Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Long-Term Debt Measured at Fair Value

The carrying amounts and estimated fair values of the Company's long-term debt at December 31, 2021 and December 31, 2020, were as follows:

	As of December 31,
	2021				2020
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Fair value level hierarchy
	(in millions)
8.00% senior secured notes	$	510.0	$	530.4	$	850.0	$	886.0	Level 3
Fixed-rate term loans	1,223.5		1,262.6		1,301.9		1,362.9		Level 3
Unsecured term loans	136.3		146.4		73.3		83.1		Level 3
2015-1 EETC Class A	300.6		311.1		322.6		323.4		Level 2
2015-1 EETC Class B	56.0		56.4		64.0		62.5		Level 2
2015-1 EETC Class C	75.2		74.0		86.6		77.8		Level 2
2017-1 EETC Class AA	200.3		203.3		214.4		207.4		Level 2
2017-1 EETC Class A	66.8		65.8		71.5		68.8		Level 2
2017-1 EETC Class B	55.8		53.6		60.6		56.2		Level 2
2017-1 EETC Class C	85.5		84.1		85.5		76.3		Level 2
4.75% convertible notes due 2025	28.2		55.6		175.0		380.3		Level 2
1.00% convertible notes due 2026	500.0		432.5		—		—		Level 2
Revolving credit facilities	—		—		275.1		275.1		Level 3
Total long-term debt	$	3,238.2	$	3,275.8	$	3,580.5	$	3,859.8

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:

 

	Fair Value Measurements as of December 31, 2021
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	1,333.5	$	1,333.5	$	—	$	—
Restricted cash	95.4		95.4		—		—
Short-term investment securities	106.3		106.3		—		—
Assets held for sale	2.5		—		—		2.5
Total assets	$	1,537.7	$	1,535.2	$	—	$	2.5
Total liabilities	$	—	$	—	$	—	$	—

 

	Fair Value Measurements as of December 31, 2020
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	1,789.7	$	1,789.7	$	—	$	—
Restricted cash	71.4		71.4		—		—
Short-term investment securities	106.3		106.3		—		—
Assets held for sale	2.3		—		—		2.3
Total assets	$	1,969.7	$	1,967.4	$	—	$	2.3
Total liabilities	$	—	$	—	$	—	$	—

The following table presents the Company's activity for assets and liabilities measured at gross fair value on a recurring basis using significant unobservable inputs (Level 3):

	Assets Held for Sale Activity for the Twelve Months Ended December 31, 2021
	(in millions)
Balance at December 31, 2020	$	2.3
Additions	0.2
Sales	—
Total realized or unrealized gains (losses) included in earnings, net	—
Balance at December 31, 2021	$	2.5