Operating Revenues (Details) $ in Thousands		2 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) aircraft	Oct. 31, 2024 aircraft	Sep. 30, 2024 USD ($) aircraft	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) aircraft item	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Agreements with other airlines
Percentage of ASMs flown under fixed-fee arrangements					86.80%	87.20%
EAS contract term					2 years
Percentage of ASMs flown under pro-rate arrangements					13.20%	12.80%
Rental income under operating leases
Operating lease revenue | $			$ 22,134	$ 16,091	$ 60,918	$ 49,442
Total operating revenues | $			912,786	766,171	2,583,518	2,183,645
Future minimum rental income
October 2024 through December 2024 | $	$ 11,711		11,711		11,711
2025 | $	42,248		42,248		42,248
2026 | $	36,641		36,641		36,641
2027 | $	36,626		36,626		36,626
2028 | $	35,739		35,739		35,739
Thereafter | $	54,543		54,543		54,543
Total future minimum rental income under operating leases | $	217,508		217,508		217,508
Deferred revenue recognized | $					24,500	111,900
Decreased unbilled revenue | $					900	8,700
Deferred revenue | $	348,600		348,600		348,600		$ 374,600
Deferred revenue in other current liabilities | $	59,600		59,600		59,600		61,000
Deferred revenue in other long-term liabilities | $	289,000		289,000		289,000		313,600
Unbilled revenue | $	6,400		6,400		6,400		7,300
Property and equipment and related assets | $	5,417,268		5,417,268		5,417,268		5,482,967
Gross receivables current | $	112,900		112,900		112,900
Gross receivables Non-current | $	202,400		202,400		202,400
Balance | $					18,699
Adjustments to credit loss reserves | $					(1,379)
Balance | $	17,320		17,320		17,320
Other Current Assets
Future minimum rental income
Unbilled revenue | $	1,100		1,100		1,100		1,200
Other Noncurrent Assets
Future minimum rental income
Unbilled revenue | $	5,300		5,300		5,300		$ 6,100
Other Noncurrent Liabilities
Future minimum rental income
Deferred lease revenue | $	1,500		1,500	59,300	$ 1,500	59,300
Aircraft in schedule service or under contract
Future minimum rental income
Number of aircraft					484
Aircraft
Future minimum rental income
Number of aircraft acquired					8
United
Future minimum rental income
Number of aircraft					210
United | United Express Prorate Agreement
Future minimum rental income
Agreement term					120 days
Delta
Future minimum rental income
Number of aircraft					141
Delta | Delta Connection Prorate Agreement
Future minimum rental income
Agreement term					30 days
American
Future minimum rental income
Number of aircraft					91
Jet aircraft and spare engines leased to third parties
Future minimum rental income
Property and equipment and related assets | $	$ 202,400		$ 202,400		$ 202,400
CRJ 200 | United | United Express Agreements
Future minimum rental income
Number of aircraft					61
CRJ 200 | United | United Express Prorate Agreement
Future minimum rental income
Number of aircraft					20
C R J 550
Future minimum rental income
Number of used aircraft acquired	11
Number of aircraft acquired	1
C R J 550 | United
Future minimum rental income
Aircraft placed under multi-year contract		40
Number of used aircraft acquired		11
Number of aircraft acquired			1
CRJ 700
Future minimum rental income
Number of seats on aircraft | item					50
CRJ 700 | United
Future minimum rental income
Number of aircraft converted		29
CRJ 700 | United | United Express Agreements
Future minimum rental income
Number of aircraft					19
CRJ 700 | Delta | Delta Connection Prorate Agreement
Future minimum rental income
Number of aircraft					14
CRJ 700 | Delta | Delta Connection Agreements
Future minimum rental income
Number of aircraft					5
CRJ 700 | American | American Capacity Purchase Agreement
Future minimum rental income
Number of aircraft					71
CRJ 900 | Delta | Delta Connection Prorate Agreement
Future minimum rental income
Number of aircraft					1
CRJ 900 | Delta | Delta Connection Agreements
Future minimum rental income
Number of aircraft					35
E175
Future minimum rental income
Q4 2024					4
2025					8
2026					8
Total					20
Number of aircraft under purchase agreement					20
E175 | Sky West Airlines Inc. | Alaska Capacity Purchase Agreement
Future minimum rental income
Number of aircraft					42
E175 | United | United Express Agreements
Future minimum rental income
Q4 2024					4
2025					7
2026					8
Total					19
Number of aircraft					110
E175 | Delta | Delta Connection Agreements
Future minimum rental income
Number of aircraft					86
E175 | American | American Capacity Purchase Agreement
Future minimum rental income
Number of aircraft					20
E175 | Alaska | Alaska Capacity Purchase Agreement
Future minimum rental income
2025					1
Total					1
Number of aircraft					42
Flying agreements
Rental income under operating leases
Total operating revenues | $			$ 883,494	741,898	$ 2,499,953	2,106,130
Flight operations revenue
Rental income under operating leases
Total operating revenues | $			624,342	511,929	1,763,629	1,479,987
Capacity purchase agreements fixed aircraft lease revenue
Rental income under operating leases
Total operating revenues | $			75,084	73,794	225,374	222,316
Capacity purchase agreements variable aircraft lease revenue
Rental income under operating leases
Total operating revenues | $			61,308	46,495	180,035	134,584
Prorate agreements and SWC revenue
Rental income under operating leases
Total operating revenues | $			122,760	109,680	330,915	269,243
Airport customer service and other revenue
Rental income under operating leases
Total operating revenues | $			7,158	8,182	22,647	28,073
Lease, airport services and other.
Rental income under operating leases
Total operating revenues | $			$ 29,292	$ 24,273	$ 83,565	$ 77,515