Business segment data - Revenues (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total revenues	$ 364,482	$ 302,020	$ 276,185
BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	23,791	25,802	23,177
Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Total revenues	25,960	26,347	25,052
PTC [Member]
Segment Reporting Information [Line Items]
Total revenues	51,664
Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	75,283	75,650	68,577
McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	51,814	53,209	49,450
Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	39,879	38,209	34,747
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	364,653	301,884	276,512
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	83,403	74,576	69,460
Interest, dividend and other investment income	11,619	7,734	5,662
Total revenues	95,022	82,310	75,122
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member]
Segment Reporting Information [Line Items]
Premiums earned	39,264	38,984	37,706
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	17,129	13,746	11,575
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	27,010	21,846	20,179
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	23,876	25,888	23,282
Operating Businesses [Member] | Berkshire Hathaway Energy ("BHE") [Member]
Segment Reporting Information [Line Items]
Total revenues	26,008	26,393	25,096
Operating Businesses [Member] | PTC [Member]
Segment Reporting Information [Line Items]
Total revenues	51,739
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	75,405	75,781	68,730
Operating Businesses [Member] | McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	52,607	53,209	49,450
Operating Businesses [Member] | Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	39,996	38,303	34,832
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (171)	$ 136	$ (327)