Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2018

Accounting Policies [Abstract]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

Stock-based compensation expense charged to the Condensed Consolidated Statements of Operations is as follows:

	Three months ended June 30,				Six months ended June 30,
(dollars in thousands)	2018		2017		2018		2017
Stock-based compensation expense	$	1,166	$	1,316	$	1,456	$	2,148

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]

The effect of the retrospective presentation change related to the net periodic pension and non-pension benefit costs (credits) on our Condensed Consolidated Statement of Operations was as follows:

	Three months ended June 30, 2017									Six months ended June 30, 2017
(dollars in thousands)	Previously Reported			Reclassification			As Revised			Previously Reported			Reclassification			As Revised
Cost of sales	$	157,483		$	(615	)	$	156,868		$	300,839		$	(1,498	)	$	299,341
Selling, general and administrative expenses	33,676			407			34,083			66,651			764			67,415
Other income (expense)	(644		)	(208		)	(852		)	(2,904		)	(734		)	(3,638		)