Condensed Consolidating Financial Statements - Condensed Consolidating Statements of Cash Flows (Unaudited) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Condensed Financial Statements [Line Items]
Net cash provided by operating activities	[1]			$ 587	$ 1,081
Cash flows from investing activities:
Business acquisitions, net of cash acquired				(19)	(10,039)
Capital expenditures				(606)	(447)
Other, net				2	169
Net cash used by investing activities				(604)	(10,317)
Cash flows from financing activities:
Proceeds from notes				0	6,461
Proceeds from commercial paper, net				947	1,668
Dividends paid		$ (295)	$ (275)	(858)	(801)
Purchases of common stock				(231)	(533)
Repayment of CSRA accounts receivable purchase agreement				0	(450)
Other, net				207	(68)
Net cash provided by financing activities				65	7,277
Net cash used by discontinued operations				(37)	(14)
Cash sweep/funding by parent				0	0
Net increase (decrease) in cash and equivalents				11	(1,973)
Cash and equivalents at beginning of period				963	2,983
Cash and equivalents at end of period		974	1,010	974	1,010
Floating-rate notes
Cash flows from financing activities:
Proceeds from notes				0	1,000
Consolidating Adjustments
Condensed Financial Statements [Line Items]
Net cash provided by operating activities	[1]			0	0
Cash flows from investing activities:
Business acquisitions, net of cash acquired					0
Capital expenditures				0	0
Other, net				0	0
Net cash used by investing activities				0	0
Cash flows from financing activities:
Proceeds from notes					0
Proceeds from commercial paper, net				0	0
Dividends paid				0	0
Purchases of common stock				0	0
Repayment of CSRA accounts receivable purchase agreement					0
Other, net				0	0
Net cash provided by financing activities				0	0
Net cash used by discontinued operations				0	0
Cash sweep/funding by parent				0	0
Net increase (decrease) in cash and equivalents				0	0
Cash and equivalents at beginning of period				0	0
Cash and equivalents at end of period		0	0	0	0
Consolidating Adjustments | Floating-rate notes
Cash flows from financing activities:
Proceeds from notes					0
Parent
Condensed Financial Statements [Line Items]
Net cash provided by operating activities	[1]			181	(204)
Cash flows from investing activities:
Business acquisitions, net of cash acquired					(9,749)
Capital expenditures				(65)	(36)
Other, net				6	93
Net cash used by investing activities				(59)	(9,692)
Cash flows from financing activities:
Proceeds from notes					6,461
Proceeds from commercial paper, net				947	1,668
Dividends paid				(858)	(801)
Purchases of common stock				(231)	(533)
Repayment of CSRA accounts receivable purchase agreement					0
Other, net				24	(10)
Net cash provided by financing activities				(118)	7,785
Net cash used by discontinued operations				(37)	(14)
Cash sweep/funding by parent				(15)	844
Net increase (decrease) in cash and equivalents				(48)	(1,281)
Cash and equivalents at beginning of period				460	1,930
Cash and equivalents at end of period		412	649	412	649
Parent | Floating-rate notes
Cash flows from financing activities:
Proceeds from notes					1,000
Guarantors on a Combined Basis
Condensed Financial Statements [Line Items]
Net cash provided by operating activities	[1]			679	1,561
Cash flows from investing activities:
Business acquisitions, net of cash acquired					(74)
Capital expenditures				(404)	(331)
Other, net				21	76
Net cash used by investing activities				(383)	(329)
Cash flows from financing activities:
Proceeds from notes					0
Proceeds from commercial paper, net				0	0
Dividends paid				0	0
Purchases of common stock				0	0
Repayment of CSRA accounts receivable purchase agreement					0
Other, net				(1)	0
Net cash provided by financing activities				(1)	0
Net cash used by discontinued operations				0	0
Cash sweep/funding by parent				(295)	(1,232)
Net increase (decrease) in cash and equivalents				0	0
Cash and equivalents at beginning of period				0	0
Cash and equivalents at end of period		0	0	0	0
Guarantors on a Combined Basis | Floating-rate notes
Cash flows from financing activities:
Proceeds from notes					0
Other Subsidiaries on a Combined Basis
Condensed Financial Statements [Line Items]
Net cash provided by operating activities	[1]			(273)	(276)
Cash flows from investing activities:
Business acquisitions, net of cash acquired					(216)
Capital expenditures				(137)	(80)
Other, net				(25)	0
Net cash used by investing activities				(162)	(296)
Cash flows from financing activities:
Proceeds from notes					0
Proceeds from commercial paper, net				0	0
Dividends paid				0	0
Purchases of common stock				0	0
Repayment of CSRA accounts receivable purchase agreement					(450)
Other, net				184	(58)
Net cash provided by financing activities				184	(508)
Net cash used by discontinued operations				0	0
Cash sweep/funding by parent				310	388
Net increase (decrease) in cash and equivalents				59	(692)
Cash and equivalents at beginning of period				503	1,053
Cash and equivalents at end of period		$ 562	$ 361	$ 562	361
Other Subsidiaries on a Combined Basis | Floating-rate notes
Cash flows from financing activities:
Proceeds from notes					$ 0

[1] * Continuing operations only