CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
OPERATING REVENUES:
Passenger	$ 781,475	$ 777,480	$ 2,310,678	$ 2,293,085
Ground handling and other	18,301	16,524	52,512	49,734
Total operating revenues	799,776	794,004	2,363,190	2,342,819
OPERATING EXPENSES:
Salaries, wages and benefits	305,958	304,633	915,743	906,051
Aircraft maintenance, materials and repairs	143,573	147,396	424,722	461,972
Aircraft rentals	65,766	68,003	205,458	206,857
Depreciation and amortization	71,743	66,603	209,431	196,953
Aircraft fuel	33,189	31,762	90,827	90,254
Ground handling services	16,498	18,892	54,225	62,981
Other, net	77,215	78,419	231,004	235,447
Total operating expenses	713,942	715,708	2,131,410	2,160,515
OPERATING INCOME	85,834	78,296	231,780	182,304
OTHER INCOME (EXPENSE):
Interest income	591	311	1,506	1,647
Interest expense	(19,865)	(19,914)	(55,876)	(56,460)
Other, net		1,070		1,070
Total other expense, net	(19,274)	(18,533)	(54,370)	(53,743)
INCOME BEFORE INCOME TAXES	66,560	59,763	177,410	128,561
PROVISION FOR INCOME TAXES	25,238	23,495	68,751	51,198
NET INCOME	$ 41,322	$ 36,268	$ 108,659	$ 77,363
BASIC EARNINGS PER SHARE (in dollars per share)	$ 0.80	$ 0.72	$ 2.11	$ 1.51
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 0.79	$ 0.71	$ 2.08	$ 1.49
Weighted average common shares:
Basic (in shares)	51,627	50,616	51,421	51,143
Diluted (in shares)	52,471	51,282	52,224	51,882
COMPREHENSIVE INCOME:
Net income	$ 41,322	$ 36,268	$ 108,659	$ 77,363
Net unrealized appreciation (depreciation) on marketable securities, net of taxes	(11)	161	217	239
TOTAL COMPREHENSIVE INCOME	$ 41,311	$ 36,429	$ 108,876	$ 77,602