CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net sales	$ 19,328	$ 52,367
Cost of sales	5,224	10,221
Gross profit	14,104	42,146
Operating expenses:
Commissions expense	9,498	22,980
Selling, general and administrative expenses	7,315	9,122
Total operating expenses	16,813	32,102
Income (loss) from operations	(2,709)	10,044
Other income, net	432	163
Income (loss) before income taxes	(2,277)	10,207
Income tax provision (benefit)	(354)	1,383
Net income (loss)	$ (1,923)	$ 8,824
Net income (loss) per common share:
Basic (in dollars per share)	$ (0.17)	$ 0.78
Diluted (in dollars per share)	$ (0.17)	$ 0.78
Weighted-average number of common shares outstanding:
Basic (in shares)	11,333	11,286
Diluted (in shares)	11,333	11,288