Goodwill and Other Intangible Assets - Intangibles Assets (Details) $ in Millions	3 Months Ended	6 Months Ended
Jul. 03, 2020 USD ($) divestiture	Jul. 03, 2020 USD ($) divestiture	Jun. 28, 2019 USD ($)	Jan. 03, 2020 USD ($)
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 7,739	$ 7,739		$ 7,461
Accumulated Amortization	1,227	1,227		875
Net Carrying Amount(1)	6,512	6,512		6,586
Total intangibles assets, Gross Carrying Amount	9,563	9,563		9,333
Total intangibles assets	$ 8,336	8,336		8,458
Intangible assets derecognized as part of the gain on sale of businesses		$ (52)	$ 0
Number of pending divestitures \| divestiture	2	2
Intangibles reclassified as assets of disposal group held for sale	$ 15	$ 15
Airport Security and Automation and Applied Kilovolts And Analytical Instrumentation Businesses \| Discontinued Operations, Held-for-sale or Disposed of by Sale
Finite-Lived Intangible Assets [Line Items]
Intangible assets derecognized as part of the gain on sale of businesses	286
In-process research and development
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangibles	21	21		69
L3 trade name
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangibles	1,803	1,803		1,803
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,911	6,911		6,518
Accumulated Amortization	950	950		653
Net Carrying Amount(1)	5,961	5,961		5,865
Developed technologies
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	667	667		768
Accumulated Amortization	222	222		183
Net Carrying Amount(1)	445	445		585
Contract backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	19	19	0
Accumulated Amortization	13	13	0
Net Carrying Amount(1)	6	6	$ 0
L3 trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	138	138		165
Accumulated Amortization	40	40		35
Net Carrying Amount(1)	98	98		130
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4	4		10
Accumulated Amortization	2	2		4
Net Carrying Amount(1)	$ 2	$ 2		$ 6

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