Schedule of Accrued Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020	Oct. 31, 2020
Schedule Of Accrued Liabilities [Line Items]
Product warranty accrual, payment and adjustments	$ 6	$ 10	$ 12	$ 30
Loss reserve on service agreements	5,500		5,500		$ 5,500
Bridgeport Fuel Cell Project [Member]
Schedule Of Accrued Liabilities [Line Items]
Reserve for performance guarantees	$ 1,600		$ 1,600		$ 1,400