Segment Information Major Geographic Area (Details) (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
Revenues and Long-Lived Assets
Long-Lived Assets	$ 899.8				$ 884.3				$ 899.8	$ 884.3
Revenue	2,207.1	1,841.1	1,851.4	1,637.5	2,122.7	1,700.4	1,756.2	1,543.0	7,537.1	7,122.3	6,956.2
Domestic
Revenues and Long-Lived Assets
Long-Lived Assets	572.9				545.7				572.9	545.7
Revenue									4,184.0	3,972.6	3,803.6
Total international
Revenues and Long-Lived Assets
Long-Lived Assets	326.9				338.6				326.9	338.6
Revenue									3,353.1	3,149.7	3,152.6
United Kingdom
Revenues and Long-Lived Assets
Long-Lived Assets	56.7				60.8				56.7	60.8
Revenue									688.3	568.3	572.0
Continental Europe
Revenues and Long-Lived Assets
Long-Lived Assets	66.4				79.6				66.4	79.6
Revenue									804.7	800.6	823.1
Asia Pacific
Revenues and Long-Lived Assets
Long-Lived Assets	102.2				88.8				102.2	88.8
Revenue									922.5	868.9	838.1
Latin America
Revenues and Long-Lived Assets
Long-Lived Assets	69.2				72.3				69.2	72.3
Revenue									470.4	464.5	450.1
Other
Revenues and Long-Lived Assets
Long-Lived Assets	32.4				37.1				32.4	37.1
Revenue									$ 467.2	$ 447.4	$ 469.3