Business Segment Information - Summary of Business (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)
Business Segment Information
Number of reportable segments | segment			4
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	$ 2,953	$ 2,946	$ 8,755	$ 8,832
Reconciling items
Other	27	6	38	40
Business consolidation and other activities	(133)	(32)	(147)	(131)
Amortization of acquired Rexam intangibles	(46)	(50)	(142)	(154)
Earnings before interest and taxes	198	268	726	737
Interest expense	(79)	(76)	(237)	(226)
Debt refinancing and other costs			(4)	(1)
Total interest expense	(79)	(76)	(241)	(227)
Earnings before taxes	119	192	485	510
Undistributed corporate expenses	5	21	44	64
Operating Segments
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	2,695	2,594	7,990	7,574
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	342	334	953	952
Operating Segments | Beverage packaging, North And Central America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	1,230	1,237	3,647	3,513
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	157	153	416	423
Reconciling items
Business consolidation and other activities	(2)	(14)	(8)	(16)
Operating Segments | Beverage packaging, South America
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	392	391	1,210	1,229
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	60	71	193	235
Reconciling items
Business consolidation and other activities	(14)	12	22	11
Operating Segments | Beverage packaging, Europe
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	699	683	2,052	1,995
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	90	84	241	219
Reconciling items
Business consolidation and other activities	(9)	(3)	(24)	(17)
Operating Segments | Aerospace
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	374	283	1,081	837
Segment Reporting Information, Operating Income (Loss) [Abstract]
Reportable segment comparable operating earnings	35	26	103	75
Other
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	258	352	765	1,258
Reconciling items
Business consolidation and other activities	(108)	(27)	(137)	(109)
Rexam
Reconciling items
Amortization of acquired Rexam intangibles	$ (38)	$ (40)	$ (118)	$ (124)