Property, Plant and Equipment (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, plant and equipment
Property, plant and equipment		$ 937,927	$ 843,589
Less accumulated depreciation and amortization		358,820	277,633
Total property, plant and equipment, net		579,107	565,956
Depreciation expense		85,400	75,100	$ 74,500
Selling price of parcel of land and warehouse	$ 13,900
Commissions and other costs paid through escrow			800
Proceeds from sale, net of commissions and other costs paid				13,118
Gain on sale of parcel of land and warehouse				$ 6,546
Amount required to spend on training employees on broadband telecommunication deployment and operation			300
Proceeds received from sale of radio towers			$ 2,900
Minimum lease term under sale and leaseback			10 years
Land
Property, plant and equipment
Property, plant and equipment		67,278	$ 67,278
Buildings
Property, plant and equipment
Property, plant and equipment		114,351	110,852
Central office equipment
Property, plant and equipment
Property, plant and equipment		194,707	177,283
Outside communications plant
Property, plant and equipment
Property, plant and equipment		377,042	334,179
Furniture, vehicles and other equipment
Property, plant and equipment
Property, plant and equipment		74,377	60,290
Construction in progress
Property, plant and equipment
Property, plant and equipment		32,595	28,214
Software
Property, plant and equipment
Property, plant and equipment		66,704	54,635
Other
Property, plant and equipment
Property, plant and equipment		$ 10,873	$ 10,858