Segments, Geographical (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Net Revenues by Geographic Region [Line Items]
Total net revenues	$ 1,248.6	$ 1,125.9	$ 3,538.2	$ 3,525.5
Property and equipment, net and purchased intangible assets, net	999.1		999.1		$ 966.7
United States [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	665.6	621.3	1,869.7	1,905.7
Property and equipment, net and purchased intangible assets, net	879.1		879.1		871.7
Other [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	47.2	57.0	167.9	165.1
Americas [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	712.8	678.3	2,037.6	2,070.8
EMEA [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	355.0	290.5	975.1	911.0
Asia Pacific [Member]
Net Revenues by Geographic Region [Line Items]
Total net revenues	180.8	$ 157.1	525.5	$ 543.7
International [Member]
Net Revenues by Geographic Region [Line Items]
Property and equipment, net and purchased intangible assets, net	$ 120.0		$ 120.0		$ 95.0