Jun. 30, 2016
$ / shares
shares
Shares  
Beginning Balance | shares 10,094,000
Forfeited or cancelled | shares (723,000)
Ending Balance | shares 9,371,000
Warrants exercisable at June 30, 2016 | shares 9,236,000
Vested warrants expired during the quarter ended June 30, 2016 | shares (723,000)
Weighted Average Grant Date Fair Value  
Beginning Balance | $ / shares $ 4.18
Weighted Average Exercise Price, Forfeited, cancelled, or expired | $ / shares 6.50
Ending Balance | $ / shares 4.00
Warrants exercisable at June 30, 2016 | $ / shares 4.00
Vested warrants expired during the quarter ended June 30, 2016 | $ / shares $ 6.50