Investments in H.J. Heinz Holding Corporation (Detail) (Heinz Holding [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 30, 2014		Dec. 29, 2013
Heinz Holding [Member]
Schedule of Equity Method Investments [Line Items]
Assets	$ 38,962		$ 38,972
Liabilities	22,461		22,429
Sales	2,800
Net earnings	195
Preferred stock dividends earned by Berkshire	(180)
Net earnings attributable to common stockholders	15
Earnings attributable to Berkshire	$ 188	[1]

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