Employee Benefit Plans - Schedule of Net Periodic Pension Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Service cost	$ 0	$ 0
Interest cost on benefit obligation	1,725	1,855
Expected return on plan assets	(1,830)	(1,863)
Curtailment and settlements	0	929
Amortization of actuarial losses	222	137
Net periodic benefit cost	$ 117	$ 1,058