Retirement Plans (Schedule Of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
United States
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 9	$ 0	$ 27
Interest cost	171	186	513	559
Expected return on plan assets	(178)	(179)	(533)	(538)
Recognized net actuarial loss	33	69	98	207
Net periodic pension cost	26	85	78	255
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Interest cost	56	73	168	223
Expected return on plan assets	(67)	(82)	(201)	(250)
Amortization of prior service costs and transition amount	4	5	12	15
Recognized net actuarial loss	72	38	216	116
Net periodic pension cost	$ 65	$ 34	$ 195	$ 104