Retirement Plans (Schedule Of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 9
Interest cost	$ 171	186
Expected return on plan assets	(178)	(179)
Recognized net actuarial loss	33	69
Net periodic pension cost	26	85
UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Interest cost	55	75
Expected return on plan assets	(65)	(84)
Amortization of prior service cost and transition amount	4	5
Recognized net actuarial loss	69	39
Net periodic pension cost	$ 63	$ 35