| Cover | Nov. 25, 2019 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Nov. 25, 2019 |
| Entity Registrant Name | Penumbra, Inc. |
| Entity Central Index Key | 0001321732 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-37557 |
| Entity Tax Identification Number | 05-0605598 |
| Entity Address, Address Line One | One Penumbra Place |
| Entity Address, City or Town | Alameda |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94502 |
| City Area Code | 510 |
| Local Phone Number | 748-3200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, Par value $0.001 per share |
| Trading Symbol | PEN |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
