Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Fair Values of Certain Financial Liabilities and Other Financial Instruments

The fair value of certain financial liabilities is shown below (in millions):  

	March 31, 2020				December 31, 2019
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial liabilities
Senior notes (Level 1)	$	2,777	$	2,490	$	2,776	$	2,953
Credit facility (Level 2)		2,489		2,426		989		1,000