Commitments and Contingencies - Additional Information (Details) $ in Millions										3 Months Ended		9 Months Ended		47 Months Ended
	May 04, 2020 patent	Apr. 01, 2020 USD ($)	Nov. 04, 2018 defendant	Feb. 13, 2018 patent	May 25, 2017 USD ($)	Mar. 03, 2017 USD ($) patent	Jan. 06, 2017 patent	May 12, 2016 USD ($)	Sep. 04, 2013 patent	Apr. 25, 2020 USD ($)	Apr. 27, 2019 USD ($)	Apr. 25, 2020 USD ($)	Apr. 27, 2019 USD ($)	Apr. 25, 2020 USD ($)	Jul. 27, 2019 USD ($)
Contingency [Line Items]
Liability for purchase commitments										$ 131.0		$ 131.0		$ 131.0	$ 129.0
Future compensation expense & contingent consideration (up to)										292.0		292.0		292.0
Commitments and contingencies
Volume of channel partner financing										6,300.0	$ 7,200.0	20,500.0	$ 21,700.0
Balance of the channel partner financing subject to guarantees										1,200.0		1,200.0		1,200.0	1,400.0
Financing provided by third parties for leases and loans on which the Company has provided guarantees										2.0	$ 1.0	$ 8.0	11.0
SRI International | Pending Litigation
Contingency [Line Items]
Damages awarded, value		$ 8.0			$ 57.0			$ 23.7
Number of allegedly infringed patents (patent) | patent									2
Percentage of royalty awarded					3.50%
Payment														28.1
Oyster Optics | Pending Litigation
Contingency [Line Items]
Number remaining defendants, other than Cisco | defendant			1
Patent Infringement | Sprint Communications Company, L.P. vs. Time Warner Cable, Inc. | Pending Litigation
Contingency [Line Items]
Number of patents found infringed (patent) | patent						5
Damages awarded, value						$ 139.8
Pre and Post judgment interest awarded						$ 10.0
Patent Infringement | Centripetal | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent				11
Number of allegedly infringed patents, petitioned (patent) | patent				9
Number of allegedly infringed patents, unpatentable (patent) | patent				5
Patent Infringement | Finjan | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent							5
Number of allegedly infringed patents, expired (patent) | patent							4
Patent Infringement, IPR Proceedings | Centripetal | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent				6
Patent Infringement, Patent Trial and Appeal Board | Centripetal | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent				5
Patent Infringement, Not Subject to IPR Proceedings | Centripetal | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent				5
Patent Infringement, Not Subject To IPR Proceedings and IPR Declined | Centripetal | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent				3
Minimum
Contingency [Line Items]
Warranty period for products												90 days
Channel partners revolving short-term financing payment term												60 days
Maximum
Contingency [Line Items]
Warranty period for products												5 years
Channel partners revolving short-term financing payment term												90 days
End user lease and loan term												3 years
Investments in privately held companies (impaired)
Contingency [Line Items]
Commitments and contingencies										344.0		$ 344.0		344.0	$ 326.0
Inventories
Contingency [Line Items]
Purchase commitment												5,100.0	$ 5,000.0
Tax Year 2003 - 2007 | Brazilian tax authority
Contingency [Line Items]
Penalty and interest asserted by the Brazilian federal tax authorities										$ 800.0		800.0		$ 800.0
Income tax examination, tax												100.0
Income tax examination, interest												700.0
Income tax examination, penalties												$ 400.0
COVID-19
Contingency [Line Items]
Increase in certain channel partners revolving short-term financing payment term										30 days
Subsequent event | Patent Infringement, European Patents | Centripetal | Pending Litigation
Contingency [Line Items]
Number of allegedly infringed patents (patent) | patent	3