Quarterly report pursuant to Section 13 or 15(d)

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

v3.7.0.1
Common Stock - Summary of Restricted Stock Unit Award Activity (Detail) - Restricted Stock Unit [Member]
3 Months Ended
Mar. 31, 2017
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of Shares, Beginning Balance | shares 253,221
Number of Shares, Vested | shares (93,175)
Number of Shares, Forfeited or expired | shares (18,329)
Number of Shares, Ending Balance | shares 141,717
Weighted-Average Grant Date Fair Value, Beginning Balance | $ / shares $ 4.56
Weighted-Average Grant Date Fair Value, Vested | $ / shares 5.95
Weighted-Average Grant Date Fair Value, Forfeited or expired | $ / shares 3.68
Weighted-Average Grant Date Fair Value, Ending Balance | $ / shares $ 3.71