Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Measurements

Assets and liabilities measured at fair value on a recurring basis (in millions)

Fair Value Measurements at June 30, 2015:

Description	Level 1		Level 2		Level 3		Netting and Collateral		Total Fair Value
Assets:
Commodity derivatives	$	139	$	35	$	—	$	(139)	$	35
Available for sale investment	$	432	$	—	$	—	$	—	$	432
Liabilities:
Commodity derivatives	$	130	$	162	$	—	$	(127)	$	165

Fair Value Measurements at December 31, 2014:

Description	Level 1		Level 2		Level 3		Netting and Collateral		Total Fair Value
Assets:
Commodity derivatives	$	712	$	127	$	—	$	(742)	$	97
Available for sale investment	$	394	$	—	$	—	$	—	$	394
Liabilities:
Commodity derivatives	$	750	$	246	$	—	$	(756)	$	240