NET INCOME (LOSS) PER SHARE - NARRATIVE (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase shares of common stock (in shares)	1,549	3,051	2,564	3,051
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase shares of common stock (in shares)	1,368	2,011	1,367	2,011
RSUs and RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase shares of common stock (in shares)	181	1,040	1,197	1,040