Percentage Of Commission ATM Offering

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Share Based Compensation Additional Expense Expected On Vesting.

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Share based compensation arrangement by share based payment award options grant in period weighted average remaining contractual term.

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Share based compensation arrangement by share based payment award options.

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Share based compensation arrangement by share based payment award options nonvested forfeitures in period weighted average contractual term.

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Number of warrants or rights outstanding.

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Face amount or stated value per share of common stock.

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The cash inflow associated with the amount received from holders exercising their stock warrants.

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Amount of consideration received by subsidiary or equity investee in exchange for shares of stock issued or sold. Includes amount of cash received, fair value of noncash assets received, and fair value of liabilities assumed by the investor.

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The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

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Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

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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 equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Date the equity-based award expires, in CCYY-MM-DD format.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Number of share options (or share units) exercised during the current period.

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Value of stock issued as a result of the exercise of stock options.

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Stockholders' Equity And Stock-Based Compensation (Narrative) (Details) - USD ($)					1 Months Ended	12 Months Ended
	Feb. 12, 2021	Jan. 01, 2021	Nov. 13, 2020	Mar. 27, 2020	Aug. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from exercise of warrants						$ 4,940,000	$ 5,866,000
Number of shares execrise						554,019	4,504,091
Award expiration period						4 years
Dividend yield						0.00%	0.00%
Compensation costs prior to forfeiture						$ 1,500,000
Weighted average remaining recognition period						2 years 1 month 6 days
Stock options exercised						71,105
Proceeds from stock options exercised						$ 256,000
Offering of common stock shares						120,000,000	120,000,000
Par value per share						$ 0.001	$ 0.001
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised		20,385
Proceeds from stock options exercised		$ 169,000
ATM [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued						0
Percentage of commission in ATM offering				3.00%
ATM [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate offering price				$ 100,000,000
2008 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period						10 years
2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of stock options granted						10 years
Offering of common stock shares						1,000,000
Par value per share						$ 0.001
Performance Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional stock compensation expense						$ 2,300,000
Performance awards vested
Performance Award [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance awards expiration date						Dec. 31, 2026
Performance Award [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance awards expiration date						Jan. 01, 2022
Common Stock [Member] \| 2021 Registered Direct Offering [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued	4,081,633
Price per share	$ 49.00
Net proceeds from offering	$ 189,700,000
Common Stock [Member] \| Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued			9,375,000
Price per share			$ 8.00
Net proceeds from offering			$ 70,251,000
Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares execrise						554,019	4,496,116
Warrants [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from exercise of warrants		$ 700,000
Number of shares execrise		600,000
Warrants [Member] \| Common Stock Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued					9,100,000
Proceeds from exercise of warrants						$ 4,900,000	$ 5,900,000
Number of shares execrise						4,000,000	4,600,000
Warrants [Member] \| Common Stock Warrants [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from exercise of warrants		$ 700,000
Number of shares execrise		600,000
Placement Agent Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares execrise							7,975