STOCK-BASED COMPENSATION PLANS - Stock Plan (Details) shares in Thousands	12 Months Ended
Dec. 31, 2019 $ / shares shares
Outstanding Number of Shares \| shares \| shares	1,855
WA Remaining Contractual Life (years)	6 years 5 months 1 day
WA Outstanding Strike Price	$ 2.48
Exercisable Number of Shares \| shares \| shares	965
Remaining Exercisable Contractual Life (years)	4 years 1 month 24 days
WA Exercisable Strike Price	$ 0.60
Exercise Price Range One [Member]
Exercise Price Minimum	0
Exercise Price Maximum	$ 2.00
Outstanding Number of Shares \| shares \| shares	1,040
WA Remaining Contractual Life (years)	4 years 3 months 29 days
WA Outstanding Strike Price	$ 0.42
Exercisable Number of Shares \| shares \| shares	889
Remaining Exercisable Contractual Life (years)	3 years 9 months 18 days
WA Exercisable Strike Price	$ 0.41
Exercise Price Range Two [Member]
Exercise Price Minimum	2.01
Exercise Price Maximum	$ 4.00
Outstanding Number of Shares \| shares \| shares	367
WA Remaining Contractual Life (years)	8 years 8 months 5 days
WA Outstanding Strike Price	$ 3.11
Exercisable Number of Shares \| shares \| shares	76
Remaining Exercisable Contractual Life (years)	8 years 3 months 4 days
WA Exercisable Strike Price	$ 2.78
Exercise Price Range Three [Member]
Exercise Price Minimum	4.01
Exercise Price Maximum	$ 6.00
Outstanding Number of Shares \| shares \| shares	210
WA Remaining Contractual Life (years)	9 years 2 months 5 days
WA Outstanding Strike Price	$ 5.35
Remaining Exercisable Contractual Life (years)	0 years
Exercise Price Range Four [Member]
Exercise Price Minimum	$ 6.01
Exercise Price Maximum	$ 8.00
Outstanding Number of Shares \| shares \| shares	200
WA Remaining Contractual Life (years)	9 years 6 months 22 days
WA Outstanding Strike Price	$ 7.87
Remaining Exercisable Contractual Life (years)	0 years
Exercise Price Range Five [Member]
Exercise Price Minimum	$ 8.01
Exercise Price Maximum	$ 10.00
Outstanding Number of Shares \| shares \| shares	38
WA Remaining Contractual Life (years)	9 years 10 months 10 days
WA Outstanding Strike Price	$ 8.96
Remaining Exercisable Contractual Life (years)	0 years

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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-Publisher FASB
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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Publisher FASB
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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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

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