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STOCK BASED COMPENSATION: (Details Textual) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | 36 Months Ended |
--- | --- | --- | --- | ---
Mar. 31, 2018 | Mar. 31, 2017 | Mar. 31, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2013 | Feb. 05, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting period |  |  |  | 3 years |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost | $ 745 | $ 706 | $ 700 |  |  |  |
Stock Incentive Plan 2011 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) |  |  |  |  |  |  | 700,000
Granted (shares) |  |  |  |  |  | 166,289 |
Number of additional shares authorized (shares) |  |  |  | 533,711 |  |  |
Restricted Stock |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Granted (shares) |  |  |  | 17,220,000 | 16,562,000 |  |
Vesting period |  |  |  | 3 years |  |  |
Total compensation cost not yet recognized, stock options |  |  |  | $ 674 | $ 741 |  |
Total compensation cost not yet recognized, period for recognition |  |  |  | 1 year 6 months |  |  |
Options, vested in period, fair value |  |  |  | $ 700 | $ 865 |  |
Restricted Stock | First Anniversary |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Purchase price of common stock (percent) |  |  |  | 33.00% |  |  |
Restricted Stock | Second Anniversary |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Purchase price of common stock (percent) |  |  |  | 33.00% |  |  |
Restricted Stock | Third Anniversary |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Purchase price of common stock (percent) |  |  |  | 34.00% |  |  |

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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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