Reportable Segments (Reportable Segment Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Jan. 01, 2011	Oct. 02, 2010	Jul. 03, 2010	Apr. 03, 2010	Dec. 31, 2011	Jan. 01, 2011		Jan. 02, 2010
Net sales	$ 3,015	$ 3,312	$ 3,386	$ 3,485	$ 2,860	$ 3,157	$ 3,062	$ 3,318	$ 13,198	$ 12,397		$ 12,575
Operating profit									1,976	1,990		2,001
Depreciation and amortization									369	392		384
Interest expense									233	248		295
Income taxes									503	502		476
Total assets	11,901				11,847				11,901	11,847		11,200
Additions to long-lived assets									594	474		377
Research and development expenses reallocated to Corporate from North America businesses										11		13
U.S. Morning Foods and Kashi [Member]
Net sales									3,635	3,480		3,587
Operating profit									648	630		728
Depreciation and amortization									131	125		132
U.S. Snacks [Member]
Net sales									2,908	2,745		2,758
Operating profit									431	475		436
Depreciation and amortization									91	96		94
U.S. Specialty [Member]
Net sales									955	916		913
Operating profit									216	240		190
Depreciation and amortization									5	5		4
North America Other [Member]
Net sales									1,375	1,261		1,252
Operating profit									258	220		228
Depreciation and amortization									30	31		26
North America [Member]
Total assets	9,128				8,623				9,128	8,623		8,465
Additions to long-lived assets									421	327		236
Europe [Member]
Net sales									2,334	2,230		2,361
Operating profit									338	364		348
Depreciation and amortization									57	53		60
Interest expense									4	1		1
Income taxes									40	23		22
Total assets	1,584				1,700				1,584	1,700		1,630
Additions to long-lived assets									61	57		50
Latin America [Member]
Net sales									1,049	923		963
Operating profit									176	153		179
Depreciation and amortization									20	17		28
Interest expense									6	0		0
Income taxes									49	29		32
Total assets	798				784				798	784		585
Additions to long-lived assets									53	43		58
Asia Pacific [Member]
Net sales									942	842		741
Operating profit									106	74		86
Depreciation and amortization									27	53		22
Interest expense									2	1		0
Income taxes									21	19		16
Total assets	529				596				529	596		535
Additions to long-lived assets									54	45		30
Total Reportable Segments [Member]
Operating profit									2,173	2,156		2,195
Depreciation and amortization									361	380		366
Corporate [Member]
Operating profit									(197)	(166)	[1]	(194)	[1]
Depreciation and amortization									8	12		18
Interest expense									221	246		294
Total assets	2,275				3,006				2,275	3,006		3,354
Additions to long-lived assets									5	2		3
Corporate and North America [Member]
Income taxes									393	431		406
Elimination entries [Member]
Total assets	$ (2,413)				$ (2,862)				$ (2,413)	$ (2,862)		$ (3,369)

[1] Research and Development expense totaling $11 million for 2010 and $13 million for 2009 was reallocated to Corporate from the North America businesses.