Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Assets Measured at Fair Value on a Recurring Basis, Categorized by the Level of Inputs Used in the Valuation

Derivative instruments measured at fair value on a recurring basis, categorized by the level of inputs used in the valuation, include:

	Derivative Instruments at Fair Value as of March 31, 2019
(Dollars in thousands)	Level 1		Level 2			Level 3		Total
Foreign currency contracts	$	—	$	(357	)	$	—	$	(357	)
Copper derivative contracts	$	—	$	1,120		$	—	$	1,120
Interest rate swap	$	—	$	(171	)	$	—	$	(171	)

	Derivative Instruments at Fair Value as of December 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Foreign currency contracts	$	—	$	522	$	—	$	522
Copper derivative contracts	$	—	$	583	$	—	$	583
Interest rate swap	$	—	$	461	$	—	$	461