Revenues (Revenue, Remaining Performance Obligation) (Details) $ in Millions	Jul. 05, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Remaining Performance Obligations	$ 2,506
Enterprise Security
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Remaining Performance Obligations	1,911
Consumer Cyber Safety
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Remaining Performance Obligations	$ 595
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-12-29
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	72.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-12-29 | Enterprise Security
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	65.00%
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-12-29 | Consumer Cyber Safety
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	95.00%
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-12-29
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	19.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-12-29 | Enterprise Security
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	24.00%
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-12-29 | Consumer Cyber Safety
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	4.00%
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-12-29
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	7.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-12-29 | Enterprise Security
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	9.00%
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-12-29 | Consumer Cyber Safety
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	1.00%
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-12-29
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	1.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-12-29 | Enterprise Security
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	2.00%
Remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-12-29 | Consumer Cyber Safety
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	0.00%
Remaining performance obligation, expected timing of satisfaction, period