Consolidated Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net sales	$ 3,522	$ 3,401
Cost of goods sold	2,415	2,149
Selling, general and administrative expense	726	742
Operating profit	381	510
Interest expense	74	69
Other income (expense), net	52	70
Income before income taxes	359	511
Income taxes	72	67
Earnings (loss) from unconsolidated entities	(2)	0
Net income	285	444
Net income (loss) attributable to noncontrolling interests	3	0
Net income attributable to Kellogg Company	$ 282	$ 444
Per share amounts:
Basic earnings (in dollars per share)	$ 0.82	$ 1.28
Diluted earnings (in dollars per share)	$ 0.82	$ 1.27
Average shares outstanding:
Basic (in shares)	342	346
Diluted (in shares)	343	348
Actual shares outstanding at period end (in shares)	340	347