Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Total
Balance at Dec. 31, 2017	$ 424	$ 114,302	$ 8,727	$ 123,453
Balance (in shares) at Dec. 31, 2017	42,398,140
Issuance of common stock upon exercise of stock options and warrants	$ 0	17	0	17
Issuance of common stock upon exercise of stock options and warrants (in shares)	5,000
Issuance of common stock for services	$ 2	346	0	348
Issuance of common stock for services (in shares)	196,291
Value of share-based arrangements	$ 0	286	0	286
Value of share-based arrangements (in shares)	0
Net loss	$ 0	0	(47,552)	(47,552)
Balance at Sep. 30, 2018	$ 426	114,951	(38,825)	76,552
Balance (in shares) at Sep. 30, 2018	42,599,431
Balance at Jun. 30, 2018	$ 424	114,531	(24,945)	90,010
Balance (in shares) at Jun. 30, 2018	42,403,140
Issuance of common stock for services	$ 2	346	0	348
Issuance of common stock for services (in shares)	196,291
Value of share-based arrangements	$ 0	74	0	74
Value of share-based arrangements (in shares)	0
Net loss	$ 0	0	(13,880)	(13,880)
Balance at Sep. 30, 2018	$ 426	114,951	(38,825)	76,552
Balance (in shares) at Sep. 30, 2018	42,599,431
Balance at Dec. 31, 2018	$ 426	115,719	(46,932)	69,213
Balance (in shares) at Dec. 31, 2018	42,602,431
Issuance of common stock upon exercise of stock options and warrants	$ 0	9	0	9
Issuance of common stock upon exercise of stock options and warrants (in shares)	10,000
Issuance of common stock for services	$ 0	10	0	10
Issuance of common stock for services (in shares)	16,129
Value of share-based arrangements	$ 0	890	0	890
Value of share-based arrangements (in shares)	0
Net loss	$ 0	0	(15,169)	(15,169)
Balance at Sep. 30, 2019	$ 426	116,628	(62,101)	54,953
Balance (in shares) at Sep. 30, 2019	42,628,560
Balance at Jun. 30, 2019	$ 426	116,356	(64,768)	52,014
Balance (in shares) at Jun. 30, 2019	42,612,431
Issuance of common stock for services	$ 0	10	0	10
Issuance of common stock for services (in shares)	16,129
Value of share-based arrangements	$ 0	262	0	262
Net loss	0	0	2,667	2,667
Balance at Sep. 30, 2019	$ 426	$ 116,628	$ (62,101)	$ 54,953
Balance (in shares) at Sep. 30, 2019	42,628,560