CONVERTIBLE SENIOR NOTES AND CAPPED CALLS - Carrying Amount of the Liability Component (Details) - Convertible Debt - Aggregate Notes - USD ($)	Jun. 30, 2021	Mar. 31, 2021	Dec. 01, 2019
Debt Instrument [Line Items]
Principal	$ 362,500,000	$ 362,500,000	$ 362,500,000
Unamortized debt discount	(48,990,000)	(53,323,000)
Unamortized issuance costs	(682,000)	(742,000)
Net carrying amount	$ 312,828,000	$ 308,435,000