Benefit Plan (Components Of Net Periodic Benefit Expense) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Pension plan contributions			$ 0	$ 0
Service cost	$ 1,750,000	$ 1,559,000	3,500,000	3,118,000
Interest cost	1,719,000	1,631,000	3,438,000	3,262,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(454,000)	(334,000)	(908,000)	(668,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1,750,000	1,559,000	3,500,000	3,118,000
Interest cost	1,719,000	1,631,000	3,438,000	3,262,000
Expected return on plan assets	(3,935,000)	(3,536,000)	(7,870,000)	(7,072,000)
Recognized net actuarial loss	12,000	12,000	24,000	24,000
Benefit expense	(454,000)	(334,000)	(908,000)	(668,000)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	769,000	234,000	985,000	468,000
Interest cost	155,000	175,000	310,000	351,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	924,000	409,000	1,295,000	819,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	769,000	234,000	985,000	468,000
Interest cost	155,000	175,000	310,000	351,000
Benefit expense	$ 924,000	$ 409,000	$ 1,295,000	$ 819,000