Segment Information (Details 1) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Geographic information
Product, net		$ 2,425.9	$ 2,391.7	$ 2,198.6	$ 2,172.3	$ 2,287.0	$ 2,117.3	$ 2,056.3	$ 1,742.8	$ 9,188.5	$ 8,203.4	$ 5,542.3
Revenues from unconsolidated joint business										1,339.2	1,195.4	1,126.0
Other revenues from external customers		79.5	$ 49.0	$ 55.6	$ 52.0	49.2	$ 103.4	$ 61.9	$ 90.1	236.1	304.5	263.9
Long-lived assets		2,187.6				1,765.7				2,187.6	1,765.7	1,750.7
U.S
Geographic information
Product, net										6,545.8	5,566.7	3,581.0
Revenues from unconsolidated joint business										1,269.8	1,117.1	1,087.3
Other revenues from external customers										142.0	212.6	193.5
Long-lived assets		1,296.5				1,055.5				1,296.5	1,055.5	984.4
Europe
Geographic information
Product, net	[1]									1,497.6	1,383.9	1,170.2
Revenues from unconsolidated joint business	[1]									3.5	7.7	1.6
Other revenues from external customers	[1]									29.6	31.6	26.1
Long-lived assets	[1]	879.4				701.9				879.4	701.9	758.3
Germany
Geographic information
Product, net										668.1	811.8	417.7
Revenues from unconsolidated joint business										0.0	0.0	0.0
Other revenues from external customers										1.6	1.8	1.2
Long-lived assets		2.3				2.5				2.3	2.5	2.5
Asia
Geographic information
Product, net										143.7	112.8	93.2
Revenues from unconsolidated joint business										0.0	0.0	3.2
Other revenues from external customers										62.9	58.5	43.1
Long-lived assets		7.7				2.6				7.7	2.6	2.1
Other
Geographic information
Product, net										333.3	328.2	280.2
Revenues from unconsolidated joint business										65.9	70.6	33.9
Other revenues from external customers										0.0	0.0	0.0
Long-lived assets		$ 1.7				$ 3.2				$ 1.7	$ 3.2	$ 3.3

[1] Represents amounts related to Europe less those attributable to Germany.