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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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 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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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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Shares vesting for performance nonvested equity based awards based on the most recent information available.

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Share-Based Compensation Arrangements (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 5,100
Weighted average recognition period (in years)	1 year 10 months 24 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options exercised total intrinsic value	$ 897	$ 46	$ 580
Cliff vesting period (years)	3 years	3 years	3 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units	19,185	27,385	26,070
Cliff vesting period (years)	3 years
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units	40,975
Performance share awards, shares vesting	159,572
Minimum [Member] \| Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period (years)	3 years
Maximum [Member] \| Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period (years)	5 years