Employee Benefits (Schedule of Fair Value of Qualified Pension Plan Assets) (Details) - Qualified Pension Plan [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 86,180	$ 87,364	$ 75,787
Asset allocations by category	100.00%	100.00%
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 51,435	$ 65,355
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	34,745	22,009
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 25,986	$ 3,760
Asset allocations by category	30.20%	4.30%
Cash and cash equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 25,986	$ 3,760
Cash and cash equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of U.S government-sponsored enterprises [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,787	5,926
Obligations of U.S government-sponsored enterprises [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of U.S government-sponsored enterprises [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,787	5,926
Obligations of U.S government-sponsored enterprises [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of states and political subdivisions [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,597	2,971
Obligations of states and political subdivisions [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of states and political subdivisions [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,597	2,971
Obligations of states and political subdivisions [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,361	13,112
Corporate bonds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate bonds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,361	13,112
Corporate bonds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,957	38,508
Common stocks [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,957	38,508
Common stocks [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common stocks [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,492	23,087
Mutual funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,492	23,087
Mutual funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Mutual funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0
Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations by category	40.30%	30.00%
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations by category	29.50%	65.70%