GOODWILL AND INTANGIBLE ASSETS

Goodwill activity for each period was as follows:



(In thousands)	Specialty Chemicals and Engineered Materials			Microcontamination Control			Advanced Materials Handling		Total
December 31, 2017	$	304,270		8,007			$	47,411	$	359,688
Addition due to acquisitions	—			175,476			9,660		185,136
Foreign currency translation	(2,562		)	(27		)	—		(2,589		)
September 29, 2018	$	301,708		$	183,456		$	57,071	$	542,235

Identifiable intangible assets at September 29, 2018 and December 31, 2017 consist of the following:



September 29, 2018
(In thousands)	Gross carrying Amount		Accumulated amortization		Net carrying value
Developed technology	$	251,960	$	169,625	$	82,335
Trademarks and trade names	25,653		14,471		11,182
Customer relationships	331,059		126,335		204,724
Other	40,758		15,620		25,138
	$	649,430	$	326,051	$	323,379



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 September 29, 2018 to be the following:




Fiscal year ending December 31	(In thousands)
2018	$	20,480
2019	65,973
2020	42,788
2021	36,102
2022	35,322
Thereafter	122,714
	$	323,379