Other Financial Information, Deferred Revenue (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Deferred revenue:
Total deferred revenue	$ 1,295.6	$ 1,168.1
Reported as:
Current	933.0	822.9
Long-term	362.6	345.2
Total deferred revenue	1,295.6	1,168.1
Sales Revenue, Product, Net [Member]
Deferred revenue:
Undelivered product commitments and other product deferrals	242.5	210.1
Distributor inventory and other sell-through items	99.9	81.8
Deferred gross product revenue	342.4	291.9
Deferred cost of product revenue	(51.6)	(51.6)
Total deferred revenue	290.8	240.3
Reported as:
Total deferred revenue	290.8	240.3
Sales Revenue, Service, Net [Member]
Deferred revenue:
Total deferred revenue	1,004.8	927.8
Reported as:
Total deferred revenue	$ 1,004.8	$ 927.8