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LONG-TERM OBLIGATIONS - Bank Facilities (Details) € in Millions		6 Months Ended
	May 21, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2024 EUR (€)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 EUR (€)	May 21, 2024 EUR (€)	May 15, 2024 USD ($)	Feb. 14, 2024 USD ($)	Jan. 12, 2024 USD ($)	Dec. 31, 2023 USD ($)
Line of Credit Facility [Line Items]
Borrowings under credit facilities		$ 5,097,900,000		$ 4,780,000,000
American Tower Corporation
Line of Credit Facility [Line Items]
Long-term debt		36,520,200,000								$ 36,472,000,000
0.600% senior notes \| American Tower Corporation \| Senior notes
Line of Credit Facility [Line Items]
Debt interest rate (as a percent)									0.60%	0.60%
Long-term debt		0							$ 0	$ 500,000,000.0
5.00% senior notes \| American Tower Corporation \| Senior notes
Line of Credit Facility [Line Items]
Debt interest rate (as a percent)								5.00%		5.00%
Long-term debt		0						$ 0		$ 1,000,100,000
2021 EUR Three Year Delayed Draw Term Loan \| American Tower Corporation \| Unsecured debt
Line of Credit Facility [Line Items]
Debt instrument term	3 years
Long-term debt	$ 895,500,000	0				€ 825.0				$ 910,700,000
3.375% senior notes \| American Tower Corporation \| Senior notes
Line of Credit Facility [Line Items]
Debt interest rate (as a percent)							3.375%			3.375%
Long-term debt		0					$ 0			$ 649,700,000
Revolving Credit Facility \| 2021 Multicurrency Credit Facility \| American Tower Corporation
Line of Credit Facility [Line Items]
Borrowings under credit facilities		3,600,000,000
Repayment of indebtedness under credit facility		3,100,000,000
Line of credit maximum borrowing capacity		6,000,000,000
Long-term debt		1,170,000,000								723,400,000
Revolving Credit Facility \| 2021 Multicurrency Credit Facility In Euros \| American Tower Corporation
Line of Credit Facility [Line Items]
Borrowings under credit facilities		1,000,000,000	€ 900.0
Repayment of indebtedness under credit facility		1,200,000,000	€ 1,100.0
Long-term debt \| €					€ 0.0
Revolving Credit Facility \| 2021 Credit Facility \| American Tower Corporation
Line of Credit Facility [Line Items]
Borrowings under credit facilities		1,500,000,000
Repayment of indebtedness under credit facility		1,000,000,000
Line of credit maximum borrowing capacity		4,000,000,000
Long-term debt		$ 2,113,400,000								$ 1,603,400,000