Restricted Cash - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jan. 31, 2020	Oct. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	$ 35,700	$ 30,300
Restricted cash and cash equivalents - long-term	$ 27,481	26,871
Letter of credit date of expiration	Aug. 31, 2028
Letters of credit outstanding, amount	$ 5,700	5,700
Groton CT [Member] | Minimum [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Balance to become unrestricted upon certain performance related to Groton project	30,000
Finance Obligations for Sale Leaseback Agreements [Member] | PNC Energy Capital, LLC [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Reserves for obligations	18,100	17,900
Orion Energy Partners Investment Agent, LLC Credit Facility [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Reserves for obligations	5,000
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Groton CT [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Balance to become unrestricted upon certain performance related to Groton project	30,000
Bridgeport Fuel Cell Project [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	4,900
Dominion Bridgeport FuelCell Park [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents - long-term	$ 5,900	$ 4,900