Nature of Business and Basis of Presentation - Additional Information (Details) $ in Millions			1 Months Ended
	Jun. 26, 2019 USD ($)	Jun. 11, 2019 USD ($)	May 08, 2019 shares	May 07, 2019 shares	Apr. 30, 2019 shares	Oct. 31, 2018 shares
Nature Of Business And Basis Of Presentation [Line Items]
Common stock, shares outstanding					13,709,330	7,972,686
Common stock, shares authorized					225,000,000	225,000,000
Preferred stock, shares authorized					250,000
EMRE [Member] | Hercules Capital, Inc. [Member] | Scenario Forecast [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Repayments of loan | $	$ 6.0
Subsequent Event [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Reverse stock split			1-for-12 reverse stock split
Reverse stock split, conversion ratio			0.084
Common stock, shares outstanding			15,284,269	183,411,230
Common stock, shares authorized			225,000,000
Preferred stock, shares authorized			250,000
Subsequent Event [Member] | Hercules Capital, Inc. [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Repayments of loan | $		$ 1.4
Subsequent Event [Member] | EMRE [Member]
Nature Of Business And Basis Of Presentation [Line Items]
License agreement payment received | $		$ 10.0