Business segment data - Revenues (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Total revenues	$ 92,503	$ 76,201	$ 177,896	$ 147,044
BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	5,808	6,612	11,809	12,556
Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Total revenues	6,350	6,540	12,789	12,555
Pilot Travel Centers ("Pilot") [Member]
Segment Reporting Information [Line Items]
Total revenues	14,733		24,229
Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	19,074	19,736	37,339	38,121
McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	12,697	13,262	25,578	25,776
Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	10,109	9,593	20,011	18,684
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	92,549	76,201	177,994	147,092
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Interest, dividend and other investment income	2,918	2,284	5,310	3,648
Total revenues	23,479	20,365	45,667	39,217
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member]
Segment Reporting Information [Line Items]
Premiums earned	9,714	9,807	19,340	19,361
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	4,233	3,313	8,194	6,431
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	6,614	4,961	12,823	9,777
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	5,828	6,640	11,847	12,608
Operating Businesses [Member] | Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Total revenues	6,362	6,545	12,813	12,565
Operating Businesses [Member] | Pilot Travel Centers ("Pilot") [Member]
Segment Reporting Information [Line Items]
Total revenues	14,754		24,262
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	19,102	19,772	37,391	38,193
Operating Businesses [Member] | McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	12,883	13,262	25,942	25,777
Operating Businesses [Member] | Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	10,141	$ 9,617	20,072	18,732
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (46)		$ (98)	$ (48)