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Employee Benefit Plans (Details Textual) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract] |  |  |  |
Maximum compensation percentage |  | 90.00% |  |
Age requirement for 401 K contributions |  | 21 years |  |
Employer matching contribution, percent of employees' gross pay |  | 4.50% |  |
Employers matching contribution, immediate vesting percentage | 100.00% |  |  |
Defined contribution plan, cost recognized |  | $ 171,000 | $ 134,000 | $ 115,000

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- Definition Represents age requirement for 401K contributions. + References No definition available. + Details
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- References No definition available. + Details
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- Definition Commitment made to pay deferred cash remuneration expressed as a percentage of the individual's base salary. + References No definition available. + Details
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- Definition The amount of the cost recognized during the period for defined contribution plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
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- Definition Percentage of employer's matching contributions to a defined contribution plan that vests in a given year. + References No definition available. + Details
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