Employee Benefit Plans (Net Periodic Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during the period	$ 587	$ 564	$ 547
Interest cost on projected benefit obligation	4,495	5,059	5,419
Expected return on assets	(5,572)	(5,424)	(6,076)
Prior service cost	0	0	0
Amortization of net loss (gain)	1,804	2,009	1,855
Net expense	1,314	2,208	1,745
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during the period	4	5	5
Interest cost on projected benefit obligation	330	368	385
Expected return on assets	0	0	0
Prior service cost	4	0	0
Amortization of net loss (gain)	(41)	(54)	(75)
Net expense	$ 297	$ 319	$ 315