Stockholders' Equity (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Aug. 23, 2018	Dec. 31, 2018	Dec. 31, 2017
Issuance of common stock for cash in a private placement		$ 1,800
Stock based compensation expense relating to unvested		$ 2,100
Exercise price of warrant		$ 1.20
Number of warrants exercised		1,000,000
Proceeds from warrants exercised		$ 200
Weighted average remaining contractual terms		3 years
Number of warrants vested immediately			250,000
Number of other warrants will be vested upon performance of services			250,000
Stock-based compensation expense (income)		$ 2,280	$ 4,189
General and Administrative Expense [Member]
Stock-based compensation expense (income)		2,800	3,000
Research and Development Expense [Member]
Stock-based compensation expense (income)		$ 467	1,400
Stock Options [Member]
Expected dividend yield		0.00%
Fair value of stock option granted		$ 8,200	4,300
Stock based compensation expense relating to unvested		$ 7,500	$ 2,100
Amortized period		3 years 9 months 18 days	2 years 9 months 18 days
Weighted average remaining contractual life		4 years 6 months
Warrants [Member] | Stock Purchase Agreement [Member]
Warrants recorded as an advisory fee		78,000
Warrants recorded as an advisory fee fair value		$ 40,000
Investor [Member]
Issuance of common stock for cash in a private placement, shares		41,322
Several Accredited and Institutional Investors [Member] | Warrants [Member] | Stock Purchase Agreement [Member]
Warrant purchase of common stock, shares		975,000	910,000
Exercise price of warrant		$ 2.00	$ 2.00
Service Provider [Member] | Warrants [Member] | Stock Purchase Agreement [Member]
Exercise price of warrant		$ 1.75	$ 1.20
Number of warrants granted		78,000	500,000
Two Service Providers [Member] | Warrants [Member] | Stock Purchase Agreement [Member]
Exercise price of warrant			$ 1.76
Number of warrants granted			62,417
Private Placement [Member]
Issuance of common stock for cash in a private placement, shares	666,665	826,446
Issuance of common stock for cash in a private placement	$ 800	$ 1,000