Passenger and Ground Handling and Other Revenue (Details)	6 Months Ended
	Jun. 30, 2017 aircraft
Agreements with other airlines
Percentage of ASMs flown under fixed-fee arrangements	88.60%
Percentage of ASMs flown under pro-rate arrangements	11.40%
Sky West Airlines Inc | Delta Connection Prorate Agreement
Agreements with other airlines
Term of agreement	30 days
Sky West Airlines Inc | United Express Prorate Agreement
Agreements with other airlines
Term of agreement	120 days
Sky West Airlines Inc | American Prorate Agreement
Agreements with other airlines
Term of agreement	120 days
CRJ 200 | Sky West Airlines Inc | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	57
CRJ 200 | Sky West Airlines Inc | Delta Connection Prorate Agreement
Agreements with other airlines
Number of aircraft under contract	25
CRJ 200 | Sky West Airlines Inc | United Express Agreements
Agreements with other airlines
Number of aircraft under contract	47
CRJ 200 | Sky West Airlines Inc | United Express Prorate Agreement
Agreements with other airlines
Number of aircraft under contract	22
CRJ 200 | Sky West Airlines Inc | American Capacity Purchase Agreement
Agreements with other airlines
Number of aircraft under contract	22
CRJ 200 | Sky West Airlines Inc | American Prorate Agreement
Agreements with other airlines
Number of aircraft under contract	8
CRJ 200 | ExpressJet | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	23
CRJ 200 | ExpressJet | American Capacity Purchase Agreement
Agreements with other airlines
Number of aircraft under contract	2
CRJ 700 | Sky West Airlines Inc | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	27
CRJ 700 | Sky West Airlines Inc | United Express Agreements
Agreements with other airlines
Number of aircraft under contract	20
CRJ 700 | Sky West Airlines Inc | Alaska Capacity Purchase Agreement
Agreements with other airlines
Number of aircraft under contract	20
CRJ 700 | Sky West Airlines Inc | American Capacity Purchase Agreement
Agreements with other airlines
Number of aircraft under contract	37
CRJ 700 | ExpressJet | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	33
CRJ 700 | ExpressJet | American Capacity Purchase Agreement
Agreements with other airlines
Number of aircraft under contract	12
CRJ 900 | Sky West Airlines Inc | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	36
CRJ 900 | ExpressJet | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	28
E 175 | Sky West Airlines Inc
Agreements with other airlines
Number of aircraft under contract	1
E 175 | Sky West Airlines Inc | Delta Connection Agreements
Agreements with other airlines
Number of aircraft under contract	18
E 175 | Sky West Airlines Inc | United Express Agreements
Agreements with other airlines
Number of aircraft under contract	65
ERJ 145 | ExpressJet | United Express Agreements
Agreements with other airlines
Number of aircraft under contract	119
ERJ 135 | ExpressJet | United Express Agreements
Agreements with other airlines
Number of aircraft under contract	5