Reportable Segments (Reportable Segment Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011
Segment Reporting Information [Line Items]
Net sales	$ 3,440	$ 3,485
Operating profit	535	572
Reportable segments information	The Company currently manages its operations through nine operating segments that are based on product category or geographic location. These operating segments are evaluated for similarity with regards to economic characteristics, products, production processes, types or classes of customers, distribution methods and regulatory environments to determine if they can be aggregated into reportable segments.  Beginning in the fourth quarter of 2011, the Company has the following reportable segments: U.S. Morning Foods and Kashi; U.S. Snacks; U.S. Specialty; North America Other; Europe; Latin America; and Asia Pacific.  In addition, subsequent to the filing of the Company’s Annual Report on Form 10-K, the Company reclassified certain customers between reportable segments within North America. Segment results of prior periods were recast to conform to the current presentation.  The reportable segments are discussed in greater detail below.
U.S. Morning Foods and Kashi [Member]
Segment Reporting Information [Line Items]
Net sales	941	958
Operating profit	159	181
Reportable segments information	U.S. Morning Foods and Kashi aggregates the U.S. Morning Foods and U.S. Kashi operating segments.  The U.S. Morning Foods operating segment includes cereal, toaster pastries, and health and wellness products generally marketed under the Kellogg’s name.  The U.S. Kashi operating segment represents Kashi-branded cereal, cereal bars, crackers, cookies and Stretch Island fruit snacks.
U.S. Snacks [Member]
Segment Reporting Information [Line Items]
Net sales	742	725
Operating profit	118	124
Reportable segments information	U.S. Snacks represents the U.S. snacks business which includes products such as cookies, crackers, cereal bars and fruit-flavored snacks.
U.S. Specialty [Member]
Segment Reporting Information [Line Items]
Net sales	348	323
Operating profit	71	65
Reportable segments information	U.S. Specialty primarily represents the food service, convenience and Girl Scouts businesses. The food service business is mostly non-commercial, servicing institutions such as schools and hospitals.
North America Other [Member]
Segment Reporting Information [Line Items]
Net sales	368	358
Operating profit	70	70
Reportable segments information	North America Other represents the U.S. Frozen and Canada operating segments.  As these operating segments are not considered economically similar enough to aggregate with other operating segments and are immaterial for separate disclosure, they have been grouped together as a single reportable segment.
Europe [Member]
Segment Reporting Information [Line Items]
Net sales	538	621
Operating profit	78	101
Reportable segments information	Europe which consists principally of European countries;
Latin America [Member]
Segment Reporting Information [Line Items]
Net sales	270	261
Operating profit	51	48
Reportable segments information	Latin America which is comprised of Central and South America and includes Mexico;
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net sales	233	239
Operating profit	34	31
Reportable segments information	Asia Pacific which is comprised of South Africa, Australia and other Asian and Pacific markets.
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating profit	581	620
Corporate [Member]
Segment Reporting Information [Line Items]
Operating profit	$ (46)	$ (48)