Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Equity securities held	$ 101	$ 77
Purchase of long-term investments	34	32	$ 22
Debt and equity securities, unrealized gain (loss)		7
Proceeds from the sale of long-term investments	0	6	10
Realized gain on equity securities	$ 2	$ 5	$ 3