Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Total net revenues	$ 1,222.2	$ 1,229.5	$ 2,289.6	$ 2,399.6
Routing [Member]
Segment Reporting Information [Line Items]
Total net revenues	602.4	617.8	1,107.2	1,167.6
Switching [Member]
Segment Reporting Information [Line Items]
Total net revenues	190.2	199.8	356.7	391.8
Security [Member]
Segment Reporting Information [Line Items]
Total net revenues	107.1	111.6	199.9	245.8
Total product [Member]
Segment Reporting Information [Line Items]
Total net revenues	899.7	929.2	1,663.8	1,805.2
Total service [Member]
Segment Reporting Information [Line Items]
Total net revenues	$ 322.5	$ 300.3	$ 625.8	$ 594.4