Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Total net revenues	$ 1,067.4	$ 1,170.1
Routing [Member]
Segment Reporting Information [Line Items]
Total net revenues	504.8	549.8
Switching [Member]
Segment Reporting Information [Line Items]
Total net revenues	166.5	192.0
Security [Member]
Segment Reporting Information [Line Items]
Total net revenues	92.8	134.2
Total product [Member]
Segment Reporting Information [Line Items]
Total net revenues	764.1	876.0
Total service [Member]
Segment Reporting Information [Line Items]
Total net revenues	$ 303.3	$ 294.1