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Restricted Cash - Additional Information (Details) - USD ($)
$ in Thousands
 6 Months Ended
Apr. 30, 2018
Oct. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]    
Restricted cash and cash equivalents $ 38,200 $ 38,200
Restricted cash and cash equivalents - long-term 32,965 33,526
Reserves for obligations $ 17,200 17,000
Letter of credit date of expiration Apr. 30, 2019  
Letters of credit outstanding, amount $ 2,300 2,900
Dominion Bridgeport FuelCell Park [Member]    
Restricted Cash and Cash Equivalents Items [Line Items]    
Restricted cash and cash equivalents - long-term $ 15,000 $ 15,000
Restricted cash and cash equivalents - long-term service agreement 15 years