STOCK-BASED COMPENSATION - 2004 Equity Incentive Plan Narrative (Details) - shares	1 Months Ended	12 Months Ended
May 31, 2004	Dec. 31, 2020
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
The 2004 Plan \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under plan (in shares)	14,450,000
Term of awards (may not exceed)	10 years
Vesting percentage	25.00%
The 2004 Plan \| Incentive stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of awards as percentage of the fair value of common stock (at least)	100.00%
The 2004 Plan \| Nonstatutory stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of awards as percentage of the fair value of common stock (at least)	80.00%

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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-Publisher FASB
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-Section 50
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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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Percentage of vesting of award under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Purchase price of common stock expressed as a percentage of its fair value.

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