Nature of Business, Basis of Presentation and Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Millions					12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 07, 2020 USD ($)	Jun. 14, 2019 USD ($)	May 08, 2019 shares	Oct. 31, 2020 USD ($) shares	Oct. 31, 2019 USD ($) shares	Oct. 31, 2018 USD ($) shares	Dec. 17, 2020 USD ($)	Dec. 17, 2020 CAD ($)	Dec. 04, 2020 shares	May 11, 2020 shares	Nov. 01, 2019 USD ($)	May 07, 2019 shares	Oct. 31, 2017 shares
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Reverse stock split				1-for-12 reverse stock split
Reverse stock split, conversion ratio				0.084
Common stock, shares outstanding | shares				15,284,269	294,706,758	193,608,684							183,411,230
Common stock, shares authorized | shares				225,000,000	337,500,000	225,000,000					112,500,000
Preferred stock, shares authorized | shares				250,000		250,000
Cash and cash equivalents, unrestricted					$ 149,867,000	$ 9,434,000
Unrestricted cash					47,500,000
Impairment charges					$ 0	0	$ 0
Milestone-based payments			$ 10,000,000.0
Project represented value of contract						10,000,000.0
Extended Product Warranty Description					We warranty our products for a specific period of time against manufacturing or performance defects. Our U.S. warranty is generally limited to a term of 15 months after shipment or 12 months after acceptance of our products.
Foreign Currency Transaction Gains (Losses), Net					$ 200,000	$ (100,000)	$ 300,000
Operating lease liability					10,756,000							$ 10,100,000
Operating lease right-of-use assets, net					10,098,000							$ 10,300,000
ASC 842 [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Operating lease liability					10,300,000
Operating lease right-of-use assets, net					$ 10,100,000
Sales Revenue Net [Member] | Customer Concentration Risk [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Significant customer revenue percentage					86.00%	81.00%	88.00%
Joint Development Agreement II [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Proceeds from license fees received					$ 4,000,000.0
Specific Upgrades [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Revenues					0	$ 0
Unspecific Upgrades [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Revenues					$ 800,000	$ 1,100,000
Common Stock [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Common stock, shares outstanding | shares					294,706,758	193,608,684	7,972,686							5,791,068
Subsequent Event [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Common stock, shares outstanding | shares										319,706,758
Underwritten Offering Shares | $ / shares	$ 25,000,000.0
Net proceeds from underwriting shares after deducting underwriting discounts and commissions	$ 156,300,000
Common stock, shares reserved for issuance | shares	5,185,674
Subsequent Event [Member] | Common Stock [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Common stock, shares available for issuance | shares	15,093,242
Subsequent Event [Member] | Enbridge Inc. [Member] | Series 1 Preferred Shares [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Related Party Transaction, Due from (to) Related Party								$ 21,500,000	$ 27.4
Subsequent Event [Member] | Sr. Secured Debt [Member]
Nature of Business, Basis of Presentation and Significant Accounting Policies [Line items]
Settlement of outstanding principal payment and interest		$ 87,300,000
Unrestricted cash		$ 11,200,000