Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - 6 months ended Apr. 30, 2018 - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Oct. 31, 2017	$ 109,995	$ 7	$ 149,173	$ (259,005)	$ 170
Balance, shares at Oct. 31, 2017	3,230,655	6,515,524
Conversion of Series A preferred stock to common stock	$ (769)	$ 1	768
Conversion of Series A preferred stock to common stock, shares	(3,146,671)	713,036
Conversion of Series B preferred stock to common stock	$ (4,020)	$ 1	4,019
Conversion of Series B preferred stock to common stock, shares	(47,689)	794,820
Conversion of Series C preferred stock to common stock	$ (201)		201
Conversion of Series C preferred stock to common stock, shares	(2,578)	59,950
Conversion of Series D preferred stock to common stock	$ (312)		312
Conversion of Series D preferred stock to common stock, shares	(26,667)	44,445
Conversion of Series E preferred stock to common stock	$ (104,693)	$ 7	104,686
Conversion of Series E preferred stock to common stock, shares	(7,050)	7,050,000
Exchange of Series F preferred stock and dividends to common stock		$ 1	13,060		13,061
Exchange of Series F preferred stock and dividends to common stock, shares		1,103,391
Extinguishment of warrant liability			3,045		3,045
Extinguishment of warrant liability, shares		151,871
Option exercises			91		91
Option exercises, shares		25,417
Proceeds received from issuance of common stock, net of issuance costs of $2,782		$ 2	34,593		34,595
Proceeds received from issuance of common stock, net of issuance costs of $2,782, shares		2,335,937
Stock-based compensation expense			17,752		17,752
Stock-based compensation expense, shares		137,387
Deemed dividend - accretion of discount on Series F preferred stock			(1,290)		(1,290)
Cumulative dividends on Series F preferred stock			(373)		373
Series F preferred stock dividends paid in common stock			306		306
Series F preferred stock dividends paid in common stock, shares		11,710
Net loss				(25,708)	(25,708)
Balance at Apr. 30, 2018		$ 19	$ 326,343	$ (284,713)	$ 41,649
Balance, shares at Apr. 30, 2018		18,843,488