Redeemable Preferred Stock - Additional Information (Details) $ / shares in Units, $ in Millions					3 Months Ended				6 Months Ended				12 Months Ended
	Feb. 21, 2019 USD ($) TradingDay $ / shares	Dec. 01, 2018 USD ($) Installment	Aug. 29, 2018 USD ($) shares	Nov. 01, 2017 USD ($) Installment	Apr. 30, 2019 USD ($) $ / shares shares	Apr. 30, 2019 CAD ($) shares	Apr. 30, 2018 USD ($) $ / shares	Apr. 30, 2018 CAD ($)	Apr. 30, 2019 USD ($) TradingDay $ / shares shares	Apr. 30, 2019 CAD ($) TradingDay shares	Apr. 30, 2018 USD ($) $ / shares	Apr. 30, 2018 CAD ($)	Oct. 31, 2018 USD ($) $ / shares shares	Oct. 31, 2017 $ / shares shares	Jun. 13, 2019 shares	Apr. 30, 2019 CAD ($) shares	Jan. 31, 2019 USD ($)	Jan. 02, 2019 $ / shares	Dec. 17, 2018 $ / shares	Dec. 03, 2018 $ / shares	Oct. 31, 2018 CAD ($) shares	Aug. 27, 2018 $ / shares shares	Aug. 26, 2018 $ / shares
Class Of Stock [Line Items]
Preferred stock, shares authorized | shares					250,000				250,000							250,000
Preferred stock, par value | $ / shares					$ 0.01				$ 0.01
Convertible preferred stock, reduction in carrying amount					$ 10,400,000				$ 12,300,000
Waiver Agreement [Member]
Class Of Stock [Line Items]
Decrease in net loss attributable to common shareholders					$ 500,000
Installment Conversion of Series D Preferred Stock to Common Stock [Member]
Class Of Stock [Line Items]
Conversion of common stock, shares issued | shares					1,994,413	1,994,413			2,926,557	2,926,557
Convertible preferred stock, reduction in carrying amount					$ 6,300,000				$ 10,600,000
Series B Cumulative Convertible Perpetual Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares authorized | shares					105,875				105,875				105,875			105,875					105,875
Preferred stock, dividend rate, percentage									5.00%	5.00%	5.00%	5.00%
Preferred stock sale of shares | shares					64,020				64,020				64,020			64,020					64,020
Preferred stock shares outstanding | shares					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
Preferred stock redemption, stated value					$ 64,020,000				$ 64,020,000				$ 64,020,000
Preferred stock, liquidation preference per share | $ / shares					$ 1,000.00				$ 1,000.00				$ 1,000.00
Dividends, preferred stock, cash					$ 800,000		$ 800,000		$ 1,600,000		$ 1,600,000
Series D Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, dividend rate, percentage									15.00%	15.00%
Preferred stock sale of shares | shares			30,680		18,462				18,462				30,680		8,396	18,462					30,680
Conversion of stock conversion price | $ / shares					$ 16.56				$ 16.56
Proceeds from Issuance of preferred stock			$ 25,300,000
Preferred stock shares outstanding | shares					18,462				18,462				30,680		8,396	18,462					30,680
Temporary equity, carrying amount, attributable to parent					$ 20,546,000				$ 20,546,000				$ 27,392,000
Convertible preferred stock, converted into common stock | shares					6,964	6,964			12,218	12,218
Preferred stock deemed dividends					$ 1,000,000				$ 2,900,000
Preferred stock, redemption accretion value									$ 3,800,000
Percentage of lowest volume weighted average price of common stock considered as conversion price									85.00%	85.00%
Number of consecutive trading days | TradingDay									5	5
Conversion right description									The Series D Preferred Shares are convertible into shares of the Company’s common stock, subject to the beneficial ownership limitation provided in the Series D Certificate of Designation, at a conversion price equal to $16.56 per share of common stock, subject to adjustment as provided in the Series D Certificate of Designation, including adjustments if the Company sells shares of common stock or equity securities convertible into or exercisable for shares of common stock, at prices below $16.56 per share, in certain types of transactions.	The Series D Preferred Shares are convertible into shares of the Company’s common stock, subject to the beneficial ownership limitation provided in the Series D Certificate of Designation, at a conversion price equal to $16.56 per share of common stock, subject to adjustment as provided in the Series D Certificate of Designation, including adjustments if the Company sells shares of common stock or equity securities convertible into or exercisable for shares of common stock, at prices below $16.56 per share, in certain types of transactions.
Threshold percentage of reserved for issuance of common stock issuable upon conversion									150.00%	150.00%
Threshold amount to declare default amounts due on agreement					750,000				$ 750,000
Preferred stock redemption maturity date		Mar. 01, 2020
Number of preferred stock redemption equal installments | Installment		31
Preferred stock redemption, stated value		$ 30,680,000,000			$ 18,462,000				$ 18,462,000				30,680,000
Redemption of preferred shares in installments, each installment amount		$ 989,677
Reserving percentage of common stock to conversion of preferred shares		150.00%
Premium percentage of preferred stock installment amount		8.00%
Repayment percentage of installment amount									108.00%	108.00%
Preferred shares, triggering event redemption terms									Redemption Upon a Triggering Event. In the event of a triggering event (as defined in the Series D Certificate of Designation and summarized above), the holders of Series D Preferred Shares may require the Company to redeem such Series D Preferred Shares in cash at a price equal to the greater of (a) 125% of the stated value of the Series D Preferred Shares being redeemed plus accrued dividends, if any, and (b) the market value of the number of shares issuable on conversion of the Series D Preferred Shares, valued at the greatest closing sales price during the period from the date immediately before the triggering event through the date the Company makes the redemption payment.	Redemption Upon a Triggering Event. In the event of a triggering event (as defined in the Series D Certificate of Designation and summarized above), the holders of Series D Preferred Shares may require the Company to redeem such Series D Preferred Shares in cash at a price equal to the greater of (a) 125% of the stated value of the Series D Preferred Shares being redeemed plus accrued dividends, if any, and (b) the market value of the number of shares issuable on conversion of the Series D Preferred Shares, valued at the greatest closing sales price during the period from the date immediately before the triggering event through the date the Company makes the redemption payment.
Redemption pice percentage									125.00%	125.00%
Preferred shares, change of control, redemption terms									Redemption Upon a Change of Control. In the event of a change of control, as defined in the Series D Certificate of Designation, the holders of Series D Preferred Shares can force redemption at a price equal to the greater of (a) the conversion amount to be redeemed multiplied by 125%, (b) the product of (i) the conversion amount being redeemed multiplied by (ii) the quotient determined by dividing (A) the greatest closing sale price of the common stock on any Trading Day during the period commencing immediately preceding the earlier to occur of (1) the consummation of the applicable change of control and (2) the public announcement of such change of control and ending on the date such holder delivers the change of control redemption notice, by (B) the conversion price then in effect and (c) the product of (i) the conversion amount being redeemed multiplied by (ii) the quotient determined by dividing (A) the aggregate value of the cash and non-cash consideration per share of common stock being paid to holders of common stock in the change of control transaction by (B) the conversion price then in effect. Redemptions of the Series D Preferred Shares required under the Series D Certificate of Designation in connection with a change of control will have priority over payments to all other stockholders of the Company in connection with such change of control.	Redemption Upon a Change of Control. In the event of a change of control, as defined in the Series D Certificate of Designation, the holders of Series D Preferred Shares can force redemption at a price equal to the greater of (a) the conversion amount to be redeemed multiplied by 125%, (b) the product of (i) the conversion amount being redeemed multiplied by (ii) the quotient determined by dividing (A) the greatest closing sale price of the common stock on any Trading Day during the period commencing immediately preceding the earlier to occur of (1) the consummation of the applicable change of control and (2) the public announcement of such change of control and ending on the date such holder delivers the change of control redemption notice, by (B) the conversion price then in effect and (c) the product of (i) the conversion amount being redeemed multiplied by (ii) the quotient determined by dividing (A) the aggregate value of the cash and non-cash consideration per share of common stock being paid to holders of common stock in the change of control transaction by (B) the conversion price then in effect. Redemptions of the Series D Preferred Shares required under the Series D Certificate of Designation in connection with a change of control will have priority over payments to all other stockholders of the Company in connection with such change of control.
Preferred stock, participation rights									Limited Voting Rights. The holders of Series D Preferred Shares have no voting rights, except as required by law; provided, however, that any amendment to the Company’s certificate of incorporation or bylaws or the Series D Certificate of Designation that adversely affects the powers, preferences and rights of the Series D Preferred Stock requires the approval of the holders of a majority of the Series D Preferred Shares then outstanding. Participation Rights. Until August 29, 2019, the holders of the Series D Preferred Shares have the right to receive notice of and to participate in any offering, issuance or sale of equity or equity-equivalent securities by the Company or its subsidiaries, other than issuances under certain employee benefit plans, upon the conversion of certain options or other convertible securities, or pursuant to certain acquisitions or strategic transactions. Pursuant to such participation rights, the Company must offer to issue and sell to such holders at least 35% of the offered securities.	Limited Voting Rights. The holders of Series D Preferred Shares have no voting rights, except as required by law; provided, however, that any amendment to the Company’s certificate of incorporation or bylaws or the Series D Certificate of Designation that adversely affects the powers, preferences and rights of the Series D Preferred Stock requires the approval of the holders of a majority of the Series D Preferred Shares then outstanding. Participation Rights. Until August 29, 2019, the holders of the Series D Preferred Shares have the right to receive notice of and to participate in any offering, issuance or sale of equity or equity-equivalent securities by the Company or its subsidiaries, other than issuances under certain employee benefit plans, upon the conversion of certain options or other convertible securities, or pursuant to certain acquisitions or strategic transactions. Pursuant to such participation rights, the Company must offer to issue and sell to such holders at least 35% of the offered securities.
Series D Preferred Stock [Member] | Volume Weighted Average Price [Member]
Class Of Stock [Line Items]
Percentage of common stock on trading day immediately prior to applicable installment date									87.50%	87.50%
Series D Preferred Stock [Member] | Arithmetic Average Of Two Lowest Volume Weighted Average Price [Member]
Class Of Stock [Line Items]
Percentage of common stock on trading day immediately prior to applicable installment date									87.50%	87.50%
Common stock consecutive trading day | TradingDay									10	10
Series D Preferred Stock [Member] | Maximum [Member]
Class Of Stock [Line Items]
Conversion of stock conversion price | $ / shares					$ 16.56				$ 16.56
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%
Preferred stock, percentage of offered securities									35.00%	35.00%
Series D Preferred Stock [Member] | Convertible Preferred Offering [Member]
Class Of Stock [Line Items]
Percentage of lowest volume weighted average price of common stock considered as conversion price									85.00%	85.00%
Conversion terms, increase beneficial ownership limitation percentage upon notice periods									60 days	60 days
Series D Preferred Stock [Member] | Convertible Preferred Offering [Member] | Maximum [Member]
Class Of Stock [Line Items]
Conversion terms, beneficial ownership increase, percentage									9.99%	9.99%
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%
Conversion terms, beneficial ownership limitation, percentage									4.99%	4.99%
Series D Preferred Stock [Member] | Convertible Preferred Offering [Member] | Oppenheimer & Co [Member]
Class Of Stock [Line Items]
Preferred stock, par value | $ / shares																						$ 0.01
Preferred stock sale of shares | shares																						30,680
Preferred stock, initial convertibel shares | shares																						1,852,657
Conversion of stock conversion price | $ / shares																						$ 16.56
Series C Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, dividend rate, percentage									15.00%	15.00%
Conversion of stock conversion price | $ / shares					$ 5.16		$ 22.08		$ 5.16		$ 22.08											$ 18.00	$ 22.08
Temporary equity, carrying amount, attributable to parent					$ 3,162,000				$ 3,162,000				7,480,000
Convertible preferred stock, converted into common stock | shares					5,852	5,852			7,374	7,374
Preferred stock deemed dividends					$ 1,100,000				$ 600,000
Preferred stock redemption maturity date									Mar. 01, 2019	Mar. 01, 2019
Number of preferred stock redemption equal installments | Installment				33
Preferred stock redemption, stated value					1,618,000				$ 1,618,000				$ 8,992,000
Redemption of preferred shares in installments, each installment amount				$ 1,000,000
Common stock consecutive trading day | TradingDay									10	10
Repayment percentage of installment amount									108.00%	108.00%
Preferred shares, triggering event redemption terms									Redemption. In the event of a triggering event, as defined in the Series C Certificate of Designations, the holders of the Series C Preferred Shares could force redemption at a price equal to the greater of (a) the conversion amount to be redeemed multiplied by 125% and (b) the product of (i) the conversion rate with respect to the conversion amount in effect at such time as such holder delivers a triggering event redemption notice multiplied by (ii) the greatest closing sale price of the common stock on any trading day during the period commencing on the date immediately preceding such triggering event and ending on the date the Company makes the entire payment required.	Redemption. In the event of a triggering event, as defined in the Series C Certificate of Designations, the holders of the Series C Preferred Shares could force redemption at a price equal to the greater of (a) the conversion amount to be redeemed multiplied by 125% and (b) the product of (i) the conversion rate with respect to the conversion amount in effect at such time as such holder delivers a triggering event redemption notice multiplied by (ii) the greatest closing sale price of the common stock on any trading day during the period commencing on the date immediately preceding such triggering event and ending on the date the Company makes the entire payment required.
Redemption pice percentage									125.00%	125.00%
Adjusted conversion price | $ / shares																		$ 5.16	$ 6.00	$ 6.96
Preferred stock redemption terms									Installment Payments Prior to Execution of Waiver Agreement. On November 1, 2017 and on the sixteenth day and first day of each calendar month thereafter until March 1, 2019, subject to extension in certain circumstances (the “Series C Maturity Date”), inclusive, the Company was required to redeem the stated value of Series C Preferred Shares in thirty-three equal installments of approximately $1.0 million (each bimonthly amount, a “Series C Installment Amount” and the date of each such payment, a “Series C Installment Date”). The holders had the ability to defer installment payments, but not beyond the Series C Maturity Date. In addition, during each period commencing on the 11th trading day prior to a Series C Installment Date and prior to the immediately subsequent Series C Installment Date, the holders could elect to accelerate the conversion of Series C Preferred Shares at the then applicable installment conversion price, provided that the holders could not elect to effect any such acceleration during such installment period if either (a) in the aggregate, all the accelerations in such installment period would exceed the sum of three other Series C Installment Amounts, or (b) the number of Series C Preferred Shares subject to prior accelerations would exceed in the aggregate twelve Series C Installment Amounts.	Installment Payments Prior to Execution of Waiver Agreement. On November 1, 2017 and on the sixteenth day and first day of each calendar month thereafter until March 1, 2019, subject to extension in certain circumstances (the “Series C Maturity Date”), inclusive, the Company was required to redeem the stated value of Series C Preferred Shares in thirty-three equal installments of approximately $1.0 million (each bimonthly amount, a “Series C Installment Amount” and the date of each such payment, a “Series C Installment Date”). The holders had the ability to defer installment payments, but not beyond the Series C Maturity Date. In addition, during each period commencing on the 11th trading day prior to a Series C Installment Date and prior to the immediately subsequent Series C Installment Date, the holders could elect to accelerate the conversion of Series C Preferred Shares at the then applicable installment conversion price, provided that the holders could not elect to effect any such acceleration during such installment period if either (a) in the aggregate, all the accelerations in such installment period would exceed the sum of three other Series C Installment Amounts, or (b) the number of Series C Preferred Shares subject to prior accelerations would exceed in the aggregate twelve Series C Installment Amounts.
Preferred shares, dividends declared | $ / shares									$ 0				$ 0	$ 0
Preferred shares voting rights									no voting rights	no voting rights
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 lowest volume weighted average price of common stock considered as conversion price	85.00%
Number of consecutive trading days | TradingDay	20
Conversion right description									Under the Waiver Agreement, the conversion price of the Series C Preferred Stock is 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 is delivered to the Company and ending on and including the date on which the applicable conversion notice is delivered to the Company, and (iii) 85% of the quotient of (A) the sum of the five lowest VWAPs of the Company’s common stock during the twenty consecutive trading day period ending and including the trading day immediately preceding the applicable conversion date divided by (B) five (5).	Under the Waiver Agreement, the conversion price of the Series C Preferred Stock is 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 is delivered to the Company and ending on and including the date on which the applicable conversion notice is delivered to the Company, and (iii) 85% of the quotient of (A) the sum of the five lowest VWAPs of the Company’s common stock during the twenty consecutive trading day period ending and including the trading day immediately preceding the applicable conversion date divided by (B) five (5).
Percentage of shares will receive upon conversion prior to execution of waiver agreement	25.00%
Conversion price of preferred stock | $ / shares	$ 4.45
Percentage of conversion price of common stock	125.00%
Percentage of stated redemption value adjustment									108.00%	108.00%
Stated redemption value corresponding charge to common shareholders																	$ 8,600,000
Convertible preferred stock embedded conversion amount					$ 6,600,000
Change in fair value of convertible preferred stock	$ (500,000)
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] | Volume Weighted Average Price [Member]
Class Of Stock [Line Items]
Percentage of common stock on trading day immediately prior to applicable installment date									87.50%	87.50%
Series C Preferred Stock [Member] | Arithmetic Average Of Two Lowest Volume Weighted Average Price [Member]
Class Of Stock [Line Items]
Percentage of common stock on trading day immediately prior to applicable installment date									87.50%	87.50%
Series C Preferred Stock [Member] | Maximum [Member]
Class Of Stock [Line Items]
Adjusted conversion price | $ / shares					$ 4.45				$ 4.45
Series C Preferred Stock [Member] | Minimum [Member]
Class Of Stock [Line Items]
Adjusted conversion price | $ / shares					$ 2.51				$ 2.51
Series C Preferred Stock [Member] | Convertible Preferred Offering [Member]
Class Of Stock [Line Items]
Preferred stock sale of shares | shares					1,618				1,618				8,992			1,618					8,992
Conversion of stock conversion price | $ / shares					$ 2.51				$ 2.51
Preferred stock shares outstanding | shares					1,618				1,618				8,992			1,618					8,992
Temporary equity, carrying amount, attributable to parent					$ 3,200,000				$ 3,200,000				$ 7,500,000
Percentage of lowest volume weighted average price of common stock considered as conversion price									85.00%	85.00%
Conversion right description									Conversion Rights. As of April 30, 2019, the Series C Preferred Shares were convertible into shares of common stock, subject to the beneficial ownership limitations provided in the Series C Certificate of Designations, at a conversion price equal to $2.51 per share. The conversion price was subject to adjustment as provided in the Series C Certificate of Designations, including adjustments if the Company sold shares of common stock or equity securities convertible into or exercisable for shares of common stock, at variable prices below the conversion price then in effect. Under the Series C Certificate of Designations, in the event of a triggering event, as defined in the Series C Certificate of Designations, the Series C Preferred Shares would have been convertible into shares of common stock at a conversion price equal to the lower of the conversion price then in effect and 85% of the lowest VWAP of the common stock of the five trading days immediately prior to delivery of the applicable conversion notice. The holders were prohibited from converting Series C Preferred Shares into shares of common stock if, as a result of such conversion, such holder, together with its affiliates, would own more than 8.99% of the total number of shares of common stock then issued and outstanding. Each holder had the right to increase its maximum percentage up to 9.99% upon 60 days’ notice to the Company.	Conversion Rights. As of April 30, 2019, the Series C Preferred Shares were convertible into shares of common stock, subject to the beneficial ownership limitations provided in the Series C Certificate of Designations, at a conversion price equal to $2.51 per share. The conversion price was subject to adjustment as provided in the Series C Certificate of Designations, including adjustments if the Company sold shares of common stock or equity securities convertible into or exercisable for shares of common stock, at variable prices below the conversion price then in effect. Under the Series C Certificate of Designations, in the event of a triggering event, as defined in the Series C Certificate of Designations, the Series C Preferred Shares would have been convertible into shares of common stock at a conversion price equal to the lower of the conversion price then in effect and 85% of the lowest VWAP of the common stock of the five trading days immediately prior to delivery of the applicable conversion notice. The holders were prohibited from converting Series C Preferred Shares into shares of common stock if, as a result of such conversion, such holder, together with its affiliates, would own more than 8.99% of the total number of shares of common stock then issued and outstanding. Each holder had the right to increase its maximum percentage up to 9.99% upon 60 days’ notice to the Company.
Conversion terms, increase beneficial ownership limitation percentage upon notice periods									60 days	60 days
Aggregate number of shares issued | shares														33,500
Sale of stock price per share | $ / shares														$ 0.01
Preferred stock, stated value per share | $ / shares														$ 1,000
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 C Preferred Stock [Member] | Convertible Preferred Offering [Member] | Maximum [Member]
Class Of Stock [Line Items]
Conversion terms, beneficial ownership increase, percentage									9.99%	9.99%
Series C Preferred Stock [Member] | Convertible Preferred Offering [Member] | Minimum [Member]
Class Of Stock [Line Items]
Conversion terms, beneficial ownership limitation, percentage									8.99%	8.99%
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
Return of capital and dividend payments										$ 0.3		$ 0.6
Interest expense, other						$ 0.0		$ 0.7		$ 0.7		$ 1.4
Carrying value of preferred shares, total					$ 15,900,000				$ 15,900,000				$ 15,900,000			$ 21.3					$ 20.9