Revenue from contracts with customers disaggregated by reportable segment and source of revenue (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 41,509
Other revenue	16,964
Total revenues	58,473	$ 64,370
Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,608
Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,920
Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,696
Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,512
Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,643
Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,931
Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,210
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,465
Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,524
Manufacturing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,874
Other revenue	38
Total revenues	12,912
Manufacturing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,393
Manufacturing Businesses [Member] | Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,919
Manufacturing Businesses [Member] | Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,848
Manufacturing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	496
Manufacturing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	218
McLane Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,172
Other revenue	17
Total revenues	12,189
McLane Company [Member] | Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,512
McLane Company [Member] | Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,643
McLane Company [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	17
Service and Retailing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,621
Other revenue	939
Total revenues	6,560
Service and Retailing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	54
Service and Retailing Businesses [Member] | Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,931
Service and Retailing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,694
Service and Retailing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	942
BNSF [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,580
Other revenue	10
Total revenues	5,590
BNSF [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,580
Berkshire Hathaway Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,224
Other revenue	288
Total revenues	4,512
Berkshire Hathaway Energy [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	700
Berkshire Hathaway Energy [Member] | Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,524
Finance and Financial Products Reportable Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,038
Other revenue	1,022
Total revenues	2,060
Finance and Financial Products Reportable Segment [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	161
Finance and Financial Products Reportable Segment [Member] | Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1
Finance and Financial Products Reportable Segment [Member] | Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	848
Finance and Financial Products Reportable Segment [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	20
Finance and Financial Products Reportable Segment [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8
Insurance Corporate And Other [Member]
Disaggregation of Revenue [Line Items]
Other revenue	14,650
Total revenues	$ 14,650