Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2020	Jul. 31, 2019	Oct. 31, 2019
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 4,075		$ 4,075	$ 4,075		$ 4,075
Intangible assets	20,291		20,291	20,291		21,264
Impairment of goodwill			0
Impairment of Intangible Assets, Indefinite-lived			0
Versa Acquisition [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill	4,100		4,100	4,100		4,100
Intangible assets	20,300		20,300	20,300		21,300
Bridgeport Fuel Cell, LLC [Member]
Goodwill And Intangible Assets [Line Items]
Intangible assets	10,700		$ 10,700	10,700		11,700
Intangible assets recorded during the period						$ 12,300
Amortization expenses	$ 300	$ 300		$ 1,000	$ 300