Benefit Plan (Components Of Net Periodic Benefit Expense) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Pension plan contributions			$ 0	$ 0
Service cost	$ 1,750,000	$ 1,559,000	5,250,000	4,677,000
Interest cost	1,719,000	1,631,000	5,157,000	4,893,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(6,237,000)	(334,000)	(7,145,000)	(1,002,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	(5,783,000)	0	(5,783,000)	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1,750,000	1,559,000	5,250,000	4,677,000
Interest cost	1,719,000	1,631,000	5,157,000	4,893,000
Expected return on plan assets	(3,936,000)	(3,536,000)	(11,806,000)	(10,608,000)
Recognized net actuarial loss	13,000	12,000	37,000	36,000
Benefit expense	(6,237,000)	(334,000)	(7,145,000)	(1,002,000)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	216,000	234,000	1,201,000	702,000
Interest cost	154,000	176,000	464,000	527,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	370,000	410,000	1,665,000	1,229,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	216,000	234,000	1,201,000	702,000
Interest cost	154,000	176,000	464,000	527,000
Benefit expense	$ 370,000	$ 410,000	$ 1,665,000	$ 1,229,000