CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating Revenues
Passenger, Mainline	$ 1,556	$ 1,036	$ 2,828	$ 1,963
Passenger, Regional	251	227	463	433
Total passenger revenue	1,807	1,263	3,291	2,396
Freight and mail	32	27	56	51
Other—net	263	204	504	394
Total Operating Revenues	2,102	1,494	3,851	2,841
Operating Expenses
Wages and benefits	469	332	917	668
Variable incentive pay	27	32	58	64
Aircraft fuel, including hedging gains and losses	344	201	683	368
Aircraft maintenance	96	65	183	133
Aircraft rent	69	26	134	55
Landing fees and other rentals	99	63	214	143
Contracted services	77	60	158	120
Selling expenses	97	55	178	104
Depreciation and amortization	90	92	180	180
Food and beverage service	50	31	95	62
Third-party regional carrier expense	27	24	54	47
Special items—merger-related costs	24	14	64	14
Other	140	81	274	175
Total Operating Expenses	1,609	1,076	3,192	2,133
Operating Income	493	418	659	708
Nonoperating Income (Expense)
Interest income	9	7	16	13
Interest expense	(26)	(9)	(51)	(22)
Interest capitalized	4	7	8	15
Other—net	(1)	(3)	(1)	(2)
Nonoperating Income (Expense) Total	(14)	2	(28)	4
Income before income tax	479	420	631	712
Income tax expense	183	160	236	268
Net Income	$ 296	$ 260	$ 395	$ 444
Basic Earnings Per Share (usd per share)	$ 2.40	$ 2.11	$ 3.19	$ 3.58
Diluted Earnings Per Share (usd per share)	$ 2.38	$ 2.10	$ 3.17	$ 3.56
Shares used for computation:
Basic shares (shares)	123,573	123,250	123,534	123,900
Diluted shares (shares)	124,332	123,988	124,374	124,715
Cash dividend declared per share (usd per share)	$ 0.30	$ 0.275	$ 0.6	$ 0.550