Defined Contribution Plan (Details Textual) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Description of Defined Contribution Pension and Other Postretirement Plans | Participants may contribute up to 100% of their total compensation to the Plan, not to exceed the limit as defined in the Code. | |
| Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay | 50.00% | |
| Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent | 6.00% | |
| Defined Contribution Plan, Employer Discretionary Contribution Amount | $ 97,000 | $ 105,000 |