v3.19.2
Cover Page - shares
6 Months Ended
Jun. 30, 2019
Jul. 26, 2019
Cover page.    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2019  
Document Transition Report false  
Entity File Number 001-36189  
Entity Registrant Name Tandem Diabetes Care, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 20-4327508  
Entity Address, Address Line One 11075 Roselle Street  
Entity Address, Postal Zip Code 92121  
Entity Address, City or Town San Diego  
Entity Address, State or Province CA  
City Area Code 858  
Local Phone Number 366-6900  
Title of 12(b) Security Common Stock, par value $0.001 per share  
Trading Symbol TNDM  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   58,652,286
Amendment Flag false  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001438133  
Current Fiscal Year End Date --12-31