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

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The highest quantity of shares an employee can purchase under the plan per period.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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Number of additional shares authorized for issuance under share-based payment arrangement.

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Number of shares authorized for issuance under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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

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Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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Stock-Based Compensation - Narrative (Details)			3 Months Ended		9 Months Ended
Stock-Based Compensation - Narrative (Details)	May 28, 2020	May 25, 2016 shares	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($)	Jul. 15, 2020 shares	Dec. 31, 2019 shares
Stock Based Compensation Details [Line Items]
Reverse stock split, conversion ratio	0.10
Unrecognized compensation costs \| $			$ 600,000		$ 600,000
Plan 2016
Stock Based Compensation Details [Line Items]
Shares approved and authorized (in shares)		4,000,000
Maximum number of shares to any individual (in shares)		1,000,000
Shares of common stock options outstanding (in shares)			18,561		18,561			13,655,000
Shares available for grant (in shares)			4,341,349		4,341,349			233,416
Plan 2016 \| Common Stock
Stock Based Compensation Details [Line Items]
Shares of common stock options outstanding (in shares)			331,803		331,803			283,559,000
Amended 2016 Plan
Stock Based Compensation Details [Line Items]
Shares approved and authorized (in shares)							400,000
Additional shares authorized (in shares)		2,000,000
July 2020 Amendment
Stock Based Compensation Details [Line Items]
Shares approved and authorized (in shares)							4,400,000
Employee Stock Option
Stock Based Compensation Details [Line Items]
Compensation expense \| $			$ 100,000	$ 200,000	$ 700,000
Number of options forfeited (in shares)					40,911
Shares of common stock options outstanding (in shares)			595,212		595,212			516,820
Restricted Stock
Stock Based Compensation Details [Line Items]
Compensation expense \| $			$ 14,100	$ 57,100	$ 89,800	$ 190,600
Shares of RSUs outstanding (in shares)			1,362		1,362
Unrecognized compensation costs \| $			$ 66,500		$ 66,500
Restricted Stock \| Minimum
Stock Based Compensation Details [Line Items]
Vesting period					1 year
Restricted Stock \| Maximum
Stock Based Compensation Details [Line Items]
Vesting period					3 years
Restricted Stock \| Plan 2016
Stock Based Compensation Details [Line Items]
RSUs outstanding (in shares)								6,268,000