Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Preferred Stock
Stock offering costs		$ 377
May 2018 Registered Direct Offering | Common Stock
Stock offering costs	$ 640
July 2018 Registered Direct Offering | Common Stock
Stock offering costs	$ 458