Contingencies (Details)								1 Months Ended	12 Months Ended
	Oct. 30, 2020 USD ($)	May 22, 2020 USD ($)	Mar. 13, 2020 USD ($)	Nov. 22, 2019 patent	Aug. 30, 2018 USD ($)	Apr. 10, 2018 USD ($)	Sep. 29, 2017 USD ($)	Jan. 31, 2021 USD ($)	Jan. 01, 2021 USD ($)	Jul. 23, 2020	Dec. 10, 2019 USD ($)	Nov. 10, 2015 USD ($)
Leidos
Loss Contingencies [Line Items]
Proceeds from legal settlements		$ 85,000,000
Gain on legal settlement									$ 81,000,000
Litigation settlement, percentage of total (percentage)									25.00%
Virnet X Inc
Loss Contingencies [Line Items]
Amount awarded to other party, pre interest							$ 343,000,000
Awarded to the other party, interest and legal fees					$ 93,000,000		96,000,000
Awarded from other party	$ 503,000,000				595,000,000	$ 502,000,000	$ 439,000,000
Proceeds from legal settlements			$ 454,000,000
Royalty rate awarded (per device)	$ 0.84				$ 1.20
Number of infringed patents | patent				2
Number of infringed other patents | patent				2
Additional costs and interest								$ 75,000,000
Customer
Loss Contingencies [Line Items]
Royalty rate, percentage										4.00%
MSA Venture
Loss Contingencies [Line Items]
Estimate of loss									$ 64,000,000		$ 29,000,000	$ 64,000,000
Estimate of possible loss, amount deferred									32,000,000
Loss contingency accrual									$ 42,000,000
MSA Venture | Lockheed Martin
Loss Contingencies [Line Items]
Percentage of damages covered, between $38 million and $64 million settlement amount (percentage)									100.00%
Percentage of damages covered, in excess of $64 million settlement amount (percentage)									50.00%
MSA Venture | Leidos
Loss Contingencies [Line Items]
Estimate of loss									$ 38,000,000