Employee Benefit Plans (Components Of Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Service cost	$ 3,693	$ 3,207	$ 3,346
Interest cost on projected benefit obligation	2,537	2,777	2,387
Expected return on plan assets	(5,136)	(4,736)	(5,284)
Amortization of unrecognized loss	1,270	1,445	725
Amortization of unrecognized prior service (credit) cost			(5)
Net periodic pension cost	$ 2,364	$ 2,693	$ 1,169