Goodwill (Details) $ in Millions	6 Months Ended
	Jun. 30, 2015 USD ($)
Goodwill
Balance at the beginning of the period	$ 2,254.5
Business acquisition	35.5
Effects of currency exchange rates	(80.8)
Balance at the end of the period	2,209.2
Metal beverage packaging, Americas and Asia
Goodwill
Balance at the beginning of the period	739.5
Balance at the end of the period	739.5
Metal beverage packaging, Europe
Goodwill
Balance at the beginning of the period	913.9
Effects of currency exchange rates	(69.2)
Balance at the end of the period	844.7
Metal food & household products packaging
Goodwill
Balance at the beginning of the period	592.5
Business acquisition	35.5
Effects of currency exchange rates	(11.6)
Balance at the end of the period	616.4
Aerospace & technologies
Goodwill
Balance at the beginning of the period	8.6
Balance at the end of the period	$ 8.6