Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net (Loss) Income	$ (8,635,000)	$ 2,378,000	$ (52,982,000)
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	16,084,000	16,627,000	17,771,000
Asset impairments	0	65,000	3,872,000
Gain on investments	(5,127,000)	(5,802,000)	(11,434,000)
Stock-based compensation expense	7,480,000	6,834,000	6,962,000
Deferred income taxes	(1,784,000)	(1,356,000)	30,070,000
Gain on contingency payment			(1,230,000)
Gain on life insurance proceeds			(1,000,000)
Other, net	112,000	216,000	(33,000)
Inventory reserves	(5,029,000)	(5,398,000)	(4,154,000)
Change in operating assets and liabilities:
Accounts receivable, net	(60,864,000)	(7,269,000)	8,282,000
Other receivables	9,752,000	(4,732,000)	20,046,000
Inventory	(10,638,000)	(20,184,000)	5,406,000
Prepaid expenses and other assets	(7,146,000)	(5,239,000)	2,749,000
Accounts payable	53,270,000	4,543,000	(13,494,000)
Accrued expenses and other liabilities	10,063,000	5,093,000	(4,598,000)
Income taxes payable	5,470,000	(2,294,000)	(8,705,000)
Net cash provided by (used in) operating activities	3,008,000	(16,518,000)	(2,472,000)
Cash flows from investing activities:
Purchases of property, plant and equipment	(5,669,000)	(6,413,000)	(9,494,000)
Proceeds from disposals of property, plant and equipment		2,000
Proceeds from sales and maturities of available-for-sale investments	50,466,000	105,100,000	47,268,000
Purchases of available-for-sale investments	(35,031,000)	(56,767,000)	(48,578,000)
Acquisition of note receivable		(523,000)
Insurance proceeds received	500,000		1,000,000
Acquisition of business			13,000
Net cash provided by (used in) investing activities	10,266,000	41,399,000	(9,791,000)
Cash flows from financing activities:
Dividend payments	(17,529,000)	(17,334,000)	(17,212,000)
Repayment of bonds payable		(24,600,000)
Proceeds from draw on line of credit	10,000,000
Repayment of line of credit	(10,000,000)
Tax withholdings related to stock-based compensation settlements	(1,860,000)	(1,043,000)
Proceeds from stock option exercises	6,431,000		526,000
Purchases of treasury stock			(184,000)
Payments on long-term debt			(1,000,000)
Net cash used in financing activities	(12,958,000)	(42,977,000)	(17,870,000)
Net increase (decrease) in cash and cash equivalents	316,000	(18,096,000)	(30,133,000)
Effect of exchange rate changes	(3,677,000)	4,502,000	(1,598,000)
Cash, cash equivalents and restricted cash, beginning of year	60,179,000	73,773,000	105,504,000
Cash, cash equivalents and restricted cash, end of year	56,818,000	60,179,000	73,773,000
Supplemental disclosure of cash flow information
Cash paid during the year for interest	13,000	24,000	512,000
Cash paid during the year for income taxes	1,780,000	7,609,000	9,357,000
Supplemental disclosure of non-cash investing activities
Purchases of property, plant and equipment included in accounts payable	$ 638,000	$ 108,000	$ 90,000