Employee Benefit Plans (Schedule of Changes in Benefit Obligation and Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in accumulated other comprehensive loss
Total	$ 3,944	$ 3,470	$ 2,157	$ 3,988
Supplemental Executive Retirement Plan [Member]
Benefit obligations:
Beginning of year	14,682	12,717
Service cost	464	395	446
Interest cost	460	523	488
Actuarial loss	911	1,524
Defined Benefit Plan, Benefit Obligation, Benefits Paid	486	477
End of year	16,031	14,682	12,717
Fair value of plan assets:
Beginning of year	0	0
Employer contributions	486	477
Defined Benefit Plan, Plan Assets, Benefits Paid	486	477
End of year	0	0	0
Unfunded status at end of year(1)	16,031	14,682
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss	3,090	2,864
Total	3,090	2,864
Other Postretirement Benefits Plan [Member]
Benefit obligations:
Beginning of year	4,049	3,616
Service cost	28	48	46
Interest cost	123	148	132
Actuarial loss	371	394
Defined Benefit Plan, Benefit Obligation, Benefits Paid	151	157
End of year	4,420	4,049	3,616
Fair value of plan assets:
Beginning of year	0	0
Employer contributions	151	157
Defined Benefit Plan, Plan Assets, Benefits Paid	151	157
End of year	0	0	$ 0
Unfunded status at end of year(1)	4,420	4,049
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss	967	738
Prior service credit	(113)	(132)
Total	$ 854	$ 606