GOODWILL AND OTHER INTANGIBLES

The following table provides changes in carrying value of goodwill by segment through the year ended September 30, 2018:



	At September 30, 2016		Goodwill from acquisitions		Foreign currency translation adjustments		September 30, 2017		Goodwill from acquisitions		Foreign currency translation adjustments		September 30, 2018
Home & Building Products	$	287,618	$	12,417	$	559	$	300,594	$	119,907	$	349	$	420,850
Defense Electronics	18,545		—		—		18,545		—		—		18,545
Total	$	306,163	$	12,417	$	559	$	319,139	$	119,907	$	349	$	439,395

The following table provides the gross carrying value and accumulated amortization for each major class of intangible asset:



	At September 30, 2018					At September 30, 2017
	Gross Carrying Amount		Accumulated Amortization		Average Life (Years)	Gross Carrying Amount		Accumulated Amortization
Customer relationships & other	$	186,031	$	49,822	23	$	152,025	$	43,421
Unpatented technology	19,004		6,238		13	6,193		4,719
Total amortizable intangible assets	205,035		56,060			158,218		48,140
Trademarks	221,883		—			95,049		—
Total intangible assets	$	426,918	$	56,060		$	253,267	$	48,140

Amortization expense for intangible assets subject to amortization was $9,070, $6,658 and $6,608 for the years ended September 30, 2018, 2017 and 2016, respectively. Amortization expense for each of the next five years and thereafter, based on current intangible balances and classifications, is estimated as follows: 2019 - $9,285; 2020 - $8,825; 2021 - $8,825; 2022 - $8,825 and 2023 - $8,746; thereafter - $104,469.

No event or indicator or impairment occurred during the current year, which would require impairment testing of long-lived intangible assets including goodwill.