Schedule of Accrued Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019	Oct. 31, 2019
Schedule Of Accrued Liabilities [Line Items]
Product warranty accrual, payment and adjustments	$ 10	$ 40	$ 30	$ 80
Loss reserve on service agreements	3,000		3,000		$ 3,300
Bridgeport Fuel Cell Project [Member]
Schedule Of Accrued Liabilities [Line Items]
Reserve for performance guarantees	$ 1,000		$ 1,000		$ 800