Business Segment Information - Summary of Business (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)
Business Segment Information
Number of Reportable Segments | segment			4
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	$ 2,801	$ 3,017	$ 5,586	$ 5,802
Reconciling items
Other	(1)	5	(11)	(10)
Business consolidation and other activities	(112)		(227)	(14)
Amortization of acquired Rexam intangibles	(44)	(48)	(89)	(96)
Earnings before interest and taxes	178	307	333	528
Interest expense	(67)	(81)	(138)	(158)
Debt refinancing and other costs			(40)	(4)
Total interest expense	(67)	(81)	(178)	(162)
Earnings before taxes	111	226	155	366
Undistributed corporate expenses	6	15	20	38
Depreciation and Amortization
Depreciation and amortization	170	171	339	341
Capital Expenditures
Capital expenditures			447	275
Operating Segments
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	2,733	2,810	5,420	5,394
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	328	342	645	632
Operating Segments | Beverage packaging, North And Central America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	1,267	1,286	2,448	2,417
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	189	141	335	259
Reconciling items
Business consolidation and other activities	(1)	(5)	(4)	(6)
Operating Segments | Beverage packaging, South America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	329	377	734	818
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	46	65	109	133
Reconciling items
Business consolidation and other activities	(3)	37	(4)	36
Operating Segments | Beverage packaging, EMEA
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	699	768	1,368	1,452
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	63	98	131	172
Reconciling items
Business consolidation and other activities	(3)	(16)	(6)	(15)
Operating Segments | Aerospace
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	438	379	870	707
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	30	38	70	68
Other
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	68	207	166	408
Reconciling items
Business consolidation and other activities	(105)	(16)	(213)	(29)
Rexam
Reconciling items
Amortization of acquired Rexam intangibles	$ (37)	$ (40)	$ (74)	$ (80)