Segments, Geographical (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Net Revenues by Geographic Region [Line Items]
Total net revenues	$ 1,221.3	$ 1,222.2	$ 2,319.2	$ 2,289.6
Property and equipment, net and purchased intangible assets, net	1,135.7		1,135.7		$ 1,054.9
United States [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	661.3	670.6	1,240.3	1,204.1
Property and equipment, net and purchased intangible assets, net	996.2		996.2		925.5
Other [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	58.7	65.2	107.9	120.7
Americas [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	720.0	735.8	1,348.2	1,324.8
EMEA [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	300.1	316.3	585.5	620.1
Asia Pacific [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	201.2	$ 170.1	385.5	$ 344.7
International [Member]
Net Revenues by Geographic Region [Line Items]
Property and equipment, net and purchased intangible assets, net	$ 139.5		$ 139.5		$ 129.4