XML 104 R81.htm IDEA: XBRL DOCUMENT
v3.20.4

Debt - Additional Information (Details) |  |  |  |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Apr. 24, 2020 USD ($) | Nov. 22, 2019 USD ($) $ / shares MW shares | May 09, 2019 USD ($) MW | Feb. 28, 2019 USD ($) MW | Jan. 09, 2019 USD ($) | Jun. 08, 2020 USD ($) | Apr. 30, 2019 USD ($) | Jan. 31, 2019 USD ($) Position | Oct. 31, 2015 USD ($) Position | Oct. 31, 2020 USD ($) $ / shares | Oct. 31, 2020 USD ($) $ / shares | Oct. 31, 2019 USD ($) $ / shares shares | Oct. 31, 2018 USD ($) | Oct. 06, 2020 $ / shares | Apr. 30, 2020 USD ($) | Dec. 31, 2019 USD ($) | May 16, 2019 | Feb. 06, 2019 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit, discount |  |  |  |  |  |  |  |  |  | $ 5,152,000 | $ 5,152,000 | $ 4,251,000 |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares |  |  |  |  |  |  |  |  |  | $ 0.242 | $ 0.242 |  |  | $ 0.242 |  |  |  |
Class of warrants or rights issued value |  |  |  |  |  |  |  |  |  |  |  | 3,900,000 |  |  |  |  |  |
Interest expense |  |  |  |  |  |  |  |  |  |  | $ 15,294,000 | $ 10,623,000 | $ 9,055,000 |  |  |  |  |
Sale-leaseback Arrangements with PNC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase right percentage of projected assets at fair market value |  |  |  |  |  |  |  |  |  |  | 31.00% |  |  |  |  |  |  |
Liberty Bank [Member] | CARES Act [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from PPP Note |  |  |  |  |  |  |  |  |  |  | $ 2,000,000.0 |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of aggregate principal amount on discount |  |  |  |  |  |  |  |  |  |  |  | 2.50% |  |  |  |  |  |
Percentage of cash interest paid |  |  |  |  |  |  |  |  |  |  | 9.90% |  |  |  |  |  |  |
Percentage of payment-in-kind interest |  |  |  |  |  |  |  |  |  |  | 2.05% |  |  |  |  |  |  |
Class of warrants or rights issued value |  |  |  |  |  |  |  |  |  |  |  | $ 3,900,000 |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Senior Secured Credit Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit |  |  |  |  |  |  |  |  |  |  |  | 200,000,000.0 |  |  |  |  |  |
Long-term Line of Credit |  |  |  |  |  |  |  |  |  |  |  | 200,000,000.0 |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Initial Funding [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Drew down to fully repay debt outstanding |  |  |  |  |  |  |  |  |  |  |  | 14,500,000 |  |  |  |  |  |
Long-term line of credit after discount |  |  |  |  |  |  |  |  |  |  |  | 14,100,000 |  |  |  |  |  |
Long-term line of credit, discount |  |  |  |  |  |  |  |  |  |  |  | $ 400,000 |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares |  |  |  |  |  |  |  |  |  |  |  | $ 0.310 |  |  |  |  |  |
Debt instrument term |  |  |  |  |  |  |  |  |  |  | 7 years |  |  |  |  |  |  |
Quarterly payment payable date |  |  |  |  |  |  |  |  |  |  | Oct. 31, 2027 |  |  |  |  |  |  |
Administrative fee |  |  |  |  |  |  |  |  |  |  | $ 100,000 |  |  |  |  |  |  |
Debt instrument, description |  |  |  |  |  |  |  |  |  |  | Outstanding principal under the Orion Facility was to be amortized on a straight-line basis over a seven-year term with the initial payment due 21 business days after the end of the first quarter of fiscal year 2021. The maturity date of the Orion Facility was October 31, 2027. The Orion Facility contained an administrative fee of $0.1 million per year paid on a quarterly basis and also included a prepayment premium of up to 35%. Such prepayment fee was to be reduced over time based on the aggregate amount of principal and interest paid. |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Initial Funding [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number Of Securities Called By Warrants | shares |  |  |  |  |  |  |  |  |  |  |  | 6,000,000 |  |  |  |  |  |
Percentage of premium prepaid amount |  |  |  |  |  |  |  |  |  |  | 35.00% |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Drew down to fully repay debt outstanding |  | $ 65,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit after discount |  | 63,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit, discount |  | $ 1,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] | Exercise Price 0.242 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares |  | $ 0.242 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of warrants or rights exercised | shares |  | 8,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] | Exercise Price 0.620 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares |  | $ 0.620 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of warrants or rights exercised | shares |  | 6,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] | Groton Project [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capacity of plant | MW |  | 7.4 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] | LIPA Yaphank Solid Waste Management Project [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capacity of plant | MW |  | 7.4 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] | Tulare BioMAT [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capacity of plant | MW |  | 2.8 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of warrants or rights issued | shares |  | 14,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Second Funding [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit agreement requires to establish debt reserve |  |  |  |  |  |  |  |  |  | $ 5,000,000.0 | $ 5,000,000.0 |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Secondary Facility Loans[Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit agreement to establish additional covenants expired unused |  |  |  |  |  |  |  |  |  | 35,000,000 | 35,000,000 |  |  |  |  |  |  |
Orion Energy Partners Investment Agent, LLC Credit Facility [Member] | Fifth Orion Amendment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Agreed to pay option premium in exchange for loan commitment |  |  |  |  |  | $ 1,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |
Interest expense |  |  |  |  |  |  |  |  |  | 1,000,000.0 |  |  |  |  |  |  |  |
Connecticut Green Bank Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit |  |  |  |  |  |  |  |  |  | $ 4,800,000 | $ 4,800,000 |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  |  |  | $ 1,800,000 |  |  |  | $ 3,000,000.0 |  |
Debt instrument, interest rate, stated percentage rate |  |  |  |  |  |  |  |  |  | 8.00% | 8.00% |  |  |  |  |  |  |
Long-term Line of Credit |  |  |  |  |  |  |  |  |  | $ 4,800,000 | $ 4,800,000 |  |  |  |  |  |  |
Connecticut Green Bank Loan [Member] | Groton Commitment Letter [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subordinated project term loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,000,000.0
Subordinated Credit Agreement [Member] | Bridgeport Fuel Cell, LLC [Member] | Connecticut Green Bank Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit |  |  |  |  |  |  |  |  |  | 5,100,000 | 5,100,000 |  |  |  |  |  |  |
Capacity of plant | MW |  |  | 14.9 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, interest rate, stated percentage rate |  |  | 8.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Line of Credit |  |  |  |  |  |  |  |  |  | 5,100,000 | $ 5,100,000 |  |  |  |  |  |  |
Proceeds from long-term lines of credit |  |  | $ 6,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, covenant terms |  |  |  |  |  |  |  |  |  |  | On May 9, 2019, in connection with the closing of the purchase of the membership interests of Bridgeport Fuel Cell, LLC (“BFC”) (and the 14.9 MW Bridgeport Fuel Cell Project), BFC entered into a subordinated credit agreement with the Connecticut Green Bank whereby Connecticut Green Bank provided financing in the amount of $6.0 million (the “Subordinated Credit Agreement”). This $6.0 million consisted of $1.8 million in incremental funding that was received by BFC and $4.2 million of funding previously received by FuelCell Energy, Inc. with respect to which BFC became the primary obligor. As security for the Subordinated Credit Agreement, Connecticut Green Bank received a perfected lien, subordinated and second in priority to the liens securing the $25.0 million loaned under the BFC Credit Agreement (as defined below), in all of the same collateral securing the BFC Credit Agreement. The interest rate under the Subordinated Credit Agreement is 8% per annum. Principal and interest are due monthly in amounts sufficient to fully amortize the loan over an 84-month period ending in May 2026. The Subordinated Credit Agreement contains a debt coverage ratio which is required to be maintained and may not be less than 1.10 as of the end of each fiscal quarter, beginning with the quarter ended July 31, 2020. The balance under the Subordinated Credit Agreement as of October 31, 2020 was $5.1 million |  |  |  |  |  |  |
Subordinated Credit Agreement [Member] | Minimum [Member] | Bridgeport Fuel Cell, LLC [Member] | Connecticut Green Bank Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt service coverage ratio |  |  | 110.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subordinated Credit Agreement [Member] | Incremental Funding | Bridgeport Fuel Cell, LLC [Member] | Connecticut Green Bank Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from long-term lines of credit |  |  | $ 1,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subordinated Credit Agreement [Member] | Incremental Funding [Member] | Bridgeport Fuel Cell, LLC [Member] | Connecticut Green Bank Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from long-term lines of credit |  |  | 4,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subordinated Credit Agreement [Member] | Senior Term Loan [Member] | Bridgeport Fuel Cell, LLC [Member] | Connecticut Green Bank Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Liens securing senior term loan amount |  |  | $ 25,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit Agreement | Bridgeport Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, covenant terms |  |  |  |  |  |  |  |  |  |  | The BFC Credit Agreement requires BFC to maintain a debt service reserve. Each of Liberty Bank and Fifth Third Bank also has an operation and module replacement reserve (“O&M Reserve”) under the BFC Credit Agreement. BFC is required to deposit $100,000 per month into each O&M Reserve for the first five years of the BFC Credit Agreement, with such funds to be released at the sole discretion of Liberty Bank and Fifth Third Bank, as applicable. BFC is also required to maintain excess cash flow reserve accounts at each of Liberty Bank and Fifth Third Bank. Excess cash flow consists of cash generated by BFC from the Bridgeport Fuel Cell Project after payment of all expenses (including after payment of intercompany service fees to the Company), debt service to Liberty Bank and Fifth Third Bank, the funding of all required reserves, and payments to Connecticut Green Bank for the subordinated facility. BFC is also required to maintain a debt service coverage ratio of not less than 1.20, measured for the trailing year based on fiscal quarters beginning with the quarter ended July 31, 2020. The Company has certain quarterly and annual financial reporting requirements under the BFC Credit Agreement. The annual financial statements to be provided pursuant to such requirements are to be audited and accompanied by a report of an independent certified public accountant, which report shall not include a “going concern” matter of emphasis or any qualification as to the scope of such audit. |  |  |  |  |  |  |
Maturity date |  |  | May 09, 2025 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate description |  |  |  |  |  |  |  |  |  |  | The interest rate under the BFC Credit Agreement fluctuates monthly at the 30-day LIBOR rate plus 275 basis points |  |  |  |  |  |  |
Debt instrument, interest rate basis term |  |  | 30 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit Agreement | Bridgeport Loans [Member] | Interest Rate Swap |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.09% |
Credit Agreement | Bridgeport Loans [Member] | Fair Value, Inputs, Level 2 | Interest Rate Swap |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair value adjustments, charge |  |  |  |  |  |  |  |  |  |  | $ 300,000 | 600,000 |  |  |  |  |  |
Fair value interest rate |  |  |  |  |  |  |  |  |  | 900,000 | 900,000 | 600,000 |  |  |  |  |  |
Credit Agreement | Bridgeport Loans [Member] | Fifth Third Bank [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operation and module replacement reserve to be deposited per month |  |  |  |  |  |  |  |  |  | 100,000 | 100,000 |  |  |  |  |  |  |
Credit Agreement | Bridgeport Loans [Member] | Liberty Bank [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operation and module replacement reserve to be deposited per month |  |  |  |  |  |  |  |  |  | 100,000 | $ 100,000 |  |  |  |  |  |  |
Credit Agreement | Bridgeport Fuel Cell, LLC [Member] | Bridgeport Loans [Member] | Fifth Third Bank [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from long-term lines of credit |  |  | $ 12,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit Agreement | Bridgeport Fuel Cell, LLC [Member] | Bridgeport Loans [Member] | Liberty Bank [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from long-term lines of credit |  |  | $ 12,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit Agreement | Minimum [Member] | Bridgeport Loans [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt service coverage ratio |  |  |  |  |  |  |  |  |  |  | 120.00% |  |  |  |  |  |  |
Finance Obligations for Sale Leaseback Agreements [Member] | PNC Energy Capital, LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit |  |  |  |  |  |  |  |  |  | 49,300,000 | $ 49,300,000 | 45,200,000 |  |  |  |  |  |
Long-term Line of Credit |  |  |  |  |  |  |  |  |  | 49,300,000 | 49,300,000 | 45,200,000 |  |  |  |  |  |
Embedded gain on termination of lease |  |  |  |  |  |  |  |  |  |  | 29,000,000.0 |  |  |  |  |  |  |
State of Connecticut [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument term |  |  |  |  |  |  |  |  | 15 years |  |  |  |  |  |  |  |  |
Debt instrument, interest rate, stated percentage rate |  |  |  |  |  |  |  |  | 2.00% |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  | $ 10,000,000.0 | 9,454,000 | $ 9,454,000 | 10,000,000 |  |  | $ 10,000,000.0 |  |  |
Debt instrument, payment terms, period principal payments are deferred |  |  |  |  |  |  |  |  | 4 years |  |  |  |  |  |  |  |  |
Debt instrument, date of first required payment |  |  |  |  |  |  |  |  | Dec. 01, 2019 |  |  |  |  |  |  |  |  |
Loan forgiveness terms |  |  |  |  |  |  |  |  |  |  | if the Company created 165 full-time positions and retained 538 full-time positions for two consecutive years (the “Employment Obligation”) as measured on October 28, 2017 (the “Target Date”). The Assistance Agreement was subsequently amended in April 2017 to extend the Target Date by two years to October 28, 2019. |  |  |  |  |  |  |
Debt instrument period for deferment of principal and interest payments |  |  |  |  |  |  |  |  |  |  | 3 months |  |  |  |  |  |  |
Debt instrument, payment terms |  |  |  |  |  |  |  |  |  |  | In April of 2020, as a result of the COVID-19 pandemic, the State of Connecticut agreed to defer three months of principal and interest payments under the Assistance Agreement, beginning with the May 2020 payment. These deferred payments will be added at the end of the loan, thus extending out the maturity date by three months. |  |  |  |  |  |  |
State of Connecticut [Member] | Employment Obligation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of full time positions required to be created | Position |  |  |  |  |  |  |  |  | 165 |  |  |  |  |  |  |  |  |
Number of full time positions required to be retained | Position |  |  |  |  |  |  |  |  | 538 |  |  |  |  |  |  |  |  |
State of Connecticut [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of loan forgiveness |  |  |  |  |  |  |  |  |  |  | 5.00% |  |  |  |  |  |  |
State of Connecticut [Member] | Second Amendment [Member] | Employment Obligation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of minimum full time positions required to be maintained | Position |  |  |  |  |  |  |  | 538 |  |  |  |  |  |  |  |  |  |
Number of consecutive months maintain full time positions |  |  |  |  |  |  |  | 24 months |  |  |  |  |  |  |  |  |  |
Additional number of full time positions required to be create | Position |  |  |  |  |  |  |  | 91 |  |  |  |  |  |  |  |  |  |
Additional credits to be earned |  |  |  |  |  |  |  | $ 2,000,000.0 |  |  |  |  |  |  |  |  |  |
Target date of job audit |  |  |  |  |  |  |  | 90 days |  |  |  |  |  |  |  |  |  |
Principal payable number of employee under employee obligation target |  |  |  |  |  |  |  | $ 18,587.36 |  |  |  |  |  |  |  |  |  |
Liberty Bank Promissory Note (PPP Note) [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit |  |  |  |  |  |  |  |  |  | 6,515,000 | $ 6,515,000 |  |  |  |  |  |  |
Long-term Line of Credit |  |  |  |  |  |  |  |  |  | $ 6,515,000 | $ 6,515,000 |  |  |  |  |  |  |
Proceeds from long-term lines of credit | $ 6,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Liberty Bank Promissory Note (PPP Note) [Member] | Liberty Bank [Member] | CARES Act [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity date |  |  |  |  |  |  |  |  |  |  | Apr. 16, 2022 |  |  |  |  |  |  |
Loan forgiveness terms |  |  |  |  |  |  |  |  |  |  | The loan may be fully forgiven if (i) proceeds are used to pay eligible payroll costs, rent, mortgage interest and utilities and (ii) full-time employee headcount and salaries are either maintained during the 24-week period following disbursement or restored by December 31, 2020. If not so maintained or restored, any forgiveness of the loan would be reduced in accordance with the regulations that were issued by the SBA. |  |  |  |  |  |  |
Debt instrument, interest rate, stated percentage rate range |  |  |  |  |  |  |  |  |  |  | 1.00% |  |  |  |  |  |  |
Debt instrument, collateral or guarantees |  |  |  |  |  |  |  |  |  |  | The Company did not provide any collateral or guarantees for the PPP Note, nor did the Company pay any facility charge to obtain the PPP Note. |  |  |  |  |  |  |
Prepayment penalties |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  |  |  |  |
Proceeds used for payroll costs on an annualized basis for each employee |  |  |  |  |  |  |  |  |  |  | $ 100,000 |  |  |  |  |  |  |
New Britain Renewable Energy Term Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, interest rate, stated percentage rate range |  |  |  |  |  |  |  |  |  |  | 5.00% |  |  |  |  |  |  |
Notes payable to bank, current |  |  |  |  |  |  |  |  |  |  |  | 500,000 |  |  |  |  |  |
Enhanced Capital Loan and Security Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term line of credit |  |  |  |  |  |  |  |  |  |  |  | 1,500,000 |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  | $ 1,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Line of Credit |  |  |  |  |  |  |  |  |  |  |  | 1,500,000 |  |  |  |  |  |
Interest rate, basis points |  |  |  |  | 6.00% |  |  |  |  |  |  |  |  |  |  |  |  |
New Construction Loan Facility [Member] | Fifth Third Bank Groton Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total outstanding balance |  |  |  | $ 11,100 |  |  |  |  |  |  |  |  |  |  |  |  |  |
New Construction Loan Facility [Member] | Fifth Third Bank Groton Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  | 23,000,000.0 |  |  |  |  |  |  |  | $ 18,000,000.0 |  |  |  |  |  |
Loan advance |  |  |  | $ 9,700,000 |  |  | $ 1,400,000 |  |  |  |  |  |  |  |  |  |  |
New Construction Loan Facility [Member] | Fifth Third Bank Groton Loan [Member] | Groton CT [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capacity of plant | MW |  |  |  | 7.4 |  |  |  |  |  |  |  |  |  |  |  |  |  |
PNC Energy Capital, LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument term |  |  |  |  |  |  |  |  |  |  | 10 years |  |  |  |  |  |  |
Bridgeport Fuel Cell, LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument term |  |  |  |  |  |  |  |  |  |  | 8 years |  |  |  |  |  |  |
Orion Credit Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument term |  |  |  |  |  |  |  |  |  |  | 8 years |  |  |  |  |  |  |

X
- Definition Additional credits to be earned under assistance agreement. + References No definition available. + Details
Name: | fcel_AdditionalCreditsToBeEarnedUnderAssistanceAgreement
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Additional number of full time positions required to be create. + References No definition available. + Details
Name: | fcel_AdditionalNumberOfFullTimePositionsRequiredToBeCreate
Namespace Prefix: | fcel_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Capacity of plant. + References No definition available. + Details
Name: | fcel_CapacityOfPlant
Namespace Prefix: | fcel_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of warrants or rights exercised. + References No definition available. + Details
Name: | fcel_ClassOfWarrantsOrRightsExercised
Namespace Prefix: | fcel_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Class of warrants or rights issued. + References No definition available. + Details
Name: | fcel_ClassOfWarrantsOrRightsIssued
Namespace Prefix: | fcel_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Class of warrants or rights issued value. + References No definition available. + Details
Name: | fcel_ClassOfWarrantsOrRightsIssuedValue
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Consecutive term for full time positions. + References No definition available. + Details
Name: | fcel_ConsecutiveTermForFullTimePositions
Namespace Prefix: | fcel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Credit agreement to establish additional covenants expired unused. + References No definition available. + Details
Name: | fcel_CreditAgreementToEstablishAdditionalCovenantsExpiredUnused
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Credit agreement to establish debt reserve. + References No definition available. + Details
Name: | fcel_CreditAgreementToEstablishDebtReserve
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt instrument decrease forgiveness percentage. + References No definition available. + Details
Name: | fcel_DebtInstrumentDecreaseForgivenessPercentage
Namespace Prefix: | fcel_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument, interest rate basis term. + References No definition available. + Details
Name: | fcel_DebtInstrumentInterestRateBasisTerm
Namespace Prefix: | fcel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument, payment terms, period principal payments are deferred. + References No definition available. + Details
Name: | fcel_DebtInstrumentPaymentTermsPeriodPrincipalPaymentsAreDeferred
Namespace Prefix: | fcel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument period for deferment of principal and interest payments. + References No definition available. + Details
Name: | fcel_DebtInstrumentPeriodForDefermentOfPrincipalAndInterestPayments
Namespace Prefix: | fcel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt service coverage ratio. + References No definition available. + Details
Name: | fcel_DebtServiceCoverageRatio
Namespace Prefix: | fcel_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line of credit facility agreed to pay option premium in exchange for agreement payable. + References No definition available. + Details
Name: | fcel_LineOfCreditFacilityAgreedToPayOptionPremiumInExchangeForAgreementPayable
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Loan Advance + References No definition available. + Details
Name: | fcel_LoanAdvance
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Loan forgiveness terms. + References No definition available. + Details
Name: | fcel_LoanForgivenessTerms
Namespace Prefix: | fcel_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net proceeds from PPP Note + References No definition available. + Details
Name: | fcel_NetProceedsFromPPPNote
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of full time positions required to be created. + References No definition available. + Details
Name: | fcel_NumberOfFullTimePositionsRequiredToBeCreated
Namespace Prefix: | fcel_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of full time positions required to be retained. + References No definition available. + Details
Name: | fcel_NumberOfFullTimePositionsRequiredToBeRetained
Namespace Prefix: | fcel_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of minimum full time positions required to be maintain. + References No definition available. + Details
Name: | fcel_NumberOfMinimumFullTimePositionsRequiredToBeMaintain
Namespace Prefix: | fcel_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operation and module replacement reserve to be deposited per month. + References No definition available. + Details
Name: | fcel_OperationAndModuleReplacementReserveToBeDepositedPerMonth
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage of cash interest paid. + References No definition available. + Details
Name: | fcel_PercentageOfCashInterestPaid
Namespace Prefix: | fcel_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of payment in kind interest. + References No definition available. + Details
Name: | fcel_PercentageOfPaymentInKindInterest
Namespace Prefix: | fcel_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of premium prepaid amount. + References No definition available. + Details
Name: | fcel_PercentageOfPremiumPrepaidAmount
Namespace Prefix: | fcel_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Principal payable number of employee under employee obligation target. + References No definition available. + Details
Name: | fcel_PrincipalPayableNumberOfEmployeeUnderEmployeeObligationTarget
Namespace Prefix: | fcel_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Purchase right percentage of projected assets at fair market value. + References No definition available. + Details
Name: | fcel_PurchaseRightPercentageOfProjectedAssetsAtFairMarketValue
Namespace Prefix: | fcel_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Target date of job audit. + References No definition available. + Details
Name: | fcel_TargetDateOfJobAudit
Namespace Prefix: | fcel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense for administrative services provided to the limited liability company (LLC) or limited partnership (LP) by the managing member or general partner, affiliate of managing member or general partner, or affiliate of LLC or LP, for example, but not limited to, salaries, rent, or overhead costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 + Details
Name: | us-gaap_AdministrativeFeesExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discussion of whether the debt instrument is secured or unsecured, and, if secured, a description of the collateral and guarantees required or provided. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentCollateral
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentCovenantDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentDateOfFirstRequiredPayment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Identification of the lender and information about a contractual promise to repay a short-term or long-term obligation, which includes borrowings under lines of credit, notes payable, commercial paper, bonds payable, debentures, and other contractual obligations for payment. This may include rationale for entering into the arrangement, significant terms of the arrangement, which may include amount, repayment terms, priority, collateral required, debt covenants, borrowing capacity, call features, participation rights, conversion provisions, sinking-fund requirements, voting rights, basis for conversion if convertible and remarketing provisions. The description may be provided for individual debt instruments, rational groupings of debt instruments, or by debt in total. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(13)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The average effective interest rate during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6036836-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateTerms
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(3)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentPaymentTerms
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of principal amount of debt redeemed. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after accumulated amortization, of debt discount. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of gain (loss) included in earnings for the period from the increase (decrease) in fair value of interest rate derivatives not designated as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959 + Details
Name: | us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of gain (loss) on termination of lease before expiration of lease term. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 40 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121604053&loc=SL77918607-209975 + Details
Name: | us-gaap_GainLossOnTerminationOfLease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of the cost of borrowed funds accounted for as interest expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (210.5-03(11)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.9) -URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities. + References No definition available. + Details
Name: | us-gaap_InterestRateDerivativeLiabilitiesAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
Name: | us-gaap_LineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Date the credit facility terminates, in CCYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Current portion of the total carrying amount as of the balance sheet date due within one year or the operating cycle, if longer, on all notes payable to banks paid on an installment with long term maturities. This can include the amount of any loans from the applicant firm. This does not, however, include any mortgage balances. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(a)(1),20) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_NotesPayableToBankCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsOfDebtExtinguishmentCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(f)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 + Details
Name: | us-gaap_ProceedsFromLinesOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromLongTermLinesOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_SecuredLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_SubordinatedDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_SaleLeasebackTransactionDescriptionAxis=fcel_SaleLeasebackArrangementsWithPNCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LineOfCreditFacilityAxis=fcel_LibertyBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis=fcel_CoronavirusAidReliefAndEconomicSecurityActMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_OrionEnergyPartnersInvestmentAgentLLCCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_SeniorSecuredCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_InitialFundingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_SecondFundingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=fcel_ExercisePriceZeroPointTwoFourTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=fcel_ExercisePriceZeroPointSixTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=fcel_GrotonProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=fcel_LIPAYaphankSolidWasteManagementProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=fcel_TulareBioMATMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_OrionCreditAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_SecondaryFacilityLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_FifthOrionAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_ConnecticutGreenBankNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_GrotonCommitmentLetterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_SubordinatedCreditAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=fcel_BridgeportFuelCellLimitedLiabilityCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=fcel_ConnecticutGreenBankLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_IncrementalFundingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_PreviouslyReceivedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_SeniorTermLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_CreditAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=fcel_BridgeportLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LineOfCreditFacilityAxis=fcel_FifthThirdBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_FinanceObligationsForSaleLeaseBackAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=fcel_PNCEnergyCapitalLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_StateOfConnecticutMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=fcel_EmploymentObligationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=fcel_SecondAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_LibertyBankPromissoryNoteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_NewBritainRenewableEnergyTermLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_EnhancedCapitalTermLoanAndSecurityAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_NewConstructionLoanFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=fcel_FifthThirdBankGrotonLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=fcel_FifthThirdBankGrotonLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=fcel_GrotonCTMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_PNCEnergyCapitalLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_BridgeportFuelCellLimitedLiabilityCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fcel_OrionCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |