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Notes payable and other borrowings - Narrative (Detail) € in Millions, £ in Millions, $ in Millions, ¥ in Billions	1 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	May 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Apr. 30, 2023 JPY (¥)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 JPY (¥)	Jun. 30, 2023 EUR (€)	Jun. 30, 2023 GBP (£)	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Notes payable and other borrowings									¥ 1,137.0	€ 6,850	£ 1,750
Line of Credit and Commercial Paper Facilities [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Unused lines of credit available	$ 12,000				$ 12,000		$ 12,000
Line of Credit and Commercial Paper Facilities [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Unused lines of credit available	8,600				8,600		8,600
Insurance and Other [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	41,389				41,389		41,389					$ 46,538
Insurance and Other [Member] \| Berkshire Hathaway Inc. (Parent) [Member] \| Subsidiaries Excluding Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Guarantee obligation	2,700				2,700		2,700
Insurance and Other [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	4,908				4,908		4,908					5,967
Insurance and Other [Member] \| Senior Notes [Member] \| Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Repayments of borrowings							4,300
Principal amount of debt issued			$ 1,200	¥ 164.4
Insurance and Other [Member] \| Senior Notes [Member] \| Berkshire Hathaway Inc. (Parent) [Member] \| Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Gains (loss) attributable to changes in foreign currency exchange rates					555	$ 1,400	$ 529	$ 2,100
Insurance and Other [Member] \| Maximum [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Debt maturity year							2051
Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	83,958				$ 83,958		$ 83,958					$ 76,206
Railroad, Utilities and Energy [Member] \| 5.5% First Mortgage Bonds Due [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy ("BHE") [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 1,200
Debt instrument, interest rate, stated percentage		5.50%
Debt maturity year		2054
Railroad, Utilities and Energy [Member] \| Term Debt [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy ("BHE") [Member]
Debt Instrument [Line Items]
Repayments of borrowings							$ 1,400
Railroad, Utilities and Energy [Member] \| Term Debt [Member] \| Subsidiaries [Member] \| BNSF [Member]
Debt Instrument [Line Items]
Repayments of borrowings	700
Railroad, Utilities and Energy [Member] \| Senior Unsecured Debenture [Member] \| 5.2% Debentures Due [Member] \| Subsidiaries [Member] \| BNSF [Member]
Debt Instrument [Line Items]
Principal amount of debt issued	$ 1,600
Debt instrument, interest rate, stated percentage	5.20%				5.20%		5.20%		5.20%	5.20%	5.20%
Debt maturity year	2054
Railroad, Utilities and Energy [Member] \| Maximum [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy ("BHE") [Member]
Debt Instrument [Line Items]
Debt maturity year							2053