Business segment data - Revenues (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Total revenues	$ 76,180	$ 69,114	$ 146,990	$ 133,713
BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	6,612	5,778	12,556	11,156
Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Total revenues	6,513	6,085	12,491	12,009
Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	19,736	17,375	38,121	33,255
McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	13,262	12,295	25,776	23,917
Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	9,593	8,954	18,684	16,897
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	76,180	69,200	147,038	133,856
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Interest, dividend and other investment income	2,284	1,459	3,648	2,873
Total revenues	20,371	18,622	39,227	36,460
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member]
Segment Reporting Information [Line Items]
Premiums earned	9,807	9,546	19,361	18,469
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	4,967	4,862	9,787	9,709
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	3,313	2,755	6,431	5,409
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	6,640	5,809	12,608	11,210
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Total revenues	6,518	6,085	12,501	12,009
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	19,772	17,412	38,193	33,325
Operating Businesses [Member] | McLane [Member]
Segment Reporting Information [Line Items]
Total revenues	13,262	12,295	25,777	23,917
Operating Businesses [Member] | Service and Retailing [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 9,617	8,977	18,732	16,935
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Total revenues		$ (86)	$ (48)	$ (143)