| Cover | Sep. 05, 2023 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 05, 2023 |
| Entity File Number | 001-40149 |
| Entity Registrant Name | Altimar Acquisition Corp. III |
| Entity Central Index Key | 0001841004 |
| Entity Tax Identification Number | 98-1576586 |
| Entity Incorporation, State or Country Code | E9 |
| Entity Address, Address Line One | 40 West 57th Street |
| Entity Address, Address Line Two | 33rd Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10019 |
| City Area Code | 212 |
| Local Phone Number | 287-6767 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Units, each consisting of one Class A ordinary share, $0.0001 par value, and one-fourth of one redeemable warrant | |
| Title of 12(b) Security | Units, each consisting of one Class A ordinary share, $0.0001 par value, and one-fourth of one redeemable warrant |
| Trading Symbol | ATAQ.U |
| Security Exchange Name | NYSE |
| Class A ordinary share, $0.0001 par value | |
| Title of 12(b) Security | Class A ordinary share, $0.0001 par value |
| Trading Symbol | ATAQ |
| Security Exchange Name | NYSE |
| Warrants, each whole warrant exercisable for one Class A ordinary share, each at an exercise price of $11.50 per share | |
| Title of 12(b) Security | Warrants, each whole warrant exercisable for one Class A ordinary share, each at an exercise price of $11.50 per share |
| Trading Symbol | ATAQ.WS |
| Security Exchange Name | NYSE |
