Amortization Of Lease Incentive, Period

No definition available.

Name:	amt_AmortizationOfLeaseIncentivePeriod
Namespace Prefix:	amt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482130/360-10-45-4

+ Details

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of incentive granted by lessor to lessee.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 840
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481178/840-20-25-6

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 840
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481178/840-20-25-7

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 5
-Subparagraph (a)
-SubTopic 10
-Topic 842
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479924/842-10-30-5

+ Details

Name:	us-gaap_IncentiveToLessee
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479773/842-30-50-3

+ Details

Name:	us-gaap_LessorLeaseDescriptionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of lessee's right to use underlying asset under operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-1

+ Details

Name:	us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_ChangeInAccountingEstimateByTypeAxis=us-gaap_ServiceLifeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_LeaseAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

LEASES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
LEASES - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Lessor, Lease, Description [Line Items]
Amortization of lease incentive, period	10 years
Right-of-use asset	$ 9,199.8		$ 8,878.8
Service Life
Lessor, Lease, Description [Line Items]
Right-of-use asset	515.0
Lease Agreements
Lessor, Lease, Description [Line Items]
Asset impairment charges	0.0	$ 0.0
Other Current Assets
Lessor, Lease, Description [Line Items]
Lease incentives	35.5
Other Noncurrent Assets
Lessor, Lease, Description [Line Items]
Lease incentives	$ 339.4