Operating Leases (Narrative) (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2024 USD ($) Engine	Jun. 30, 2024 USD ($) Aircraft	Dec. 31, 2023 USD ($)
Lessee Lease Description [Line Items]
Operating lease right-of-use assets, net	$ 821,895	$ 821,895	$ 778,216
Lease liabilities, net	877,849	$ 877,849	$ 825,529
Number of aircraft engines | Aircraft		25
Lease income	7,700	$ 9,600
Net book value of lease assets	$ 137,800	137,800
Number of engines sold | Engine	3
Net book value	$ 17,500	$ 17,500
Gain loss on sale of aircraft engines	$ 19,800
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