Investments - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	$ 0
Payments to Acquire Equity Method Investments	26
Equity Method Investments	34	$ 9
Cost Method Investments	$ 4	8
Maximum
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss		1
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		70
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		0
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		$ 42