Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of fair value measurement of financial assets (liabilities) measured at fair value on a recurring basis

The following table provides information for financial assets (liabilities) measured at fair value on a recurring basis as of December 31, 2018 and 2017:

	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Total Fair Value
			($ in millions)
As of December 31, 2018
Derivative Assets (Liabilities):
Commodity assets	$	—	$	319		$	103		$	422
Commodity liabilities	—		(131		)	(16		)	(147		)
Utica divestiture contingent consideration	—		—			7			7
Total derivatives	$	—	$	188		$	94		$	282
As of December 31, 2017
Derivative Assets (Liabilities):
Commodity assets	$	—	$	—		$	8		$	8
Commodity liabilities	—		(20		)	(23		)	(43		)
Total derivatives	$	—	$	(20	)	$	(15	)	$	(35	)

A summary of the changes in the fair values of our financial assets (liabilities) classified as Level 3 during 2018 and 2017 is presented below:

	Commodity Derivatives			Utica Contingent Consideration
	($ in millions)
Balance, as of January 1, 2018	$	(15	)	$	—
Total gains (losses) (realized/unrealized):
Included in earnings(a)	77			7
Total purchases, issuances, sales and settlements:
Settlements	25			—
Balance, as of December 31, 2018	$	87		$	7
Balance, as of January 1, 2017	$	(10	)	$	—
Total gains (losses) (realized/unrealized):
Included in earnings(a)	2			—
Total purchases, issuances, sales and settlements:
Settlements	(7		)	—
Balance, as of December 31, 2017	$	(15	)	$	—

___________________________________________

(a)		Commodity Derivatives					Utica Contingent Consideration
		2018		2017			2018		2017
		($ in millions)
	Total gains included in earnings for the period	$	77	$	2		$	7	$	—
	Change in unrealized gains (losses) related to assets still held at reporting date	$	86	$	(14	)	$	7	$	—

The following table provides fair value measurement information for the above-noted financial assets (liabilities) measured at fair value on a recurring basis as of December 31, 2018 and 2017:

	Quoted Prices in Active Markets (Level 1)			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Fair Value
	($ in millions)
As of December 31, 2018
Financial Assets (Liabilities):
Other current assets	$	50		$	—	$	—	$	50
Other current liabilities	(51		)	—		—		(51		)
Total	$	(1	)	$	—	$	—	$	(1	)
As of December 31, 2017
Financial Assets (Liabilities):
Other current assets	$	57		$	—	$	—	$	57
Other current liabilities	(60		)	—		—		(60		)
Total	$	(3	)	$	—	$	—	$	(3	)