Subsequent Event (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 16, 2018	Mar. 22, 2018	Jan. 12, 2018	May 10, 2017	Sep. 30, 2018
Sale of stock, number of shares issued in transaction		2,743,640	4,000,000	2,584,085
Sale of stock, price per share		$ 1.10	$ 1.00
Exercise price of warrants					$ 2.76
Proceeds from equity offerings, gross		$ 3.0	$ 4.0
Pre-Funded Warrant [Member]
Number of securities called by warrants				4,483,334
Number of shares called by each warrant				1
Sale of stock, price per share				$ 1.49
Exercise price of warrants				$ 0.01
Common Warrant [Member]
Number of securities called by warrants				8,000,000
Sale of stock, price per share				$ 1.50
Exercise price of warrants				$ 1.50
Expiration term of warrants (in years)				5 years
Subsequent Event [Member]
Sale of stock, number of shares issued in transaction	14,875,000
Proceeds from equity offerings, gross	$ 6.8
Subsequent Event [Member] | Pre-Funded Warrant [Member]
Number of securities called by warrants	2,125,000
Number of shares called by each warrant	1
Sale of warrant, price per warrant	$ 0.39
Exercise price of warrants	$ 0.01
Subsequent Event [Member] | Common Warrant [Member]
Number of securities called by warrants	17,500,000
Sale of stock, price per share	$ 0.40
Exercise price of warrants	$ 0.40
Expiration term of warrants (in years)	5 years