Retirement Plans (Schedule Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9	$ 10	$ 27	$ 29
Interest cost	186	185	559	555
Expected return on plan assets	(179)	(203)	(538)	(611)
Recognized net actuarial loss	(69)	(69)	(207)	(207)
Net periodic pension cost	85	61	255	180
UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Interest cost	73	78	223	231
Expected return on plan assets	(82)	(83)	(250)	(249)
Amortization of prior service cost and transition amount	5	5	15	15
Recognized net actuarial loss	(38)	(60)	(116)	(177)
Net periodic pension cost	$ 34	$ 60	$ 104	$ 174