FUELCELL ENERGY INC - 10-K filing on 2021-01-21

Redeemable Preferred Stock - Additional Information (Details)					1 Months Ended		3 Months Ended									12 Months Ended
	Aug. 15, 2019 USD ($)	May 15, 2019 USD ($)	Feb. 21, 2019 USD ($) TradingDay $ / shares	Mar. 31, 2005 shares	Jul. 03, 2019 $ / shares	Aug. 31, 2018 USD ($) $ / shares shares	Oct. 31, 2020 USD ($) $ / shares shares	Jul. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Jan. 31, 2020 USD ($)	Oct. 31, 2019 USD ($) $ / shares shares	Jul. 31, 2019 USD ($)	Apr. 30, 2019 USD ($)	Jan. 31, 2019 USD ($)	Apr. 30, 2018 USD ($)	Oct. 31, 2020 USD ($) TradingDay $ / shares shares	Oct. 31, 2020 CAD ($) TradingDay	Oct. 31, 2019 USD ($) $ / shares shares	Oct. 31, 2019 CAD ($) shares	Oct. 31, 2018 USD ($) $ / shares shares	Oct. 31, 2018 CAD ($) shares	Oct. 31, 2017 USD ($) shares	Oct. 31, 2020 CAD ($) shares	Oct. 31, 2019 CAD ($) shares	May 23, 2019 $ / shares shares	May 22, 2019 $ / shares	May 08, 2019 shares	Jan. 02, 2019 $ / shares	Dec. 17, 2018 $ / shares	Dec. 03, 2018 $ / shares	Aug. 27, 2018 $ / shares	Aug. 26, 2018 $ / shares
Class Of Stock [Line Items]
Preferred stock, shares authorized \| shares											250,000							250,000						250,000			250,000
Preferred stock, par value \| $ / shares											$ 0.01							$ 0.01
Redemption value adjustment of net loss attributable to common stockholders														$ 8,600,000
Dividends declared																				$ 3,200,000
Derivative liability, fair value, gross liability							$ 600,000				$ 600,000					$ 600,000		$ 600,000
Common Stock [Member]
Class Of Stock [Line Items]
Convertible preferred stock, converted into number of common stock shares \| shares																		3,914,218	3,914,218
Waiver Agreement [Member]
Class Of Stock [Line Items]
Decrease in net loss attributable to common shareholders															$ 500,000
Installment and Optional Conversions, Triggering Event Conversions of Series D Preferred Stock to Common Stock [Member]
Class Of Stock [Line Items]
Conversion of common stock, shares issued \| shares																		62,040,496	62,040,496
Convertible preferred stock, reduction in carrying amount																		$ 31,200,000
Installment Conversion of Series C Preferred Stock to Common Stock [Member]
Class Of Stock [Line Items]
Convertible preferred stock, reduction in carrying amount																				20,200,000
Series D Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock sale of shares \| shares						30,680
Preferred stock, initial convertible shares \| shares						1,852,657
Conversion of stock conversion price \| $ / shares						$ 16.56
Proceeds from Issuance of preferred stock						$ 25,300,000										$ 0		$ 0		$ 25,317,000
Convertible preferred stock, converted into common stock \| shares																		30,680	30,680
Preferred stock deemed dividends																		$ 6,000,000.0
Preferred stock, redemption accretion value																		$ 3,800,000
Series D Preferred Stock [Member] \| Minimum [Member]
Class Of Stock [Line Items]
Preferred stock, conversion basis, stock issuance, threshold percentage of outstanding voting stock																		20.00%	20.00%
Reduced conversion price \| $ / shares					$ 0.14
Series D Preferred Stock [Member] \| Maximum [Member]
Class Of Stock [Line Items]
Reduced conversion price \| $ / shares					$ 0.61
Series D Preferred Stock [Member] \| Convertible Preferred Offering [Member] \| Minimum [Member]
Class Of Stock [Line Items]
Conversion terms, prior receiving beneficial ownership, percentage																		20.00%	20.00%
Series C Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock sale of shares \| shares																				8,992
Conversion of stock conversion price \| $ / shares																															$ 18.00	$ 22.08
Convertible preferred stock, converted into common stock \| shares																		8,992	8,992	24,308	24,308
Convertible preferred stock, reduction in carrying amount																		$ 15,500,000
Preferred stock deemed dividends																		$ 1,500,000		$ 9,600,000
Preferred stock shares outstanding \| shares																				8,992					0
Temporary equity, carrying amount, attributable to parent																				$ 7,500,000
Adjusted conversion price \| $ / shares																				$ 18.00								$ 5.16	$ 6.00	$ 6.96
Convertible preferred stock, converted into number of common stock shares \| shares																		3,914,218	3,914,218
Series C Preferred Stock [Member] \| Common Stock [Member]
Class Of Stock [Line Items]
Convertible preferred stock, converted into number of common stock shares \| shares																				1,496,368	1,496,368
Series C Preferred Stock [Member] \| Waiver Agreement [Member]
Class Of Stock [Line Items]
Temporary equity, carrying amount, attributable to parent			$ 13,500,000
Percentage of shares will receive upon conversion prior to execution of waiver agreement			25.00%
Conversion right description																		Under the Waiver Agreement, the conversion price of the Series C Preferred Stock was stated to be the lowest of (i) $4.45, (ii) 85% of the lowest closing bid price of the Company’s common stock during the period beginning on and including the fifth trading day prior to the date on which the applicable conversion notice was delivered to the Company and ending on and including the date on which the applicable conversion notice was delivered to the Company, and (iii) 85% of the quotient of (A) the sum of the five lowest volume weighted average prices of the Company’s common stock during the 20 consecutive trading day period ending on and including the trading day immediately preceding the applicable conversion date divided by (B) five.	Under the Waiver Agreement, the conversion price of the Series C Preferred Stock was stated to be the lowest of (i) $4.45, (ii) 85% of the lowest closing bid price of the Company’s common stock during the period beginning on and including the fifth trading day prior to the date on which the applicable conversion notice was delivered to the Company and ending on and including the date on which the applicable conversion notice was delivered to the Company, and (iii) 85% of the quotient of (A) the sum of the five lowest volume weighted average prices of the Company’s common stock during the 20 consecutive trading day period ending on and including the trading day immediately preceding the applicable conversion date divided by (B) five.
Conversion price of preferred stock \| $ / shares			$ 4.45
Percentage of lowest volume weighted average price of common stock considered as conversion price			85.00%
Number of consecutive trading days \| TradingDay			20
Percentage of conversion price of common stock			125.00%
Convertible preferred stock embedded conversion amount													$ 6,600,000
Change in fair value of convertible preferred stock			$ (600,000)
Percentage of stated redemption value adjustment																		108.00%	108.00%
Stated redemption value corresponding charge to common shareholders											$ 8,600,000							$ 8,600,000
Series C Preferred Stock [Member] \| Waiver Agreement [Member] \| Volatility [Member]
Class Of Stock [Line Items]
Convertible preferred stock, measurement input			75.00%
Series C Preferred Stock [Member] \| Waiver Agreement [Member] \| Discount Rate [Member]
Class Of Stock [Line Items]
Convertible preferred stock, measurement input			20.00%
Series C Preferred Stock [Member] \| Minimum [Member]
Class Of Stock [Line Items]
Adjusted conversion price \| $ / shares																									$ 1.27
Series C Preferred Stock [Member] \| Maximum [Member]
Class Of Stock [Line Items]
Adjusted conversion price \| $ / shares																										$ 4.45
Series C Preferred Stock [Member] \| Convertible Preferred Offering [Member]
Class Of Stock [Line Items]
Proceeds from Issuance of preferred stock																						$ 27,900,000
Aggregate number of shares issued \| shares																						33,500
Series C Preferred Stock [Member] \| Convertible Preferred Offering [Member] \| Waiver Agreement [Member]
Class Of Stock [Line Items]
Convertible preferred stock, reduction in carrying amount																		$ 6,600,000
Series B Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares authorized \| shares							105,875				105,875					105,875		105,875					105,875	105,875
Preferred stock sale of shares \| shares				105,875			64,020				64,020					64,020		64,020					64,020	64,020
Redemption price percentage				5.00%
Preferred stock shares outstanding \| shares							64,020				64,020					64,020		64,020					64,020	64,020
Temporary equity, carrying amount, attributable to parent							$ 59,857,000				$ 59,857,000					$ 59,857,000		$ 59,857,000
Number of consecutive trading days \| TradingDay																30	30
Preferred stock, liquidation preference per share \| $ / shares							$ 1,000.00				$ 1,000.00					$ 1,000.00		$ 1,000.00
Preferred stock, dividends per share, declared \| $ / shares																$ 50.00
Dividends, preferred stock, cash		$ 2,400,000														$ 4,800,000		$ 1,600,000		$ 3,200,000
Cumulative unpaid dividends							$ 800,000				$ 2,400,000					800,000		2,400,000
Dividends declared	$ 0	$ 0					800,000	$ 800,000	$ 800,000	$ 931,000	821,000	$ 810,000	$ 800,000	$ 800,000		3,331,000		3,231,000		3,200,000
Dividends payment date	Aug. 15, 2019	May 15, 2019
Aggregate amount of dividend payment	$ 1,600,000	$ 1,600,000
Preferred stock, dividend rate, percentage	5.00%	5.00%
Preferred stock failed to pay dividend payments multiplier percentage	0.0625%	0.0625%
Payment on junior shares							0									0
Preferred Stock, Liquidation Preference, Value							$ 64,020,000				64,020,000					$ 64,020,000		64,020,000
Shares of common stock issued upon conversion \| shares							0.591									0.591							0.591
Stock conversion price \| $ / shares							$ 1,692.00									$ 1,692.00
Percent of conversion price to exceed to exercise conversion right							150.00%									150.00%							150.00%
Number of trading days \| TradingDay																20	20
Percentage of voting rights							50.00%									50.00%							50.00%
Consecutive number of years																2 years	2 years
Percentage of aggregate voting power																100.00%	100.00%
Percentage of conversion price																105.00%	105.00%
Discount on market price of shares of common stock							5.00%									5.00%							5.00%
Preferred stock, voting rights																no voting rights	no voting rights
Series B Preferred Stock [Member] \| Common Stock [Member]
Class Of Stock [Line Items]
Number of consecutive trading days \| TradingDay																10	10
Number of trading days \| TradingDay																5	5
Series B Preferred Stock [Member] \| Minimum [Member]
Class Of Stock [Line Items]
Percentage of consideration excluding cash payments for fractional shares																90.00%	90.00%
Class A Cumulative Redeemable Exchangeable Preferred Shares [Member]
Class Of Stock [Line Items]
Preferred stock shares outstanding \| shares							1,000,000									1,000,000							1,000,000
Cumulative unpaid dividends																							$ 12,500,000
Aggregate amount of dividend payment																	$ 500,000
Preferred stock, dividend rate, percentage																1.25%	1.25%
Return of capital payments																	$ 750,000
Return of capital and dividend payments																$ 1,600,000	1,900,000	200,000	$ 300,000	1,000,000.0	$ 1,300,000
Interest expense, other																2,900,000	4,000,000.0	2,300,000	$ 3,000,000.0	$ 2,200,000	$ 2,800,000
Carrying value of preferred shares, total							$ 19,200,000				$ 17,200,000					$ 19,200,000		$ 17,200,000					25,600,000	$ 22,700,000
Class A Preferred Shares [Member]
Class Of Stock [Line Items]
Aggregate amount of dividend payment																	$ 500,000
Increase in dividend rate annually																15.00%	15.00%
Return of capital payments																	$ 750,000
Dividend payment terms																annual	annual
Accrued and unpaid dividend obligation							17,700,000									$ 17,700,000							23,400,000
Loss resulted from revised fair value of preferred shares																200,000	$ 200,000
Dividends payable							17,400,000									17,400,000							23,200,000
Preferred stock, redemption amount							$ 3,200,000									$ 3,200,000							$ 4,300,000
Class A Preferred Shares [Member] \| Minimum [Member]
Class Of Stock [Line Items]
Preferred stock, redemption date																Dec. 31, 2020	Dec. 31, 2020
Class A Preferred Shares [Member] \| Maximum [Member]
Class Of Stock [Line Items]
Preferred stock, redemption date																Dec. 31, 2021	Dec. 31, 2021