Schedule of Accrued Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019	Oct. 31, 2019
Schedule Of Accrued Liabilities [Line Items]
Product warranty accrual, payment and adjustments	$ 10	$ 40	$ 40	$ 80
Loss reserve on service agreements	5,600		5,600		$ 3,300
Bridgeport Fuel Cell Project [Member]
Schedule Of Accrued Liabilities [Line Items]
Reserve for performance guarantees	$ 700		$ 700		$ 800