Segment Reporting (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) segment	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting
Number of operating segments | segment	3
Operating revenues	$ 723,694	$ 783,400
Operating expense	627,275	695,225
Depreciation and amortization expense	89,986	77,585
Special items	21,869
Interest expense	32,507	26,234
Segment profit (loss)	114,444	67,204
Identifiable intangible assets, other than goodwill		3,672
Total assets	6,544,532	5,600,187	$ 6,313,212
Capital expenditures (including non-cash)	414,579	267,788
Segments
Segment Reporting
Segment profit (loss)	63,912	61,941
SkyWest Airlines
Segment Reporting
Operating revenues	585,768	556,294
Operating expense	545,901	498,875
Depreciation and amortization expense	40,053	37,487
Special items	18,508
Interest expense	3,818	4,476
Total assets	2,738,248	2,184,306
Capital expenditures (including non-cash)	68,650	36,283
SkyWest Airlines | Segments
Segment Reporting
Segment profit (loss)	36,049	52,943
ExpressJet Airlines Inc
Segment Reporting
Operating revenues	24,050	161,081
Operating expense	28,690	166,824
Depreciation and amortization expense	971	11,161
Special items	3,361
Interest expense		827
Identifiable intangible assets, other than goodwill		3,672
Total assets		581,722
Capital expenditures (including non-cash)		1,338
ExpressJet Airlines Inc | Segments
Segment Reporting
Segment profit (loss)	(4,640)	(6,570)
SkyWest Leasing
Segment Reporting
Operating revenues	113,876	66,025
Operating expense	52,684	29,526
Depreciation and amortization expense	48,962	28,937
Interest expense	28,689	20,931
Total assets	3,806,284	2,834,159
Capital expenditures (including non-cash)	345,929	230,167
SkyWest Leasing | Segments
Segment Reporting
Segment profit (loss)	$ 32,503	$ 15,568