Segment Reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) segment aircraft	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Segment Reporting
Number of operating segments | segment									3
Operating revenues	$ 758,017	$ 799,776	$ 801,338	$ 762,075	$ 752,744	$ 794,004	$ 788,417	$ 760,398	$ 3,121,206	$ 3,095,563	$ 3,237,447
Operating expense									3,293,890	2,861,048	3,212,599
Depreciation and amortization expense									284,969	264,507	259,642
Special items									465,649		74,777
Interest expense									78,177	75,850	65,995
Segment profit (loss)									(250,861)	158,665	(41,147)
Identifiable intangible assets, other than goodwill	8,249				10,499				8,249	10,499	12,748
Total assets	5,137,251				4,781,984				5,137,251	4,781,984	4,388,818
Capital expenditures (including non-cash)									$ 1,159,001	715,089	696,923
CRJ 200
Segment Reporting
Number of aircraft lease to third party | aircraft									2
Special items									$ 424,466
SkyWest Airlines
Segment Reporting
Operating revenues									1,935,378	1,848,363	1,873,675
Operating expense									1,886,173	1,630,200	1,758,145
Depreciation and amortization expense									139,159	141,189	162,699
Special items									184,295		57,046
Interest expense									26,211	36,141	39,451
Segment profit (loss)									22,994	182,022	76,079
Total assets	2,343,814				2,300,388				2,343,814	2,300,388	2,475,283
Capital expenditures (including non-cash)									57,761	30,897	137,678
ExpressJet Airlines Inc
Segment Reporting
Operating revenues									1,044,828	1,169,923	1,346,859
Operating expense									1,339,569	1,192,070	1,446,050
Depreciation and amortization expense									83,935	86,382	88,459
Special items									281,354		17,731
Interest expense									6,773	12,091	18,754
Segment profit (loss)									(301,514)	(34,238)	(117,945)
Identifiable intangible assets, other than goodwill	8,249				10,499				8,249	10,499	12,748
Total assets	618,637				1,331,000				618,637	1,331,000	1,386,564
Capital expenditures (including non-cash)									15,396	24,679	23,790
ExpressJet Airlines Inc | CRJ 200
Segment Reporting
Special items									240,200
SkyWest Leasing
Segment Reporting
Operating revenues									141,000	77,277	16,913
Operating expense									68,148	38,778	8,404
Depreciation and amortization expense									61,875	36,936	8,484
Interest expense									45,193	27,618	7,790
Segment profit (loss)									27,659	10,881	719
Total assets	$ 2,174,800				$ 1,150,596				2,174,800	1,150,596	526,971
Capital expenditures (including non-cash)									$ 1,085,844	$ 659,513	$ 535,455