Leases Narrative (Details)	9 Months Ended
	Sep. 30, 2020 USD ($) aircraft_engine aircraft	Dec. 31, 2019 USD ($) a residentialUnits
Lessee, Lease, Description [Line Items]
Number of aircraft held	155
Number of spare engines capitalized	16
Area of land | a		8.5
Land | $		$ 41,000,000.0
Number of residential units | residentialUnits		200
Operating lease not yet commenced, amount | $	$ 2,300,000
Operating lease not yet commenced, amount, year two | $	$ 0
Aircraft
Lessee, Lease, Description [Line Items]
Number of capitalized aircraft or engine purchased off lease	29
A320 Family | Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft capitalized	100
Airbus A319
Lessee, Lease, Description [Line Items]
Number of aircraft to be purchased from finance lease	2
Aircraft
Lessee, Lease, Description [Line Items]
Number of delivered aircraft financed with debt	7
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Operating leases, term	8 years
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Operating leases, term	18 years
Aircraft | A320 Family
Lessee, Lease, Description [Line Items]
Number of leased assets financed under operating leases	55
Other Leased Equipment and Property
Lessee, Lease, Description [Line Items]
Operating leases, term		99 years
Area of land | a		2.6
Other Leased Equipment and Property | Maximum
Lessee, Lease, Description [Line Items]
Operating leases, term	99 years
Spare Engines
Lessee, Lease, Description [Line Items]
Number of leased assets financed under operating leases | aircraft_engine	8
Number of spare engines purchased | aircraft_engine	2
Number Of spare engines returned | aircraft_engine	1
Leased Computer And Office Equipment | Minimum
Lessee, Lease, Description [Line Items]
Finance leases, term	4 years
Leased Computer And Office Equipment | Maximum
Lessee, Lease, Description [Line Items]
Finance leases, term	5 years
Third Party Lessor
Lessee, Lease, Description [Line Items]
Number of delivered leased aircraft	3