Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Restricted Stock Unit Award Activity (Detail)

v3.3.0.814
Common Stock - Summary of Restricted Stock Unit Award Activity (Detail) - Restricted Stock Unit [Member]
9 Months Ended
Sep. 30, 2015
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of Shares, Beginning Balance | shares 680,201
Number of Shares, Granted | shares 245,400
Number of Shares, Settled | shares (260,676)
Number of Shares, Forfeited or expired | shares (19,816)
Number of Shares, Ending Balance | shares 645,109
Weighted-Average Grant Date Fair Value, Beginning Balance $ 7.34
Weighted-Average Grant Date Fair Value, Granted 1.93
Weighted-Average Grant Date Fair Value, Settled 8.21
Weighted-Average Grant Date Fair Value, Forfeited or expired 7.27
Weighted-Average Grant Date Fair Value, Ending Balance $ 4.94