Employee Benefit Plans (Components of Net Period Benefit Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Components of the net periodic benefit cost
Service cost	$ 0	$ 0	$ 0
Interest cost	130	155	194
Expected return on plan assets	0	0	0
Recognized net actuarial loss	243	252	146
Benefit cost (income)	373	407	340
Postretirement Benefits
Components of the net periodic benefit cost
Service cost	319	391	760
Interest cost	752	985	1,549
Expected return on plan assets	(910)	(455)	(355)
Recognized net actuarial loss	0	0	768
Benefit cost (income)	$ 161	$ 921	$ 2,722