Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Mar. 31, 2018
Series A Convertible Preferred Stock
Issuance of shares, offering costs		$ 0.4
Series B Convertible Preferred Stock
Issuance of shares, offering costs	$ 0.5