| Document and Entity Information | Feb. 23, 2021 |
| Document And Entity Information [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 23, 2021 |
| Entity Registrant Name | AtriCure, Inc. |
| Entity Central Index Key | 0001323885 |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 000-51470 |
| Entity Tax Identification Number | 34-1940305 |
| Entity Address, Address Line One | 7555 Innovation Way |
| Entity Address, City or Town | Mason |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 45040 |
| City Area Code | 513 |
| Local Phone Number | 755-4100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-Commencement Tender Offer | false |
| Pre-Commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $.001 par value |
| Trading Symbol | ATRC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
