Goodwill and Other Intangible Assets - Intangible Assets Not Subject to Amortization (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	$ 2,282
Purchase price allocation adjustment	(11)
Currency translation adjustment	48
Intangible assets not subject to amortization, ending balance	2,319
U.S. Morning Foods
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	0
Purchase price allocation adjustment	0
Currency translation adjustment	0
Intangible assets not subject to amortization, ending balance	0
U.S. Snacks
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	1,625
Purchase price allocation adjustment	0
Currency translation adjustment	0
Intangible assets not subject to amortization, ending balance	1,625
U.S. Specialty
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	0
Purchase price allocation adjustment	0
Currency translation adjustment	0
Intangible assets not subject to amortization, ending balance	0
North America Other
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	176
Purchase price allocation adjustment	0
Currency translation adjustment	0
Intangible assets not subject to amortization, ending balance	176
Europe
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	383
Purchase price allocation adjustment	0
Currency translation adjustment	45
Intangible assets not subject to amortization, ending balance	428
Latin America
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	98
Purchase price allocation adjustment	(11)
Currency translation adjustment	3
Intangible assets not subject to amortization, ending balance	90
Asia Pacific
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets not subject to amortization, beginning balance	0
Purchase price allocation adjustment	0
Currency translation adjustment	0
Intangible assets not subject to amortization, ending balance	$ 0