Segment Information - Revenues by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Schedule Of Revenues By Geographic Area [Line Items]
Revenues	$ 11,041	$ 22,712	$ 9,216	$ 17,783	$ 17,884	$ 12,110	$ 20,830	$ 38,613	$ 60,752	$ 89,437	$ 95,666
UNITED STATES
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									56,211	50,953	47,539
SOUTH KOREA
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									2,686	36,279	44,217
ENGLAND
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									1,496	387	368
GERMANY
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									$ 359	1,795	2,740
CANADA
Schedule Of Revenues By Geographic Area [Line Items]
Revenues										$ 23	729
SPAIN
Schedule Of Revenues By Geographic Area [Line Items]
Revenues											$ 73