v3.26.3
LONG-TERM OBLIGATIONS - Offerings of Senior Notes (Details)
€ in Millions, $ in Millions
9 Months Ended
Sep. 14, 2026
USD ($)
Jun. 18, 2026
May 27, 2026
USD ($)
May 27, 2026
EUR (€)
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
May 27, 2026
EUR (€)
Dec. 31, 2025
Debt Instrument [Line Items]                
Proceeds from issuance of senior notes         $ 2,466.6 $ 2,153.3    
American Tower Corporation | Senior notes                
Debt Instrument [Line Items]                
Proceeds from issuance of senior notes $ 1,600.0              
Maximum adjusted EBITDA         3.5      
American Tower Corporation | Senior notes | Debt Instrument, Redemption Option Two                
Debt Instrument [Line Items]                
Redemption price percentage         101.00%      
American Tower Corporation | Senior notes | 4.000% senior notes                
Debt Instrument [Line Items]                
Stated interest rate (as a percent)     4.00%   4.00%   4.00%  
Aggregate principal amount issued     $ 872.0   $ 872.0   € 750.0  
Proceeds from issuance of senior notes     $ 863.5 € 742.7        
American Tower Corporation | Senior notes | 4.125% senior notes                
Debt Instrument [Line Items]                
Stated interest rate (as a percent)   4.125%     4.125%      
Redemption price percentage   100.969%            
American Tower Corporation | Senior notes | 5.300% senior notes                
Debt Instrument [Line Items]                
Stated interest rate (as a percent) 5.30%       5.30%      
Aggregate principal amount issued $ 500.0       $ 500.0      
American Tower Corporation | Senior notes | 5.560% senior notes                
Debt Instrument [Line Items]                
Stated interest rate (as a percent) 5.56%       5.56%      
Aggregate principal amount issued $ 500.0       $ 500.0      
American Tower Corporation | Senior notes | 5.750% senior notes                
Debt Instrument [Line Items]                
Stated interest rate (as a percent) 5.75%       5.75%      
Aggregate principal amount issued $ 600.0       $ 600.0      
American Tower Corporation | Senior notes | 1.450% senior notes                
Debt Instrument [Line Items]                
Stated interest rate (as a percent) 1.45%             1.45%