Goodwill and other intangible assets (Tables)

12 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Reconciliation of the change in goodwill

Reconciliations of the changes in the carrying value of goodwill during 2023 and 2022 follow (in millions).

	December 31,
	2023			2022
Balance at the beginning of the year	$	78,119		$	73,875
Business acquisitions		7,347			4,657
Other, including acquisition period remeasurements and foreign currency translation		(840	)		(413	)
Balance at the end of the year*	$	84,626		$	78,119

* Net of accumulated goodwill impairments of $11.1 billion as of December 31, 2023 and $11.0 billion as of December 31, 2022.

Schedule of intangible assets

Other intangible assets are summarized below (in millions).

	December 31, 2023						December 31, 2022
	Gross carrying amount		Accumulated amortization		Net carrying value		Gross carrying amount		Accumulated amortization		Net carrying value
Insurance and other:
Customer relationships	$	28,305	$	7,901	$	20,404	$	27,765	$	7,174	$	20,591
Trademarks and trade names		5,619		846		4,773		5,603		822		4,781
Patents and technology		5,238		4,109		1,129		4,943		3,748		1,195
Other		4,826		1,805		3,021		4,150		1,530		2,620
	$	43,988	$	14,661	$	29,327	$	42,461	$	13,274	$	29,187
Railroad, utilities and energy:
Customer relationships and contracts	$	4,092	$	791	$	3,301	$	1,507	$	541	$	966
Trademarks and trade names		3,592		98		3,494		217		39		178
Other		1,174		156		1,018		190		42		148
	$	8,858	$	1,045	$	7,813	$	1,914	$	622	$	1,292