Business Segment Information - Summary of Business (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Business Segment Information
Number of Reportable Segments | segment			4
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	$ 3,459	$ 2,801	$ 6,584	$ 5,586
Reconciling items
Other	(30)	(1)	(53)	(11)
Business consolidation and other activities	12	(112)	5	(227)
Amortization of acquired Rexam intangibles	(45)	(44)	(90)	(89)
Earnings before interest and taxes	373	178	673	333
Interest expense	(66)	(67)	(133)	(138)
Debt refinancing and other costs				(40)
Total interest expense	(66)	(67)	(133)	(178)
Earnings before taxes	307	111	540	155
Undistributed corporate expenses	28	6	54	20
Depreciation and Amortization
Depreciation and amortization	172	170	340	339
Capital Expenditures
Capital expenditures			757	447
Operating Segments
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	3,341	2,733	6,344	5,420
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	429	328	797	645
Operating Segments | Beverage packaging, North And Central America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	1,524	1,267	2,820	2,448
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	193	189	333	335
Reconciling items
Business consolidation and other activities	(2)	(1)	(1)	(4)
Operating Segments | Beverage packaging, EMEA
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	906	699	1,702	1,368
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	124	63	224	131
Reconciling items
Business consolidation and other activities	(1)	(3)	(3)	(6)
Operating Segments | Beverage packaging, South America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	452	329	939	734
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	78	46	171	109
Reconciling items
Business consolidation and other activities	21	(3)	20	(4)
Operating Segments | Aerospace
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	459	438	883	870
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	34	30	69	70
Other
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	118	68	240	166
Reconciling items
Business consolidation and other activities	(6)	(105)	(11)	(213)
Rexam
Reconciling items
Amortization of acquired Rexam intangibles	$ (38)	$ (37)	$ (76)	$ (74)