Property, Plant and Equipment (Tables)

6 Months Ended

Jun. 30, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, plant and equipment consisted of the following:

(in thousands)	Estimated Useful Lives	June 30, 2018		December 31, 2017
Land		$	6,459	$	6,418
Buildings and structures	10 - 40 years	205,373		195,540
Cable and wire	4 - 40 years	296,276		286,999
Equipment and software	2 - 17 years	756,643		730,228
Plant in service		1,264,751		1,219,185
Plant under construction		67,584		62,202
Total property, plant and equipment		1,332,335		1,281,387
Less accumulated amortization and depreciation		663,996		595,060
Property, plant and equipment, net		$	668,339	$	686,327