Goodwill and other intangible assets

6 Months Ended

Jun. 30, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Note 12. Goodwill and other intangible assets

Reconciliations of the changes in the carrying value of goodwill for the first six months of 2021 and for the year ended December 31, 2020 follow (in millions).

	June 30, 2021			December 31, 2020
Balance at beginning of year	$	73,734		$	81,882
Acquisitions of businesses		25			1,758
Impairment charges		—			(10,033	)
Other, including foreign currency translation		(1	)		127
Balance at end of period*	$	73,758		$	73,734

*	Net of accumulated goodwill impairments of $11.0 billion as of June 30, 2021 and December 31, 2020.

Other intangible assets and related accumulated amortization are summarized as follows (in millions).

	June 30, 2021				December 31, 2020
	Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated amortization
Insurance and other:
Customer relationships	$	27,310	$	6,113	$	27,374	$	5,756
Trademarks and trade names		5,176		790		5,206		779
Patents and technology		4,667		3,314		4,766		3,313
Other		3,328		1,411		3,339		1,375
	$	40,481	$	11,628	$	40,685	$	11,223
Railroad, utilities and energy:
Customer relationships	$	678	$	380	$	678	$	361
Trademarks, trade names and other		1,003		121		1,003		98
	$	1,681	$	501	$	1,681	$	459

Notes to Consolidated Financial Statements (Continued)

Note 12. Goodwill and other intangible assets (Continued)

Intangible asset amortization expense in the first six months was $637 million in 2021 and $647 million in 2020. Intangible assets with indefinite lives were $18.3 billion as of June 30, 2021 and December 31, 2020 and primarily related to certain customer relationships and trademarks and trade names.

During 2020, we concluded it was necessary to reevaluate goodwill and indefinite-lived intangible assets of certain of our reporting units for impairment due to the disruptions arising from the COVID-19 pandemic. We recorded pre-tax goodwill impairment charges of approximately $10 billion and pre-tax indefinite-lived intangible asset impairment charges of $638 million in the second quarter of 2020. Approximately $10 billion of these charges related to Precision Castparts Corp. (“PCC”), the largest business within Berkshire's manufacturing segment. The carrying value of PCC-related goodwill and indefinite-lived intangible assets prior to the impairment charges was approximately $31 billion.