Acquisition - Additional Information (Details)		3 Months Ended	9 Months Ended
	May 09, 2019 USD ($) MW	Jul. 31, 2019 USD ($)	Jul. 31, 2019 USD ($)
Bridgeport Fuel Cell, LLC [Member]
Business Acquisition [Line Items]
Business acquisition, purchase price	$ 35,500,000
Working capital post-closing adjustment for purchase price	1,000,000
Purchase price, estimated working capital adjustment	400,000
Accounts receivable	2,700,000
Unbilled receivables	15,300,000
Accrued performance guarantees	1,300,000
Assets acquired, fuel cell power plants installation	38,800,000
Assets acquired, power purchase agreement	12,300,000	$ 12,000,000	$ 12,000,000
Gain or loss recorded for pre-existing service agreement	$ 0
Amortization expenses		300,000
Remaining amortization period			10 years
Bridgeport Fuel Cell, LLC [Member] | Project Asset [Member]
Business Acquisition [Line Items]
Purchase price and adjusted balances of project assets value		37,400,000	$ 37,400,000
Bridgeport Fuel Cell, LLC [Member] | Project Asset [Member] | Balance of Plant Assets [Member]
Business Acquisition [Line Items]
Project assets estimated remaining useful lives			15 years
Bridgeport Fuel Cell, LLC [Member] | Project Asset [Member] | Minimum [Member] | Fuel Cell Modules
Business Acquisition [Line Items]
Project assets estimated remaining useful lives			1 year
Bridgeport Fuel Cell, LLC [Member] | Project Asset [Member] | Maximum [Member] | Fuel Cell Modules
Business Acquisition [Line Items]
Project assets estimated remaining useful lives			7 years
Bridgeport Fuel Cell, LLC [Member] | Bridgeport, Connecticut [Member]
Business Acquisition [Line Items]
Capacity of plant | MW	14.9
Plant operation period	2013-12
Bridgeport Fuel Cell Project [Member]
Business Acquisition [Line Items]
Restricted cash	$ 15,000,000	$ 6,900,000	$ 6,900,000