Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		$ 9,574	$ 10,037	$ 7,547
Charged to operations		4,873	2,958	3,101
Credited to operations		0	0	0
Written off		(3,133)	(3,421)	(611)
Effect of exchange rate changes or Other adjustments		0	0	0
Balance at end of year		11,314	9,574	10,037
Deferred Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		1,994	21,038	27,264
Charged to operations		586	164	1,797
Credited to operations		0	0	0
Written off		(2,236)	(3,000)	(9,106)
Effect of exchange rate changes or Other adjustments		0	0	0
Valuation allowance and reserves, other adjustments	[1]	6,283	(16,208)	1,083
Balance at end of year		$ 6,627	$ 1,994	$ 21,038

[1] Inclusive of (1) the effects of acquisitions and (2) the inclusion of small cells in the REIT in January 2016.