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Stock-Based Compensation - Additional Information (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
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12 Months Ended |
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|
Dec. 31, 2013
Plan
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
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| Stock-based compensation expense |
$ 4,368 |
$ 4,167 |
$ 4,772 |
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| Number of stock based Compensation Plan |
2 |
|
|
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| Stock option award period |
3 years |
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|
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| Stock option vesting period |
4 years |
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| Stock option granting period after granted |
1 year |
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|
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| Grant date fair value per share |
$ 1.28 |
$ 3.24 |
$ 2.64 |
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| Expected dividend Yield |
0 |
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|
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| Unrecognized compensation cost |
4,749 |
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|
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| Recognized cost, 2014 |
2,609 |
|
|
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| Recognized cost, 2015 |
1,446 |
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|
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| Recognized cost, 2016 |
580 |
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| Recognized cost, 2017 |
114 |
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| Remaining common stock shares |
1,082 |
2,815 |
2,009 |
1,858 |
| Common stock purchased under ESPP |
89 |
110 |
94 |
|
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Employee Stock Option [Member]
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|
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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|
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| Stock option awards granted in percentage |
50.00% |
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Performance Based Stock Option [Member]
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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|
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| Performance based stock options |
1,032 |
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| Stock-based compensation expense |
0 |
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Maximum [Member]
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|
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
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| Stock option contractual terms |
10 years |
|
|
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Minimum [Member]
|
|
|
|
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
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| Stock option contractual terms |
5 years |
|
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Incentive Plan [Member]
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|
|
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
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| Stock-based compensation expense |
4,253 |
4,010 |
4,589 |
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| Stock option awards granted to nonemployee director vesting period description |
Stock option awards granted to non-employee directors of the Company generally vest monthly over one year. |
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| Stock option vesting period |
2 years |
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| Stock option contractual terms |
4 years 10 months 24 days |
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| Intrinsic value of stock options exercised under Incentive Plan |
738 |
877 |
374 |
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| Aggregate intrinsic value of stock option Exercisable under stock incentive plan |
11,189 |
|
|
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| Fair value of stock option awards vested under Incentive Plan |
3,483 |
3,373 |
4,775 |
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| Number of stock option awards vested and expected to vest |
8,146 |
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| Weighted average exercise price of stock option awards |
$ 5.11 |
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| Weighted average remaining contractual life |
6 years 7 months 6 days |
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Incentive Plan [Member] | Employee Stock Option [Member]
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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| Stock option awards granted in percentage |
25.00% |
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ESPP [Member]
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
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| Stock-based compensation expense |
115 |
157 |
146 |
|
| Stock-based compensation expense |
115 |
157 |
146 |
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| Common stock shares reserved |
975 |
|
|
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| Remaining common stock shares |
88 |
|
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| Percentage of salary to purchase common stock |
15.00% |
|
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| Percentage of common stock shares Beginning |
85.00% |
|
|
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| Percentage of common stock shares Ending |
85.00% |
|
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| Purchase of common stock shares |
3 |
|
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| Maximum number of shares per employee amount |
$ 25 |
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| Purchase intervals |
6 months |
|
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| Common stock purchased under ESPP |
89 |
110 |
94 |
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| Weighted average exercise price of stock issued under ESPP |
$ 1.39 |
$ 2.93 |
$ 3.21 |
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| Weighted average grant date fair value per share under ESPP |
$ 1.27 |
$ 1.48 |
$ 1.33 |
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Inducement Grant [Member]
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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| Stock-based compensation expense |
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|
$ 37 |
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