Acquisitions (Narrative) (Details) $ in Millions		3 Months Ended
	Apr. 01, 2016 USD ($) item	Mar. 31, 2016 USD ($) item
Other Acquisitions [Member]
Business Acquisition [Line Items]
Number of towers acquired | item		117
Cash paid for acquisition		$ 74.8
Property and equipment		24.6
Intangible assets		45.8
Working capital adjustments		$ 4.4
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of towers acquired | item	31
Cash paid for acquisition	$ 32.5