Organization, Nature of Operations and Basis of Presentation (Details Textual) - USD ($) $ in Thousands, shares in Millions			3 Months Ended	12 Months Ended
	Oct. 15, 2018	Aug. 10, 2018	Mar. 31, 2019	Dec. 31, 2018	May 31, 2019	Jan. 01, 2019	Mar. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents, at Carrying Value			$ 24,694	$ 28,918	$ 23,000		$ 11,037	$ 17,116
Proceeds from Issuance Initial Public Offering	$ 16,700
Proceeds from Issuance of Common Stock				12,200
Stock Issued During Period, Shares, Reverse Stock Splits		128.5	3.7
Lessee, Operating Lease, Term of Contract			12 months
Operating Lease, Right-of-Use Asset			$ 510	0		$ 537
Operating Lease, Liability, Current			$ 225	$ 0		$ 939