Goodwill and Intangible Assets (Carrying Amount of Goodwill by Reportable Segment) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
Jul. 03, 2020	Jan. 03, 2020
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 4,912	$ 4,860
Goodwill re-allocation	0	0
Goodwill acquired during period	1,363	50
Divestiture of health staff augmentation business		(5)
Foreign currency translation adjustments	(9)	4
Adjustment to goodwill		3
Ending balance, Goodwill	6,266	4,912
Defense Solutions
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,039	2,015
Goodwill re-allocation	429	25
Goodwill acquired during period	764	0
Divestiture of health staff augmentation business		0
Foreign currency translation adjustments	(9)	(4)
Adjustment to goodwill		3
Ending balance, Goodwill	3,223	2,039
Civil
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,907	1,924
Goodwill re-allocation	(429)	(25)
Goodwill acquired during period	599	0
Divestiture of health staff augmentation business		0
Foreign currency translation adjustments	0	8
Adjustment to goodwill		0
Ending balance, Goodwill	2,077	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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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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.

+ References

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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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