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STOCK-BASED COMPENSATION - 2014 Omnibus Incentive Plan Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2014	Dec. 31, 2020	Dec. 31, 2019
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
The 2014 Plan \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized under plan (in shares)		13,000,000
Number of shares authorized under plan (in shares)	28,780,000
Shares available for future issuance (in shares)		17,378,077
Vesting period	4 years
The 2014 Plan \| Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
The 2014 Plan \| Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of awards (may not exceed)	10 years
The 2014 Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of awards vested		$ 1.1	$ 3.1
Number of units awarded (in shares)		5,985,196
Weighted-average grant date fair value (in dollars per share)		$ 0.97
The 2014 Plan \| Restricted stock units \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Vesting percentage		33.00%
The 2014 Plan \| Restricted stock units \| Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Vesting percentage		25.00%
The 2014 Plan \| Performance-based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 months
Number of units awarded (in shares)		0	643,266
Weighted-average grant date fair value (in dollars per share)		$ 0	$ 8.2327
The 2014 Plan \| Performance-based Restricted Stock Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			0.00%
The 2014 Plan \| Performance-based Restricted Stock Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			200.00%