Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2022	Jul. 03, 2021	Jul. 02, 2022	Jul. 03, 2021
Income Statement [Abstract]
Net sales	$ 3,864	$ 3,555	$ 7,536	$ 7,139
Cost of goods sold	2,721	2,331	5,234	4,749
Selling, general and administrative expense	728	720	1,370	1,414
Operating profit	415	504	932	976
Interest expense	54	58	110	117
Other income (expense), net	60	86	134	155
Income before income taxes	421	532	956	1,014
Income tax expense (benefit)	97	144	209	253
Earnings (loss) from unconsolidated entities	2	(3)	3	(5)
Net income	326	385	750	756
Net income attributable to noncontrolling interests	0	5	2	8
Net income attributable to Kellogg Company	$ 326	$ 380	$ 748	$ 748
Per share amounts:
Basic earnings (in dollars per share)	$ 0.96	$ 1.12	$ 2.20	$ 2.19
Diluted earnings (in dollars per share)	$ 0.95	$ 1.11	$ 2.19	$ 2.18
Average shares outstanding:
Basic (in shares)	339,000	341,000	340,000	341,000
Diluted (in shares)	342,000	343,000	342,000	343,000
Actual shares outstanding at period end (in shares)	340,000	341,000	340,000	341,000