Revenue from contracts with customers disaggregated by reportable segment and source of revenue (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 37,378	$ 44,460	$ 78,830	$ 86,852
Other revenues	19,462	19,138	39,275	37,424
Total revenues	56,840	63,598	118,105	124,276
Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,676	6,549	10,839	13,054
Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,665	4,143	7,360	7,695
Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,009	3,669	6,337	6,959
Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,287	8,042	15,146	16,077
Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,787	4,321	7,593	8,446
Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,895	2,125	3,804	4,062
Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,107	3,626	6,645	7,091
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,633	8,556	14,272	16,352
Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,319	3,429	6,834	7,116
Manufacturing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,140	15,278	26,274	29,471
Other revenues	877	913	1,757	1,779
Total revenues	13,017	16,191	28,031	31,250
Manufacturing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,631	6,503	10,750	12,962
Manufacturing Businesses [Member] | Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,665	4,143	7,360	7,695
Manufacturing Businesses [Member] | Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,009	3,669	6,337	6,959
Manufacturing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	487	534	1,092	1,078
Manufacturing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	348	429	735	777
McLane Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,196	12,386	22,993	24,566
Other revenues	22	25	46	44
Total revenues	11,218	12,411	23,039	24,610
McLane Company [Member] | Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,287	8,042	15,146	16,077
McLane Company [Member] | Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,787	4,321	7,593	8,446
McLane Company [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	122	23	254	43
Service and Retailing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,194	6,307	11,041	12,201
Other revenues	827	1,133	1,918	2,242
Total revenues	6,021	7,440	12,959	14,443
Service and Retailing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	45	46	89	92
Service and Retailing Businesses [Member] | Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,895	2,125	3,804	4,062
Service and Retailing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,620	3,092	5,553	6,013
Service and Retailing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	634	1,044	1,595	2,034
BNSF [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,558	5,837	9,924	11,550
Other revenues	14	14	28	26
Total revenues	4,572	5,851	9,952	11,576
BNSF [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,558	5,837	9,924	11,550
Berkshire Hathaway Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,290	4,652	8,598	9,064
Other revenues	369	318	568	578
Total revenues	4,659	4,970	9,166	9,642
Berkshire Hathaway Energy [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	971	1,223	1,764	1,948
Berkshire Hathaway Energy [Member] | Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,319	3,429	6,834	7,116
Insurance Corporate And Other [Member]
Disaggregation of Revenue [Line Items]
Other revenues	17,353	16,735	34,958	32,755
Total revenues	$ 17,353	$ 16,735	$ 34,958	$ 32,755