Organization and Basis of Presentation (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jun. 04, 2018	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents		$ 62,961	$ 14,680
Net working capital		59,200
Accumulated deficit		165,252	$ 152,331
Net proceeds from sale of stock	$ 41,900
Number of shares sold (in shares)	25,555,556
Price per share (in usd per share)	$ 1.80
Proceeds from exercise of warrants		$ 6,900
Number of warrant sold (in shares)		8,300,000