Leases, Commitments, Guarantees and Contingencies - Guarantees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2025
Leases, Commitments, Guarantees and Contingencies
Guaranteed amount received as consideration, percentage		6.50%
Debt
Leases, Commitments, Guarantees and Contingencies
Balance of debt under the guarantee			$ 10.3
Debt | Aircraft and engines
Leases, Commitments, Guarantees and Contingencies
Guaranteed amount	$ 12.0	$ 19.8
Term of guarantee obligations	5 years	5 years
Guaranteed amount received as consideration, percentage	2.00%
Balance of debt under the guarantee			$ 13.7