Quarterly report pursuant to Section 13 or 15(d)

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

v3.5.0.2
Common Stock - Summary of Restricted Stock Unit Award Activity (Detail) - Restricted Stock Unit [Member]
9 Months Ended
Sep. 30, 2016
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of Shares, Beginning Balance | shares 640,759
Number of Shares, Settled | shares (207,296)
Number of Shares, Forfeited or expired | shares (92,378)
Number of Shares, Ending Balance | shares 341,085
Weighted-Average Grant Date Fair Value, Beginning Balance | $ / shares $ 4.92
Weighted-Average Grant Date Fair Value, Settled | $ / shares 5.21
Weighted-Average Grant Date Fair Value, Forfeited or expired | $ / shares 6.39
Weighted-Average Grant Date Fair Value, Ending Balance | $ / shares $ 4.35