The percentage of RSUs vesting period contingent upon the achievement of certain performance metrics.

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Percentage Of Shares Vested

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No definition available.

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

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Aggregate number of common shares reserved for future issuance.

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

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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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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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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

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No definition available.

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

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- Definition

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

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No definition available.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Description of terms of award under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of stock repurchase plan authorized.

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Period which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Amount allocated to previously issued common shares repurchased by the issuing entity and held in treasury.

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Stock-Based Compensation And Stock Repurchases (Narrative) (Details) - USD ($)							1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 11, 2021	Dec. 16, 2020	Dec. 16, 2020	Mar. 10, 2020	Mar. 05, 2020	May 07, 2019	Apr. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Mar. 02, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Stock Options, Granted										0
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense								$ 101,000	$ 103,000	$ 302,000	$ 343,000
Unrecognized estimated compensation cost related to non-vested stock options granted								300,000		$ 300,000
Recognition period of unrecognized compensation cost										1 year 21 days
Share price										$ 5.06
Intrinsic unrealized value of all options outstanding, vested and expected to vest
2020 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Terms of award										the grantee to receive one share for every RSU based on a vesting plan
Minimum [Member] \| 2020 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and RSU										1 year
Maximum [Member] \| 2020 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and RSU										4 years
Stock option expiry period										5 years
Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock authorized for issuance								1,505,598		1,505,598
Shares repurchased plan, shares										0
Number of Stock Options, Granted												38,803
Class A [Member] \| 2020 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock authorized for issuance								1,250,000		1,250,000
Common Stock shares remaining for future issuances								784,296		784,296
Class A [Member] \| Maximum [Member] \| 2020 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized										176,086
2017 Stock Repurchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase program, amount authorized				$ 25,000,000.0
Repurchase program, remaining amount authorized								$ 26,000,000.0		$ 26,000,000.0
Stock buy-back program period										2 years
2017 Stock Repurchase Plan [Member] \| Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase program, amount authorized													$ 25,000,000.0
Repurchase program, remaining amount authorized				$ 26,000,000.0
$25 Million Stock Repurchase Program [Member] \| Class A Nonvoting Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase value								24,000,000.0		$ 24,000,000.0
Share price					$ 7.30					$ 13.39
Shares repurchased plan, shares					25,000					1,792,819
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 35,000		505,000	$ 237,000	$ 1,290,000	$ 708,000
Unrecognized estimated compensation cost related to non-vested stock options granted								$ 3,300,000		$ 3,300,000
Vesting period of stock options and RSU										1 year 9 months 21 days
Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Granted							262,830
Executive Officer [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and RSU										4 years
Percentage of shares vested										50.00%
Percentage of RSUs Vesting Period Contingent On Performance Metrics										50.00%
Management [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and RSU										4 years
Percentage of shares vested										25.00%
Non-employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Stock Options, Granted			38,803
Non-employee Director [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested										100.00%
Number of options, Granted	26,924		60,084
Executive Management And Other Employees [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and RSU										1 year
Percentage of shares vested										100.00%
Number of options, Granted		114,803		287,163
Other employees [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and RSU										4 years
Percentage of shares vested										25.00%
Number of options, Granted										22,888