DOCUMENT AND ENTITY INFORMATION (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 29, 2015	Mar. 30, 2014	Apr. 29, 2015
Entity Information [Line Items]
Entity Registrant Name	SMITHFIELD FOODS INC
Entity Central Index Key	0000091388
Current Fiscal Year End Date	--12-28
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 29, 2015
Document Fiscal Year Focus	2015
Net Income (Loss) Attributable to Parent	$ 97.0	$ 105.3
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding			1,000