INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Aug. 15, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2022	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Valuation allowance		$ 138,710	$ 131,839
Initial deferred tax liability related to 2018 convertible debt		24	2,933
Convertible notes due from related-party extinguished in connection with the exchange transaction, net of deferred issuance costs		49,624	0	$ 0
Capital contribution from related-party in connection with exchange transaction		29,847
Unrecognized tax benefits		13,596	7,556	$ 4,866		$ 3,712
Uncertain tax positions that would impact the effective tax rate		100
August 2022 Exchange Transaction | Jack W. Schuler Living Trust | Embeded Warrant
Operating Loss Carryforwards [Line Items]
Warrants fair value	$ 3,800
August 2022 Exchange Transaction | Jack W. Schuler Living Trust | Embeded Warrant | Level 3
Operating Loss Carryforwards [Line Items]
Warrants fair value	3,800
Cumulative impact of accounting change | Accounting Standards Update 2020-06
Operating Loss Carryforwards [Line Items]
Initial deferred tax liability related to 2018 convertible debt					$ (3,000)
Total convertible notes					$ 11,500
Convertible Notes | 2.50% Convertible Notes due 2023
Operating Loss Carryforwards [Line Items]
Total convertible notes		56,413	$ 107,984
Convertible Notes | August 2022 Exchange Transaction | 2.50% Convertible Notes due 2023 | Jack W. Schuler Living Trust
Operating Loss Carryforwards [Line Items]
Convertible notes due from related-party extinguished in connection with the exchange transaction, net of deferred issuance costs	49,900
PPP Loan
Operating Loss Carryforwards [Line Items]
Initial deferred tax liability related to 2018 convertible debt							$ 14,000
Senior Notes | August 2022 Exchange Transaction | Five Point Zero Percent Secured Promissory Note | Jack W. Schuler Living Trust
Operating Loss Carryforwards [Line Items]
Convertible notes due from related-party extinguished in connection with the exchange transaction, net of deferred issuance costs	34,900
Secured Debt | August 2022 Exchange Transaction | Five Point Zero Percent Secured Promissory Note | Jack W. Schuler Living Trust
Operating Loss Carryforwards [Line Items]
Convertible notes due from related-party extinguished in connection with the exchange transaction, net of deferred issuance costs	49,600
Capital contribution from related-party in connection with exchange transaction	$ 29,800
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		383,700
Operating loss carryforwards, subject to expiration		169,800
Operating loss carryforwards, not subject to expiration		213,900
Federal | R&D tax credits
Operating Loss Carryforwards [Line Items]
Tax credits		14,500
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		369,600
State | R&D tax credits
Operating Loss Carryforwards [Line Items]
Tax credits		$ 12,400