Employee Benefit Plans (Benefit Obligations in Excess of the Fair Value of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 95,869	$ 106,218	$ 103,681
Accumulated benefit obligation	95,869	106,218
Fair value of plan's assets	63,109	71,541	$ 66,057
Projected benefit obligation greater than fair value of plan's assets	32,760	34,677
Accumulated benefit obligation greater than fair value of plan's assets	32,760	34,677
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	92,816	102,806
Accumulated benefit obligation	92,816	102,806
Fair value of plan's assets	63,109	71,541
Projected benefit obligation greater than fair value of plan's assets	29,707	31,265
Accumulated benefit obligation greater than fair value of plan's assets	29,707	31,265
Benefit Equalization Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	3,053	3,412
Accumulated benefit obligation	3,053	3,412
Projected benefit obligation greater than fair value of plan's assets	3,053	3,412
Accumulated benefit obligation greater than fair value of plan's assets	$ 3,053	$ 3,412