Cap on fair value of shares available for purchase by participants.

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Employee Stock Purchase Plan, Number of Shares Purchased by Employee

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Exercise price of options percentage of fair market value of common stock.

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- Definition

Percentage of incentive stock option granted.

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Percentage of voting stock.

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Percentage of Annualized Forfeiture Rate For Award Granted

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Reduction In Reserve, Equity Instruments Other Than Options, Quantity Of Reduction

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Reduction In Reserve, Options, Quantity Of Reduction

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Term of options granted, years

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- Definition

Aggregate number of common shares reserved for future issuance.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 210
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- Definition

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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- Definition

Discount rate from fair value on offering date that participants pay for shares.

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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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No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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- Definition

The highest quantity of shares an employee can purchase under the plan per period.

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- Definition

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

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No definition available.

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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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- Definition

Per share weighted-average price paid for shares purchased on open market for issuance under share-based payment arrangement.

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STOCK PLANS - Narrative (Details)				12 Months Ended
STOCK PLANS - Narrative (Details)	Sep. 12, 2019 shares	Nov. 08, 2018 shares	Sep. 07, 2011 USD ($) shares	Mar. 31, 2020 USD ($) $ / shares shares	Mar. 31, 2019	Mar. 31, 2018
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost \| $				$ 93,600,000
Unrecognized cost, period for recognition, years				1 year 4 months 24 days
Employee stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased by employees (in shares)				594,661
Shares issued under ESPP plan, weighted average purchase price per share (in dollars per share) \| $ / shares				$ 23.92
Shares available for future issuance under the ESPP (in shares)				2,313,482
Maximum \| Incentive options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of options granted, years				5 years
2011 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, equity awards reserved for issuance (in shares)			2,500,000
Number of additional shares available (in shares)		3,000,000
Maximum payroll deductions for purchase of shares by participants			20.00%
Maximum number of shares available for purchased by participants (in shares)			2,000
Cap on fair value of shares available for purchase by participants \| $			$ 25,000
Percentage of common stock price for employees			85.00%
2011 Employee Stock Purchase Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cap on fair value of shares available for purchase by participants \| $			$ 50,000
2007 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares available (in shares)	1,294,651
Shares available for grant (in shares)				6,967,333
2007 Equity Incentive Plan \| Independent Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of annualized forfeiture rate for awards granted				0.00%	0.00%	0.00%
2007 Equity Incentive Plan \| Senior Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of annualized forfeiture rate for awards granted				2.00%	2.00%	2.00%
2007 Equity Incentive Plan \| Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of annualized forfeiture rate for awards granted				5.00%	5.00%	5.00%
2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, equity awards reserved for issuance (in shares)	6,794,651
Number of additional shares available (in shares)	5,500,000
Reduction for each share of common stock pursuant to option	1
Reduction for each share of common stock pursuant to other than option	2.76
Share-based awards generally vest, years				4 years
Percentage of incentive stock option granted				110.00%
Shares available for grant (in shares)				4,274,473
2019 Equity Incentive Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of options granted, years				7 years
2019 Equity Incentive Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of fair market value of common stock				100.00%
Percentage of voting stock				10.00%