Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
REVENUES	$ 768,870	$ 619,264	$ 589,592
OPERATING EXPENSES
Salaries, wages and benefits	231,667	181,785	173,226
Fuel	87,134	52,615	53,521
Maintenance, materials and repairs	105,735	96,044	91,528
Depreciation and amortization	135,496	125,443	108,254
Travel	20,048	18,007	17,662
Contracted ground and aviation services	57,491	18,983	13,245
Rent	11,625	11,677	26,650
Landing and ramp	13,455	9,727	10,305
Insurance	4,456	3,645	5,304
Other operating expenses	38,015	28,548	25,372
Operating Expenses	705,122	546,474	525,067
OPERATING INCOME	63,748	72,790	64,525
OTHER INCOME (EXPENSE)
Interest income	131	85	92
Interest expense	(11,318)	(11,232)	(13,937)
Net gain (loss) on financial instruments	(18,107)	920	1,096
Other Nonoperating Income (Expense)	(29,294)	(10,227)	(12,749)
EARNINGS FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	34,454	62,563	51,776
INCOME TAX EXPENSE	(13,394)	(23,408)	(19,702)
EARNINGS FROM CONTINUING OPERATIONS	21,060	39,155	32,074
EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAXES	2,428	2,067	(2,214)
NET EARNINGS	$ 23,488	$ 41,222	$ 29,860
BASIC EARNINGS (LOSS) PER SHARE
Basic earnings per share from continuing operations (in dollars per share)	$ 0.34	$ 0.61	$ 0.50
Discontinued operations (in dollars per share)	0.04	0.03	(0.04)
TOTAL BASIC EARNINGS PER SHARE (in dollars per share)	0.38	0.64	0.46
DILUTED EARNINGS (LOSS) PER SHARE
Diluted earnings per share from continuing operations (in dollars per share)	0.33	0.60	0.49
Discontinued operations (in dollars per share)	0.04	0.03	(0.03)
TOTAL DILUTED NET EARNINGS PER SHARE (in dollars per share)	$ 0.37	$ 0.63	$ 0.46
WEIGHTED AVERAGE SHARES
Basic (in shares)	61,330	64,242	64,253
Diluted (in shares)	62,994	65,127	65,211