Goodwill and intangible assets

6 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

The changes in the carrying amount of goodwill for the six months ended December 31, 2021 are as follows:


	Diversified Industrial Segment		Aerospace Systems Segment		Total
Balance at June 30, 2021	$	7,457,309	$	602,378	$	8,059,687



Foreign currency translation and other	(59,774)		(12)		(59,786)
Balance at December 31, 2021	$	7,397,535	$	602,366	$	7,999,901

Intangible assets are amortized using the straight-line method over their legal or estimated useful lives. The following summarizes the gross carrying value and accumulated amortization for each major category of intangible assets:


	December 31, 2021				June 30, 2021
	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Patents and technology	$	997,295	$	239,347	$	999,952	$	216,314
Trademarks	756,405		346,209		762,130		331,905
Customer lists and other	3,841,777		1,666,309		3,869,772		1,563,838
Total	$	5,595,477	$	2,251,865	$	5,631,854	$	2,112,057

Total intangible amortization expense for the six months ended December 31, 2021 and 2020 was $159 million and $163 million, respectively. The estimated amortization expense for the five years ending June 30, 2022 through 2026 is $320 million, $304 million, $297 million, $287 million and $282 million, respectively.

Intangible assets are evaluated for impairment whenever events or circumstances indicate that the undiscounted net cash flows to be generated by their use over their expected useful lives and eventual disposition may be less than their net carrying value. No material intangible asset impairments occurred during the six months ended December 31, 2021 and 2020.