Retirement Plans (Schedule Of Net Benefit Costs) (Details) - Pension Plan - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
United States
Defined Benefit Plan Disclosure
Interest cost	$ 155	$ 171	$ 466	$ 513
Expected return on plan assets	(213)	(178)	(640)	(533)
Recognized net actuarial loss	24	33	72	98
Net periodic pension (income) cost	(34)	26	(102)	78
United Kingdom
Defined Benefit Plan Disclosure
Interest cost	51	56	153	168
Expected return on plan assets	(70)	(67)	(210)	(201)
Amortization of prior service costs and transition amount	5	4	15	12
Recognized net actuarial loss	48	72	144	216
Net periodic pension (income) cost	$ 34	$ 65	$ 102	$ 195

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

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- Definition

Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

+ References

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+ References

No definition available.

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- Definition

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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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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

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