| Cover Page Document | Feb. 10, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 10, 2021 |
| Entity Registrant Name | TRUPANION, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-36537 |
| Entity Tax Identification Number | 83-0480694 |
| Entity Address, Address Line One | 6100 4th Avenue S, Suite 200 |
| Entity Address, City or Town | Seattle |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98108 |
| City Area Code | 855 |
| Local Phone Number | 727 - 9079 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Amendment Flag | false |
| Document Fiscal Year Focus | 2020 |
| Document Fiscal Period Focus | FY |
| Entity Central Index Key | 0001371285 |
| Title of 12(b) Security | Common stock, $0.00001 par value per share |
| Trading Symbol | TRUP |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
