Fixed Assets (Narrative) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) Engine	Dec. 31, 2024 USD ($) Engine Aircraft	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Depreciation and amortization		$ 62,398	$ 60,533	$ 50,615
Number of aircraft engines | Aircraft		18
Net book value of lease assets		$ 121,300
Lease income		$ 25,300
Other Income [Member]
Property, Plant and Equipment [Line Items]
Number of engines sold | Engine		11
Net book value		$ 59,400
11 Aircraft Engines [Member] | Other Income [Member]
Property, Plant and Equipment [Line Items]
Gain loss on sale of aircraft engines		$ 46,500
Other Assets [Member]
Property, Plant and Equipment [Line Items]
Number of engines sold | Engine	22
Net book value	$ 152,100