| Document and Entity Information Document | Nov. 03, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 3, 2021 |
| Entity Registrant Name | iRhythm Technologies, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-37918 |
| Entity Tax Identification Number | 20-8149544 |
| Entity Address, Address Line One | 699 8th Street |
| Entity Address, Address Line Two | Suite 600 |
| Entity Address, City or Town | San Francisco |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94103 |
| City Area Code | 415 |
| Local Phone Number | 632-5700 |
| 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 | IRTC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001388658 |
| Amendment Flag | false |
