Revenues (Revenue, Remaining Performance Obligation) (Details) $ in Millions	3 Months Ended
	Jun. 29, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Remaining Performance Obligations	$ 2,800
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	77.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	15.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-06-30
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]: 2021-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	1.00%
Enterprise Security
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Remaining Performance Obligations	$ 1,747
Enterprise Security | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	65.00%
Expected timing of satisfaction, period	1 year
Enterprise Security | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	23.00%
Expected timing of satisfaction, period	1 year
Enterprise Security | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	10.00%
Expected timing of satisfaction, period	1 year
Enterprise Security | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	2.00%
Expected timing of satisfaction, period
Consumer Digital Safety
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Remaining Performance Obligations	$ 1,053
Consumer Digital Safety | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	96.00%
Expected timing of satisfaction, period	1 year
Consumer Digital Safety | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	3.00%
Expected timing of satisfaction, period	1 year
Consumer Digital Safety | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	1.00%
Expected timing of satisfaction, period	1 year
Consumer Digital Safety | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent Expected to be Recognized as Revenue	0.00%
Expected timing of satisfaction, period