Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 42,467	$ 29,887
Cost of revenues	27,738	20,920
Gross profit	14,729	8,967
Operating expenses:
Research and development	4,283	3,726
Sales, general, and administrative	6,238	4,629
Total operating expenses	10,521	8,355
Income from operations	4,208	612
Other income (expense):
Interest expense, net	(219)	(502)
Other income (expense)	76	(167)
Income (loss) before income taxes	4,065	(57)
Income tax expense	1,149	1,156
Net income (loss)	2,916	(1,213)
Less: Income allocated to preferred stockholders	(2,916)	0
Net income (loss) attributable to common stockholders	$ 0	$ (1,213)
Net income (loss) per share, basic and diluted (in dollars per share)	$ 0.00	$ (0.47)
Shares used in basic and diluted per share calculations (in shares)	3,031	2,600