OPERATING SEGMENT INFORMATION (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

Operating segment information is as follows (in millions):

Year Ended December 31, 2017	Mainline			Regional		Horizon			Consolidating & Other(b)			Air Group Adjusted(c)			Special Items(d)			Consolidated
Operating revenues
Passenger
Mainline	$	5,858		$	—	$	—		$	—		$	5,858		$	—		$	5,858
Regional	—			960		—			—			960			—			960
Total passenger revenues	5,858			960		—			—			6,818			—			6,818
CPA revenues	—			—		426			(426		)	—			—			—
Freight and mail	110			4		—			—			114			—			114
Other-net	922			74		4			1			1,001			—			1,001
Total operating revenues	6,890			1,038		430			(425		)	7,933			—			7,933
Operating expenses
Operating expenses, excluding fuel	4,257			851		427			(427		)	5,108			118			5,226
Fuel expense	1,282			172		—			—			1,454			(7		)	1,447
Total operating expenses	5,539			1,023		427			(427		)	6,562			111			6,673
Nonoperating income (expense)
Interest income	39			—		—			(5		)	34			—			34
Interest expense	(92		)	—		(13		)	2			(103		)	—			(103		)
Other	14			—		2			—			16			—			16
	(39		)	—		(11		)	(3		)	(53		)	—			(53		)
Income (loss) before income tax	$	1,312		$	15	$	(8	)	$	(1	)	$	1,318		$	(111	)	$	1,207

Year Ended December 31, 2016	Mainline(a)			Regional		Horizon			Consolidating & Other(b)			Air Group Adjusted(c)			Special Items(d)			Consolidated
Operating revenues
Passenger
Mainline	$	4,098		$	—	$	—		$	—		$	4,098		$	—		$	4,098
Regional	—			908		—			—			908			—			908
Total passenger revenues	4,098			908		—			—			5,006			—			5,006
CPA revenues	—			—		424			(424		)	—			—			—
Freight and mail	104			5		—			(1		)	108			—			108
Other-net	738			74		4			1			817			—			817
Total operating revenues	4,940			987		428			(424		)	5,931			—			5,931
Operating expenses
Operating expenses, excluding fuel	2,883			769		407			(425		)	3,634			117			3,751
Fuel expense	719			125		—			—			844			(13		)	831
Total operating expenses	3,602			894		407			(425		)	4,478			104			4,582
Nonoperating income (expense)
Interest income	26			—		1			—			27			—			27
Interest expense	(42		)	—		(9		)	(4		)	(55		)	—			(55		)
Other	19			—		1			4			24			—			24
	3			—		(7		)	—			(4		)	—			(4		)
Income (loss) before income tax	$	1,341		$	93	$	14		$	1		$	1,449		$	(104	)	$	1,345

Year Ended December 31, 2015	Mainline			Regional		Horizon			Consolidating & Other(b)			Air Group Adjusted(c)			Special Items(d)			Consolidated
Operating revenues
Passenger
Mainline	$	3,939		$	—	$	—		$	—		$	3,939		$	—		$	3,939
Regional	—			854		—			—			854			—			854
Total passenger revenues	3,939			854		—			—			4,793			—			4,793
CPA revenues	—			—		408			(408		)	—			—			—
Freight and mail	103			5		—			—			108			—			108
Other-net	621			72		4			—			697			—			697
Total operating revenues	4,663			931		412			(408		)	5,598			—			5,598
Operating expenses
Operating expenses, excluding fuel	2,653			695		375			(409		)	3,314			32			3,346
Fuel expense	823			131		—			—			954			—			954
Total operating expenses	3,476			826		375			(409		)	4,268			32			4,300
Nonoperating income (expense)
Interest income	19			—		—			2			21			—			21
Interest expense	(28		)	—		(10		)	(4		)	(42		)	—			(42		)
Other	28			—		1			6			35			—			35
	19			—		(9		)	4			14			—			14
Income (loss) before income tax	$	1,206		$	105	$	28		$	5		$	1,344		$	(32	)	$	1,312

(a) As the acquisition of Virgin America closed on December 14, 2016, Mainline financial results, presented above include Virgin America for the twelve months ended December 31, 2017, and not for the prior period. Financial results also reflect the impacts of purchase accounting.

(b) Includes consolidating entries, Parent Company, McGee Air Services, and other immaterial business units.

(c) The Air Group Adjusted column excludes certain charges described in (d) and represents the financial information that is reviewed by management to assess performance of operations and determine capital allocations.

(d) Includes accounting adjustments related to mark-to-market fuel hedge accounting charges (all years), merger-related costs (2017 and 2016), pension settlement charge (2015), and a litigation-related matter (2015).

	2017			2016			2015
Depreciation and amortization:
Mainline	$	308		$	296		$	268
Horizon	64			67			52
Consolidated	$	372		$	363		$	320
Capital expenditures:
Mainline	$	734		$	608		$	821
Horizon	292			70			10
Consolidated	$	1,026		$	678		$	831
Total assets at end of period:
Mainline	$	16,650		$	15,260
Horizon	929			690
Consolidating & Other	(6,839		)	(5,988		)
Consolidated	$	10,740		$	9,962