Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated other comprehensive income (loss)
Beginning Balance	$ 27,153	$ 27,153	$ 27,428	$ 23,725
Other comprehensive income (loss) before reclassifications		(50)	(174)	266
Amounts reclassified from accumulated other comprehensive loss				112
Other Comprehensive Income (Loss), Net of Income Taxes		(7)	(75)	378
Ending Balance		27,169	27,153	27,428
Income taxes reclassified to retained earnings	(89)
Defined Benefit Plans
Accumulated other comprehensive income (loss)
Beginning Balance	(472)	(472)	(598)	(713)
Other comprehensive income (loss) before reclassifications		(140)	14	3
Amounts reclassified from accumulated other comprehensive loss		49	112	112
Other Comprehensive Income (Loss), Net of Income Taxes		(91)	126	115
Ending Balance		(656)	(472)	(598)
Income taxes reclassified to retained earnings	(93)
Foreign Currency Translation
Accumulated other comprehensive income (loss)
Beginning Balance	(228)	(228)	(26)	(285)
Other comprehensive income (loss) before reclassifications		95	(192)	259
Amounts reclassified from accumulated other comprehensive loss		0	(10)
Other Comprehensive Income (Loss), Net of Income Taxes		95	(202)	259
Ending Balance		(131)	(228)	(26)
Income taxes reclassified to retained earnings	2
Hedging
Accumulated other comprehensive income (loss)
Beginning Balance	8	8	7	3
Other comprehensive income (loss) before reclassifications			4	4
Amounts reclassified from accumulated other comprehensive loss			(3)
Other Comprehensive Income (Loss), Net of Income Taxes			1	4
Ending Balance			8	7
Hedging
Accumulated other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications		(5)
Amounts reclassified from accumulated other comprehensive loss		(6)
Other Comprehensive Income (Loss), Net of Income Taxes		(11)
Ending Balance		(1)
Income taxes reclassified to retained earnings	2
Accumulated Other Comprehensive Loss
Accumulated other comprehensive income (loss)
Beginning Balance	$ (692)	(692)	(617)	(995)
Other Comprehensive Income (Loss), Net of Income Taxes		(7)	(75)	378
Ending Balance		$ (788)	$ (692)	$ (617)