Business Segment Information - Summary of Business (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)
Business Segment Information
Number of Reportable Segments | segment			4
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	$ 3,093	$ 2,953	$ 8,679	$ 8,755
Reconciling items
Other	(15)	12	(26)	2
Business consolidation and other activities	(8)	(133)	(235)	(147)
Amortization of acquired Rexam intangibles	(45)	(46)	(134)	(142)
Earnings before interest and taxes	374	198	707	726
Interest expense	(68)	(79)	(206)	(237)
Debt refinancing and other costs	(1)		(41)	(4)
Total interest expense	(69)	(79)	(247)	(241)
Earnings before taxes	305	119	460	485
Undistributed corporate expenses	13	4	33	42
Depreciation and Amortization
Depreciation and amortization	160	169	499	510
Capital Expenditures
Capital expenditures			683	425
Operating Segments
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	3,019	2,759	8,439	8,153
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	434	357	1,079	989
Operating Segments | Beverage packaging, North And Central America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	1,327	1,230	3,775	3,647
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	209	157	544	416
Reconciling items
Business consolidation and other activities		(2)	(4)	(8)
Operating Segments | Beverage packaging, South America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	432	392	1,166	1,210
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	64	60	173	193
Reconciling items
Business consolidation and other activities	3	(14)	(1)	22
Operating Segments | Beverage packaging, EMEA
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	809	763	2,177	2,215
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	117	105	248	277
Reconciling items
Business consolidation and other activities	(2)	(9)	(8)	(24)
Operating Segments | Aerospace
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	451	374	1,321	1,081
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	44	35	114	103
Other
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	74	194	240	602
Reconciling items
Business consolidation and other activities	(9)	(108)	(222)	(137)
Rexam
Reconciling items
Amortization of acquired Rexam intangibles	$ (37)	$ (38)	$ (111)	$ (118)