Income Taxes (Reconciliation Of Income Tax Rates) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount
Statutory rate	$ 2,815	$ (51,509)	$ (17,702)
Foreign tax rate differential	(717)	(485)	(419)
State income taxes, net of federal benefit	368	(2,893)	(159)
Non-deductible goodwill impairment	0	11,448	12,737
Non-deductible expenses	323	262	452
Domestic production activities deduction	(405)	700	(507)
U.S. Tax Cuts and Jobs Act: remeasurement of deferred taxes	10,260	0	0
U.S. Tax Cuts and Jobs Act: deferred foreign earnings	4,009	0	0
Tax on unremitted foreign earnings	(6,712)	7,932	0
Change in valuation allowance	(6,023)	29,719	0
Other	11	(683)	(534)
Total income tax expense (benefit)	$ 3,929	$ (5,509)	$ (6,132)
Effective Income Tax Rate Reconciliation, Percent
Statutory rate	35.00%	35.00%	35.00%
Foreign tax rate differential	(8.90%)	0.30%	0.80%
State income taxes, net of federal benefit	4.60%	2.00%	0.30%
Non-deductible goodwill impairment	0.00%	(7.80%)	(25.20%)
Non-deductible expenses	4.00%	(0.20%)	(0.90%)
Domestic production activities deduction	(5.00%)	(0.50%)	1.00%
U.S. Tax Cuts and Jobs Act: remeasurement of deferred taxes	127.60%	0.00%	0.00%
U.S. Tax Cuts and Jobs Act: deferred foreign earnings	49.90%	0.00%	0.00%
Tax on unremitted foreign earnings	(83.50%)	(5.40%)	0.00%
Change in valuation allowance	(74.90%)	(20.20%)	0.00%
Other	0.10%	0.50%	1.10%
Total income tax expense (benefit) / Effective rate	48.90%	3.70%	12.10%