Notes payable and other borrowings (Detail) (USD $) In Millions, unless otherwise specified					3 Months Ended			3 Months Ended			3 Months Ended					3 Months Ended			3 Months Ended					3 Months Ended			3 Months Ended
	Mar. 31, 2014 Railroad, Utilities and Energy [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member]	Mar. 31, 2014 Railroad, Utilities and Energy [Member] Berkshire Hathaway Energy [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] Berkshire Hathaway Energy [Member]	Mar. 31, 2014 Railroad, Utilities and Energy [Member] Berkshire Hathaway Energy [Member] Debt [Member]	Mar. 31, 2014 Railroad, Utilities and Energy [Member] Berkshire Hathaway Energy Subsidiaries [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] Berkshire Hathaway Energy Subsidiaries [Member]	Mar. 31, 2014 Railroad, Utilities and Energy [Member] Berkshire Hathaway Energy Subsidiaries [Member] Debt [Member]	Mar. 31, 2014 Railroad, Utilities and Energy [Member] BNSF [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] BNSF [Member]	Mar. 31, 2014 Railroad, Utilities and Energy [Member] BNSF [Member] Debt [Member]	Mar. 31, 2014 Insurance and Other [Member]	Dec. 31, 2013 Insurance and Other [Member]	Mar. 31, 2014 Insurance and Other [Member] Berkshire Hathaway (Parent) [Member]	Dec. 31, 2013 Insurance and Other [Member] Berkshire Hathaway (Parent) [Member]	Mar. 31, 2014 Insurance and Other [Member] Berkshire Hathaway (Parent) [Member] Debt [Member]	Mar. 31, 2014 Insurance and Other [Member] Insurance and Other Subsidiaries [Member]	Dec. 31, 2013 Insurance and Other [Member] Insurance and Other Subsidiaries [Member]	Mar. 31, 2014 Insurance and Other [Member] Insurance and Other Subsidiaries [Member] Debt [Member]	Mar. 31, 2014 Finance and Financial Products [Member]	Dec. 31, 2013 Finance and Financial Products [Member]	Mar. 31, 2014 Finance and Financial Products [Member] Berkshire Hathaway Finance Corporation [Member]	Dec. 31, 2013 Finance and Financial Products [Member] Berkshire Hathaway Finance Corporation [Member]	Mar. 31, 2014 Finance and Financial Products [Member] Berkshire Hathaway Finance Corporation [Member] Debt [Member]	Mar. 31, 2014 Finance and Financial Products [Member] Other Finance Subsidiaries [Member]	Dec. 31, 2013 Finance and Financial Products [Member] Other Finance Subsidiaries [Member]	Mar. 31, 2014 Finance and Financial Products [Member] Other Finance Subsidiaries [Member] Debt [Member]
Notes payable and other borrowings [Line Items]
Maturity date, range, start					2017			2014			2014					2014			2014					2014			2014
Maturity date, range, end					2043			2043			2097					2047			2035					2043			2036
Short-term debt, weighted average interest rate																	0.30%
Senior unsecured debt			$ 6,366	$ 6,616
Weighted average interest rate, percentage			5.70%			5.30%			5.20%					2.70%			6.00%					3.30%			4.90%
Notes payable and other borrowings	47,751	46,655				23,436	23,033		17,949	17,006		12,448	12,440	8,305	8,311					13,024	13,129	11,177	11,178		1,847	1,951
Short-term borrowings																	978	949
Other borrowings																	$ 3,165	$ 3,180