Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Depreciable Lives Used for the Principal Depreciable Asset Classifications and Components of Depreciation and Amortization

The depreciable lives used for the principal depreciable asset classifications are:

	Estimated Useful Life
Aircraft, engines and flight simulators	25
Spare rotables and flight assemblies	7 to 25 years
Other equipment and vehicles	5 to 7 years
Internal use software	3 to 10 years
Finance leases	Lease term or estimated useful life of the asset
Leasehold improvements	Lesser of lease term or estimated useful life of the improvement
Buildings	Lesser of lease term or 30 years

The following table illustrates the components of depreciation and amortization expense:

	Year Ended December 31,
	2022		2021		2020
	(in thousands)
Depreciation	$	199,118	$	193,079	$	179,470
Amortization of heavy maintenance	96,707		91,929		88,927
Amortization of capitalized software	17,265		12,203		10,191
Total depreciation and amortization	$	313,090	$	297,211	$	278,588

Schedule of Revenue Disaggregation

The following table shows disaggregated operating revenues for the twelve months ended December 31, 2022, 2021 and 2020:

	Twelve Months Ended December 31,
	2022		2021		2020
	(in thousands)
Operating revenues:
Fare	$	2,455,817	$	1,422,927	$	756,225
Non-fare	2,533,548		1,752,875		1,009,308
Total passenger revenues	4,989,365		3,175,802		1,765,533
Other	79,082		54,973		44,489
Total operating revenues	$	5,068,447	$	3,230,775	$	1,810,022

Total Cash Proceeds Received from the Sale of Mileage Credit

The following table illustrates total cash proceeds received from the sale of points and the portion of such proceeds recognized in non-ticket revenue immediately as marketing component:

	Consideration received from credit card loyalty programs		Portion of proceeds recognized immediately as marketing component
Year Ended	(in thousands)
December 31, 2022	$	80,970	$	40,987
December 31, 2021	48,035		23,681
December 31, 2020	33,201		25,918

Aircraft Maintenance Expense

The table below summarizes the components of the Company’s maintenance cost:

	Year Ended December 31,
	2022		2021		2020
	(in thousands)
Utilization-based maintenance expense	$	97,930	$	81,591	$	52,092
Non-utilization-based maintenance expense	89,890		77,911		59,135
Total maintenance, materials and repairs	$	187,820	$	159,502	$	111,227