Intangible Assets and Goodwill (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of cost, accumulated amortization and net book value of intangible assets

The cost and accumulated amortization of intangible assets subject to amortization as of December 31, 2018 and 2017, is as follows:

	2018					2017
(Thousands)	Gross Carrying Amount		Accumulated Amortization			Gross Carrying Amount		Accumulated Amortization
Customer relationships	$	39,601	$	(37,077	)	$	40,751	$	(36,949	)
Technology	13,377		(12,238		)	13,467		(11,495		)
Licenses and other	4,257		(2,725		)	4,519		(2,672		)
Total	$	57,235	$	(52,040	)	$	58,737	$	(51,116	)

Finite-lived Intangible Assets Amortization Expense

The aggregate amortization expense relating to intangible assets for the year ended December 31, 2018 and estimated amortization expense for each of the five succeeding years is as follows:

	Amortization
(Thousands)	Expense
2018	$	2,265
2019	1,366
2020	603
2021	485
2022	485
2023	485

Schedule of Goodwill

The balance of goodwill at both December 31, 2018 and 2017 was $90.7 million and assigned to the following segments:

(Thousands)	2018		2017
Performance Alloys and Composites	$	1,899	$	1,899
Advanced Materials	50,276		50,296
Precision Coatings	38,482		38,482
Total	$	90,657	$	90,677