Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	$ 59,752	$ 60,160
Net change	(295)	823
Ending Balance	58,955	63,255
Accumulated Foreign Currency Adjustment Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(8,869)
Net change	(258)
Ending Balance	(9,127)
Accumulated Net Investment Gain (Loss) Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	0
Net change	0
Ending Balance	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(6,158)
Net change	169
Ending Balance	(5,989)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(195)
Net change	(206)
Ending Balance	(401)
AOCI Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(15,222)	(13,199)
Net change	(295)	823
Ending Balance	$ (15,517)	$ (12,608)