Consolidated Statements of Earnings (Parenthetical) (Class B [Member], USD $)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Ratio of earnings per Class B share to earnings per Class A share	0.000667
Net earnings per share attributable to Berkshire Hathaway shareholders	$ 4.14	$ 5.29	$ 3.46

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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+ Details