STOCK-BASED COMPENSATION - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Stock Option Rollforward
Stock options outstanding at the beginning of the period (in shares)	2,274	3,114
Options granted (in shares)	0	0
Options exercised (in shares)	(1)	(124)
Options forfeited (in shares)	(14)	(16)
Options outstanding at the end of the period (in shares)	2,259	2,974
Weighted-average fair value of grants during the period (in dollars per share)	$ 0	$ 0
Total intrinsic value of options exercised during the period	$ 5	$ 1,402
Weighted-average remaining recognition period (in years)	1 year 8 months 23 days	2 years 5 months 15 days
Stock Award Rollforward
Stock awards outstanding at the beginning of the period (in shares)	9,191	7,820
Stock awards granted (in shares)	1,304	1,147
Stock awards vested (in shares)	(721)	(329)
Stock awards canceled and forfeited (in shares)	(331)	(445)
Stock awards outstanding at the end of the period (in shares)	9,443	8,193
Weighted-average fair value of grants during the period (in dollars per share)	$ 19.22	$ 22.40
Weighted-average remaining recognition period (in years)	1 year 9 months 3 days	2 years 1 month 9 days
Total unrecognized compensation expense at period-end	$ 116,957	$ 109,422

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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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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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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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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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