| Document and Entity Information | Jan. 31, 2023 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Jan. 31, 2023 |
| Entity Registrant Name | Ascendant Digital Acquisition Corp. III |
| Entity Incorporation, State or Country Code | E9 |
| Entity File Number | 001-41036 |
| Entity Tax Identification Number | 00-0000000 |
| Entity Address, Address Line One | 667 Madison Avenue |
| Entity Address, Address Line Two | 5th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10065 |
| City Area Code | 212 |
| Local Phone Number | 209-6126 |
| 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 |
| Amendment Flag | false |
| Entity Central Index Key | 0001850316 |
| Units, each consisting of one Class A ordinary share, $0.0001 par value, and one-half of one redeemable warrant [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Units, each consisting of one Class A ordinary share and one-half of one redeemable warrant |
| Trading Symbol | ACDI.U |
| Security Exchange Name | NYSE |
| Common Class A [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Class A ordinary shares, par value $0.0001 per share |
| Trading Symbol | ACDI |
| Security Exchange Name | NYSE |
| Warrant [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Redeemable warrants, each warrant exercisable for one Class A ordinary share, each at an exercise price of $11.50 |
| Trading Symbol | ACDI WS |
| Security Exchange Name | NONE |
