Derivatives Financial Instruments - Derivative Income Statement Location (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Derivative [Line Items]
Total gain (loss)	$ (7)		$ (1)		$ 7	$ (7)
Purchased product costs
Derivative [Line Items]
Realized gain (loss)	(1)		(1)		(2)	(3)
Total gain (loss)	(7)		(1)		7	(7)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Unrealized Gain (Loss) on Derivatives and Commodity Contracts	(6)	[1]	0	[1],[2]	9	(4)
Not Designated as Hedging Instrument [Member] | Purchased product costs
Derivative [Line Items]
Unrealized Gain (Loss) on Derivatives and Commodity Contracts	$ (6)		$ 0		$ 9	$ (4)

[1] See below for the reconciliation from Segment Adjusted EBITDA to net income.

[2] Financial information for the three and six months ended June 30, 2019 has been retrospectively adjusted for the acquisition of ANDX. See Notes 1 and 3.