Schedule III - SCHEDULE OF REAL ESTATE AND ACCUMULATED DEPRECIATION -Schedule of Real Estate and Accumulated Depreciation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) communicationSite	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Number of units | communicationSite	183,860
Encumbrances	$ 3,136.7	$ 3,100.0
Gross amount carried at close of current period	18,492.9	17,429.3	$ 15,960.1	$ 15,349.0
Accumulated depreciation at close of current period	$ (6,921.0)	$ (6,382.2)	$ (5,724.7)	$ (5,181.2)
Percentage exceeds total amounts		5.00%
Maximum
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Life on which depreciation in latest income statements is computed	20 years