| Cover | Dec. 12, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 12, 2024 |
| Entity File Number | 01-39294 |
| Entity Registrant Name | ASSERTIO HOLDINGS, INC. |
| Entity Central Index Key | 0001808665 |
| Entity Tax Identification Number | 85-0598378 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 100 S. Saunders Road |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | Lake Forest |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60045 |
| City Area Code | 224 |
| Local Phone Number | 419-7106 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.0001 par value |
| Trading Symbol | ASRT |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
