v3.22.0.1
Cover Page - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2021
Feb. 07, 2022
Jun. 30, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 1-33409    
Entity Registrant Name T-MOBILE US, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 20-0836269    
Entity Address, Address Line One 12920 SE 38th Street    
Entity Address, City or Town Bellevue    
Entity Address, State or Province WA    
Entity Address, Postal Zip Code 98006-1350    
City Area Code (425)    
Local Phone Number 378-4000    
Title of 12(b) Security Common Stock, par value $0.00001 per share    
Trading Symbol TMUS    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
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    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 86.1
Entity Common Stock, Shares Outstanding (in shares)   1,249,289,954  
Documents Incorporated by Reference Part III of this Annual Report on Form 10-K will be incorporated by reference from certain portions of the definitive Proxy Statement for the Registrant’s 2022 Annual Meeting of Stockholders, which definitive Proxy Statement will be filed with the Securities and Exchange Commission pursuant to Regulation 14A or will be included in an amendment to this Report.    
Entity Central Index Key 0001283699    
Amendment Flag false    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY