CONSOLIDATED STATEMENT OF EQUITY - 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
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 28, 2019	$ 3,314							$ 567
Balance, in shares at Dec. 28, 2019		421			79
Balance at Dec. 28, 2019		$ 105	$ 921	$ 7,859	$ (4,690)	$ (1,448)	$ 2,747
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,264			1,251			1,251	13
Divestiture	(3)						0	(3)
Dividends declared	(782)			(782)			(782)
Distributions to noncontrolling interest	(1)						0	(1)
Other comprehensive income (loss)	(336)					(284)	(284)	(52)
Stock compensation	76		76				76
Stock options exercised and other	104		(25)	(2)	$ 131		104
Stock options exercised and other (in shares)		0			(2)
Balance, in shares at Jan. 02, 2021		421			77
Balance at Jan. 02, 2021		$ 105	972	8,326	$ (4,559)	(1,732)	3,112
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Jan. 02, 2021	3,636							524
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchases	(240)				$ (240)		(240)
Common stock repurchases (in shares)					4
Net income (loss)	1,495			1,488			1,488	7
Acquisition of noncontrolling interest	52		22				22	30
Dividends declared	(788)			(788)			(788)
Distributions to noncontrolling interest	(36)						0	(36)
Other comprehensive income (loss)	(19)					11	11	(30)
Stock compensation	68		68				68
Stock options exercised and other	47		(39)	2	$ 84		47
Stock options exercised and other (in shares)		0			(1)
Balance, in shares at Jan. 01, 2022		421			80
Balance at Jan. 01, 2022	3,720	$ 105	1,023	9,028	$ (4,715)	(1,721)	3,720
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Jan. 01, 2022	4,215							495
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchases	(300)				$ (300)		(300)
Common stock repurchases (in shares)					5
Net income (loss)	962			960			960	2
Dividends declared	(797)			(797)			(797)
Distributions to noncontrolling interest	(17)						0	(17)
Other comprehensive income (loss)	(33)					13	13	(46)
Stock compensation	96		96				96
Stock options exercised and other	249		(51)	6	$ 294		249
Stock options exercised and other (in shares)		0			(6)
Balance, in shares at Dec. 31, 2022		421			79
Balance at Dec. 31, 2022	3,941	$ 105	$ 1,068	$ 9,197	$ (4,721)	$ (1,708)	$ 3,941
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2022	$ 4,375							$ 434