Comprehensive Income Statement - USD ($) $ in Millions	12 Months Ended
	Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 614	$ 633	$ 1,808
Other comprehensive income (loss), pre-tax:
Foreign currency translation adjustment before tax	(170)	(231)	(24)
Cash flow hedges, pre-tax:
Unrealized gain (loss) on cash flow hedges, pre-tax	8	(35)	11
Reclassifications to net income, pre-tax	(23)	(10)	(6)
Postretirement and postemployment benefit amounts arising during the period, pre-tax:
Net experience gain (loss)	0	(8)	17
Prior service credit (cost)	63	10	9
Postretirement and postemployment benefits reclassification to net income, pre-tax:
Net experience loss, pre-tax	3	3	5
Prior service cost, pre-tax	9	10	13
Other comprehensive income (loss), pre-tax	(110)	(261)	25
Other comprehensive income (loss), tax (expense) benefit:
Foreign currency translation adjustments tax (expense) benefit	(26)	(32)	0
Cash flow hedges, tax (expense) benefit:
Unrealized gain (loss) on cash flow hedges, tax (expense) benefit	(3)	18	(1)
Reclassifications to net income, tax (expense) benefit	3	2	0
Postretirement and postemployment benefit amounts arising during the period, tax (expense) benefit:
Net experience gain (loss), tax (expense) benefit	0	3	(6)
Prior service credit (cost), tax (expense) benefit	(24)	(3)	(2)
Postretirement and postemployment benefits reclassification to net income, tax (expense) benefit:
Net experience loss, tax (expense) benefit	(1)	(1)	(2)
Prior service cost, tax (expense) benefit	(3)	(3)	(4)
Other comprehensive income (loss), tax (expense) benefit	(54)	(16)	(15)
Other comprehensive income (loss), after-tax
Foreign currency translation adjustments after tax	(196)	(263)	(24)
Cash flow hedges, after-tax:
Unrealized gain (loss) on cash flow hedges, after-tax	5	(17)	10
Reclassification to net income, after-tax	(20)	(8)	(6)
Postretirement and postemployment benefit amounts arising during the period, after-tax
Net experience gain (loss), after tax	0	(5)	11
Prior service credit (cost), after-tax	39	7	7
Postretirement and postemployment benefits reclassification to net income, after-tax
Net experience loss, after-tax	2	2	3
Prior service cost, after-tax	6	7	9
Other comprehensive income (loss)	(164)	(277)	10
Comprehensive income	450	356	1,818
Net income (loss) attributable to noncontrolling interests	0	1	1
Other comprehensive income (loss) attributable to noncontrolling interests	(1)	0	0
Comprehensive income attributable to Kellogg Company	$ 451	$ 355	$ 1,817