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Investments - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
Investments - Narrative (Details) - USD ($)	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Available for sale realized gain (loss)		$ 0	$ 0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 0	0
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value				$ 0
Payments to Acquire Equity Method Investments	32,000,000
Equity Method Investments	64,000,000	64,000,000		31,000,000
Cost method investments	3,000,000	3,000,000		4,000,000
Short-term Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale investment securities	295,000,000	295,000,000		$ 0
Maximum
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	1,000,000	1,000,000
Corporate And Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	3,000,000	3,000,000
Commercial Paper [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 7,000,000	$ 7,000,000