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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Stock-Based Compensation - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		29 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation	$ 604	$ 876	$ 1,842	$ 2,910
Expected cost on shares expected to vest	$ 4,096		$ 4,096		$ 4,096
Recognition period for compensation expense not yet recognized			3 years 6 months
Restricted Stock \| Vesting Period 2
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period			3 years
Restricted Stock \| Vesting Period 2 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period					1 year
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period			3 years