Benefit Plan (Components Of Net Periodic Benefit Expense) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Pension plan contributions			$ 0	$ 0
Service cost	$ 2,437,000	$ 2,479,000	7,311,000	7,437,000
Interest cost	1,426,000	1,340,000	4,278,000	4,020,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(590,000)	441,000	(1,770,000)	1,323,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2,437,000	2,479,000	7,311,000	7,437,000
Interest cost	1,426,000	1,340,000	4,278,000	4,020,000
Expected return on plan assets	(4,449,000)	(3,933,000)	(13,347,000)	(11,799,000)
Recognized net actuarial loss	(4,000)	555,000	(12,000)	1,665,000
Benefit expense	(590,000)	441,000	(1,770,000)	1,323,000
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	212,000	203,000	637,000	611,000
Interest cost	183,000	150,000	549,000	448,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	395,000	353,000	1,186,000	1,059,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	212,000	203,000	637,000	611,000
Interest cost	183,000	150,000	549,000	448,000
Benefit expense	$ 395,000	$ 353,000	$ 1,186,000	$ 1,059,000