Income Taxes (Reconciliation Of Income Tax Rates) (Details) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount
Statutory rate							$ (5,609)	$ 3,518
Foreign tax rate differential							156	(641)
State income taxes, net of federal benefit							(706)	368
Non-deductible expenses							261	323
Domestic production activities deduction							0	(405)
U.S Tax Cuts and Jobs Act: remeasurement of deferred taxes							0	9,573
U.S. Tax Cuts and Jobs Act: deferred foreign earnings							0	4,009
Global intangible low-taxed income							171	0
Income tax credit							(633)	(123)
Nondeductable executive compensation							351	0
Tax on unremitted foreign earning							149	(6,712)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount							10,226	(5,354)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount							91	134
Total income tax expense	$ 18	$ 728	$ 525	$ 66	$ 475	$ 431	$ 4,457	$ 4,690
Effective Income Tax Rate Reconciliation, Percent
Statutory rate							21.00%	35.00%
Foreign tax rate differential							(0.60%)	(6.40%)
State income tax rate, net of federal benefit							2.60%	3.70%
Non-deductible expenses							(1.00%)	3.20%
Domestic production activities deductions							0.00%	(4.00%)
U.S. Tax Cuts and Jobs Act: remeasurement of deferred taxes							0.00%	95.20%
U.S. Tax Cuts and Jobs Act: deferred foreign earnings							0.00%	39.90%
Global intangible low-taxed income							(0.60%)	0.00%
Income tax credit							2.40%	(1.20%)
Nondeductable executive compensation							(1.30%)	0.00%
Tax on unremitted foreign earnings							(0.60%)	(66.80%)
Change in valuation allowance							(38.30%)	(53.30%)
Other							(0.30%)	1.30%
Total income tax expense/ Effective rate							(16.70%)	46.70%