Consolidated Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Income Statement [Abstract]
Net sales	$ 3,498	$ 3,685	$ 7,054	$ 7,427
Cost of goods sold	2,257	2,274	4,568	4,512
Selling, general and administrative expense	829	944	1,690	1,834
Operating profit	412	467	796	1,081
Interest expense	58	50	112	102
Other income (expense), net	(46)	3	(72)	13
Income before income taxes	308	420	612	992
Income taxes	85	122	161	287
Earnings (loss) from joint ventures	(1)	(3)	(2)	(4)
Net income	222	295	449	701
Net income (loss) attributable to noncontrolling interests	(1)	0	(1)	0
Net income attributable to Kellogg Company	$ 223	$ 295	$ 450	$ 701
Per share amounts:
Basic (in dollars per share)	$ 0.63	$ 0.82	$ 1.27	$ 1.95
Diluted (in dollars per share)	0.63	0.82	1.26	1.94
Dividends per share (in dollars per share)	$ 0.49	$ 0.46	$ 0.98	$ 0.92
Average shares outstanding:
Basic (in shares)	353	359	354	360
Diluted (in shares)	355	362	356	362
Actual shares outstanding at period end (in shares)	353	360	353	360