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Share-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Jun. 30, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Number of shares outstanding under Equity plan |  | 604,003 | 611,975 | 629,629
Stock options award, expiration |  | 10 years |  |
Weighted Average exercise Price of Options Outstanding |  | $ 5.37 | $ 6.00 | $ 6.30
Employee Stock Option |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Unrecognized compensation expense related to unvested options |  | $ 186 |  |
Maturity period of weighted average period of compensation expenses |  | 1 year 1 month 6 days |  |
Minimum |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Stock options award, vesting period |  | 3 years |  |
Percentage holding for stock options exercise price |  | 10.00% |  |
Minimum | Incentive Stock Option |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Percentage of exercise price of stock option |  | 100.00% |  |
Minimum | Incentive Stock Option | Stockholders |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Percentage of exercise price of stock option |  | 110.00% |  |
Minimum | Restricted Stock Units (RSUs) |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Restricted Stock Units award, requisite service period |  | 3 years |  |
Maximum |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Stock options award, vesting period |  | 4 years |  |
Maximum | Restricted Stock Units (RSUs) |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Restricted Stock Units award, requisite service period |  | 4 years |  |
2013 Plan |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Increase in number of shares reserve for issuance under amended Equity Plan | 1,000,000 |  |  |
Number of shares issuable under Equity plan | 1,321,428 |  |  |
Number of shares outstanding under Equity plan |  | 597,342 |  |
Shares reserved for future |  | 615,976 |  |
Options granted |  | 40,000 | 469,600 |
Two Thousand And Four Stock Option Plan |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Number of shares outstanding under Equity plan |  | 5,383 |  |
Weighted Average exercise Price of Options Outstanding |  | $ 102.16 |  |
Other Stock Option Plan |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Number of shares outstanding under Equity plan |  | 1,278 |  |
Weighted Average exercise Price of Options Outstanding |  | $ 233.94 |  |

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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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