RESTATEMENTS Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 58,812			$ 32,415	$ 16,596	$ 40,663
Short term investments	0			40,885	61,678	55,480
Trade accounts receivable, net	7,987		$ 5,292	4,044	3,721	4,139
Other receivables	1,233			925	1,359
Inventories, net	5,068			3,013	3,146	6,037
Prepaid expenses and other current assets	3,633			4,034	3,335	627
Total current assets	76,733			85,316	89,835	106,946
Property and equipment, net	6,618			6,015	5,788	5,842
Operating lease right-of-use assets	350			178
Other assets	391			347	305	385
Total assets	84,745			91,856	95,928	113,173
Current liabilities:
Accounts payable	2,438			1,504	1,423	2,348
Accrued expenses and other current liabilities	9,396			7,009	7,188	20,088
Current portion of operating lease liabilities	108			103
Total current liabilities	12,311			8,616	8,611	22,436
Related party note payable	0			140	140	140
Long-term operating lease liabilities	235			75
Other liabilities	519			194	0
Liabilities	13,486			9,025	8,751	22,576
STOCKHOLDERS' EQUITY
Common stock	34			34	34	33
Additional paid-in capital	56,708			54,182	52,920	51,798
Retained earnings	14,517	$ 19,950	24,320	28,615	34,223	38,766
Total stockholders’ equity	71,259			82,831	87,177	90,597	$ 22,032	$ 26,223
Total liabilities and stockholders’ equity	$ 84,745			91,856	95,928	113,173
As Originally Reported
ASSETS
Cash and cash equivalents				32,415	16,466	40,663
Short term investments				40,885	61,678	55,480
Trade accounts receivable, net			5,233	4,006	3,656	4,080
Other receivables				925	1,359
Inventories, net				3,013	3,061	6,037
Prepaid expenses and other current assets				3,996	3,297	627
Total current assets				85,240	89,517	106,887
Property and equipment, net				6,015	5,788	5,842
Operating lease right-of-use assets				178
Other assets				270	305	385
Total assets				91,703	95,610	113,114
Current liabilities:
Accounts payable				1,504	1,423	2,348
Accrued expenses and other current liabilities				5,868	6,279	19,324
Current portion of operating lease liabilities				103
Total current liabilities				7,475	7,702	21,672
Related party note payable				140	140	140
Long-term operating lease liabilities				75
Other liabilities				0
Liabilities				7,690	7,842	21,812
STOCKHOLDERS' EQUITY
Common stock				34	34	33
Additional paid-in capital				53,147	52,221	51,798
Retained earnings		$ 21,031	$ 25,342	30,832	35,513	39,471
Total stockholders’ equity				84,013	87,768	91,302
Total liabilities and stockholders’ equity				91,703	95,610	113,114
Adjustments | Material Corrections
ASSETS
Cash and cash equivalents				0	130	0
Short term investments				0	0	0
Trade accounts receivable, net				38	65	59
Other receivables				0	0
Inventories, net				0	85	0
Prepaid expenses and other current assets				38	38	0
Total current assets				76	318	59
Property and equipment, net				0	0	0
Operating lease right-of-use assets				0
Other assets				77	0	0
Total assets				153	318	59
Current liabilities:
Accounts payable				0	0	0
Accrued expenses and other current liabilities				1,141	909	764
Current portion of operating lease liabilities				0
Total current liabilities				1,141	909	764
Related party note payable				0	0	0
Long-term operating lease liabilities				0
Other liabilities				194
Liabilities				1,335	909	764
STOCKHOLDERS' EQUITY
Common stock				0	0	0
Additional paid-in capital				1,035	699	0
Retained earnings				(2,217)	(1,290)	(705)
Total stockholders’ equity				(1,182)	(591)	(705)
Total liabilities and stockholders’ equity				$ 153	$ 318	$ 59