|
Stock-Based Compensation Plans - Additional Information (Detail) (USD $)
|
12 Months Ended |
|
Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2012
Employee
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Remaining available shares for issuance under the plan |
6,255,156 |
|
|
| Stock Option Awards expiry range |
5 years |
|
|
| Vest in designated installments over |
4 years |
|
|
| Stock Option Awards to purchase shares of the company's common stock |
|
|
2 |
| Stock Option Awards granted |
0 |
0 |
825,000 |
| Exercise price per share |
|
|
$ 1.45 |
| Stock Option Awards expiration date |
|
|
Jan. 31, 2017 |
| Compensation expense related to Stock Option |
|
|
$ 522,000 |
| Compensation expense related to Stock Option amortized |
|
|
504,000 |
| Remaining Compensation expense amortized through January 2016 |
|
|
18,000 |
| Fair value of Stock Option Awards with expected volatility |
|
|
73.00% |
| Risk-free interest rate |
|
|
0.71% |
| Dividend yield rate |
|
|
0.00% |
| Expected term |
|
|
5 years |
| Value of options granted per share |
|
|
$ 0.63 |
| Risk-free interest rate, duration |
|
|
5 years |
| Weighted average remaining contractual life of options outstanding |
2 years 4 months 24 days |
|
|
| Exercisable/vested |
2 years 4 months 24 days |
|
|
| Number of shares vested |
75,135 |
|
|
| Compensation expense to purchase shares under the ESPP |
185,000 |
243,000 |
604,000 |
| Employee Stock Purchase Plan [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Percentage of authorize payroll deductions |
15.00% |
|
|
| Maximum Amount of outstanding stock to be subscribed |
25,000 |
|
|
| Company reserved shares of common stock for issuance under the ESPP |
400,000 |
|
|
| Employees purchase shares |
31,000 |
35,000 |
40,000 |
| Compensation expense to purchase shares under the ESPP |
11,000 |
7,000 |
11,000 |
| Shares remain available for issuance under the ESPP |
87,635 |
|
|
| Executive Officer One [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Stock Option Awards granted |
|
|
750,000 |
| Vesting percent of shares |
|
|
40.00% |
| Remainder vesting in equal installments |
|
|
3 years |
| Executive Officer Two [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Stock Option Awards granted |
|
|
75,000 |
| Vesting percent of shares |
|
|
20.00% |
| Remainder vesting in equal installments |
|
|
4 years |
| Employee Stock Options [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Stock Option Awards expiry range |
10 years |
|
|
| Vest in designated installments over |
5 years |
|
|
| Restricted Stock [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Restricted Stock Awards granted |
0 |
0 |
0 |
| Aggregate fair values of Restricted Stock Awards vested |
$ 54,000 |
$ 99,000 |
$ 134,000 |