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

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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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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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Price of a single share of a number of saleable stocks of a company.

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Share-based Payments - Stock Options Narrative (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Mar. 29, 2020	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 $ / shares	Jun. 25, 2020 shares	Dec. 31, 2019 $ / shares	Jun. 28, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payments \| $		$ 15,361	$ 11,619	$ 8,151
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payments \| $		$ 7,185	$ 10,278	$ 8,151
Share price at grant date (in dollars per share)		$ 6.96
Stock options \| 2015 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards to be granted (in shares) \| shares								0
Stock options \| 2018 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards to be granted (in shares) \| shares						0
Stock options \| 2020 Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	7 years
Stock options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Share price at grant date (in dollars per share)							$ 15.34
Stock options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Share price at grant date (in dollars per share)							24.75
Stock options \| Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price at grant date (in dollars per share)					$ 4.84		$ 13.03