CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited)
Revenues	$ 37,968	$ 40,103	$ 81,563	$ 81,717
Cost of goods sold	20,499	21,511	44,226	44,422
Gross profit	17,469	18,592	37,337	37,295
Operating expenses:
Selling	1,703	2,098	3,773	4,482
General and administrative	4,628	4,304	9,028	8,490
Research and development	1,092	1,224	2,776	2,319
Total Operating Expense	7,423	7,626	15,577	15,291
Operating income	10,046	10,966	21,760	22,004
Interest and dividend income	367	581	858	1,163
Other investment income (losses)	354	161	(673)	372
Total Non Operating Income Expenses	721	742	185	1,535
Income before provision for income taxes	10,767	11,708	21,945	23,539
Provision for income taxes	(2,162)	(2,044)	(4,443)	(4,437)
Net income	$ 8,605	$ 9,664	$ 17,502	$ 19,102
Net income per basic share	$ 4.69	$ 5.21	$ 9.49	$ 10.30
Weighted average basic shares outstanding	1,835	1,854	1,844	1,854
Net income per diluted share	$ 4.68	$ 5.18	$ 9.47	$ 10.25
Weighted average diluted shares outstanding	1,839	1,864	1,849	1,863
Dividends per common share	$ 1.55	$ 1.35	$ 3.10	$ 2.70