Acquisitions (Narrative) (Details) $ in Millions	1 Months Ended	3 Months Ended
	Oct. 31, 2015 USD ($) item	Sep. 30, 2015 item
Other Acquisitions [Member]
Business Acquisition [Line Items]
Number of towers acquired		225
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of towers acquired	24
Cash paid for acquisition | $	$ 19.8