Employee Benefit Plans (Schedule of Plan's Pension Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	$ 4,329	$ 3,554
Interest cost on projected benefit obligations	3,908	4,103
Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	4,329	3,555	$ 4,017
Interest cost on projected benefit obligations	3,908	4,103	3,703
Expected return on plan assets	(6,049)	(4,753)	(5,202)
Net amortization and deferral	1,946	1,559	1,522
Net periodic pension cost	$ 4,134	$ 4,464	$ 4,040