Nature of Business and Basis of Presentation (Policies)	6 Months Ended
Nature of Business and Basis of Presentation (Policies)	Apr. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial information. Accordingly, they do not contain all of the information and footnotes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements. In the opinion of management, all normal and recurring adjustments necessary to fairly present our financial position and results of operations as of and for the six months ended April 30, 2017 have been included. All intercompany accounts and transactions have been eliminated. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted. The balance sheet as of October 31, 2016 has been derived from the audited financial statements at that date, but it does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. These financial statements should be read in conjunction with our financial statements and notes thereto for the year ended October 31, 2016, which are contained in our Annual Report on Form 10-K previously filed with the Securities and Exchange Commission. The results of operations for the interim periods presented are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year. Certain reclassifications have been made to conform to the current year presentation. The Company has adopted Accounting Standards Update (“ASU”) 2015-03, Interest – Imputation of Interest effective January 31, 2017, and retrospective application is required which resulted in a reclassification in our Consolidated Balance Sheet as of October 31, 2016 of $0.3 million of debt issuance costs from Current assets to be a direct deduction of Current portion of debt and a reclassification of $1.1 million of debt issuance costs from Other assets, net to be a direct deduction of Long-term debt and Other liabilities. The Company has also early adopted ASU 2016-18, “Statement of Cash Flows (Topic 230) Restricted Cash” effective October 31, 2016 and has applied a retrospective transition method. Accordingly, Restricted Cash and Cash Equivalents has been reclassified as a component of Cash, Cash Equivalents, and Restricted Cash in the Consolidated Statement of Cash Flows for the prior year period presented. The Company has also included an additional caption, Generation, in the Revenue and Cost of Revenues sections of the Statements of Operations to include revenues generated from the Company’s project assets (refer to the Revenue Recognition section below for more information). The prior year amounts associated with power purchase agreements have been reclassified to the new caption.
Revenue Recognition	Revenue Recognition We earn revenue from (i) the sale and installation of fuel cell power plants (ii) the sale of component part kits, modules and spare parts to customers, (iii) site engineering and construction services, (iv) performance under long-term service agreements, (v) the sale of electricity and other value streams under power purchase agreements (“PPAs”) and project assets retained by the Company under sales-leaseback transactions, (vi) license fees and royalty income from manufacturing and technology transfer agreements, and (vii) customer-sponsored advanced technology projects. Given the growing revenue related to PPAs and project assets retained by the Company, beginning in the first quarter of 2017, the Company has begun classifying such revenues in a separate line item called Generation, and prior period amounts have been reclassified. As further clarification, revenue elements are classified as follows: Product; Includes the sale and installation of fuel cell power plants, the sale of component part kits, modules and spare parts to customers, and site engineering and construction services, Service and license; Includes performance under long-term service agreements for power plants owned by third parties and license fees and royalty income from manufacturing and technology transfer agreements, Generation; Includes the sale of electricity under PPAs and project assets retained by the Company, revenue received from the sale of other value streams from these assets including the sale of heat, steam and renewable energy credits. Advanced Technologies; Includes revenue from customer-sponsored and government-sponsored advanced technology projects that is recorded as advanced technologies revenues in the consolidated statements of operations. Our revenue is primarily generated from customers located throughout the U.S., Europe and Asia and from agencies of the U.S. Government. For customer contracts for complete SureSource power plants, with which the Company has adequate cost history and estimating experience, and that management believes it can reasonably estimate total contract costs, revenue is recognized under the percentage of completion method of accounting. The use of percentage of completion accounting requires significant judgment relative to estimating total contract costs, including assumptions relative to the length of time to complete the contract, the nature and complexity of the work to be performed, anticipated increases in wages and prices for subcontractor services and materials, and the availability of subcontractor services and materials. Our estimates are based upon the professional knowledge and experience of our engineers, project managers and other personnel, who review each long-term contract on a quarterly basis to assess the contract’s schedule, performance, technical matters and estimated cost at completion. When changes in estimated contract costs are identified, such revisions may result in current period adjustments to operations applicable to performance in prior periods. Revenues are recognized based on the percentage of the contract value that incurred costs to date bear to estimated total contract costs, after giving effect to estimates of costs to complete based on most recent information. For customer contracts for new or significantly customized products, where management does not believe it has the ability to reasonably estimate total contract costs, revenue is recognized using the completed contract method and therefore all revenue and costs for the contract are deferred and not recognized until installation and acceptance of the power plant is complete. We recognize anticipated contract losses as soon as they become known and estimable. Actual results could vary from initial estimates and estimates will be updated as conditions change. Site engineering and construction services revenue is recognized on a percentage of completion basis as costs are incurred. Revenue from fuel cell kits, modules and spare parts sales is recognized upon shipment or title transfer under the terms of the customer contract. Terms for certain contracts provide for a transfer of title and risk of loss to our customers at our factory locations upon completion of our contractual requirement to produce products and prepare the products for shipment. A shipment in place may occur in the event that the customer is not ready to take delivery of the products on the contractually specified delivery dates. Revenue from service agreements is generally recorded ratably over the term of the service agreement, as our performance of routine monitoring and maintenance under these service agreements is generally expected to be incurred on a straight-line basis. For service agreements where we expect to have a module exchange at some point during the term (generally service agreements in excess of five years), the costs of performance are not expected to be incurred on a straight-line basis, and therefore, a portion of the initial contract value related to the module exchange is deferred and is recognized upon such module replacement event. The Company receives license fees and royalty income from POSCO Energy as a result of manufacturing and technology transfer agreements entered into in 2007, 2009 and 2012. The Cell Technology Transfer Agreement we entered into on October 31, 2012 provides POSCO Energy with a technology license to manufacture SureSource power plants in South Korea. On March 17, 2017, the Company entered into a Memorandum of Understanding (“2017 MOU”) with POSCO Energy to engage in discussions to further amend the above referenced agreements and other agreements between the parties, as well as engaging in discussions relating to entering into new agreements to further the parties mutual interests. The 2017 MOU contemplates that POSCO Energy will continue to service the existing installed base of fuel cell plants in South Korea. In addition, the 2017 MOU contemplates entering into a module procurement agreement with POSCO Energy that the Company anticipates will provide that POSCO Energy will commit to a specified level of module purchases from the Company to supplement its own local manufacturing for servicing its existing fleet. Definitive agreements are expected to be finalized in autumn 2017 subject to completion of due diligence, regulatory approvals, and customary closing conditions. Pursuant the 2017 MOU, the Company will immediately commence marketing the entire suite of SureSource solutions in Korea as well as the broader Asian markets for the supply, recovery and storage of energy. Under PPAs and project assets retained by the Company, revenue from the sale of electricity and other value streams is recognized as electricity is provided to the customer. These revenues are classified as a component of generation revenues. Revenue from advanced technology projects is recognized as direct costs are incurred plus allowable overhead less cost share requirements, if any. Advanced technology programs are often multi-year projects or structured in phases with subsequent phases dependent on reaching certain milestones prior to additional funding being authorized. Government contracts are typically structured with cost-reimbursement and/or cost-shared type contracts or cooperative agreements. We are reimbursed for reasonable and allocable costs up to the reimbursement limits set by the contract or cooperative agreement, and on certain contracts we are reimbursed only a portion of the costs incurred.
Use of Estimates	Use of Estimates The preparation of financial statements and related disclosures in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Estimates are used in accounting for, among other things, revenue recognition, excess, slow-moving and obsolete inventories, product warranty costs, accruals for service agreements, allowance for uncollectible receivables, depreciation and amortization, impairment of goodwill, indefinite-lived intangible assets and long-lived assets, income taxes, and contingencies. Estimates and assumptions are reviewed periodically, and the effects of revisions are reflected in the consolidated financial statements in the period they are determined to be necessary. Due to the inherent uncertainty involved in making estimates, actual results in future periods may differ from those estimates.
Related Parties	Related Parties POSCO Energy (“POSCO”), is a related party and owned approximately 5.0% of the outstanding common shares of the Company as of April 30, 2017. Revenues from POSCO Energy for the three months ended April 30, 2017 and 2016 represent 7% and 52%, respectively, of consolidated revenues and revenues from POSCO Energy for the six months ended April 30, 2017 and 2016 represent 8% and 48%, respectively, of consolidated revenues. NRG Energy, Inc. (“NRG”) is a related party and owned approximately 3.0% of the outstanding common shares of the Company as of April 30, 2017. NRG Yield is a dividend growth-oriented company formed by NRG that owns, operates and acquires a diversified portfolio of contracted renewable and conventional generation and thermal infrastructure assets in the United States. Revenues from NRG and NRG Yield for the three months ended April 30, 2017 and 2016 represent 0.3% and 0.4%, respectively, of consolidated revenues and revenues for the six months ended April 30, 2017 and 2016 represent 0.4% and 0.2%, respectively, of consolidated revenues.