Segments, Geographical (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Net Revenues by Geographic Region [Line Items]
Total net revenues	$ 1,222.2	$ 1,229.5	$ 2,289.6	$ 2,399.6
Property and equipment, net and purchased intangible assets, net	966.0		966.0		$ 966.7
United States [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	670.6	660.7	1,204.1	1,284.4
Property and equipment, net and purchased intangible assets, net	865.1		865.1		871.7
Other [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	65.2	50.3	120.7	108.1
Americas [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	735.8	711.0	1,324.8	1,392.5
EMEA [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	316.3	324.8	620.1	620.5
Asia Pacific [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	170.1	$ 193.7	344.7	$ 386.6
International [Member]
Net Revenues by Geographic Region [Line Items]
Property and equipment, net and purchased intangible assets, net	$ 100.9		$ 100.9		$ 95.0