Retirement Plans (Schedule Of Net Benefit Costs) (Details) - Pension Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
United States
Defined Benefit Plan Disclosure
Interest cost	$ 162	$ 155
Expected return on plan assets	(180)	(213)
Recognized net actuarial loss	31	24
Net periodic pension cost	13	(34)
United Kingdom
Defined Benefit Plan Disclosure
Interest cost	54	53
Expected return on plan assets	(62)	(72)
Amortization of prior service costs and transition amount	11	5
Recognized net actuarial loss	53	49
Net periodic pension cost	$ 56	$ 35