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

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

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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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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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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Common Stock Equity Incentive Plan (Narrative) (Details) - USD ($)				3 Months Ended
	May 09, 2019	May 08, 2019	May 09, 2013	Mar. 31, 2020	Mar. 31, 2019	Mar. 18, 2020	Dec. 31, 2019	Nov. 10, 2011
Share-based Compensation Arrangement by Share-based Payment Award
Share-based compensation expense				$ 177,000	$ 48,000
2009 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized				1,692,379
Number of shares remained available for issuance				957,345
Evergreen increase (percent)	3.00%	4.00%		4.00%
2010 Non-Employee Directors' Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized								26,455
Number of shares remained available for issuance				29,650
Increase in number of shares authorized			17,989
2010 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized								23,809
Number of shares remained available for issuance				2,628
Increase in number of shares authorized			20,635
Lumos 2012 EIP
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized						26,248
Number of options outstanding (in shares)						26,248
Options outstanding, weighted average exercise price (in dollars per share)						$ 1.39
Lumos 2016 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized						163,864
Number of options outstanding (in shares)						163,864
Options outstanding, weighted average exercise price (in dollars per share)						$ 3.66
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award
Number of options outstanding (in shares)				578,264			596,385
Options outstanding, weighted average exercise price (in dollars per share)				$ 31.64			$ 29.68
Total compensation cost related to non-vested option awards				$ 505,000
Weighted average vesting period for non-vested option awards, in years				3 years
Intrinsic value of options exercised				$ 0
Fair value of awards vested				$ 391,000
Performance Stock
Share-based Compensation Arrangement by Share-based Payment Award
Granted (in shares)				0