Stockholders' Equity and Warrant Liabilities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands							3 Months Ended
	Dec. 07, 2020	Dec. 04, 2020	Jan. 08, 2020	Nov. 22, 2019	Oct. 31, 2019	May 03, 2017	Jan. 31, 2021	Jan. 31, 2020	Dec. 01, 2020	Oct. 31, 2020
Stockholders' Equity Note
Sale of stock, price per share	$ 7.95		$ 2.29					$ 1.59
Common stock issuance, net of fees							$ 156,363	$ 0
Class of warrants or rights issued								9,396,320
Class of warrants or rights exercised								12,000,000
Expected volatility	117.02%		103.70%					104.90%
Risk-free interest rate	0.70%		1.81%					1.45%
Class of warrants or rights charge			$ 23,700				$ 16,000	$ 10,500
Reclassification of estimated fair value of warrant liability to additional paid in capital	$ 21,200		$ 26,000
Common Stock [Member]
Stockholders' Equity Note
Stock issued during period shares new issues							25,000,000	7,938,228
Orion Energy Partners Investment Agent, LLC Credit Facility [Member]
Stockholders' Equity Note
Class of warrants or rights exercised										2,700,000
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Exercise Price 0.242 [Member]
Stockholders' Equity Note
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.242
Class of warrants or rights issued	2,700,000
Class of warrants or rights issued value	$ 653,400
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Initial Funding Warrants [Member]
Stockholders' Equity Note
Class of warrants or rights issued					6,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 0.310
Drew down to fully repay debt outstanding					$ 14,500
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding Warrants [Member]
Stockholders' Equity Note
Class of warrants or rights issued				14,000,000
Drew down to fully repay debt outstanding				$ 65,500
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding Warrants [Member] | Exercise Price 0.242 [Member]
Stockholders' Equity Note
Class of warrants or rights issued				8,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 0.242
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding Warrants [Member] | Exercise Price 0.620 [Member]
Stockholders' Equity Note
Class of warrants or rights issued				6,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 0.62
Underwriting Agreement [Member]
Stockholders' Equity Note
Stock issued to underwriters		19,822,219
Sale of stock, number of shares issued in transaction		14,696,320
Sale of stock, price per share									$ 6.50
Stock issued during period shares new issues		25,000,000
Common stock issuance, net of fees		$ 162,500
Underwriting discounts and commissions		$ 0.2275
Net proceeds from issuance of common stock		$ 156,400
Underwriting Agreement [Member] | Senior Secured Credit Facility [Member]
Stockholders' Equity Note
Credit facility		$ 200,000
Underwriting Agreement [Member] | Maximum [Member]
Stockholders' Equity Note
Option to purchase additional common stock shares		5,177,781
Underwritten Public Offering [Member]
Stockholders' Equity Note
Stock issued during period shares new issues						1,000,000
Underwritten Public Offering [Member] | Series C Warrants [Member]
Stockholders' Equity Note
Class of warrants or rights issued						1,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights						$ 19.20
Class of warrant or right term						5 years
Underwritten Public Offering [Member] | Common Stock [Member] | Series C Warrants [Member]
Stockholders' Equity Note
Class of warrants or rights exercised							0