Share-based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1.7	$ 2.5
Intrinsic value of options outstanding	$ 0.3
Average remaining life of option outstanding	2 years 10 months 24 days
Intrinsic value of exercisable options	$ 0.3
Average remaining life of exercisable options	2 years 10 months 24 days
Unvested shares expected to vest (in shares)	1,350
Weighted average remaining life	6 months
Weighted average exercise price (in usd per share)	$ 2.62
Intrinsic value	$ 0.1
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 1.5
Unrecognized compensation expense, period for recognition	2 years
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 0.1
Unrecognized compensation expense, period for recognition	7 years 6 months

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 nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. 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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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. 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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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for 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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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