Goodwill and Intangible Asset	9 Months Ended
Goodwill and Intangible Asset	Jul. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Asset	Note 8. Goodwill and Intangible Asset As of July 31, 2017 and October 31, 2016, the Company had goodwill of $4.1 million and an intangible asset of $9.6 million associated with the December 2012 acquisition of Versa Power Systems. The intangible asset represents indefinite lived in-process research and development for cumulative research and development efforts associated with the development of solid oxide fuel cells (SOFC) stationary power generation. The Company completed its annual impairment analysis of goodwill and in-process research and development assets as of July 31, 2017. The Company performed a quantitative assessment in the prior year and determined that the estimated fair value of the reporting unit and in-process research and development intangible asset exceeded the respective carrying value and therefore no impairment was recognized as of July 31, 2016. The Company performed a qualitative assessment for the current year and determined that it was more likely than not that there was no impairment of goodwill or the indefinite lived intangible asset.

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.