Revenue Recognition	6 Months Ended
Apr. 30, 2020
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Note 3. Revenue Recognition Contract Balances Contract assets as of April 30, 2020 and October 31, 2019 were $11.9 million and $11.3 million, respectively. The contract assets relate to the Company’s rights to consideration for work completed but not billed. These amounts are included on a separate line item as Unbilled receivables, and balances expected to be billed later than one year from the balance sheet date are included within Other assets on the accompanying consolidated balance sheets. The net change in contract assets represent amounts recognized as revenue offset by customer billings. Contract liabilities as of April 30, 2020 and October 31, 2019 were $42.5 million and $40.2 million, respectively. The contract liabilities relate to the advance billings to customers for services that will be recognized over time and in some instances for deferred revenue relating to license performance obligations that will be recognized at a future point in time. These amounts are included within Deferred revenue and Long-term deferred revenue on the accompanying consolidated balance sheets. The net change in contract liabilities represents customer billings offset by revenue recognized. Remaining Performance Obligations Remaining performance obligations are the aggregate amount of total contract transaction price that is unsatisfied or partially unsatisfied. As of April 30, 2020, the Company’s total remaining performance obligations for service agreements, license agreements and Advanced Technologies contracts were $192.4 million. License revenue recognized over time will be recognized over the remaining term of the applicable license agreement. License revenue recognized at a point in time will be recognized when the first specified upgrade that has been developed is delivered and when the second specified upgrade is developed and delivered. Service revenue in periods in which there are no module replacements is expected to be relatively consistent from period to period, whereas module replacements will result in an increase in revenue when replacements occur. Advanced technologies revenue will be recognized as costs are incurred. The Company has elected practical expedients in the accounting guidance that allow for revenue to be recorded in the amount that the Company has a right to invoice, if that amount corresponds directly with the value to the customer of the Company's performance to date, and not to disclose related unsatisfied performance obligations. Generation sales, to the extent the related power purchase agreements are within the scope of Topic 606, fall into this category, as these sales are recognized as revenue in the period the Company provides the electricity and completes the performance obligation, which is the same as the monthly amount billed to customers. Revenue recognition for the Joint Development Agreement with EMRE also falls into this category where revenue is recorded consistent with the amounts invoiced for research performed.

Revenue Recognition

6 Months Ended

Apr. 30, 2020

Revenue From Contract With Customer [Abstract]

Note 3. Revenue Recognition

Contract Balances

Contract assets as of April 30, 2020 and October 31, 2019 were $11.9 million and $11.3 million, respectively. The contract assets relate to the Company’s rights to consideration for work completed but not billed. These amounts are included on a separate line item as Unbilled receivables, and balances expected to be billed later than one year from the balance sheet date are included within Other assets on the accompanying consolidated balance sheets. The net change in contract assets represent amounts recognized as revenue offset by customer billings.

Contract liabilities as of April 30, 2020 and October 31, 2019 were $42.5 million and $40.2 million, respectively. The contract liabilities relate to the advance billings to customers for services that will be recognized over time and in some instances for deferred revenue relating to license performance obligations that will be recognized at a future point in time. These amounts are included within Deferred revenue and Long-term deferred revenue on the accompanying consolidated balance sheets. The net change in contract liabilities represents customer billings offset by revenue recognized.

Remaining Performance Obligations

Remaining performance obligations are the aggregate amount of total contract transaction price that is unsatisfied or partially unsatisfied. As of April 30, 2020, the Company’s total remaining performance obligations for service agreements, license agreements and Advanced Technologies contracts were $192.4 million. License revenue recognized over time will be recognized over the remaining term of the applicable license agreement. License revenue recognized at a point in time will be recognized when the first specified upgrade that has been developed is delivered and when the second specified upgrade is developed and delivered. Service revenue in periods in which there are no module replacements is expected to be relatively consistent from period to period, whereas module replacements will result in an increase in revenue when replacements occur. Advanced technologies revenue will be recognized as costs are incurred.

The Company has elected practical expedients in the accounting guidance that allow for revenue to be recorded in the amount that the Company has a right to invoice, if that amount corresponds directly with the value to the customer of the Company's performance to date, and not to disclose related unsatisfied performance obligations. Generation sales, to the extent the related power purchase agreements are within the scope of Topic 606, fall into this category, as these sales are recognized as revenue in the period the Company provides the electricity and completes the performance obligation, which is the same as the monthly amount billed to customers. Revenue recognition for the Joint Development Agreement with EMRE also falls into this category where revenue is recorded consistent with the amounts invoiced for research performed.