| Document and Entity Information | Jan. 15, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001628738 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Jan. 15, 2020 |
| Entity Registrant Name | Audentes Therapeutics, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-37833 |
| Entity Tax Identification Number | 46-1606174 |
| Entity Address, Address Line One | 600 California Street |
| Entity Address, Address Line Two | 17th Floor |
| Entity Address, City or Town | San Francisco |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94108 |
| City Area Code | (415) |
| Local Phone Number | 818-1001 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.00001 per share |
| Trading Symbol | BOLD |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
