Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

Classification	Expected Useful Life
Computer equipment	3 to 5 years
Production machinery and equipment	7 to 10 years
Buildings	25 years

PROPERTY, PLANT AND EQUIPMENT

December 31,	2016			2015
(Dollars in thousands)
Land and buildings	$	67,915		$	73,803
Machinery and equipment	485,185			486,612
Leasehold improvements and others	4,868			4,204
Construction in progress	26,301			20,455
	584,269			585,074
Accumulated depreciation	(356,866		)	(350,428		)
Property, plant and equipment, net	$	227,403		$	234,646