Income Taxes (Details 4) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Deferred compensation and retirement plan	$ 16,179	$ 15,017
Accrued expenses not deductible until paid	1,584	1,619
Employee stock-based compensation	780	1,757
Accrued payroll not deductible until paid	428	1,111
Accounts receivable, net	100	179
Investment in Foreign Subsidiaries, Outside Basis Difference	1,322	0
Goodwill	710	700
Other, net	142	290
Foreign net operating loss carryforwards	3,042	2,887
State net operating loss carryforwards	3,776	3,978
Foreign tax credit carryforwards	3,653	3,653
Federal net operating loss carryforwards	2,507	0
Total gross deferred tax assets	34,223	31,191
Less valuation allowances	(31,170)	(28,350)
Net deferred tax assets	3,053	2,841
Deferred tax liabilities
Property, plant and equipment	(1,689)	(1,941)
Goodwill and other intangibles	0	(701)
Prepaid Expenses	(331)	0
Other, net	(281)	(972)
Total gross deferred tax liabilities	(2,301)	(3,614)
Net deferred tax assets (liabilities)	$ 752
Net deferred tax assets (liabilities)		$ (773)