PROPERTY AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property and equipment

Property and equipment (including assets held under capital leases) consisted of the following as of December 31,:

	Estimated Useful  Lives (years) (1)	2017			2016
Towers	Up to 20	$	12,500.5		$	11,740.5
Equipment	2 - 15	1,423.0			1,176.3
Buildings and improvements	3 - 32	631.4			621.9
Land and improvements (2)	Up to 20	2,112.9			1,909.7
Construction-in-progress		282.1			203.4
Total		16,949.9			15,651.8
Less accumulated depreciation		(5,848.9		)	(5,134.5		)
Property and equipment, net		$	11,101.0		$	10,517.3

_______________

(1) Assets on leased land are depreciated over the shorter of the estimated useful life of the asset or the term of the corresponding ground lease taking into consideration lease renewal options and residual value.

(2) Estimated useful lives apply to improvements only.