CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
REVENUES:
Total operating revenues	$ 2,012.9	$ 1,953.6	$ 5,919.0	$ 5,656.6
Costs of operations (exclusive of items shown separately below):
Property	552.1	548.0	1,626.5	1,630.4
Depreciation, amortization and accretion	473.9	442.8	1,401.1	1,328.6
Selling, general, administrative and development expense	176.0	187.9	582.4	550.8
Other operating expenses	15.3	34.7	67.7	83.5
Total operating expenses	1,227.8	1,225.3	3,705.8	3,629.5
OPERATING INCOME	785.1	728.3	2,213.2	2,027.1
OTHER INCOME (EXPENSE):
Interest income	9.7	12.2	28.2	36.3
Interest expense	(190.9)	(201.3)	(597.4)	(613.3)
Loss on retirement of long-term obligations	(37.2)	0.0	(71.8)	(22.2)
Other (expense) income (including foreign currency (losses) gains of $(49.4), $(1.1), $(152.7) and $13.7, respectively)	(64.5)	2.8	(170.8)	19.6
Total other expense	(282.9)	(186.3)	(811.8)	(579.6)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	502.2	542.0	1,401.4	1,447.5
Income tax provision	(39.3)	(36.7)	(71.5)	(100.3)
NET INCOME	462.9	505.3	1,329.9	1,347.2
Net loss (income) attributable to noncontrolling interests	1.5	(6.7)	(4.4)	(22.1)
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION STOCKHOLDERS	464.4	498.6	1,325.5	1,325.1
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION COMMON STOCKHOLDERS	$ 464.4	$ 498.6	$ 1,325.5	$ 1,325.1
NET INCOME PER COMMON SHARE AMOUNTS:
Basic net income attributable to American Tower Corporation common stockholders (in dollars per share)	$ 1.05	$ 1.13	$ 2.99	$ 3.00
Diluted net income attributable to American Tower Corporation common stockholders (in dollars per share)	$ 1.04	$ 1.12	$ 2.97	$ 2.98
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING (in thousands):
BASIC (in shares)	443,766	442,763	443,420	442,110
DILUTED (in shares)	446,156	445,829	446,008	445,352
Property
REVENUES:
Total operating revenues	$ 1,987.6	$ 1,921.6	$ 5,854.0	$ 5,556.5
Services
REVENUES:
Total operating revenues	25.3	32.0	65.0	100.1
Costs of operations (exclusive of items shown separately below):
Services	$ 10.5	$ 11.9	$ 28.1	$ 36.2