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.

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For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Amount of investment in marketable security.

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Amount of unrealized gain (loss) on investment in marketable security.

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FAIR VALUE MEASUREMENTS - NARRATIVE (Details) - USD ($)		3 Months Ended	9 Months Ended
FAIR VALUE MEASUREMENTS - NARRATIVE (Details) - USD ($)	Feb. 28, 2018	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		$ 67,700,000	$ 67,700,000
Marketable securities, unrealized gain			500,000
Acquisition-related contingent consideration payments between value, low		0	0
Acquisition-related contingent consideration payments between value, high		900,000	900,000
Impairment charges		1,800,000	182,400,000
Tenant-related intangibles net book value		11,481,700,000	11,481,700,000	$ 11,783,300,000
Debt, long-term and short-term, combined amount		21,264,200,000	21,264,200,000	20,205,100,000
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value		21,200,000,000	21,200,000,000	20,600,000,000
Estimate of Fair Value Measurement \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value		13,500,000,000	13,500,000,000	13,300,000,000
Estimate of Fair Value Measurement \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value		7,700,000,000	7,700,000,000	7,300,000,000
Tenant-related intangible assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Tenant-related intangibles net book value		8,244,700,000	8,244,700,000	$ 8,396,200,000
Tata Teleservices \| Tenant-related intangible assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Tenant-related intangibles net book value		$ 355,700,000	355,700,000
Tower and network
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charges			$ 29,500,000
Tower and network \| Aircel, Asia
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of intangible assets	$ 40,100,000
Tenant-related intangible assets \| Aircel, Asia
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of intangible assets	$ 107,300,000