Benefit Plan (Components Of Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Pension plan contributions			$ 0	$ 0
Service cost	$ 2,437	$ 2,479	4,874	4,958
Interest cost	1,426	1,340	2,852	2,680
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(590)	441	(1,180)	882
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2,437	2,479	4,874	4,958
Interest cost	1,426	1,340	2,852	2,680
Expected return on plan assets	(4,449)	(3,933)	(8,898)	(7,866)
Recognized net actuarial loss	(4)	555	(8)	1,110
Benefit expense	(590)	441	(1,180)	882
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	212	204	425	408
Interest cost	183	149	366	298
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	395	353	791	706
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	212	204	425	408
Interest cost	183	149	366	298
Benefit expense	$ 395	$ 353	$ 791	$ 706