Share-based Compensation - Expense Other (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Expense
Total compensation cost	$ 902	$ 874
Unrecognized compensation cost	4,700
Stock options
Share-based Compensation Expense
Total compensation cost	$ 800	800
Compensation cost not yet recognized, period for recognition	2 years 8 months 12 days
RSUs
Share-based Compensation Expense
Total compensation cost	$ 100	$ 100
Compensation cost not yet recognized, period for recognition	1 year 10 months 24 days
Restricted stock
Share-based Compensation Expense
Unrecognized compensation cost	$ 0

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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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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