Financial Instruments (Debt Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Cash and Cash Equivalents	$ 9,516	$ 12,210
Marketable Securities	105,954
Level 2
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Adjusted Cost	108,844	107,008
Gross Unrealized Gains	1,140	1,861
Gross Unrealized Losses	(124)	(18)
Fair Value	109,860	108,851
Cash and Cash Equivalents	6,715	6,099
Marketable Securities	103,145	102,752
Level 2 | Time deposits
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Adjusted Cost	6,311	3,564
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	6,311	3,564
Cash and Cash Equivalents	6,311	3,564
Marketable Securities	0	0
Level 2 | Government bonds
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Adjusted Cost	50,959	55,156
Gross Unrealized Gains	497	793
Gross Unrealized Losses	(50)	(9)
Fair Value	51,406	55,940
Cash and Cash Equivalents	404	2,527
Marketable Securities	51,002	53,413
Level 2 | Corporate debt securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Adjusted Cost	34,476	31,521
Gross Unrealized Gains	444	704
Gross Unrealized Losses	(41)	(2)
Fair Value	34,879	32,223
Cash and Cash Equivalents	0	8
Marketable Securities	34,879	32,215
Level 2 | Mortgage-backed and asset-backed securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Adjusted Cost	17,098	16,767
Gross Unrealized Gains	199	364
Gross Unrealized Losses	(33)	(7)
Fair Value	17,264	17,124
Cash and Cash Equivalents	0	0
Marketable Securities	$ 17,264	$ 17,124