Retirement Plans (Schedule Of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
United States
Defined Benefit Plan Disclosure
Interest cost	$ 162	$ 155	$ 486	$ 466
Expected return on plan assets	(180)	(213)	(540)	(640)
Recognized net actuarial loss	31	24	94	72
Net periodic pension cost	13	(34)	40	(102)
United Kingdom
Defined Benefit Plan Disclosure
Interest cost	53	51	159	153
Expected return on plan assets	(60)	(70)	(180)	(210)
Amortization of prior service costs and transition amount	10	5	30	15
Recognized net actuarial loss	52	48	156	144
Net periodic pension cost	$ 55	$ 34	$ 165	$ 102