Fair Value Measurements - Fair Value of Hedges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Gain (loss) recorded in other comprehensive income	$ (1)	$ (5)	$ (5)	$ (15)
Interest rate swap
Derivatives, Fair Value [Line Items]
Gain (loss) recorded in other comprehensive income	4	$ 3	(10)	$ (13)
Interest rate swap | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative fair value	26		26		$ 16
Gain (loss) recorded in other comprehensive income	4		10
Interest rate swap | Other assets
Derivatives, Fair Value [Line Items]
Derivative fair value	39		39		$ 41
Cross-currency interest rate swaps | Other assets
Derivatives, Fair Value [Line Items]
Gain (loss) recorded in other comprehensive income	$ (20)		$ (2)