Business Segment Information - Summary of Business (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) segment	Sep. 30, 2020 USD ($)
Business Segment Information
Number of Reportable Segments | segment			4
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	$ 3,553	$ 3,093	$ 10,137	$ 8,679
Reconciling items
Other	(14)	(15)	(67)	(26)
Business consolidation and other activities	(141)	(8)	(136)	(235)
Amortization of acquired Rexam intangibles	(45)	(45)	(135)	(134)
Earnings before interest and taxes	238	374	911	707
Interest expense	(68)	(68)	(201)	(206)
Debt refinancing and other costs	(1)	(1)	(1)	(41)
Total interest expense	(69)	(69)	(202)	(247)
Earnings before taxes	169	305	709	460
Undistributed corporate expenses	17	13	71	33
Depreciation and Amortization
Depreciation and amortization	175	160	515	499
Capital Expenditures
Capital expenditures			1,204	683
Operating Segments
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	3,416	3,019	9,760	8,439
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	431	434	1,228	1,079
Operating Segments | Beverage packaging, North And Central America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	1,519	1,327	4,339	3,775
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	186	209	519	544
Reconciling items
Business consolidation and other activities			(1)	(4)
Operating Segments | Metal beverage packaging, Europe
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	937	809	2,639	2,177
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	125	117	349	248
Reconciling items
Business consolidation and other activities	(2)	(2)	(5)	(8)
Operating Segments | Beverage packaging, South America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	462	432	1,401	1,166
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	74	64	245	173
Reconciling items
Business consolidation and other activities	(9)	3	11	(1)
Operating Segments | Aerospace & technologies
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	498	451	1,381	1,321
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	46	44	115	114
Other
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	137	74	377	240
Reconciling items
Business consolidation and other activities	(130)	(9)	(141)	(222)
Rexam
Reconciling items
Amortization of acquired Rexam intangibles	$ (38)	$ (37)	$ (114)	$ (111)