Retirement Plans (Schedule Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 38	$ 23	$ 33
Interest cost	742	771	707
Expected return on plan assets	(816)	(968)	(856)
Amortization of prior service cost	3	1	1
Recognized net actuarial loss	(275)	(65)	(212)
Net periodic pension cost (income)	$ 242	$ (108)	$ 97
Net periodic benefit costs: Discount rate	4.30%	4.00%	4.90%
Net periodic benefit costs: Expected return on plan assets	5.20%	5.50%	6.50%
Projected benefit obligation	$ 17,759	$ 18,925	$ 16,112
Accumulated benefit obligation	17,759	18,925
Fair value of plan assets	14,235	15,205	15,039
UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Interest cost	295	360	348
Expected return on plan assets	(324)	(370)	(321)
Amortization of transition amount	0	(50)	(46)
Amortization of prior service cost	27	30	22
Recognized net actuarial loss	(225)	(185)	(229)
Net periodic pension cost (income)	$ 223	$ 155	$ 232
Projected benefit obligation: Discount rate	4.00%	3.60%	4.60%
Net periodic benefit costs: Expected return on plan assets	5.20%	5.00%	5.80%
Projected benefit obligation	$ 7,862	$ 8,797	$ 8,450
Accumulated benefit obligation	7,862	8,797
Fair value of plan assets	$ 6,661	$ 6,757	$ 6,769