Property, Plant and Equipment

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Property, plant and equipment consists of the following:



December 31, (dollars in thousands)	2015		2014
Land	$	19,871	$	20,353
Buildings	102,236		97,485
Machinery and equipment	470,862		448,241
Furniture and fixtures	14,313		15,431
Software	23,630		19,950
Construction in progress	9,137		34,134
Gross property, plant and equipment	640,049		635,594
Less accumulated depreciation	367,515		357,616
Net property, plant and equipment	$	272,534	$	277,978

Property, plant and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, generally 3 to 14 years for equipment and furnishings and 10 to 40 years for buildings and improvements. Software consists of internally developed and purchased software packages for internal use. Capitalized costs include software packages, installation, and/or certain internal labor costs. These costs are generally amortized over a five-year period. Depreciation expense was $41.4 million, $39.1 million and $42.8 million for the years 2015, 2014 and 2013, respectively.