Leases, Commitments, Guarantees and Contingencies - Operating Leases (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2026 USD ($) aircraft	Dec. 31, 2024
Lessee, Lease, Description [Line Items]
Lease term		5 years
Purchase obligation | $	$ 2,164,005
Minimum
Lessee, Lease, Description [Line Items]
Purchase obligation | $	15,000
Maximum
Lessee, Lease, Description [Line Items]
Purchase obligation | $	$ 18,000
E175
Lessee, Lease, Description [Line Items]
Number of aircraft under purchase agreement	67
Number of additional aircraft with secured delivery positions	33
United | E175
Lessee, Lease, Description [Line Items]
Number of aircraft to be purchased and placed into service	7
American | E175
Lessee, Lease, Description [Line Items]
Number of aircraft to be purchased and placed into service	11
Delta | E175
Lessee, Lease, Description [Line Items]
Number of aircraft to be purchased and placed into service	16