Business Segment Information (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue and property, plant and equipment by geographical area
Total revenue	$ 508.0	$ 419.8	$ 457.4	$ 423.7	$ 552.1	$ 439.0	$ 454.9	$ 393.4	$ 1,808.9	$ 1,839.4	$ 1,791.4
Total property, plant and equipment, net	249.9				299.5				249.9	299.5
United States
Revenue and property, plant and equipment by geographical area
Total revenue									387.6	359.7	377.2
Total property, plant and equipment, net	45.9				53.8				45.9	53.8
Germany
Revenue and property, plant and equipment by geographical area
Total revenue									215.1	188.9	174.8
Total property, plant and equipment, net	143.8				175.0				143.8	175.0
Rest of Europe
Revenue and property, plant and equipment by geographical area
Total revenue									522.9	583.7	531.3
Total property, plant and equipment, net	53.6				62.7				53.6	62.7
Asia Pacific
Revenue and property, plant and equipment by geographical area
Total revenue									495.5	529.1	525.7
Total property, plant and equipment, net	4.7				5.8				4.7	5.8
Other
Revenue and property, plant and equipment by geographical area
Total revenue									187.8	178.0	182.4
Total property, plant and equipment, net	$ 1.9				$ 2.2				$ 1.9	$ 2.2