Segment Data (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | segment			2
Site leasing	$ 482,403	$ 459,003	$ 974,758	$ 911,186
Total assets	9,390,539		$ 9,390,539		$ 9,759,941
Site Leasing Revenue [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | segment			2
Brazil [Member]
Segment Reporting Information [Line Items]
Site leasing			$ 115,300	$ 111,900
Total assets	$ 1,000,000		$ 1,000,000		$ 1,400,000