Flying Agreements Revenue and Lease, Airport Services and Other Revenues (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) aircraft	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Agreements with other airlines
Percentage of ASMs flown under fixed-fee arrangements			88.30%	88.30%
Percentage of ASMs flown under pro-rate arrangements			11.70%	11.70%
Rental income under operating leases
Operating lease revenue	$ 16,791	$ 16,450	$ 33,351	$ 33,005
Total operating revenues	725,643	799,085	1,417,474	1,534,237
Future minimum rental income
July 2023 through December 2023	22,880		22,880
2024	45,553		45,553
2025	40,583		40,583
2026	35,017		35,017
2027	34,995		34,995
Thereafter	86,297		86,297
Total future minimum rental income under operating leases	265,325		265,325
Deferred revenue recognized			77,400	17,600
Unbilled revenue recognized			6,000	9,300
Deferred revenue	262,100		262,100		$ 144,700
Deferred revenue in other current liabilities	7,300		7,300		5,200
Deferred revenue in other long-term liabilities	254,800		254,800		139,500
Unbilled revenue	13,900		13,900		19,900
Property and equipment and related assets	5,491,143		5,491,143		5,548,480
Gross receivables current	123,100		123,100
Gross receivables Non-current	201,700		201,700
Balance			37,385
Adjustments to credit loss reserves			2,086
Write-offs charged against allowance			(3,570)
Balance	35,901		35,901
Other Current Assets
Future minimum rental income
Unbilled revenue	7,200		7,200		9,900
Other Noncurrent Assets
Future minimum rental income
Unbilled revenue	6,700		6,700		$ 10,000
Other Noncurrent Liabilities
Future minimum rental income
Deferred lease revenue	40,000		$ 40,000
Aircraft in schedule service or under contract
Future minimum rental income
Number of aircraft | aircraft			492
United
Future minimum rental income
Number of aircraft | aircraft			198
United | United Express Prorate Agreement
Future minimum rental income
Agreement term			120 days
Delta
Future minimum rental income
Number of aircraft | aircraft			147
Delta | Delta Connection Prorate Agreement
Future minimum rental income
Agreement term			30 days
American
Future minimum rental income
Number of aircraft | aircraft			105
Jet aircraft and spare engines leased to third parties
Future minimum rental income
Property and equipment and related assets	211,800		$ 211,800
CRJ 200 | United | United Express Agreements
Future minimum rental income
Number of aircraft | aircraft			70
CRJ 200 | United | United Express Prorate Agreement
Future minimum rental income
Number of aircraft | aircraft			19
CRJ 200 | Delta | Delta Connection Prorate Agreement
Future minimum rental income
Number of aircraft | aircraft			17
CRJ 700 | United | United Express Agreements
Future minimum rental income
Number of aircraft | aircraft			19
CRJ 700 | Delta | Delta Connection Prorate Agreement
Future minimum rental income
Number of aircraft | aircraft			1
CRJ 700 | Delta | Delta Connection Agreements
Future minimum rental income
Number of aircraft | aircraft			5
CRJ 700 | American | American Capacity Purchase Agreement
Future minimum rental income
Number of aircraft | aircraft			85
CRJ 900 | Delta | Delta Connection Prorate Agreement
Future minimum rental income
Number of aircraft | aircraft			6
CRJ 900 | Delta | Delta Connection Agreements
Future minimum rental income
Number of aircraft | aircraft			35
E175
Future minimum rental income
Number of aircraft under purchase agreement | aircraft			4
E175 | Sky West Airlines Inc. | Alaska Capacity Purchase Agreement
Future minimum rental income
Number of aircraft | aircraft			42
E175 | United | United Express Agreements
Future minimum rental income
Number of aircraft | aircraft			90
E175 | Delta
Future minimum rental income
Number of aircraft under purchase agreement | aircraft			3
E175 | Delta | Delta Connection Agreements
Future minimum rental income
Number of aircraft | aircraft			83
E175 | American | American Capacity Purchase Agreement
Future minimum rental income
Number of aircraft | aircraft			20
E175 | Alaska
Future minimum rental income
Number of aircraft under purchase agreement | aircraft			1
Flying agreements
Rental income under operating leases
Total operating revenues	700,394	773,774	$ 1,364,232	1,481,837
Flight operations revenue
Rental income under operating leases
Total operating revenues	499,142	549,539	968,058	1,054,347
Capacity purchase agreements fixed aircraft lease revenue
Rental income under operating leases
Total operating revenues	74,042	129,502	148,522	253,587
Capacity purchase agreements variable aircraft lease revenue
Rental income under operating leases
Total operating revenues	44,984		88,089
Prorate agreements revenue
Rental income under operating leases
Total operating revenues	82,226	94,733	159,563	173,903
Airport customer service and other revenue
Rental income under operating leases
Total operating revenues	8,458	8,861	19,891	19,395
Lease, airport services and other.
Rental income under operating leases
Total operating revenues	$ 25,249	$ 25,311	$ 53,242	$ 52,400