Project Assets - Additional Information (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Jul. 31, 2021 USD ($)	Jul. 31, 2020 USD ($)	Jul. 31, 2021 USD ($) item	Jul. 31, 2020 USD ($)	Oct. 31, 2020 USD ($) item
Project Assets
Number of project assets \| item			9		8
Sale leaseback transaction, net book value	$ 99.6		$ 99.6		$ 70.5
Project asset depreciation	3.0	$ 3.1	10.3	$ 8.6
Long-term project assets construction in progress	99.6		99.6		91.3
PPA assets construction in progress	$ 1.8		$ 1.8		$ 4.8

The net book value of the asset(s) sold in connection with the sale of the property to another party and lease back to the seller.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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Name:	us-gaap_SaleLeasebackTransactionNetBookValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant