Comprehensive Income and Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 25,413	$ 21,540
Cumulative effect of accounting changes			$ 30
Other comprehensive income (loss) before reclassifications	45
Amounts reclassified from accumulated other comprehensive items	4
Total other comprehensive items	49	163
Balance	26,123	21,795
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(1,755)
Cumulative effect of accounting changes			(54)
Other comprehensive income (loss) before reclassifications	47
Total other comprehensive items	47
Balance	(1,762)
Unrealized Gains on Available-for-Sale Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(1)
Cumulative effect of accounting changes			1
Total other comprehensive items	0
Balance	0
Unrealized Losses on Hedging Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(50)
Cumulative effect of accounting changes			(11)
Amounts reclassified from accumulated other comprehensive items	2
Total other comprehensive items	2
Balance	(59)
Pension and Other Postretirement Benefit Liability Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(197)
Cumulative effect of accounting changes			(24)
Other comprehensive income (loss) before reclassifications	(2)
Amounts reclassified from accumulated other comprehensive items	2
Total other comprehensive items	0
Balance	(221)
Accumulated Other Comprehensive Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(2,003)	(2,636)
Cumulative effect of accounting changes			$ (88)
Total other comprehensive items	49	163
Balance	$ (2,042)	$ (2,473)