Stockholders' Equity - Summary of Non-Vested Options (Detail)
shares in Thousands
12 Months Ended
Dec. 31, 2016
$ / shares
shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Shares, Non-vested, Beginning balance | shares 450
Shares, Vested | shares (276)
Shares, Forfeited | shares (41)
Shares, Non-vested, Ending balance | shares 133
Weighted-average grant-date fair value, Non-vested, Beginning balance | $ / shares $ 1.16
Weighted-average grant-date fair value, Vested | $ / shares 1.09
Weighted-average grant-date fair value, Forfeited | $ / shares 1.45
Weighted-average grant-date fair value, Non-vested, Ending balance | $ / shares $ 1.19