Consolidated Statement of Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total		Common stock	Capital in excess of par value	Retained earnings	Treasury stock	Accumulated other comprehensive income (loss)	Total Kellogg Company equity	Non-controlling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 2,138								$ 10
Balance at Jan. 02, 2016			$ 105	$ 745	$ 6,597	$ (3,943)	$ (1,376)	$ 2,128
Balance (in shares) at Jan. 02, 2016			420			70
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchases (in shares)						6
Common stock repurchases	(426)					$ (426)		(426)
Net income	695				694			694	1
Noncontrolling Interest, Increase from Business Combination	5							0	5
Dividends	(716)				(716)			(716)
Other comprehensive income	(199)						(199)	(199)	0
Stock compensation	63			63				63
Stock options exercised and other (in shares)						(7)
Stock options exercised and other	366			(2)	(4)	$ 372		366
Balance (in shares) at Dec. 31, 2016			420			69
Balance at Dec. 31, 2016	1,910	[1]	$ 105	806	6,571	$ (3,997)	(1,575)	1,910
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 1,926	[1]							16
Common stock repurchases (in shares)	2					2
Common stock repurchases	$ (125)					$ (125)		(125)
Net income	262				262			262
Dividends	(182)				(182)			(182)
Other comprehensive income	87						87	87
Stock compensation	17			17				17
Stock options exercised and other (in shares)						(1)
Stock options exercised and other	37			(6)	(1)	$ 44		37
Balance (in shares) at Apr. 01, 2017			420			70
Balance at Apr. 01, 2017	2,006		$ 105	$ 817	$ 6,650	$ (4,078)	$ (1,488)	$ 2,006
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 2,022								$ 16

[1] Condensed from audited financial statements.