CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS - Fair value of company's financial assets (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Total	$ 409,557	$ 579,018
U.S. treasury securities
Total	242,651	246,767
U.S. government agency securities
Total	5,012	5,097
Corporate securities
Total	5,990	35,588
Commercial paper
Total	87,802	235,316
Money market funds
Total	68,102	56,250
Level 1
Total	310,753	303,017
Level 1 | U.S. treasury securities
Total	242,651	246,767
Level 1 | Money market funds
Total	68,102	56,250
Level 2
Total	98,804	276,001
Level 2 | U.S. government agency securities
Total	5,012	5,097
Level 2 | Corporate securities
Total	5,990	35,588
Level 2 | Commercial paper
Total	$ 87,802	$ 235,316