Other Financial Information, Deferred Revenue (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Deferred Product Revenue [Abstract]
Deferred revenue	$ 980.7	$ 923.4
Deferred Revenue Reported as [Abstract]
Deferred revenue, current	774.7	693.5
Deferred revenue, long-term	206.0	229.9
Sales Revenue, Goods, Net [Member]
Deferred Product Revenue [Abstract]
Undelivered product commitments and other product deferrals	250.5	256.9
Distributor inventory and other sell-through items	122.7	138.4
Deferred gross product revenue	373.2	395.3
Deferred cost of product revenue	(86.4)	(99.4)
Deferred revenue	286.8	295.9
Sales Revenue, Services, Net [Member]
Deferred Product Revenue [Abstract]
Deferred revenue	$ 693.9	$ 627.5