Organization and Description of the Business (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Sep. 30, 2017	Dec. 31, 2017
Liquidity
Accumulated deficit	$ (181,453)		$ (144,727)
Secondary public offering
Liquidity
Issuance of common stock in connection with secondary public offering (in shares)	12,000,000	10,733,334
Proceeds from issuance of common stock, net of issuance costs	$ 42,100	$ 37,700