Fair Value Measurements - Schedule of Liabilities Whose Carrying Values Differ From the Fair Value and are Not Measured on a Recurring Basis (Details) - Nonrecurring [Member] - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt and current portion of long-term debt	$ 186	$ 85
Long-term debt	4,498	4,450
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt and current portion of long-term debt	193	85
Long-term debt	$ 4,583	$ 4,706