Retirement Plans (Components Of Net Periodic Pension Benefit Cost (Income)) (Details) - United Kingdom Subsidiary [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2,451	$ 1,452	$ 4,827	$ 2,981
Expected return on plan assets	(2,878)	(3,082)	(5,669)	(6,326)
Amortization of unrecognized loss	658	528	1,297	1,084
Net periodic pension cost (income)	$ 231	$ (1,102)	$ 455	$ (2,261)

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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