Note 13. Goodwill and other intangible assets

Reconciliations of the changes in the carrying value of goodwill during 2019 and 2018 follows (in millions).


	March 31, 2019		December 31, 2018
Balance at beginning of year	$	81,025	$	81,258
Acquisitions of businesses		159		376
Other, including foreign currency translation		36		(609	)

Balance at end of period	$	81,220	$	81,025

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


	March 31, 2019				December 31, 2018
	Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated amortization
Insurance and other	$	40,553	$	9,287	$	40,493	$	8,994
Railroad, utilities and energy		1,011		373		1,011		362

	$	41,564	$	9,660	$	41,504	$	9,356


Trademarks and trade names	$	5,367	$	757	$	5,368	$	750
Patents and technology		4,472		2,862		4,446		2,790
Customer relationships		28,426		4,782		28,375		4,573
Other		3,299		1,259		3,315		1,243

	$	41,564	$	9,660	$	41,504	$	9,356

Intangible asset amortization expense in the first quarter was $333 million in 2019 and $352 million in 2018. Intangible assets with indefinite lives as of March 31, 2019 and December 31, 2018 were $18.9 billion and primarily related to certain customer relationships and trademarks and trade names.