Segment Reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment aircraft	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting
Number of operating segments | segment			3
Operating revenues	$ 809,759	$ 801,338	$ 1,575,174	$ 1,563,414
Operating expense	703,163	717,201	1,392,284	1,417,468
Depreciation and amortization expense	71,206	69,887	141,320	137,688
Interest expense	27,063	18,287	51,612	36,012
Segment profit (loss)	80,863	66,335	133,268	110,849
Identifiable intangible assets, other than goodwill	7,124	9,374	7,124	9,374	$ 8,249
Total assets	5,360,613	4,882,051	5,360,613	4,882,051	$ 5,007,966
Capital expenditures (including non-cash)	295,802	222,674	518,901	321,960
Segments
Segment Reporting
Segment profit (loss)	79,533	65,850	131,278	109,934
SkyWest Airlines
Segment Reporting
Operating revenues	537,749	504,107	1,020,703	970,403
Operating expense	460,641	428,142	896,010	842,226
Depreciation and amortization expense	32,530	34,585	64,347	68,916
Interest expense	5,735	6,754	11,535	13,413
Total assets	2,251,331	2,074,265	2,251,331	2,074,265
Capital expenditures (including non-cash)	25,346	7,927	58,777	21,885
SkyWest Airlines | Segments
Segment Reporting
Segment profit (loss)	71,373	69,211	113,158	114,764
ExpressJet Airlines Inc
Segment Reporting
Operating revenues	212,025	266,241	440,683	534,048
Operating expense	215,070	274,856	444,563	548,475
Depreciation and amortization expense	11,710	21,460	26,235	42,727
Interest expense	1,088	1,617	2,202	3,740
Identifiable intangible assets, other than goodwill	7,124	9,374	7,124	9,374
Total assets	529,175	1,389,687	529,175	1,389,687
Capital expenditures (including non-cash)	4,501	2,002	10,155	7,050
ExpressJet Airlines Inc | Segments
Segment Reporting
Segment profit (loss)	(4,133)	(10,232)	(6,082)	(18,167)
SkyWest Leasing
Segment Reporting
Operating revenues	59,985	30,990	113,788	58,963
Operating expense	27,452	14,203	51,711	26,767
Depreciation and amortization expense	26,966	13,842	50,738	26,045
Interest expense	20,240	9,916	37,875	18,859
Total assets	2,580,107	1,418,099	2,580,107	1,418,099
Capital expenditures (including non-cash)	265,955	212,745	$ 449,969	293,025
SkyWest Leasing | CRJ 200
Segment Reporting
Number of aircraft under contract | aircraft			4
SkyWest Leasing | Segments
Segment Reporting
Segment profit (loss)	$ 12,293	$ 6,871	$ 24,202	$ 13,337