GOODWILL AND INTANGIBLE ASSETS

Goodwill activity for each period was as follows:



(In thousands)	Specialty Chemicals and Engineered Materials			Micro-contamination Control		Advanced Materials Handling		Total
December 31, 2017	$	304,270		8,007		$	47,411	$	359,688
Addition due to acquisitions	—			162,251		10,381		172,632
Foreign currency translation	(2,387		)	—		—		(2,387		)
June 30, 2018	$	301,883		$	170,258	$	57,792	$	529,933

Identifiable intangible assets at June 30, 2018 and December 31, 2017 consist of the following:



June 30, 2018
(In thousands)	Gross carrying Amount		Accumulated amortization		Net carrying value
Developed technology	$	246,610	$	162,432	$	84,178
Trademarks and trade names	25,655		14,059		11,596
Customer relationships	367,723		119,049		248,674
Other	25,857		8,876		16,981
	$	665,845	$	304,416	$	361,429



December 31, 2017
(In thousands)	Gross carrying amount		Accumulated amortization		Net carrying value
Developed technology	$	206,224	$	149,215	$	57,009
Trademarks and trade names	16,807		13,712		3,095
Customer relationships	220,806		110,281		110,525
Other	20,032		8,231		11,801
	$	463,869	$	281,439	$	182,430

Future amortization expense for each of the five succeeding years and thereafter relating to intangible assets currently recorded in the Company's consolidated balance sheets is estimated at June 30, 2018 to be the following:




Fiscal year ending December 31	(In thousands)
2018	$	35,112
2019	57,590
2020	42,732
2021	36,042
2022	35,266
Thereafter	154,687
	$	361,429