Employee Benefit Plans (Benefit Obligations in Excess of the Fair Value of Plan's Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 102,607	$ 95,869	$ 106,218
Accumulated benefit obligation	102,607	95,869
Fair value of plan's assets	73,357	63,109	$ 71,541
Projected benefit obligation greater than fair value of plan's assets	29,250	32,760
Accumulated benefit obligation greater than fair value of plan's assets	29,250	32,760
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	99,515	92,816
Accumulated benefit obligation	99,515	92,816
Fair value of plan's assets	73,357	63,109
Projected benefit obligation greater than fair value of plan's assets	26,158	29,707
Accumulated benefit obligation greater than fair value of plan's assets	26,158	29,707
Benefit Equalization Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	3,092	3,053
Accumulated benefit obligation	3,092	3,053
Projected benefit obligation greater than fair value of plan's assets	3,092	3,053
Accumulated benefit obligation greater than fair value of plan's assets	$ 3,092	$ 3,053