Consolidated Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015	Jul. 02, 2016	Jul. 04, 2015
Income Statement [Abstract]
Net sales	$ 3,268	$ 3,498	$ 6,663	$ 7,054
Cost of goods sold	1,998	2,257	4,148	4,568
Selling, general and administrative expense	821	829	1,628	1,690
Operating profit	449	412	887	796
Interest expense	68	58	285	112
Other income (expense), net	4	(46)	4	(72)
Income before income taxes	385	308	606	612
Income taxes	106	85	153	161
Earnings (loss) from unconsolidated entities	1	(1)	2	(2)
Net income	280	222	455	449
Net income (loss) attributable to noncontrolling interests	0	(1)	0	(1)
Net income attributable to Kellogg Company	$ 280	$ 223	$ 455	$ 450
Per share amounts:
Basic (in dollars per share)	$ 0.80	$ 0.63	$ 1.30	$ 1.27
Diluted (in dollars per share)	0.79	0.63	1.29	1.26
Dividends per share (in dollars per share)	$ 0.50	$ 0.49	$ 1.00	$ 0.98
Average shares outstanding:
Basic (in shares)	350	353	350	354
Diluted (in shares)	354	355	354	356
Actual shares outstanding at period end (in shares)	349	353	349	353