| Document and Entity Information | Nov. 18, 2022 |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0001846253 |
| Document Type | 8-K |
| Document Period End Date | Nov. 18, 2022 |
| Entity Registrant Name | OmniAb, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-40720 |
| Entity Tax Identification Number | 98-1584818 |
| Entity Address, Address Line One | 5980 Horton Street |
| Entity Address, Address Line Two | Suite 600 |
| Entity Address, City or Town | Emeryville |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94608 |
| City Area Code | (510) |
| Local Phone Number | 250-7800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Common Stock 0.0001 Par Value Per Share [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NASDAQ |
| Security 12b Title | Common stock, $0.0001 par value per share |
| Trading Symbol | OABI |
| Warrants To Purchase Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NASDAQ |
| Security 12b Title | Warrants to purchase common stock |
| Trading Symbol | OABIW |
