Organization and Basis of Presentation	3 Months Ended
Organization and Basis of Presentation	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation The Company Tandem Diabetes Care, Inc. is a medical device company with an innovative approach to the design, development and commercialization of products for people with insulin-dependent diabetes. The Company is incorporated in the state of Delaware. Unless the context requires otherwise, the terms the “Company” or “Tandem” refer to Tandem Diabetes Care, Inc., together with its wholly-owned subsidiary in Canada. The Company manufactures, sells and supports insulin pump products that are designed to address the evolving needs and preferences of differentiated segments of the insulin-dependent diabetes market. The Company’s manufacturing, sales and support activities principally focus on the t:slim X2 Insulin Delivery System (t:slim X2), the Company’s flagship pump platform which is capable of remote feature updates and is designed to display continuous glucose monitoring (CGM) sensor information directly on the pump home screen. The Company’s insulin pump products are compatible with the t:connect cloud-based data management application (t:connect) and the Tandem Device Updater, a Mac and PC-compatible tool for the remote update of the Company’s insulin pump software. The Company’s insulin pump products are generally considered durable medical equipment and have an expected lifespan of at least four years. In addition to insulin pumps, the Company sells disposable products that are used together with the pumps and are replaced every few days, including cartridges for storing and delivering insulin, and infusion sets that connect the insulin pump to a user’s body. The Company has commercially launched seven insulin pumps in the United States since 2012 and two pumps outside the United States since 2018. Four of the insulin pumps have featured integration with CGM technology, of which two have also featured an automated insulin delivery (AID) algorithm. In June 2018, the t:slim X2 was the first insulin pump designated as compatible with integrated CGM (iCGM) devices; in February 2019, the t:slim X2 was the first insulin pump in a new device category called Alternate Controller Enabled Infusion Pumps (ACE pumps); and in December 2019, Control-IQ technology for the t:slim X2 insulin pump was the first automated insulin dosing software in a new interoperable automated glycemic controller category. The Company believes that the three new classifications by the United States Food and Drug Administration (FDA) for the interoperability of devices for AID will help support continued rapid innovation by streamlining the regulatory pathway for integrated products. As of March 31, 2020, the Company had $160.2 million in cash and cash equivalents and short-term investments. The Company has incurred operating losses since its inception and had an accumulated deficit of $639.7 million as of March 31, 2020, which included a net loss of $14.9 million for the three months ended March 31, 2020. Management believes that the cash, cash equivalents and short-term investments on hand will be sufficient to satisfy the Company’s liquidity requirements for at least the next 12 months from the date of this filing. The Company’s ability to execute on its business strategy, meet its future liquidity requirements, and achieve and maintain profitable operations, is dependent on a number of factors, including its ability to continue to gain market acceptance of its products and achieve a level of revenues adequate to support its cost structure, achieve renewal pump sales objectives, develop and launch new products, expand the commercialization of products into new international markets, maximize manufacturing efficiencies, satisfy increasing production requirements, leverage the investments made in its sales, clinical, marketing and customer support organizations, and operate its business and manufacture and sell products without infringing on third-party intellectual property rights. The Company has funded its operations primarily through cash collected from product sales, private and public offerings of equity securities, and through debt financing which has since been fully repaid. The Company may in the future seek additional capital from public or private offerings of equity or debt securities, or it may elect to borrow capital under new credit arrangements or from other sources. If the Company issues equity or debt securities to raise additional funds, its existing stockholders may experience dilution, it may incur significant financing or debt service costs, and the new equity or debt securities may have rights, preferences and privileges senior to those of its existing stockholders. There can be no assurance that equity or debt financing will be available on acceptable terms, or at all. Basis of Presentation and Principles of Consolidation The Company has prepared the accompanying unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and pursuant to the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments which are of a normal and recurring nature, considered necessary for a fair presentation of the financial information contained herein, have been included. Interim financial results are not necessarily indicative of results anticipated for the full year or any other period(s). These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (Annual Report), from which the balance sheet information herein was derived. The condensed consolidated financial statements include the accounts of Tandem Diabetes Care, Inc. and its wholly owned subsidiary in Canada. All significant intercompany balances and transactions have been eliminated in consolidation. The functional currency of our foreign subsidiary is the local currency. The Company translates the financial statements of its foreign subsidiary into U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates for each period for revenue, costs and expenses. Translation related adjustments are included in comprehensive loss and in accumulated other comprehensive income (loss) in the equity section of the Company’s condensed consolidated balance sheets. Foreign exchange gains or losses resulting from balances denominated in a currency other than the functional currency are recognized in interest and other income or interest and other expense in the Company’s condensed consolidated statements of operations. Reclassification Prior year amounts related to the presentation of proceeds from maturities and sales of short-term investments on the Company’s condensed consolidated statement of cash flows, have been reclassified to conform to the current year presentation.