Intangibles Assets, Net (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Total annual intangible asset amortization expense
Intangible assets (net of accumulated amortization)		$ 1,309.0	$ 1,417.0
Amortization expense		158.0	165.0	$ 180.0
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2024		159.0
2025		160.0
2026		156.0
2027		151.0
2028		147.0
Thereafter		536.0
Rexam
Total annual intangible asset amortization expense
Amortization expense		135.0	135.0	$ 152.0
Customer relationships and other intangibles
Total annual intangible asset amortization expense
Intangible assets (net of accumulated amortization)		1,197.0	1,320.0
Accumulated amortization and impairment losses		$ 1,060.0	914.0
Customer relationships and other intangibles | Aluminum beverage packaging business in Russia
Total annual intangible asset amortization expense
Impairment charge	$ 131.0
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]		Restructuring and Other Activities
Capitalized software
Total annual intangible asset amortization expense
Intangible assets (net of accumulated amortization)		$ 98.0	80.0
Accumulated amortization and impairment losses		222.0	204.0
Other intangibles
Total annual intangible asset amortization expense
Intangible assets (net of accumulated amortization)		14.0	17.0
Accumulated amortization and impairment losses		$ 51.0	$ 99.0