Stockholders' Equity - Additional Information (Detail) - USD ($)
|
1 Months Ended |
12 Months Ended |
|
Aug. 31, 2011 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Apr. 30, 2016 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Percentage of stock repurchase approved (as percent) |
|
|
|
20.00%
|
| Number of shares approved to be repurchased (in shares) |
|
|
|
3,500,000
|
| Number of shares repurchased (in shares) |
|
315,503
|
931,664
|
|
| Average cost per share (in dollars per share) |
|
$ 3.22
|
$ 4.48
|
|
| Stock repurchased during period |
|
$ 1,021,000
|
$ 4,184,000
|
|
| Aggregate number of stock options authorized under 1999, 2004 and 2012 plans (in shares) |
|
4,842,616
|
|
|
| Remaining shares available to be granted (in shares) |
|
2,255,692
|
|
|
| Service period |
|
3 years
|
|
|
| Total intrinsic value of options exercised |
|
$ 0
|
$ 100,000
|
|
| Number of stock options outstanding (in shares) |
|
2,147,000
|
2,168,000
|
|
| Unrecognized compensation expense |
|
$ 2,600,000
|
|
|
| Stock option plans recognized over weighted-average period |
|
2 years
|
|
|
| Dividend yield rate (as percent) |
|
0.00%
|
0.00%
|
|
| Weighted-average fair value of options granted (in dollars per share) |
|
$ 1.86
|
$ 1.79
|
|
| Capitalized stock based compensation |
|
$ 24,000
|
$ 15,000
|
|
| Incentive stock options [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Exercise price of common stock expressed as a percentage of its fair market value on grant date (as percent) |
|
100.00%
|
|
|
| Non-statutory and nonqualified stock options [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Exercise price of common stock expressed as a percentage of its fair market value on grant date (as percent) |
|
85.00%
|
|
|
| Number of stock options outstanding (in shares) |
|
519,000
|
|
|
| Employee Stock Purchase Plan [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Exercise price of common stock expressed as a percentage of its fair market value on grant date (as percent) |
85.00%
|
|
|
|
| Share reserved for future issuance (in shares) |
250,000
|
|
|
|
| Shares purchased under ESPP (in shares) |
|
0
|
0
|
|
| Performance shares [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Stock compensation expense |
|
$ 0
|
|
|
| Unrecognized compensation expense |
|
$ 1,000,000
|
|
|
| Restricted Stock Units (RSUs) [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Vesting rights (as percent) |
|
25.00%
|
|
|
| Period in force |
|
1 year
|
|
|
| Stock option plans recognized over weighted-average period |
|
3 years
|
|
|
| 1999 Plan [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Options granted to officers, directors and consultants, minimum exercisable percentage (as percent) |
|
20.00%
|
|
|