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Number Of Equity Incentive Plans

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Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercised in Period And Cancelled In Period, Intrinsic Value

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Share-based Compensation Arrangement by Share-based Payment Award, Adjustment To Compensation Cost

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested

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Share-based Compensation Arrangement by Share-based Payment Award, Options, Shares Issued Through Promissory Note

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Share-based Compensation Arrangement by Share-based Payment Award, Options Vested And Unexercised, Put

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Share-based Compensation Arrangement by Share-based Payment Award, Options Vested And Unexercised, Put, Weighted Average Exercise Price

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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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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of tax benefit for recognition of expense of award under 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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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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The weighted average fair value at grant date for nonvested equity-based awards issued 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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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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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Number of shares authorized for issuance under share-based payment arrangement.

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

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Percentage of vesting of award under share-based payment arrangement.

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Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

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Number of options vested.

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Number of share options (or share units) exercised during the current period.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Number of shares that have been repurchased during the period and are being held in treasury.

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EQUITY PLANS - Additional Information (Details)	1 Months Ended			5 Months Ended	12 Months Ended
EQUITY PLANS - Additional Information (Details)	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($) shares	Jan. 31, 2019 shares	Nov. 30, 2015 shares	Dec. 31, 2020 USD ($) plan $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 $ / shares shares	Dec. 09, 2015 shares	Jun. 14, 2011 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of incentive plans \| plan					2
Share based compensation expense \| $					$ 17,700,000	$ 3,800,000	$ (1,500,000)
Share-based income tax benefit (expense) \| $					6,900,000	900,000	(400,000)
Unrecognized share-based compensation expense \| $					$ 15,300,000
Period for recognition					1 year 4 months 24 days
Intrinsic value of options exercised or unvested Put to the company and canceled \| $					$ 400,000	0	40,500,000
Compensation cost \| $					$ 0	$ 0	$ 0
Number of common shares repurchased (in shares)					1,812,393	9,079,690
Average cost per share, including commissions (in dollar per share) \| $ / shares					$ 18.37	$ 24.57	$ 23.50
Valuation, income approach
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value measurement of common stock					0.50
Valuation, market approach
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value measurement of common stock					0.50
RSUs and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair values (in dollars per share) \| $ / shares					$ 31.27	$ 30.68	$ 27.15
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of RSUs \| $					$ 23,700,000	$ 5,400,000	$ 600,000
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					53,617
Granted (in shares)					48,209
Financed options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised (in shares)				1,864,428
Number of common shares repurchased (in shares)							331,112
Notes related to financed options (in shares)							1,439,984
Put options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised (in shares)						0		54,976
Vested but unexercised options (in shares)								13,336
Vested but unexercised options (in usd per share) \| $ / shares								$ 24.38
Vested but unexercised options (in shares)							0
Intrinsic value of outstanding stock options \| $							$ 2,900,000
Reduction to compensation expense \| $							$ 3,200,000
Liability classified restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested but unexercised options (in shares)		9,572	9,568
Granted (in shares)					9,572
Settlement price of vested RSUs \| $		$ 200,000
Liability classified restricted stock units \| Subsequent event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Settlement price of vested RSUs \| $	$ 500,000
Other stock based award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense \| $					$ 6,300,000
Granted (in shares)					131,046
2010 Option plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised (in shares)					19,564
Intrinsic value of outstanding stock options \| $					$ 4,100,000
2010 Option plan \| Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available to acquire (in shares)										2,455,368
2015 Incentive plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available to acquire (in shares)									1,700,000
Shares available for grant (in shares)					576,076
2015 Incentive plan \| Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					3 years
Vesting percentage per year					33.00%
2015 Incentive plan \| Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					31,478	48,525	0