Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 61,756	$ 84,939
Accounts receivable, net of allowance for doubtful accounts of $1,536 and $1,036, at December 31, 2021 and 2020, respectively	87,135	71,372
Inventories	139,383	100,133
Unbilled receivables	28,275	14,135
Other current assets	12,467	9,637
Total current assets	329,016	280,216
Property, plant and equipment, net	38,210	34,501
Right-of-use assets	21,252	14,217
Intangible assets, net	60,995	65,789
Goodwill, net	26,651	23,966
Deferred income taxes	4,461	5,705
Other assets	31,261	29,472
Total assets	511,846	453,866
Current liabilities:
Accounts payable	65,960	39,774
Accrued expenses	34,453	28,476
Current maturities of long-term debt	0	5,286
Operating lease liability, current	6,880	6,591
Other current liabilities	4,719	7,409
Total current liabilities	112,012	87,536
Long-term liabilities:
Long-term debt	112,500	110,294
Operating lease liability, long-term	14,668	8,064
Liability for uncertain tax positions	28,434	26,089
Minimum pension obligation and unfunded pension liability	23,909	24,620
Deferred income taxes	1,487	1,030
Other long-term liabilities	10,093	10,434
Total liabilities	303,103	268,067
Commitments and contingencies (see Note 18)
Stockholders' equity:
Preferred stock, no par value, 1,000,000 shares authorized; none issued	0	0
Additional paid-in capital	38,419	36,136
Retained earnings	187,935	166,491
Accumulated other comprehensive loss	(18,863)	(18,063)
Total stockholders' equity	208,743	185,799
Total liabilities and stockholders' equity	511,846	453,866
Common Class A [Member]
Stockholders' equity:
Common stock	214	214
Common Class B [Member]
Stockholders' equity:
Common stock	$ 1,038	$ 1,021