Employee Benefit Plans - Changes in the Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, beginning	$ 14,409	$ 13,436
Service cost	1,353	319	$ 1,310
Interest cost	468	537	453
Actuarial experience and changes in actuarial assumptions	(1,195)	117
Projected benefit obligation, ending	$ 15,035	$ 14,409	$ 13,436