Goodwill and other intangible assets (Tables)

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Reconciliation of the change in goodwill

Reconciliations of the changes in the carrying value of goodwill during 2022 and 2021 follow (in millions).

	December 31,
	2022			2021
Balance at beginning of year	$	73,875		$	73,734
Business acquisitions		4,657			353
Other, including foreign currency translation		(413	)		(212	)
Balance at end of year*	$	78,119		$	73,875

* Net of accumulated goodwill impairments of $11.0 billion as of December 31, 2022 and 2021

Schedule of intangible assets

The gross carrying amounts and related accumulated amortization of other intangible assets are summarized as follows (in millions).

	December 31, 2022						December 31, 2021
	Gross carrying amount		Accumulated amortization		Net carrying value		Gross carrying amount		Accumulated amortization		Net carrying value
Insurance and other:
Customer relationships	$	27,765	$	7,174	$	20,591	$	27,335	$	6,450	$	20,885
Trademarks and trade names		5,603		822		4,781		5,176		802		4,374
Patents and technology		4,943		3,748		1,195		4,763		3,484		1,279
Other		4,150		1,530		2,620		3,390		1,442		1,948
	$	42,461	$	13,274	$	29,187	$	40,664	$	12,178	$	28,486
Railroad, utilities and energy:
Customer relationships and contracts and other	$	1,914	$	622	$	1,292	$	1,693	$	542	$	1,151