Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Revenues	$ 166,525	[1]	$ 140,380	[1]	$ 105,481
Cost of sales	173,890		102,396		74,395
Gross profit (loss)	(7,365)	[1]	37,984	[1]	31,086
Operating expenses:
Selling, general and administrative	32,270		21,745		11,651
Amortization	2,973		1,107		488
Total operating expenses	35,243	[1]	22,852	[1]	12,139
Operating income (loss)	(42,608)	[1]	15,132	[1]	18,947
Other expense:
Interest expense	(14,755)		(3,156)		(1,118)
Other income (expense)	0		28		(564)
Total other expense	(14,755)	[1]	(3,128)	[1]	(1,682)
Income (loss) before income taxes	(57,363)	[1]	12,004	[1]	17,265
Income tax expense (benefit)	(1,704)	[1]	847	[1]	6,628
Net income (loss)	$ (55,659)		$ 11,157		$ 10,637
Net income (loss) per common share – Basic	$ (1.31)	[1]	$ 0.27	[1]	$ 0.31
Net income (loss) per common share – Diluted	$ (1.31)	[1]	$ 0.26	[1]	$ 0.30
Weighted average number of shares outstanding – Basic	42,484,972	[1]	41,764,230	[1]	34,104,476
Weighted average number of shares outstanding – Diluted	42,484,972	[1]	42,766,843	[1]	35,416,910

[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.