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Secured Notes to Related Party - Additional Information (Details)				1 Months Ended			12 Months Ended
	Aug. 05, 2016 USD ($)	Aug. 02, 2016 USD ($) shares	Jul. 29, 2011 shares	Aug. 31, 2018 USD ($)	Aug. 31, 2016 USD ($)	Apr. 30, 2011 USD ($) Day shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Proceeds from convertible debt						$ 4,300,000
Amortization of debt discount							$ 1,429,000	$ 1,050,000	$ 890,000
Debt instrument, convertible, number shares of equity instruments \| shares							9,500,000
Convertible Notes
Debt Instrument [Line Items]
Convertible debt issuable in connection with private placement						$ 4,500,000
Debt instrument, interest rate						6.00%
Debt instrument, maturity date						May 02, 2021
Debt instrument conversion ratio multiple of principal						$ 1,000
Beneficial ownership after conversion						9.99%
Notice period associated with beneficial ownership percentage limitation convertible notes \| Day						61
Common shares registered for resale in connection with convertible notes \| shares			3,500,000
Debt instrument, term						10 years
Paid-in-kind interest							$ 400,000
Debt instrument, additional debt discount							400,000
Interest expense, debt, excluding amortization							400,000	400,000	400,000
Amortization of debt discount							1,400,000	$ 1,100,000	900,000
Carrying value of debt							7,100,000
Debt instrument, face amount							7,600,000
Debt instrument, unamortized discount, total							$ 500,000
Convertible Notes \| Common Stock
Debt Instrument [Line Items]
Debt instrument, number of shares issued for convertible notes \| shares						1,250
Term Loan \| Tang Capital
Debt Instrument [Line Items]
Debt instrument, interest rate					8.00%
Debt instrument, term					2 years
Carrying value of debt									0
Debt agreement, maximum borrowing capacity					$ 100,000,000.0
Proceeds from issuance of long-term debt, total	$ 50,000,000.0
Proceeds from issuance of long-term debt, subject to achievement of corporate milestone		$ 50,000,000.0
Debt instrument, fee amount		$ 0
Debt instrument, number of warrants \| shares		0
Debt instrument, convertible, beneficial conversion feature		$ 0
Interest expense									$ 1,200,000
Debt outstanding principal paid				$ 25,000,000.0
Debt accrued interest paid				$ 200,000