Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan [Abstract]
Maximum annual contributions per employee, percent		10.00%
Employer matching contribution, percent of match		50.00%
Employer matching contribution, percent of employees' gross pay		4.00%
Cost recognized	$ 140,000	$ 124,000