Benefit Plan (Components Of Net Periodic Benefit Expense) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Pension plan contributions	$ 0	$ 0
Service cost	1,750,000	1,559,000
Interest cost	1,719,000	1,631,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(454,000)	(334,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1,750,000	1,559,000
Interest cost	1,719,000	1,631,000
Expected return on plan assets	(3,935,000)	(3,536,000)
Recognized net actuarial loss	12,000	12,000
Benefit expense	(454,000)	(334,000)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	216,000	234,000
Interest cost	155,000	176,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	371,000	410,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	216,000	234,000
Interest cost	155,000	176,000
Benefit expense	$ 371,000	$ 410,000