Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, plant and equipment consists of the following:

December 31, (dollars in thousands)	2016		2015
Land	$	19,524	$	19,871
Buildings	102,666		102,236
Machinery and equipment	473,004		470,862
Furniture and fixtures	14,208		14,313
Software	22,733		23,630
Construction in progress	16,113		9,137
Gross property, plant and equipment	648,248		640,049
Less accumulated depreciation	391,856		367,515
Net property, plant and equipment	$	256,392	$	272,534