Business segment data - Revenues (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 89,869	$ 85,393
BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	5,637	6,001
Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Total revenues	6,265	6,439
Pilot [Member]
Segment Reporting Information [Line Items]
Total revenues	12,494	9,496
Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	18,511	18,265
McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	12,300	12,881
Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	9,672	9,902
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	89,785	85,445
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Interest, dividend and other investment income	3,164	2,392
Total revenues	24,638	22,188
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member]
Segment Reporting Information [Line Items]
Premiums earned	10,234	9,626
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	4,541	3,961
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	6,699	6,209
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	5,660	6,019
Operating Businesses [Member] | Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Total revenues	6,277	6,451
Operating Businesses [Member] | Pilot [Member]
Segment Reporting Information [Line Items]
Total revenues	12,503	9,508
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	18,529	18,289
Operating Businesses [Member] | McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	12,475	13,059
Operating Businesses [Member] | Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	9,703	9,931
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 84	$ (52)