Consolidated Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Income Statement [Abstract]
Net sales	$ 3,329	$ 3,639	$ 10,383	$ 11,066
Cost of goods sold	2,096	2,347	6,664	6,859
Selling, general and administrative expense	899	927	2,589	2,761
Operating profit	334	365	1,130	1,446
Interest expense	56	54	168	156
Other income (expense), net	(6)	1	(78)	14
Income before income taxes	272	312	884	1,304
Income taxes	66	86	227	373
Earnings (loss) from unconsolidated entities	(1)	(1)	(3)	(5)
Net income	205	225	654	926
Net income (loss) attributable to noncontrolling interests	0	1	(1)	1
Net income attributable to Kellogg Company	$ 205	$ 224	$ 655	$ 925
Per share amounts:
Basic (in dollars per share)	$ 0.58	$ 0.63	$ 1.85	$ 2.58
Diluted (in dollars per share)	0.58	0.62	1.84	2.56
Dividends per share (in dollars per share)	$ 0.50	$ 0.49	$ 1.48	$ 1.41
Average shares outstanding:
Basic (in shares)	354	358	354	359
Diluted (in shares)	356	360	356	361
Actual shares outstanding at period end (in shares)	354	355	354	355