Goodwill and Intangible Assets (Carrying Amount of Goodwill by Reportable Segment) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Oct. 02, 2020	Jan. 03, 2020
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 4,912	$ 4,860
Goodwill re-allocation	0	0
Goodwill acquired during period	1,238	50
Divestiture of health staff augmentation business		(5)
Foreign currency translation adjustments	8	4
Adjustment to goodwill		3
Ending balance, Goodwill	6,158	4,912
Defense Solutions
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,039	2,015
Goodwill re-allocation	429	25
Goodwill acquired during period	776	0
Divestiture of health staff augmentation business		0
Foreign currency translation adjustments	8	(4)
Adjustment to goodwill		3
Ending balance, Goodwill	3,252	2,039
Civil
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,907	1,924
Goodwill re-allocation	(429)	(25)
Goodwill acquired during period	462	0
Divestiture of health staff augmentation business		0
Foreign currency translation adjustments	0	8
Adjustment to goodwill		0
Ending balance, Goodwill	1,940	1,907
Health
Goodwill [Roll Forward]
Goodwill, Beginning Balance	966	921
Goodwill re-allocation	0	0
Goodwill acquired during period	0	50
Divestiture of health staff augmentation business		(5)
Foreign currency translation adjustments	0	0
Adjustment to goodwill		0
Ending balance, Goodwill	$ 966	$ 966

Goodwill, Re-Allocations

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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