Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2019

Property Plant And Equipment [Abstract]

Schedule of Property, Plant and Equipment

December 31,	2019			2018
(Dollars in thousands)
Land and buildings	$	158,907		$	140,471
Machinery and equipment		856,961			769,451
Leasehold improvements and others		12,173			12,883
Construction in progress		30,179			67,559
		1,058,220			990,364
Accumulated depreciation		(528,938	)		(457,597	)
Property, plant and equipment, net	$	529,282		$	532,767