Investments in H.J. Heinz Holding Corporation (Detail) (Heinz Holding [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014		Sep. 28, 2014		Dec. 29, 2013
Heinz Holding [Member]
Schedule of Equity Method Investments [Line Items]
Assets	$ 38,055		$ 38,055		$ 38,972
Liabilities	22,039		22,039		22,429
Sales	2,594		8,122
Net earnings	172		494
Preferred stock dividends earned by Berkshire	(180)		(540)
Net loss attributable to common stockholders	(8)		(46)
Earnings attributable to Berkshire	$ 176	[1]	$ 516	[1]

[1] Includes dividends earned and Berkshire's share of net loss attributable to common stockholders.