Acquisitions (Narrative) (Details) $ in Millions	1 Months Ended	6 Months Ended
	Jul. 28, 2016 USD ($) item	Jun. 30, 2016 USD ($) item
Other Acquisitions [Member]
Business Acquisition [Line Items]
Number of towers acquired | item		159
Cash paid for acquisition		$ 113.5
Property and equipment		31.3
Intangible assets		79.6
Working capital adjustments		$ 2.6
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of towers acquired | item	12
Cash paid for acquisition	$ 8.4