v3.26.1
COVER - shares
 6 Months Ended
Jun. 30, 2026
Jul. 21, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 001-14195  
Entity Registrant Name AMERICAN TOWER CORPORATION  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 65-0723837  
Entity Address, Address Line One 222 Berkeley Street  
Entity Address, City or Town Boston  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02116  
City Area Code 617  
Local Phone Number 375-7500  
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   465,960,048
Entity Central Index Key 0001053507  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Common Stock, $0.01 par value    
Document Information [Line Items]    
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol AMT  
Security Exchange Name NYSE  
0.450% Senior Notes due 2027    
Document Information [Line Items]    
Title of 12(b) Security 0.450% Senior Notes due 2027  
Trading Symbol AMT 27C  
Security Exchange Name NYSE  
0.400% Senior Notes due 2027    
Document Information [Line Items]    
Title of 12(b) Security 0.400% Senior Notes due 2027  
Trading Symbol AMT 27D  
Security Exchange Name NYSE  
4.125% Senior Notes Due 2027    
Document Information [Line Items]    
Title of 12(b) Security 4.125% Senior Notes due 2027  
Trading Symbol AMT 27F  
Security Exchange Name NYSE  
0.500% Senior Notes due 2028    
Document Information [Line Items]    
Title of 12(b) Security 0.500% Senior Notes due 2028  
Trading Symbol AMT 28A  
Security Exchange Name NYSE  
0.875% Senior Notes due 2029    
Document Information [Line Items]    
Title of 12(b) Security 0.875% Senior Notes due 2029  
Trading Symbol AMT 29B  
Security Exchange Name NYSE  
0.950% Senior Notes due 2030    
Document Information [Line Items]    
Title of 12(b) Security 0.950% Senior Notes due 2030  
Trading Symbol AMT 30C  
Security Exchange Name NYSE  
3.900% Senior Notes due 2030    
Document Information [Line Items]    
Title of 12(b) Security 3.900% Senior Notes due 2030  
Trading Symbol AMT 30D  
Security Exchange Name NYSE  
4.625% Senior Notes due 2031    
Document Information [Line Items]    
Title of 12(b) Security 4.625% Senior Notes due 2031  
Trading Symbol AMT 31B  
Security Exchange Name NYSE  
1.000% Senior Notes due 2032    
Document Information [Line Items]    
Title of 12(b) Security 1.000% Senior Notes due 2032  
Trading Symbol AMT 32  
Security Exchange Name NYSE  
3.625% Senior Notes due 2032    
Document Information [Line Items]    
Title of 12(b) Security 3.625% Senior Notes due 2032  
Trading Symbol AMT 32B  
Security Exchange Name NYSE  
1.250% Senior Notes due 2033    
Document Information [Line Items]    
Title of 12(b) Security 1.250% Senior Notes due 2033  
Trading Symbol AMT 33  
Security Exchange Name NYSE  
4.000% Senior Notes due 2033    
Document Information [Line Items]    
Title of 12(b) Security 4.000% Senior Notes due 2033  
Trading Symbol AMT 33D  
Security Exchange Name NYSE  
4.100% Senior Notes due 2034    
Document Information [Line Items]    
Title of 12(b) Security 4.100% Senior Notes due 2034  
Trading Symbol AMT 34A  
Security Exchange Name NYSE