Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Net number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Per share amount of par value or stated value of stock classified as temporary equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable.

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Stock-Based Compensation - Additional Information (Details) - USD ($)				1 Months Ended				3 Months Ended		9 Months Ended
	Sep. 05, 2019	Sep. 07, 2017	May 15, 2015	Sep. 24, 2018	Aug. 25, 2016	Oct. 22, 2013	Mar. 20, 2007	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 17, 2020	Dec. 31, 2019	Nov. 02, 2010
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures								0	0	0	0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options								$ 406,000		$ 406,000
Temporary Equity, Par or Stated Value Per Share								$ 0.001		$ 0.001			$ 0.001
Employees \| General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense								$ 41,000	$ 59,000	$ 120,000	$ 165,000
Employees \| Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense								14,000	22,000	45,000	52,000
Consultants \| General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense								26,000	9,000	79,000	28,000
Consultants \| Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense								$ 1,000	$ 1,000	$ 7,000	$ 1,000
2007 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number							71,429	7,052		7,052
2007 Stock Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross							7,143
2010 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number								2,453,273		2,453,273				85,714
2010 Stock Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	4,000,000	500,000	228,572	1,000,000	400,000	171,429
2010 Stock Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	1,000,000	400,000	171,429	500,000	228,572	85,714
2020 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number								0		0		4,000,000