Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net sales	$ 77,632	$ 75,226	$ 216,526	$ 207,072
Cost of sales	62,013	59,751	178,370	176,808
Gross profit	15,619	15,475	38,156	30,264
Selling, general, and administrative expense	5,656	4,900	19,185	13,852
Operating income	9,963	10,575	18,971	16,412
Other income	157	2,792	815	2,976
Interest income	16	23	49	30
Interest expense	(238)	(114)	(719)	(365)
Income before income taxes	9,898	13,276	19,116	19,053
Income tax expense	2,631	2,529	5,287	3,167
Net income	$ 7,267	$ 10,747	$ 13,829	$ 15,886
us-gaap_EarningsPerShareAbstract
Basic (in dollars per share)	$ 0.74	$ 1.10	$ 1.41	$ 1.63
Diluted (in dollars per share)	$ 0.73	$ 1.10	$ 1.40	$ 1.63
Shares used in per share calculations:
Basic (in shares)	9,802	9,745	9,782	9,739
Diluted (in shares)	9,861	9,785	9,851	9,762

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227