Segment Reporting - Net Revenues by Product Category (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Total net revenues	$ 9,744	$ 9,204	$ 28,041	$ 26,837
Biscuits & Baked Snacks
Segment Reporting Information [Line Items]
Total net revenues	4,799	4,605	13,705	13,261
Chocolate
Segment Reporting Information [Line Items]
Total net revenues	3,076	2,783	8,919	8,030
Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	1,051	1,023	2,971	3,036
Beverages
Segment Reporting Information [Line Items]
Total net revenues	217	237	741	856
Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	601	556	1,705	1,654
Latin America
Segment Reporting Information [Line Items]
Total net revenues	1,238	1,204	3,635	3,755
Latin America | Biscuits & Baked Snacks
Segment Reporting Information [Line Items]
Total net revenues	286	312	868	908
Latin America | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	352	299	1,066	985
Latin America | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	396	374	1,098	1,148
Latin America | Beverages
Segment Reporting Information [Line Items]
Total net revenues	80	104	255	348
Latin America | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	124	115	348	366
AMEA
Segment Reporting Information [Line Items]
Total net revenues	2,017	1,851	5,854	5,388
AMEA | Biscuits & Baked Snacks
Segment Reporting Information [Line Items]
Total net revenues	760	661	2,182	1,865
AMEA | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	807	752	2,237	2,102
AMEA | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	243	240	747	711
AMEA | Beverages
Segment Reporting Information [Line Items]
Total net revenues	102	105	388	418
AMEA | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	105	93	300	292
Europe
Segment Reporting Information [Line Items]
Total net revenues	3,674	3,323	10,636	9,565
Europe | Biscuits & Baked Snacks
Segment Reporting Information [Line Items]
Total net revenues	1,308	1,162	3,685	3,285
Europe | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	1,806	1,640	5,335	4,703
Europe | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	153	145	461	491
Europe | Beverages
Segment Reporting Information [Line Items]
Total net revenues	35	28	98	90
Europe | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	372	348	1,057	996
North America
Segment Reporting Information [Line Items]
Total net revenues	2,815	2,826	7,916	8,129
North America | Biscuits & Baked Snacks
Segment Reporting Information [Line Items]
Total net revenues	2,445	2,470	6,970	7,203
North America | Chocolate
Segment Reporting Information [Line Items]
Total net revenues	111	92	281	240
North America | Gum & Candy
Segment Reporting Information [Line Items]
Total net revenues	259	264	665	686
North America | Beverages
Segment Reporting Information [Line Items]
Total net revenues	0	0	0	0
North America | Cheese & Grocery
Segment Reporting Information [Line Items]
Total net revenues	$ 0	$ 0	$ 0	$ 0