Property, Plant And Equipment

12 Months Ended

Dec. 31, 2014

Property, Plant And Equipment [Abstract]

Property, Plant And Equipment

(5)   Property, Plant and Equipment:

Property, plant and equipment, net at December 31, 2014 and 2013 are as follows:

($ in thousands)	Estimated Useful Lives	2014		2013
Land	N/A	$	147,044	$	126,483
Buildings and leasehold improvements	41 years		1,325,865		1,061,097
General support	5 to 17 years		1,037,279		977,941
Central office/electronic circuit equipment	5 to 11 years		5,933,450		5,222,928
Poles	49 years		671,931		549,322
Cable and wire	15 to 30 years		6,973,234		6,259,292
Conduit	60 years		509,418		359,974
Other	12 to 30 years		46,485		43,144
Construction work in progress			301,189		250,516
Property, plant and equipment			16,945,895		14,850,697
Less: Accumulated depreciation			(8,379,847)		(7,594,935)
Property, plant and equipment, net		$	8,566,048	$	7,255,762

Depreciation expense is principally based on the composite group method.  Depreciation expense was $835  million,  $841 million and $845 million for the years ended December 31, 2014, 2013 and 2012, respectively.  As a result of our annual independent study of the estimated remaining useful lives of our plant assets, we adopted new estimated remaining useful lives for certain plant assets as of October 1, 2014, with an insignificant  impact to depreciation expense. In addition, we commissioned an independent study to determine the estimated useful lives for assets acquired during the Connecticut Acquisition. These new lives were adopted effective October 24, 2014.