Goodwill and Other Intangible Assets (Carrying Amount of Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Changes in the carrying amount of goodwill
Balance	$ 3,628	$ 3,643
Impairment charge		(20)
Currency translation adjustment	(5)	5
Balance	3,623	3,628
U.S. Morning Foods and Kashi [Member]
Changes in the carrying amount of goodwill
Balance	80	80
Impairment charge		0
Currency translation adjustment	0	0
Balance	80	80
U.S. Snacks [Member]
Changes in the carrying amount of goodwill
Balance	3,257	3,257
Impairment charge		0
Currency translation adjustment	0	0
Balance	3,257	3,257
U.S. Specialty [Member]
Changes in the carrying amount of goodwill
Balance	0	0
Impairment charge		0
Currency translation adjustment	0	0
Balance	0	0
North America Other [Member]
Changes in the carrying amount of goodwill
Balance	202	202
Impairment charge		0
Currency translation adjustment	0	0
Balance	202	202
Europe [Member]
Changes in the carrying amount of goodwill
Balance	62	62
Impairment charge		0
Currency translation adjustment	(5)	0
Balance	57	62
Latin America [Member]
Changes in the carrying amount of goodwill
Balance	0	0
Impairment charge		0
Currency translation adjustment	0	0
Balance	0	0
Asia Pacific [Member]
Changes in the carrying amount of goodwill
Balance	27	42
Impairment charge		(20)
Currency translation adjustment	0	5
Balance	27	27
Corporate [Member]
Changes in the carrying amount of goodwill
Balance	0	0
Impairment charge		0
Currency translation adjustment	0	0
Balance	$ 0	$ 0