| Document and Entity Information | Aug. 04, 2023 |
| Document And Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 04, 2023 |
| Entity Registrant Name | FIFTH WALL ACQUISITION CORP. III |
| Entity Incorporation, State or Country Code | E9 |
| Entity File Number | 001-40415 |
| Entity Tax Identification Number | 98-1583957 |
| Entity Address, Address Line One | 1 Little West 12th Street |
| Entity Address, Address Line Two | 4th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10014 |
| City Area Code | 310 |
| Local Phone Number | 853-8878 |
| Written Communications | true |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Ordinary Shares, par value $0.0001 |
| Trading Symbol | FWAC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001847874 |
| Amendment Flag | false |
| Former Address [Member] | |
| Document And Entity Information [Line Items] | |
| Entity Address, Address Line One | 6060 Center Drive |
| Entity Address, Address Line Two | 10th Floor |
| Entity Address, City or Town | Los Angeles |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 90045 |
