Annual report pursuant to Section 13 and 15(d)

Retirement Plan (Details Textual)

v3.19.1
Retirement Plan (Details Textual) - Supplemental Employee Retirement Plan [Member] - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Defined Contribution Plan Disclosure [Line Items]    
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 100.00%  
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent 4.00%  
Defined Contribution Plan, Employer Discretionary Contribution Amount $ 2.0 $ 1.8