Share-Based Compensation Arrangements by Share-Based Payment Award, Performance Shares Payout Rate

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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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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Amount of noncash expense for share-based payment arrangement.

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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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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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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Gross number of share options (or share units) granted during the period.

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Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Stock-Based Compensation Plans - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (in shares)			0	0
Stock-based compensation expense	$ 7,720	$ 7,932	$ 14,423	$ 14,882
Stock-based compensation expense, tax benefits	$ 1,200	$ 1,400
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive plan, total intrinsic value of stock options exercised			7,600	$ 10,500
LTIP Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 400
Number of shares vested			10,457
Shares withheld to pay employees' portion of minimum payroll withholding taxes			4,527
Total Shareholder Return Awards (TSRs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested			782,588
Vesting performance period			3 years
Payout rate	200.00%		200.00%
Shares withheld to pay employees' portion of minimum payroll withholding taxes			205,373
Unrecognized compensation costs	$ 26,700		$ 26,700
Total Shareholder Return Awards (TSRs) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted average recognition period			2 years 1 month 6 days
Total Shareholder Return Awards (TSRs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted average recognition period			2 years 2 months 12 days
Restricted Share Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested			518,350
Shares withheld to pay employees' portion of minimum payroll withholding taxes			153,845
Unrecognized compensation costs	$ 29,900		$ 29,900
Restricted Share Units (RSUs) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted average recognition period			2 years 1 month 6 days
Restricted Share Units (RSUs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted average recognition period			2 years 2 months 12 days
2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under ESPP			55,486	72,228
2020 Equity and Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 14,400	$ 14,900
Stock-based compensation expense, tax benefits			$ 2,200	$ 2,800