Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Revenues	$ 140,380	[1]	$ 105,481	[1]	$ 79,722
Cost of sales	102,396		74,395		61,233
Gross profit	37,984	[1]	31,086	[1]	18,489
Operating expenses:
Selling, general and administrative	21,745		11,651		9,796
Amortization	1,107		488		512
Total operating expenses	22,852	[1]	12,139	[1]	10,308
Operating income	15,132	[1]	18,947	[1]	8,181
Other income (expense):
Interest expense	(3,156)		(1,118)		(776)
Other income (expense)	28		(564)		302
Total other income (expense)	(3,128)	[1]	(1,682)	[1]	(474)
Income before income taxes	12,004	[1]	17,265	[1]	7,707
Income tax expense	847	[1]	6,628	[1]	2,944
Net income	$ 11,157	[1]	$ 10,637	[1]	$ 4,763
Net income per common share - Basic	$ 0.27	[1]	$ 0.31	[1]	$ 0.15
Net income per common share - Diluted	$ 0.26	[1]	$ 0.3	[1]	$ 0.14
Weighted average number of shares outstanding - Basic	41,764,230	[1]	34,104,476	[1]	32,546,840
Weighted average number of shares outstanding - Diluted	42,766,843	[1]	35,416,910	[1]	33,936,099

[1] The sum of the net earnings per share may not add up to the full year amount due to rounding and because the quarterly calculations are based on varying numbers of shares outstanding.