Accounts Receivable, Net - Additional Information (Details) - USD ($) $ in Millions	Jul. 31, 2018	Oct. 31, 2017
Accounts Notes And Loans Receivable [Line Items]
Allowance for Doubtful Accounts Receivable, Current	$ 0.1	$ 0.1
POSCO Energy [Member]
Accounts Notes And Loans Receivable [Line Items]
Accounts Receivable, Related Parties, Current	12.4	6.2
NRG Energy, Inc. [Member]
Accounts Notes And Loans Receivable [Line Items]
Accounts Receivable, Related Parties, Current	$ 2.0	$ 0.1

Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Name:	us-gaap_AccountsReceivableRelatedPartiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant