Income Taxes - Rate Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income tax provision at the federal statutory tax rate	$ 5,699,000	$ 6,070,000	$ 17,458,000
Unremitted Earnings	2,308,000	4,383,000	7,857,000
Transition Tax	(1,059,000)	(416,000)	(3,118,000)
Global intangible low taxed income	5,140,000	574,000	2,095,000
Pension Settlement	(2,247,000)	0	0
Foreign derived intangible income	(7,339,000)	(1,699,000)	(1,034,000)
Non-deductible acquisition expenses	131,000	1,743,000	1,019,000
Withholding taxes	7,809,000	8,621,000	1,161,000
Share-based compensation	335,000	(540,000)	259,000
Differences in tax rates on foreign earnings and remittances	596,000	920,000	1,081,000
Excess Foreign Tax Credit Utilization	(4,699,000)	(3,787,000)	(1,911,000)
Research and development activities credit utilization	(475,000)	(306,000)	(230,000)
Uncertain tax positions	1,990,000	899,000	(79,000)
State income tax provisions, net	(2,245,000)	(117,000)	196,000
Non-deductible meals and entertainment	290,000	318,000	415,000
Intercompany transfer of intellectual property	(4,384,000)	(5,318,000)	0
Miscellaneous items, net	(2,530,000)	(495,000)	(119,000)
Income Tax Expense (Benefit), Total	$ (5,296,000)	$ 2,084,000	$ 25,050,000