Operating Leases (Narrative) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024 USD ($) Engine	Sep. 30, 2024 USD ($) Engine Aircraft	Dec. 31, 2023 USD ($)
Lessee Lease Description [Line Items]
Operating lease right-of-use assets, net	$ 812,659	$ 812,659	$ 778,216
Lease liabilities, net	872,369	$ 872,369	$ 825,529
Number of aircraft engines | Aircraft		24
Lease income	8,600	$ 18,200
Net book value of lease assets	$ 157,000	157,000
Other Income [Member] | 2 Aircraft Engines [Member]
Lessee Lease Description [Line Items]
Number of engines sold | Engine	2
Net book value	$ 6,200	$ 6,200
Gain loss on sale of aircraft engines	1,100
Other Income [Member] | 5 Aircraft Engines [Member]
Lessee Lease Description [Line Items]
Number of engines sold | Engine		5,000,000
Net book value	$ 23,800	$ 23,800
Gain loss on sale of aircraft engines		20,800
Other Assets [Member] | 22 Aircraft Engine [Memebr]
Lessee Lease Description [Line Items]
Number of engines sold | Engine	22
Net book value	$ 152,100	$ 152,100
Minimum [Member] | Office Space And Office Equipment [Member]
Lessee Lease Description [Line Items]
Operating leases remaining lease term		1 year
Maximum [Member] | Office Space And Office Equipment [Member]
Lessee Lease Description [Line Items]
Operating leases remaining lease term		15 years