EMPLOYEE BENEFIT PLANS - Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 24,056	$ 18,040	$ 12,074
Stock options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	0	0	94
RSUs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	14,573	11,522	9,444
PRSUs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	6,231	4,022	924
MRSUs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	1,304	711	286
Employee stock purchase rights under ESPP
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	1,948	1,785	1,326
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	2,345	1,712	1,124
Research and development expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	7,164	4,850	3,261
Selling, general and administrative expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 14,547	$ 11,478	$ 7,689