Segment Reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting
Number of operating segments | segment			3
Operating revenues	$ 350,039	$ 744,383	$ 1,079,975	$ 1,468,077
Operating expense	354,442	600,290	1,018,057	1,227,565
Depreciation and amortization expense	131,638	90,148	243,346	180,134
Special items				21,869
Interest expense	30,926	32,770	61,130	65,278
Segment profit (loss)	(33,242)	115,335	5,837	229,778
Total assets	6,773,383	6,580,019	6,773,383	6,580,019	$ 6,657,129
Capital expenditures (including non-cash)	72,260	135,662	183,384	550,241
Segments
Segment Reporting
Segment profit (loss)	(35,329)	111,323	788	175,234
SkyWest Airlines
Segment Reporting
Operating revenues	227,808	627,088	834,650	1,212,856
Operating expense	275,869	545,419	870,010	1,091,320
Depreciation and amortization expense	59,421	40,641	111,197	80,694
Special items				18,508
Interest expense	3,438	3,716	5,979	7,534
Total assets	2,789,321	2,738,868	2,789,321	2,738,868
Capital expenditures (including non-cash)	29,247	47,975	68,126	116,625
SkyWest Airlines | Segments
Segment Reporting
Segment profit (loss)	(51,499)	77,953	(41,339)	114,002
ExpressJet Airlines Inc
Segment Reporting
Operating revenues				24,050
Operating expense				28,690
Depreciation and amortization expense				971
Special items				3,361
ExpressJet Airlines Inc | Segments
Segment Reporting
Segment profit (loss)				(4,640)
SkyWest Leasing
Segment Reporting
Operating revenues	122,231	117,295	245,325	231,171
Operating expense	78,573	54,871	148,047	107,555
Depreciation and amortization expense	72,217	49,507	132,149	98,469
Interest expense	27,488	29,054	55,151	57,744
Total assets	3,984,062	3,841,151	3,984,062	3,841,151
Capital expenditures (including non-cash)	43,013	87,687	115,258	433,616
SkyWest Leasing | Segments
Segment Reporting
Segment profit (loss)	$ 16,170	$ 33,370	$ 42,127	$ 65,872