GOODWILL AND OTHER INTANGIBLE ASSETS (Other Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 17,931.6	$ 16,040.9
Accumulated Amortization	(5,613.2)	(4,866.6)
Net Book Value	$ 12,318.4	11,174.3
Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	3 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	20 years
Acquired network location intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 5,150.8	4,780.3
Accumulated Amortization	(1,920.4)	(1,704.9)
Net Book Value	$ 3,230.4	3,075.4
Acquired network location intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	20 years
Acquired tenant-related intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 12,674.1	11,156.5
Accumulated Amortization	(3,674.6)	(3,147.2)
Net Book Value	$ 8,999.5	8,009.3
Intangible assets, useful life	20 years
Acquired tenant-related intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	20 years
Acquired licenses and other intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 106.7	104.1
Accumulated Amortization	(18.2)	(14.5)
Net Book Value	$ 88.5	$ 89.6
Acquired licenses and other intangibles | Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	3 years
Acquired licenses and other intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life	20 years