v3.26.1
LONG-TERM OBLIGATIONS - Long-Term Debt Obligations (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Jun. 18, 2026
May 27, 2026
May 21, 2026
Apr. 14, 2026
Feb. 13, 2026
Dec. 31, 2025
Debt Instrument [Line Items]              
Finance lease obligations $ 14.4           $ 15.9
Total 37,189.6           37,220.3
Less current portion of long-term obligations (5,226.5)           (3,387.8)
Long-term obligations 31,963.1           33,832.5
American Tower Corporation              
Debt Instrument [Line Items]              
Long-term debt 35,379.7           35,409.2
American Tower subsidiary              
Debt Instrument [Line Items]              
Long-term debt 1,795.5           $ 1,795.2
Senior notes | 4.400% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent)           4.40% 4.40%
Long-term debt 0.0           $ 499.9
Senior notes | 1.600% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent)         1.60%   1.60%
Long-term debt 0.0       $ 0.0   $ 699.7
Senior notes | 1.950% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent)       1.95%     1.95%
Long-term debt $ 0.0     $ 0.0     $ 586.9
Senior notes | 1.450% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 1.45%            
Long-term debt $ 599.7           598.9
Senior notes | 3.375% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.375%            
Long-term debt $ 999.4           998.5
Senior notes | 3.125% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.125%            
Long-term debt $ 399.8           399.6
Senior notes | 2.750% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 2.75%            
Long-term debt $ 749.4           749.0
Senior notes | 0.450% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 0.45%            
Long-term debt $ 856.0           879.7
Senior notes | 0.400% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 0.40%            
Long-term debt $ 570.4           585.8
Senior notes | 3.650% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.65%            
Long-term debt $ 648.8           648.0
Senior notes | 4.125% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.125% 4.125%          
Long-term debt $ 399.2           703.1
Senior notes | 3.55% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.55%            
Long-term debt $ 749.1           748.7
Senior notes | 3.600% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.60%            
Long-term debt $ 698.4           697.9
Senior notes | 0.500% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 0.50%            
Long-term debt $ 854.7           878.3
Senior notes | 1.500% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 1.50%            
Long-term debt $ 648.9           648.5
Senior notes | 5.500% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.50%            
Long-term debt $ 697.2           696.5
Senior notes | 5.250% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.25%            
Long-term debt $ 647.1           646.4
Senior notes | 5.800% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.80%            
Long-term debt $ 746.5           745.9
Senior notes | 5.200% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.20%            
Long-term debt $ 645.8           645.1
Senior notes | 3.950% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.95%            
Long-term debt $ 596.6           596.0
Senior notes | 0.875% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 0.875%            
Long-term debt $ 854.4           878.2
Senior notes | 3.800% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.80%            
Long-term debt $ 1,643.4           1,642.4
Senior notes | 2.900% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 2.90%            
Long-term debt $ 746.5           746.0
Senior notes | 5.000% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.00%            
Long-term debt $ 595.1           594.4
Senior notes | 4.900% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.90%            
Long-term debt $ 848.2           848.0
Senior notes | 3.900% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.90%            
Long-term debt $ 567.6           583.3
Senior notes | 2.100% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 2.10%            
Long-term debt $ 745.7           745.2
Senior notes | 0.950% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 0.95%            
Long-term debt $ 567.3           583.1
Senior notes | 1.875% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 1.875%            
Long-term debt $ 795.7           795.2
Senior notes | 2.700% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 2.70%            
Long-term debt $ 696.6           696.3
Senior notes | 4.625% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.625%            
Long-term debt $ 566.4           582.2
Senior notes | 2.300% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 2.30%            
Long-term debt $ 694.9           694.5
Senior notes | 1.000% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 1.00%            
Long-term debt $ 738.2           758.8
Senior notes | 4.050% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.05%            
Long-term debt $ 644.8           644.4
Senior notes | 3.625% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.625%            
Long-term debt $ 567.9           583.9
Senior notes | 4.700% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.70%            
Long-term debt $ 840.9           840.4
Senior notes | 5.650% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.65%            
Long-term debt $ 792.8           792.3
Senior notes | 1.250% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 1.25%            
Long-term debt $ 566.4           582.4
Senior notes | 5.550% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.55%            
Long-term debt $ 842.6           842.2
Senior notes | 4.000% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.00%   4.00%        
Long-term debt $ 848.3           0.0
Senior notes | 5.900% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.90%            
Long-term debt $ 743.2           742.9
Senior notes | 5.450% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.45%            
Long-term debt $ 641.9           641.5
Senior notes | 4.100% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 4.10%            
Long-term debt $ 564.9           580.8
Senior notes | 5.400% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.40%            
Long-term debt $ 592.9           592.5
Senior notes | 5.350% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 5.35%            
Long-term debt $ 731.1           731.4
Senior notes | 3.700% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.70%            
Long-term debt $ 592.9           592.8
Senior notes | 3.100% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 3.10%            
Long-term debt $ 1,039.3           1,039.1
Senior notes | 2.950% senior notes | American Tower Corporation              
Debt Instrument [Line Items]              
Debt interest rate (as a percent) 2.95%            
Long-term debt $ 1,024.9           1,024.5
Secured debt | Series 2018-1A securities | American Tower subsidiary              
Debt Instrument [Line Items]              
Long-term debt 498.7           498.3
Secured debt | Series 2023-1A Securities | American Tower subsidiary              
Debt Instrument [Line Items]              
Long-term debt 1,293.6           1,291.7
Unsecured debt | 2021 Term Loan | American Tower Corporation              
Debt Instrument [Line Items]              
Long-term debt 997.9           998.1
Unsecured debt | Other subsidiary debt | American Tower subsidiary              
Debt Instrument [Line Items]              
Long-term debt 3.2           5.2
Revolving Credit Facility | 2021 Multicurrency Credit Facility | American Tower Corporation              
Debt Instrument [Line Items]              
Long-term debt 1,085.0           380.0
Revolving Credit Facility | 2021 Credit Facility | American Tower Corporation              
Debt Instrument [Line Items]              
Long-term debt $ 695.0           $ 0.0