Acquisitions (Narrative) (Details)	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2019 USD ($) item	Sep. 30, 2019 site	Mar. 31, 2019 USD ($)	Jun. 30, 2019 USD ($) item entity
Business Acquisition [Line Items]
Preliminary purchase price allocation				$ 0
Other Acquisitions [Member]
Business Acquisition [Line Items]
Number of towers acquired | item				136
Property and equipment				$ 21,200,000
Intangible assets				102,100,000
Working capital adjustments				$ 2,100,000
Business Combination [Member]
Business Acquisition [Line Items]
Number of businesses acquired | entity				1
Consideration transferred			$ 3,000,000.0
Acquisition costs paid through the issuance of common stock			$ 1,700,000
Atlas Tower South Africa [Member] | Scenario, Forecast [Member]
Business Acquisition [Line Items]
Percentage of joint venture not being acquired		6.00%
Number of years joint venture has been operating		4 years
Number of sites owned and operated by joint venture | site		900
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of towers acquired | item	59
Cash paid for acquisition	$ 17,900,000