ACQUISITIONS - SCHEDULE OF PRELIMINARY ALLOCATION OF PURCHASE PRICE FOR ACQUISITION (Details 1) $ in Millions, ₨ in Billions						3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($) site	May 31, 2018 USD ($) site	May 31, 2018 INR (₨)	Mar. 31, 2018 USD ($) site	Mar. 31, 2018 INR (₨)	Jun. 30, 2018 USD ($) site	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) site	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Business Combination:
Goodwill	$ 5,526.6					$ 5,526.6		$ 5,526.6		$ 5,638.4
Asset Acquisition:
Current assets	2,127.1					2,127.1		2,127.1		2,038.1
Property and equipment	11,067.0					11,067.0		11,067.0		11,101.0
Intangible assets	11,758.2					11,758.2		11,758.2		11,783.3
Current liabilities	(4,562.9)					(4,562.9)		(4,562.9)		(2,512.1)
Deferred tax liability	752.2					752.2		752.2		898.1
Other non-current liabilities	(1,246.9)					(1,246.9)		(1,246.9)		(1,244.2)
Goodwill	5,526.6					5,526.6		5,526.6		5,638.4
Acquisition and merger related expenses						4.5	$ 2.4	5.9	$ 8.1
Tenant-related intangible assets
Asset Acquisition:
Intangible assets	8,454.2					8,454.2		$ 8,454.2		8,396.2
Tenant-related intangible assets | Maximum
Asset Acquisition:
Estimated useful lives								20 years
Network location intangible assets
Asset Acquisition:
Intangible assets	3,259.6					3,259.6		$ 3,259.6		$ 3,333.5
Network location intangible assets | Maximum
Asset Acquisition:
Estimated useful lives								20 years		20 years
Vodafone
Business Combination:
Goodwill				$ 0.0
Asset Acquisition:
Current assets				15.1
Non-current assets				5.8
Property and equipment				194.6
Current liabilities				(13.1)
Deferred tax liability				0.0
Other non-current liabilities				(12.5)
Net assets acquired				587.9
Goodwill				0.0
Fair value of net assets acquired				587.9
Debt assumed				0.0
Purchase price				587.9
Acquisition and merger related expenses				1.3
Vodafone | Communication Sites
Asset Acquisition:
Purchase price				$ 587.9	₨ 38.3
Number of sites acquired | site				10,200
Vodafone | Tenant-related intangible assets
Asset Acquisition:
Intangible assets				$ 309.5
Vodafone | Tenant-related intangible assets | Maximum
Asset Acquisition:
Estimated useful lives				20 years	20 years
Vodafone | Network location intangible assets
Asset Acquisition:
Intangible assets				$ 88.5
Vodafone | Network location intangible assets | Maximum
Asset Acquisition:
Estimated useful lives				20 years	20 years
Other
Business Combination:
Goodwill	0.0					0.0		$ 0.0
Asset Acquisition:
Current assets	2.3					2.3		2.3
Non-current assets	3.9					3.9		3.9
Property and equipment	55.4					55.4		55.4
Current liabilities	(0.7)					(0.7)		(0.7)
Deferred tax liability				$ 0.0
Other non-current liabilities	(5.9)					(5.9)		(5.9)
Net assets acquired	153.5					153.5		153.5
Goodwill	0.0					0.0		0.0
Fair value of net assets acquired	$ 153.5					$ 153.5		153.5
Debt assumed								0.0
Purchase price								153.5
Other | Communication Sites
Asset Acquisition:
Purchase price								$ 153.5
Number of sites acquired | site	761					761		761
Other | Communication Sites | PERU
Asset Acquisition:
Number of sites acquired | site	44					44		44
Other | Tenant-related intangible assets
Asset Acquisition:
Intangible assets	$ 65.2					$ 65.2		$ 65.2
Other | Tenant-related intangible assets | Maximum
Asset Acquisition:
Estimated useful lives	20 years
Other | Network location intangible assets
Asset Acquisition:
Intangible assets	$ 33.3					$ 33.3		$ 33.3
Other | Network location intangible assets | Maximum
Asset Acquisition:
Estimated useful lives	20 years
Idea
Business Combination:
Current assets		$ 100.7
Non-current assets		2.6
Property and equipment		161.2
Current liabilities		(52.5)
Deferred tax liability		(20.7)
Other non-current liabilities		(10.5)
Net assets acquired		584.9
Goodwill		50.6
Fair value of net assets acquired		635.5
Debt assumed		0.0
Purchase price		635.5
Asset Acquisition:
Goodwill		$ 50.6
Number of sites acquired | site		9,700
Idea | Communication Sites
Asset Acquisition:
Purchase price		$ 635.5	₨ 42.8
Idea | Tenant-related intangible assets
Business Combination:
Intangible assets		$ 321.2
Idea | Tenant-related intangible assets | Maximum
Asset Acquisition:
Estimated useful lives		20 years	20 years
Idea | Network location intangible assets
Business Combination:
Intangible assets		$ 82.9
Idea | Network location intangible assets | Maximum
Asset Acquisition:
Estimated useful lives		20 years	20 years