Business segment data - Additional tabular disclosures (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Segment Reporting Information [Line Items]
Interest expense	$ 5,003		$ 4,352		$ 4,172
Income tax expense	23,019		(8,502)		20,912
Capital expenditures	19,409		15,464		13,276
Goodwill at year-end	84,626	[1]	78,119	[1]	73,875
Assets	1,069,978		948,465		959,388
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense	4,630		3,946		3,828
Income tax expense	6,910		4,981		5,141
Capital expenditures	19,409		15,464		13,276
Depreciation of tangible assets	10,658		9,666		9,465
Goodwill at year-end	84,626		78,119		73,875
Identifiable assets at year-end	921,210		807,701		815,743
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Income tax expense	3,497		1,247		1,083
Capital expenditures	68		82		62
Depreciation of tangible assets	72		69		72
Goodwill at year-end	16,563		16,548		15,181
Identifiable assets at year-end	538,860		459,917		483,417
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Interest expense	1,048		1,025		1,032
Income tax expense	1,527		1,763		1,871
Capital expenditures	3,920		3,532		2,910
Depreciation of tangible assets	2,581		2,479		2,406
Goodwill at year-end	15,350		14,852		14,852
Identifiable assets at year-end	79,227		77,752		76,586
Operating Businesses [Member] | Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Interest expense	2,283		2,140		2,054
Income tax expense	(2,022)		(1,629)		(1,153)
Capital expenditures	9,148		7,505		6,611
Depreciation of tangible assets	3,913		3,702		3,584
Goodwill at year-end	11,804		11,745		11,906
Identifiable assets at year-end	124,383		118,114		113,447
Operating Businesses [Member] | PTC [Member]
Segment Reporting Information [Line Items]
Interest expense	414
Income tax expense	169
Capital expenditures	705
Depreciation of tangible assets	510
Goodwill at year-end	6,605
Identifiable assets at year-end	21,404
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense	784		739		704
Income tax expense	2,487		2,403		2,193
Capital expenditures	2,714		2,477		2,100
Depreciation of tangible assets	2,099		2,021		2,037
Goodwill at year-end	27,831		28,460		25,463
Identifiable assets at year-end	115,875		113,578		107,231
Operating Businesses [Member] | McLane [Member]
Segment Reporting Information [Line Items]
Income tax expense	117		66		61
Capital expenditures	264		93		106
Depreciation of tangible assets	208		176		189
Goodwill at year-end	232		232		232
Identifiable assets at year-end	6,861		7,049		6,841
Operating Businesses [Member] | Service and Retailing [Member]
Segment Reporting Information [Line Items]
Interest expense	101		42		38
Income tax expense	1,135		1,131		1,086
Capital expenditures	2,590		1,775		1,487
Depreciation of tangible assets	1,275		1,219		1,177
Goodwill at year-end	6,241		6,282		6,241
Identifiable assets at year-end	34,600		31,291		28,221
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Interest expense	426		420		455
Investment and derivative gains/losses, tax	15,930		(14,166)		16,025
Interest expense, not allocated to segments, tax	(90)		(88)		(96)
Non-controlled businesses, tax	223		334		82
Goodwill at year-end	84,626		78,119		73,875
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Interest expense	(53)		(14)		(111)
Income tax expense	46		437		(240)
Identifiable assets at year-end	$ 64,142		$ 62,645		$ 69,770

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