STOCK-BASED COMPENSATION Performance-based Awards and Restricted Stock Units (Details) $ / shares in Units, $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($) $ / shares shares
Restricted Stock Units (RSUs)
Shares
Outstanding at January 1, 2021	1,518,000
Granted	262,000
Vested	(538,000)
Forfeited	(84,000)
Outstanding at September 30, 2021	1,158,000
Outstanding and expected to vest at September 30, 2021	1,081,000
Weighted- Average Grant Date Fair Value Per Share (in dollars per share)
Outstanding at January 1, 2021 \| $ / shares	$ 35.51
Granted \| $ / shares	83.27
Vested \| $ / shares	34.89
Forfeited \| $ / shares	38.38
Outstanding at September 30, 2021 \| $ / shares	$ 46.42
Weighted-Average Remaining Contractual Term (In years)
Outstanding at September 30, 2021	1 year 5 months 23 days
Outstanding and expected to vest at September 30, 2021	1 year 5 months 4 days
Aggregate Intrinsic Value (In thousands)
Outstanding at September 30, 2021 \| $	$ 114,544
Outstanding and expected to vest at September 30, 2021 \| $	$ 107,057
Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based period	3 years
Shares
Outstanding at January 1, 2021	301,000
Granted	103,000
Vested	(6,000)
Forfeited	(15,000)
Outstanding at September 30, 2021	383,000
Outstanding and expected to vest at September 30, 2021	383,000
Weighted- Average Grant Date Fair Value Per Share (in dollars per share)
Outstanding at January 1, 2021 \| $ / shares	$ 41.90
Granted \| $ / shares	82.92
Vested \| $ / shares	29.95
Forfeited \| $ / shares	40.05
Outstanding at September 30, 2021 \| $ / shares	$ 53.14
Weighted-Average Remaining Contractual Term (In years)
Outstanding at September 30, 2021	1 year 2 months 1 day
Outstanding and expected to vest at September 30, 2021	1 year 2 months 1 day
Aggregate Intrinsic Value (In thousands)
Outstanding at September 30, 2021 \| $	$ 37,871
Outstanding and expected to vest at September 30, 2021 \| $	$ 37,871
Performance Based Awards (PSUs)
Shares
Outstanding at January 1, 2021	150,000
Granted	105,000
Vested	(150,000)
Forfeited	(1,000)
Outstanding at September 30, 2021	104,000
Outstanding and expected to vest at September 30, 2021	104,000
Weighted- Average Grant Date Fair Value Per Share (in dollars per share)
Outstanding at January 1, 2021 \| $ / shares	$ 46.27
Granted \| $ / shares	84.40
Vested \| $ / shares	46.27
Forfeited \| $ / shares	85.01
Outstanding at September 30, 2021 \| $ / shares	$ 84.39
Weighted-Average Remaining Contractual Term (In years)
Outstanding at September 30, 2021	3 months
Outstanding and expected to vest at September 30, 2021	3 months
Aggregate Intrinsic Value (In thousands)
Outstanding at September 30, 2021 \| $	$ 10,342
Outstanding and expected to vest at September 30, 2021 \| $	$ 10,342
Minimum [Member] \| Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	0.00%
Minimum [Member] \| Performance Based Awards (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	0.00%
Maximum [Member] \| Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	200.00%
Maximum [Member] \| Performance Based Awards (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Based Awards Shares Released As Percentage Of Target Number	200.00%

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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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 non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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