Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Details of Impairment of Long-Lived Assets Held and Used by Asset

	March 31, 2020
	Fair Value		Asset Impairments
	(millions)
Long-lived assets	$	96	$	587
Goodwill	—		159
Direct investment in unconsolidated affiliate	256		61
Total	$	352	$	807

Fair Value Measurements, Nonrecurring

	March 31, 2020
Asset Groups	Valuation Techniques	Unobservable Inputs	Range (low-high) (a)	Average (b)
Long-lived assets, investment in unconsolidated affiliate, goodwill	Discounted cash flow	Oil prices	$34.52 - $67.61	$	55.98	Per barrel
		Natural gas prices	$2.28 - $4.12	$	3.35	Per MMBtu
		NGL prices	$0.30 - $0.62	$	0.52	Per gallon
		Discount rate	14%	14%
		Terminal value multiple	8x	8x
Goodwill	Market comparable companies	EBITDA multiple	5.2x - 16.5x	8x

(a) Commodity prices represent an average per year.

(b) Represents the arithmetic average of the inputs and is not weighted by the relative fair value or volumetric amount.

Financial Instruments Carried at Fair Value

	September 30, 2020								December 31, 2019
	Level 1		Level 2		Level 3		Total Carrying Value		Level 1		Level 2		Level 3		Total Carrying Value
	(millions)
Current assets:
Commodity derivatives	$	59	$	32	$	—	$	91	$	13	$	15	$	4	$	32
Long-term assets:
Commodity derivatives	$	16	$	20	$	4	$	40	$	1	$	1	$	—	$	2
Long-term investments	$	14	$	1	$	—	$	15	$	—	$	—	$	—	$	—
Current liabilities:
Commodity derivatives	$	(37)	$	(45)	$	(1)	$	(83)	$	(15)	$	(42)	$	(1)	$	(58)
Long-term liabilities:
Commodity derivatives	$	(13)	$	(15)	$	(1)	$	(29)	$	(2)	$	(15)	$	(3)	$	(20)

Fair Value Assets and Liabilities Measured On Recurring Basis Unobservable Input Reconciliation

	Commodity Derivative Instruments
	Current Assets		Long-Term Assets		Current Liabilities		Long-Term Liabilities
	(millions)
Three months ended September 30, 2020 (a):
Beginning balance	$	1	$	—	$	(3)	$	(4)
Net unrealized (losses) gains included in earnings	(1)		4		(1)		3
Transfers out of Level 3	—		—		2		—
Settlements	—		—		1		—
Ending balance	$	—	$	4	$	(1)	$	(1)
Net unrealized gains on derivatives still held included in earnings	$	—	$	4	$	1	$	3
Three months ended September 30, 2019 (a):
Beginning balance	$	8	$	2	$	(1)	$	—
Net unrealized gains (losses) included in earnings	7		(1)		1		(5)
Transfers out of Level 3	(8)		—		—		—
Settlements	(2)		—		(1)		—
Ending balance	$	5	$	1	$	(1)	$	(5)
Net unrealized gains (losses) on derivatives still held included in earnings	$	3	$	(1)	$	—	$	(5)

	Commodity Derivative Instruments
	Current Assets		Long-Term Assets		Current Liabilities		Long-Term Liabilities
	(millions)
Nine months ended September 30, 2020 (a):
Beginning balance	$	4	$	—	$	(1)	$	(3)
Net unrealized (losses) gains included in earnings	(1)		8		8		2
Transfers out of Level 3	—		(4)		—		—
Settlements	(3)		—		(8)		—
Ending balance	$	—	$	4	$	(1)	$	(1)
Net unrealized (losses) gains on derivatives still held included in earnings	$	(2)	$	4	$	(1)	$	1
Nine months ended September 30, 2019 (a):
Beginning balance	$	14	$	2	$	—	$	(2)
Net unrealized gains (losses) included in earnings	7		(1)		—		(6)
Transfers out of Level 3	(7)		—		—		3
Settlements	(9)		—		(1)		—
Ending balance	$	5	$	1	$	(1)	$	(5)
Net unrealized gains (losses) on derivatives still held included in earnings	$	5	$	1	$	(1)	$	(5)

(a) There were no purchases, issuances or sales of derivatives or transfers into Level 3 for the three and nine months ended September 30, 2020 and 2019.

Schedule of Valuation Processes

	September 30, 2020
Product Group	Fair Value		Valuation Techniques	Unobservable Input	Forward Curve Range	Weighted Average (a)
	(millions)
Assets
Natural gas	$	4	Market approach	Longer dated forward curve prices	$1.90-$2.68	$1.86	Per MMBtu
Liabilities
NGLs	$	(2)	Market approach	Longer dated forward curve prices	$0.14-$0.89	$0.43	Per gallon

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

September 30, 2020 and December 31, 2019, the carrying value and fair value of our total debt, including current maturities, were as follows:

		September 30, 2020				December 31, 2019
		Carrying Value (a)		Fair Value		Carrying Value (a)		Fair Value
	(millions)
Total debt		$	5,761	$	5,632	$	5,936	$	6,130

(a) Excludes unamortized issuance costs and finance lease liabilities.