Financial Instruments - Total Short-Term and Long-Term Investments and Equity Method Investments (Details) - USD ($) $ in Millions		Sep. 29, 2019	Dec. 31, 2018
Short-term investments
Equity securities with readily determinable fair value	[1]	$ 1,054	$ 1,600
Available-for-sale debt securities		4,270	15,091
Held-to-maturity debt securities		978	1,003
Total Short-term investments	[2]	6,302	17,694
Long-term investments
Equity securities with readily determinable fair values		1,530	1,273
Available-for-sale debt securities		408	491
Held-to-maturity debt securities		43	59
Private equity investments at cost		742	763
Total Long-term investments	[2]	2,723	2,586
Equity-method investments	[2]	15,999	181
Total long-term investments and equity-method investments		18,721	2,767
Held-to-maturity cash equivalents		$ 217	$ 199

[1] As of September 29, 2019 and December 31, 2018, equity securities with readily determinable fair values included money market funds primarily invested in U.S. Treasury and government debt.

[2] Amounts may not add due to rounding.