Organization and Description of Business	12 Months Ended
Organization and Description of Business	Dec. 31, 2020
Accounting Policies [Abstract]
Organization and Description of Business	Organization and Description of Business iRhythm Technologies, Inc. (the “Company”) was incorporated in the state of Delaware in September 2006. The Company is a digital healthcare company redefining the way cardiac arrhythmias are clinically diagnosed by combining wearable biosensing technology with cloud-based data analytics and deep-learning capabilities. The Company began commercial operations in the United States in 2009 following clearance by the U.S. Food and Drug Administration. The Company is headquartered in San Francisco, California, which also serves as a clinical center. The Company has additional clinical centers in Lincolnshire, Illinois and Houston, Texas and a manufacturing facility in Cypress, California. In March 2016, the Company formed a wholly-owned subsidiary in the United Kingdom. The Company manages its operations as a single operating segment. Substantially all of the Company’s assets are maintained in the United States. The Company derives substantially all of its revenue from sales to customers in the United States. On September 10, 2019, the Company issued and sold an aggregate of 1,575,342 shares (the "2019 Shares") of common stock, in a public offering at a price of $73.00 per share. The 2019 Shares included the full exercise of the underwriters’ option to purchase an additional 205,479 shares of common stock. Total proceeds received from the offering were $107.3 million, after deducting discounts and issuance costs. On August 21, 2020, the Company issued and sold an aggregate of 1,257,142 shares (the "Shares") of common stock, in a public offering at a price of $175.00 per share. The Shares included the full exercise of the underwriters’ option to purchase an additional 163,975 shares of common stock. Total proceeds received from the offering were $206.8 million, after deducting discounts and issuance costs. Revision of Prior Period Financial Statements In 2019, and as previously disclosed in the Company’s Quarterly Report on Form 10-Q for the three and nine-months ended September 30, 2019, the Company identified errors in its historical accounting for revenues, contractual allowances, allowance for doubtful accounts and certain other items. The identified errors impacted the Company's accompanying 2018 unaudited quarterly and annual financial statements and its 2019 unaudited first and second quarter financial statements. In accordance with SEC Staff Accounting Bulletin No. 99, "Materiality," and SEC Staff Accounting Bulletin No. 108,"Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements;" the Company evaluated the errors and determined that the related impacts were not material to any prior annual or interim period, but that correcting the cumulative impact of such errors would be significant to our results of operations for the three and nine months ended September 30, 2019 and the year-ended December 31, 2019. Accordingly, the Company has revised the accompanying 2018 annual consolidated financial statements to correct for such immaterial errors. A summary of the impact of the revisions to our previously issued annual financial statements is included in Note 14, Revision of Prior Period Financial Statements. Further, a summary of the impact of the revisions on the unaudited quarterly financial data is included in Note 13. Selected Quarterly Financial Data (unaudited). The affected balances in the accompanying footnotes to these consolidated financial statements have also been revised accordingly.