Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2025

Fair Value Disclosures [Abstract]

Schedule of Long-Term Debt Measured at Fair Value

The carrying amounts and estimated fair values of the Company's long-term debt at December 31, 2025 and December 31, 2024, were as follows:

	Successor				Predecessor
	December 31, 2025				December 31, 2024
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Fair value level hierarchy
	(in millions)
DIP term loans	$	358.6	$	358.6	$	309.0	$	309.0	Level 3
Fixed-rate term loans	274.8		325.9		972.2		970.7		Level 3
Unsecured term loans	—		—		136.3		130.4		Level 3
2015-1 EETC Class A	212.6		200.4		234.6		215.8		Level 2
2017-1 EETC Class AA	148.3		136.8		160.3		140.4		Level 2
2017-1 EETC Class A	49.4		44.3		53.4		45.8		Level 2
2017-1 EETC Class B	—		—		44.7		40.5		Level 2
2025 EETC Class B	215.0		208.0		—		—		Level 2
Revolving credit facility due 2028	—		—		300.0		300.0		Level 3
Total long-term debt	$	1,258.7	$	1,274.0	$	2,210.5	$	2,152.6

Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis

Assets and liabilities measured at gross fair value on a recurring basis are summarized below:

 

	Successor Fair Value Measurements as of December 31, 2025
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	273.0	$	273.0	$	—	$	—
Restricted cash	591.4		591.4		—		—
Assets held for sale	3.0		—		—		3.0
Total assets	$	867.4	$	864.4	$	—	$	3.0
Total liabilities	$	—	$	—	$	—	$	—

 

	Predecessor Fair Value Measurements as of December 31, 2024
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	902.1	$	902.1	$	—	$	—
Restricted cash	168.4		168.4		—		—
Short-term investment securities	118.3		118.3		—		—
Assets held for sale	463.0		—		—		463.0
Total assets	$	1,651.8	$	1,188.8	$	—	$	463.0
Total liabilities	$	—	$	—	$	—	$	—