Goodwill and other intangible assets

6 Months Ended

Jun. 30, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Goodwill and other intangible assets

Note 13. Goodwill and other intangible assets

Reconciliations of the changes in the carrying value of goodwill for the first six months of 2019 and for the year ended December 31, 2018 follows (in millions).

	June 30, 2019		December 31, 2018
Balance at beginning of year	$	81,025	$	81,258
Acquisitions of businesses		216		376
Other, including foreign currency translation		28		(609	)
Balance at end of period	$	81,269	$	81,025

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

	June 30, 2019				December 31, 2018
	Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated amortization
Insurance and other	$	40,613	$	9,581	$	40,493	$	8,994
Railroad, utilities and energy		1,011		385		1,011		362
	$	41,624	$	9,966	$	41,504	$	9,356
Trademarks and trade names	$	5,368	$	763	$	5,368	$	750
Patents and technology		4,502		2,927		4,446		2,790
Customer relationships		28,449		4,990		28,375		4,573
Other		3,305		1,286		3,315		1,243
	$	41,624	$	9,966	$	41,504	$	9,356

Intangible asset amortization expense in the first six months was $658 million in 2019 and $707 million in 2018. Intangible assets with indefinite lives as of June 30, 2019 and December 31, 2018 were $18.9 billion and primarily related to certain customer relationships and trademarks and trade names.