Contingencies (Details) $ in Millions				3 Months Ended		9 Months Ended		69 Months Ended
	Jan. 10, 2018 USD ($)	Aug. 04, 2015 USD ($) patent	Aug. 28, 2013 patent	Dec. 29, 2017 USD ($)	Dec. 30, 2016 USD ($)	Dec. 29, 2017 USD ($)	Dec. 30, 2016 USD ($)	Sep. 30, 2012 USD ($)	Jan. 31, 2014 USD ($)
Loss Contingencies [Line Items]
Net revenues				$ 1,209	$ 1,041	$ 3,624	$ 2,904
GSA Schedule Contract
Loss Contingencies [Line Items]
Net revenues								$ 222
GSA initial analysis of damage exposure									$ 145
GSA Schedule Contract | Minimum
Loss Contingencies [Line Items]
Estimated loss				25		25
Finjan, Inc vs. Blue Coat Systems, Inc. | Pending Litigation
Loss Contingencies [Line Items]
Number of patents allegedly infringed | patent			6
Finjan, Inc vs. Blue Coat Systems, Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Estimated loss				$ 40		$ 40
Number of patents found infringed | patent		5
Damages awarded		$ 40
Subsequent Event | Finjan, Inc vs. Blue Coat Systems, Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Damages awarded	$ 8