Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Schedule of property, plant and equipment

For financial reporting purposes, provisions for depreciation are calculated on a straight‑line basis over the following estimated useful lives of the underlying assets:

	Years
Buildings and improvements	10-15
Machinery and equipment	5-15
Office equipment	3-10

(Dollars in thousands)	December 31, 2014			December 31, 2013
Land	$	14,045		$	14,986
Buildings and improvements	132,105			136,959
Machinery and equipment	165,979			160,843
Office equipment	36,810			34,972
Equipment in process	26,573			21,360
	375,512			369,120
Accumulated depreciation	(225,092		)	(222,189		)
Total property, plant and equipment, net	$	150,420		$	146,931