SHAREHOLDERS EQUITY (Details) - USD ($) $ in Thousands, shares in Millions		3 Months Ended
	Jul. 31, 2023	Mar. 31, 2023	Mar. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized issuance costs			$ 1,687	$ 1,794
Spectrum Pharmaceuticals, Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock (in shares)	38.0
Additional Paid-In Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Induced exchange of convertible notes, gross		$ 28,300
Convertible Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized issuance costs		1,600
6.5% Convertible Senior Secured Notes due 2027 principal amount | Convertible Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from the issuance of common stock		$ 10,500
Induced exchange of convertible notes (in shares)		7.0