(14) Segments

CVR Energy’s revenues are derived from two operating segments: the petroleum segment and the nitrogen fertilizer segment. The Company evaluates the performance of its segments based primarily on segment operating income and EBITDA. For the purposes of the operating segment disclosure, the company presents operating income as it is the most comparable measure to the amounts presented on the condensed consolidated statement of operations. The other segment reflects intercompany eliminations, corporate cash and cash equivalents, income tax activities and other corporate activities that are not allocated to the operating segments.

The following table summarizes certain operating results and capital expenditures information by segment:



	Three Months Ended September 30,						Nine Months Ended September 30,
(in millions)	2018			2017			2018			2017
Net sales
Petroleum	$	1,857		$	1,386		$	5,139		$	4,148
Nitrogen Fertilizer	80			69			253			253
Other	(2		)	(1		)	(6		)	(6		)
Total	$	1,935		$	1,454		$	5,386		$	4,395
Operating Income
Petroleum	$	176		$	99		$	390		$	157
Nitrogen Fertilizer	3			(16		)	(1		)	2
Other	(5		)	(4		)	(14		)	(11		)
Total operating income	174			79			375			148
Interest expense, net	(26		)	(28		)	(79		)	(81		)
Loss on derivatives, net	5			(17		)	75			(5		)
Other income, net	3			—			6			—
Earnings before income taxes	$	156		$	34		$	377		$	62
Depreciation and amortization
Petroleum	34			33			101			100
Nitrogen Fertilizer	16			20			53			55
Other	1			1			5			4
Total	$	51		$	54		$	159		$	159
Capital expenditures
Petroleum	$	18		$	19		$	50		$	66
Nitrogen Fertilizer	6			3			15			11
Other	2			1			3			3
Total	$	26		$	23		$	68		$	80

The following table summarizes total assets by segment:



(in millions)	As of September 30, 2018		As of December 31, 2017
Total assets
Petroleum	$	2,505	$	2,270
Nitrogen Fertilizer	1,219		1,234
Other	278		303
Total	$	4,002	$	3,807