v3.10.0.1
Financial Instruments - Total Short-term and Long-term Investments (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Short-term investments    
Equity securities $ 1,600 $ 2,150
Available-for-sale debt securities 15,091 15,362
Held-to-maturity debt securities 1,003 1,138
Total Short-term investments [1] 17,694 18,650
Long-term investments    
Equity securities 1,223 1,440
Trading equity securities 50 73
Available-for-sale debt securities 491 5,090
Held-to-maturity debt securities 59 4
Private equity investments carried at equity-method or cost 944 408
Total Long-term investments [1] 2,767 7,015
Held-to-maturity cash equivalents $ 199 $ 719
[1] Amounts may not add due to rounding.