Segment Information - Revenues by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Schedule Of Revenues By Geographic Area [Line Items]
Revenues	$ 17,884	$ 12,110	$ 20,830	$ 38,613	$ 47,889	$ 10,358	$ 20,417	$ 17,002	$ 89,437	$ 95,666	$ 108,252
UNITED STATES
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									50,953	47,539	48,697
SOUTH KOREA
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									36,279	44,217	52,007
ENGLAND
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									387	368	277
GERMANY
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									1,795	2,740	7,147
CANADA
Schedule Of Revenues By Geographic Area [Line Items]
Revenues									$ 23	729	$ 124
SPAIN
Schedule Of Revenues By Geographic Area [Line Items]
Revenues										$ 73