Investments (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Short-term investments:
Total short-term investments	$ 749	$ 44
Long-term investments:
Long-term Investments, Total	466	440
Short-term Investments [Member]
Short-term investments:
Equity investment security	27	27
Available-for-sale investment securities	295	0
Held-to-maturity investment securities	23	14
Time Deposits	404	3
Long-term investments:
Debt Securities, Available-for-sale, Amortized Cost	295
Long-term investments [Member]
Long-term investments:
Equity and Cost Method Investments	67	35
Restricted investments	$ 399	$ 405