Fair Value Measurements - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) contract	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, gain on derivative	$ 1
Derivative, loss on derivative		$ 1	$ 1
Foreign exchange swap | Maturity Beyond Six Months
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of foreign currency derivatives held | contract	0
Foreign exchange forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	$ 179	291
Derivative liability	$ 1	$ 1
Maximum | Foreign exchange swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity period of swap contracts	6 months