Business segment data - Additional tabular disclosures (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Segment Reporting Information [Line Items]
Interest expense	$ 4,352		$ 4,172		$ 4,083
Income tax expense	(8,518)		20,879		12,440
Capital expenditures	15,464		13,276		13,012
Depreciation of tangible assets	8,457		8,308		8,119
Goodwill at year-end	78,119	[1]	73,875	[1]	73,734
Assets	948,452		958,784		873,729
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense	3,946		3,828		3,776
Income tax expense	4,965		5,108		4,259
Capital expenditures	15,464		13,276		13,012
Depreciation of tangible assets	9,666		9,465		9,319
Goodwill at year-end	78,119		73,875		73,734
Identifiable assets at year-end	807,688		815,139		720,120
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Income tax expense	1,231		1,050		1,089
Capital expenditures	82		62		50
Depreciation of tangible assets	69		72		74
Goodwill at year-end	16,548		15,181		15,224
Identifiable assets at year-end	459,904		482,813		399,169
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Interest expense	1,025		1,032		1,037
Income tax expense	1,763		1,871		1,631
Capital expenditures	3,532		2,910		3,063
Depreciation of tangible assets	2,479		2,406		2,423
Goodwill at year-end	14,852		14,852		14,851
Identifiable assets at year-end	77,752		76,586		73,809
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Interest expense	2,140		2,054		1,941
Income tax expense	(1,629)		(1,153)		(996)
Capital expenditures	7,505		6,611		6,765
Depreciation of tangible assets	3,702		3,584		3,376
Goodwill at year-end	11,745		11,906		11,763
Identifiable assets at year-end	118,114		113,447		109,880
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense	739		704		737
Income tax expense	2,403		2,193		1,795
Capital expenditures	2,477		2,100		2,133
Depreciation of tangible assets	2,021		2,037		2,026
Goodwill at year-end	28,460		25,463		25,512
Identifiable assets at year-end	113,578		107,231		104,318
Operating Businesses [Member] | McLane [Member]
Segment Reporting Information [Line Items]
Income tax expense	66		61		71
Capital expenditures	93		106		98
Depreciation of tangible assets	176		189		204
Goodwill at year-end	232		232		232
Identifiable assets at year-end	7,049		6,841		6,771
Operating Businesses [Member] | Service and Retailing [Member]
Segment Reporting Information [Line Items]
Interest expense	42		38		61
Income tax expense	1,131		1,086		669
Capital expenditures	1,775		1,487		903
Depreciation of tangible assets	1,219		1,177		1,216
Goodwill at year-end	6,282		6,241		6,152
Identifiable assets at year-end	31,291		28,221		26,173
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Interest expense	420		455		483
Investment and derivative gains/losses, tax	(14,166)		16,025		8,855
Interest expense, not allocated to segments, tax	(88)		(96)		(102)
Equity method investments, tax	334		82		43
Goodwill at year-end	78,119		73,875		73,734
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Interest expense	(14)		(111)		(176)
Income tax expense	437		(240)		(615)
Identifiable assets at year-end	$ 62,645		$ 69,770		$ 79,875

[1] Net of accumulated goodwill impairments of $11.0 billion as of December 31, 2022 and 2021