We believe our Chief Executive Officer (“CEO”) is our chief operating decision maker (“CODM”). Our CEO approves all major decisions, including reorganizations and new business initiatives. Our CODM reviews routine consolidated operating information and makes decisions on the allocation of resources at this level, as such, we have concluded that we have one operating segment.

All goodwill is assigned to one or more reporting units. A reporting unit represents an operating segment or a component within an operating segment for which discrete financial information is available and is regularly reviewed by segment management for performance assessment and resource allocation. Upon consideration of our components, we have concluded that our goodwill is associated with one reporting unit.

On March 31, 2021, we concluded that no goodwill impairment indicators were present. We will continue to monitor the impacts of the COVID-19 pandemic on our reporting unit fair value. The full extent to which the ongoing COVID-19 pandemic could adversely affect our financial performance will depend on future developments, many of which are outside of our control.

The changes in the carrying amount of goodwill for the six months ended March 31, 2021 are as follows (dollars in thousands):

	Total
Balance as of September 30, 2020	$	1,128,198
Effect of foreign currency translation		2,304
Balance as of March 31, 2021	$	1,130,502

As of March 31, 2021, there were no indicators of impairment present related to our long-lived asset group.

The following tables summarizes the gross carrying amounts and accumulated amortization of intangible assets by major class (dollars in thousands):

	March 31, 2021
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted Average Remaining Life (Years)
Customer relationships	$	110,839	$	(82,562	)	$	28,277		2.6
Technology and patents		90,919		(83,660	)		7,259		1.2
Total	$	201,758	$	(166,222	)	$	35,536

	September 30, 2020
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted Average Remaining Life (Years)
Customer relationships	$	110,512	$	(75,915	)	$	34,597		3.0
Technology and patents		90,658		(79,639	)		11,019		1.6
Total	$	201,170	$	(155,554	)	$	45,616

Amortization expense related to intangible assets in the aggregate was $5.1 million and $5.4 million for the three months ended March 31, 2021 and 2020, respectively, and $10.1 million and $10.6 million for the six months ended March 31, 2021 and 2020, respectively. We expect amortization of intangible assets to be approximately $10.1 million for the remainder of fiscal year 2021.