| Document and Entity Information | Mar. 28, 2022 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001642545 |
| Document Type | 8-K |
| Document Period End Date | Mar. 28, 2022 |
| Entity Registrant Name | Shockwave Medical, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38829 |
| Entity Tax Identification Number | 27-0494101 |
| Entity Address, Address Line One | 5403 Betsy Ross Drive |
| Entity Address, City or Town | Santa Clara |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 95054 |
| City Area Code | (510) |
| Local Phone Number | 279-4262 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, par value $0.001 per share |
| Trading Symbol | SWAV |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
