Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net sales	$ 198,381	$ 190,455	$ 147,843
Cost of sales	144,422	142,147	112,356
Gross profit	53,959	48,308	35,487
Selling, general, and administrative expenses	29,251	27,654	23,724
Acquisition costs		1,089
Restructuring costs			63
(Gain) Loss on sales of property, plant and equipment		(47)	7
Operating income	24,708	19,612	11,693
Interest income	0	47	216
Interest expense	(674)	(1,320)	(50)
Other (expense) income	(388)	64
Income before income tax provision	23,646	18,403	11,859
Income tax expense	3,896	4,092	2,649
Net income	$ 19,750	$ 14,311	$ 9,210
Net income per common share outstanding:
Basic (in dollars per share)	$ 2.66	$ 1.95	$ 1.27
Diluted (in dollars per share)	$ 2.63	$ 1.93	$ 1.26
Weighted average common shares outstanding:
Basic (in shares)	7,424	7,347	7,248
Diluted (in shares)	7,516	7,430	7,337

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e1043-128460