Name:	fcel_AggregateOfferingPrice
Namespace Prefix:	fcel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

It refers to average sale price per share of shares sold under Open Market Sale Agreement

No definition available.

Name:	fcel_AverageSaleOfStockPricePerShare
Namespace Prefix:	fcel_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

Class of warrant or right term of warrants or rights.

No definition available.

Name:	fcel_ClassOfWarrantOrRightTermOfWarrantsOrRights
Namespace Prefix:	fcel_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents remaining common stock available for issuance under the open market agreement.

No definition available.

Name:	fcel_CommonStockRemainingSharesAvailableForIssuance
Namespace Prefix:	fcel_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Its refers to gross proceeds from the Open Market Sale Agreement.

No definition available.

Name:	fcel_GrossProceedsFromIssuanceOfCommonStock
Namespace Prefix:	fcel_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Its refers to the percentage of commission paid to Agents on Aggregate gross proceeds from the sale of shares under the Open Market Sale Agreement.

No definition available.

Name:	fcel_PercentageOfSalesCommission
Namespace Prefix:	fcel_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Exercise price per share or per unit of warrants or rights outstanding.

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=123467817&loc=d3e21475-112644

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

The cash outflow for cost incurred directly with the issuance of an equity security.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

Name:	us-gaap_PaymentsOfStockIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The cash inflow from the additional capital contribution to the entity.

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 (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

Name:	us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of new stock issued during the period.

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(29))
-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 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

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(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	us-gaap_StockholdersEquityNoteAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_ClassOfWarrantOrRightAxis=fcel_SeriesCWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_SubsidiarySaleOfStockAxis=fcel_TwoZeroTwoTwoOpenMarketSaleAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=fcel_JefferiesLlcB.rileySecuritiesBarclaysCapitalIncBmocorpBofaSecuritiesCanacordGenuityLlcCitigroupGlobalMarketsIncJ.p.morganSecuritiesLlcAndLoopCapitalMarketsLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_SubsidiarySaleOfStockAxis=fcel_TwoZeroTwoOneOpenMarketSaleAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: