Segment Reporting (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting
Number of operating segments | segment	2
Operating revenues	$ 534,555	$ 729,936
Operating expense	453,713	663,615
Depreciation and amortization expense	109,597	111,708
Interest expense	31,354	30,204
Segment profit	49,488	36,117
Total assets as of March 31	6,894,685	6,661,411	$ 6,887,622
Capital expenditures (including non-cash)	57,508	111,124
SkyWest Airlines
Segment Reporting
Operating revenues	406,450	606,842
Operating expense	387,870	594,141
Depreciation and amortization expense	50,326	51,775
Interest expense	3,129	2,541
Segment profit	15,451	10,160
Total assets as of March 31	2,924,598	2,650,094
Capital expenditures (including non-cash)	35,206	38,879
SkyWest Leasing
Segment Reporting
Operating revenues	128,105	123,094
Operating expense	65,843	69,474
Depreciation and amortization expense	59,271	59,933
Interest expense	28,225	27,663
Segment profit	34,037	25,957
Total assets as of March 31	3,970,087	4,011,317
Capital expenditures (including non-cash)	$ 22,302	$ 72,245