ACQUISITIONS - NARRATIVE (Details) € in Millions, $ in Millions				3 Months Ended		12 Months Ended
	Dec. 31, 2019 USD ($) communication_site	Nov. 28, 2019 EUR (€) communication_site	Nov. 28, 2019 USD ($) communication_site	Mar. 31, 2020 USD ($) communication_site	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) communication_site	Apr. 01, 2020 communication_site	Dec. 19, 2019 communication_site
Business Acquisition [Line Items]
Payment received related to acquisition in France					$ 5.7
Estimated aggregate impact of acquisitions completed, revenue				$ 0.1
Estimated aggregate impact of acquisitions completed, gross margin (less than $0.1 million)				0.1
Post closing adjustments, goodwill				(0.1)
Eaton Towers Holding Limited
Business Acquisition [Line Items]
Number of communications sites acquired (in number of towers) | communication_site	5,800					5,800
Percentage of interests acquired	100.00%					100.00%
Number of markets in which entity operates | communication_site	5					5
Eaton Tower, existing debt assume						$ 2,000.0
Receivable for reimbursement of taxes						$ 9.7
Post closing adjustments, assets				15.1
Post closing adjustments, liabilities				15.0
Post closing adjustments, goodwill				$ (0.1)
Entel Acquisition
Business Acquisition [Line Items]
Number of communications sites acquired (in number of towers) | communication_site	2,400			156		2,400		3,200
Aggregate purchase price	$ 800.0			$ 39.7
Other Acquisitions 2020 | Communication Sites
Business Acquisition [Line Items]
Number of communications sites acquired (in number of towers) | communication_site				37
Aggregate purchase price				$ 11.2
Orange S.A. | Communication Sites
Business Acquisition [Line Items]
Number of communications sites acquired (in number of towers) | communication_site		2,000	2,000
Asset purchase period		5 years	5 years
Orange S.A. | Communication Sites | Subsequent Event
Business Acquisition [Line Items]
Number of communications sites acquired (in number of towers) | communication_site							113
Orange S.A. | Communication Sites | Minimum
Business Acquisition [Line Items]
Aggregate purchase price		€ 500.0	$ 550.5
Orange S.A. | Communication Sites | Maximum
Business Acquisition [Line Items]
Aggregate purchase price		€ 600.0	$ 660.5