Segment Reporting - Net Revenues by Product Category (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	[1]
Segment Reporting Information [Line Items]
Total net revenues	$ 6,765	$ 6,414
Biscuits
Segment Reporting Information [Line Items]
Total net revenues	2,753	2,568
Chocolate
Segment Reporting Information [Line Items]
Total net revenues	2,296	2,052
Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	881	880
Beverages
Segment Reporting Information [Line Items]
Total net revenues	361	407
Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	474	507
Latin America
Segment Reporting Information [Line Items]
Total net revenues	891	910
Latin America | Biscuits
Segment Reporting Information [Line Items]
Total net revenues	183	170
Latin America | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	243	259
Latin America | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	224	213
Latin America | Beverages
Segment Reporting Information [Line Items]
Total net revenues	161	193
Latin America | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	80	75
AMEA
Segment Reporting Information [Line Items]
Total net revenues	1,542	1,491
AMEA | Biscuits
Segment Reporting Information [Line Items]
Total net revenues	442	400
AMEA | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	573	514
AMEA | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	235	229
AMEA | Beverages
Segment Reporting Information [Line Items]
Total net revenues	172	173
AMEA | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	120	175
Europe
Segment Reporting Information [Line Items]
Total net revenues	2,706	2,365
Europe | Biscuits
Segment Reporting Information [Line Items]
Total net revenues	795	665
Europe | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	1,423	1,209
Europe | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	186	193
Europe | Beverages
Segment Reporting Information [Line Items]
Total net revenues	28	41
Europe | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	274	257
North America
Segment Reporting Information [Line Items]
Total net revenues	1,626	1,648
North America | Biscuits
Segment Reporting Information [Line Items]
Total net revenues	1,333	1,333
North America | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	57	70
North America | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	236	245
North America | Beverages
Segment Reporting Information [Line Items]
Total net revenues	0	0
North America | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	$ 0	$ 0

[1] During the first quarter of 2018, we realigned some of our products across product categories and as such, we reclassified the product category net revenues on a basis consistent with the 2018 presentation.