Property, Plant and Equipment - Schedule of Carrying Value of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 6,678,177	$ 6,093,541
Less accumulated depreciation	(3,984,036)	(3,720,890)
Net property, plant and equipment	2,694,141	2,372,651
Land
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	34,295	33,386
Building and Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	314,577	313,736
Real Property Interests
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	2,394
Poles
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	231,835	228,031
Fiber
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	2,217,760	1,948,192
Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	127,496
Copper
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	3,518,283	3,475,987
Conduit
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	90,538	89,460
Construction in progress
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	44,693	$ 4,749
Tower assets
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	7,307
Capital Lease Assets
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 88,999
Minimum | Building and Improvements
Property Plant And Equipment [Line Items]
Depreciable Lives	3 years
Minimum | Real Property Interests
Property Plant And Equipment [Line Items]
Depreciable Lives	50 years
Minimum | Poles
Property Plant And Equipment [Line Items]
Depreciable Lives	13 years
Minimum | Fiber
Property Plant And Equipment [Line Items]
Depreciable Lives	7 years
Minimum | Equipment
Property Plant And Equipment [Line Items]
Depreciable Lives	5 years
Minimum | Copper
Property Plant And Equipment [Line Items]
Depreciable Lives	7 years
Minimum | Conduit
Property Plant And Equipment [Line Items]
Depreciable Lives	13 years
Minimum | Tower assets
Property Plant And Equipment [Line Items]
Depreciable Lives	20 years
Maximum | Building and Improvements
Property Plant And Equipment [Line Items]
Depreciable Lives	40 years
Maximum | Poles
Property Plant And Equipment [Line Items]
Depreciable Lives	40 years
Maximum | Fiber
Property Plant And Equipment [Line Items]
Depreciable Lives	40 years
Maximum | Equipment
Property Plant And Equipment [Line Items]
Depreciable Lives	7 years
Maximum | Copper
Property Plant And Equipment [Line Items]
Depreciable Lives	40 years
Maximum | Conduit
Property Plant And Equipment [Line Items]
Depreciable Lives	47 years
Maximum | Tower assets
Property Plant And Equipment [Line Items]
Depreciable Lives	49 years