Notes payable and other borrowings (Detail) (USD $) In Millions, unless otherwise specified								12 Months Ended			12 Months Ended					12 Months Ended			12 Months Ended			12 Months Ended					12 Months Ended			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Berkshire Hathaway (Parent) [Member]	Dec. 31, 2012 Berkshire Hathaway (Parent) [Member]	Dec. 31, 2013 Insurance and Other [Member]	Dec. 31, 2012 Insurance and Other [Member]	Dec. 31, 2013 Insurance and Other [Member] Berkshire Hathaway (Parent) [Member]	Dec. 31, 2012 Insurance and Other [Member] Berkshire Hathaway (Parent) [Member]	Dec. 31, 2013 Insurance and Other [Member] Berkshire Hathaway (Parent) [Member] Debt [Member]	Dec. 31, 2013 Insurance and Other [Member] Insurance and Other Subsidiaries [Member]	Dec. 31, 2012 Insurance and Other [Member] Insurance and Other Subsidiaries [Member]	Dec. 31, 2013 Insurance and Other [Member] Insurance and Other Subsidiaries [Member] Debt [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member]	Dec. 31, 2012 Railroad, Utilities and Energy [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] MidAmerican [Member]	Dec. 31, 2012 Railroad, Utilities and Energy [Member] MidAmerican [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] MidAmerican [Member] Debt [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] MidAmerican Subsidiaries [Member]	Dec. 31, 2012 Railroad, Utilities and Energy [Member] MidAmerican Subsidiaries [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] MidAmerican Subsidiaries [Member] Debt [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] BNSF [Member]	Dec. 31, 2012 Railroad, Utilities and Energy [Member] BNSF [Member]	Dec. 31, 2013 Railroad, Utilities and Energy [Member] BNSF [Member] Debt [Member]	Dec. 31, 2013 Finance and Financial Products [Member]	Dec. 31, 2012 Finance and Financial Products [Member]	Dec. 31, 2013 Finance and Financial Products [Member] Berkshire Hathaway Finance Corporation [Member]	Dec. 31, 2012 Finance and Financial Products [Member] Berkshire Hathaway Finance Corporation [Member]	Dec. 31, 2013 Finance and Financial Products [Member] Berkshire Hathaway Finance Corporation [Member] Debt [Member]	Dec. 31, 2013 Finance and Financial Products [Member] Other Finance Subsidiaries [Member]	Dec. 31, 2012 Finance and Financial Products [Member] Other Finance Subsidiaries [Member]	Dec. 31, 2013 Finance and Financial Products [Member] Other Finance Subsidiaries [Member] Debt [Member]
Notes payable and other borrowings [Line Items]
Notes payable and other borrowings		$ 8,311	$ 8,323	$ 12,902	$ 13,535	$ 8,311	$ 8,323					$ 46,655	$ 36,156				$ 23,033	$ 17,002		$ 17,006	$ 14,533		$ 12,667	$ 13,045	$ 11,178	$ 11,186		$ 1,489	$ 1,859
Short-term borrowings									949	1,416
Other borrowings									3,642	3,796
Maturity date, range, start								2014			2014					2014			2014			2014					2014			2014
Maturity date, range, end								2047			2035					2043			2043			2097					2043			2036
Short-term debt, weighted average interest rate									0.40%
Weighted average interest rate, percentage						2.70%			5.90%					5.50%			5.30%			5.30%					3.30%			4.70%
Senior unsecured debt														6,616	4,621
Principal payments on debt - 2014	5,685	751		2,287								2,065											1,333
Principal payments on debt - 2015	5,043	1,709		1,951								1,454											1,638
Principal payments on debt - 2016	3,792	1,051		1,175								1,466											1,151
Principal payments on debt - 2017	4,850	1,100		1,385								1,622											1,843
Principal payments on debt - 2018	$ 7,506	$ 808		$ 1,259								$ 4,021											$ 2,226