Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Disclosures [Abstract]

Carrying amount and estimated fair value, long-term debt

The carrying amounts and estimated fair values of the Company's long-term debt at June 30, 2020 and December 31, 2019 were as follows:

	June 30, 2020				December 31, 2019				Fair Value Level Hierarchy
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
	(in millions)
Fixed-rate senior term loans	$	279.4	$	262.8	$	296.1	$	296.4	Level 3
Fixed-rate term loans	992.2		976.8		778.2		823.6		Level 3
Unsecured term loans	60.4		60.4		—		—		Level 3
2015-1 EETC Class A	333.5		321.9		348.6		372.2		Level 2
2015-1 EETC Class B	68.0		59.3		72.0		74.5		Level 2
2015-1 EETC Class C	92.4		65.8		98.1		100.5		Level 2
2017-1 EETC Class AA	221.4		208.1		228.4		237.0		Level 2
2017-1 EETC Class A	73.8		61.8		76.1		78.8		Level 2
2017-1 EETC Class B	65.6		51.8		70.6		72.0		Level 2
2017-1 EETC Class C	85.5		60.5		85.5		88.0		Level 2
Convertible debt	101.4		264.1		—		—		Level 2
Revolving credit facilities	291.2		291.2		160.0		160.0		Level 3
Total long-term debt	$	2,664.8	$	2,684.5	$	2,213.6	$	2,303.0

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:

	Fair Value Measurements as of June 30, ,2020
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	1,127.5	$	1,127.5	$	—	$	—
Restricted cash	30.0		30.0		—		—
Short-term investment securities	106.3		106.3		—		—
Assets held for sale	2.3		—		—		2.3
Total assets	$	1,266.1	$	1,263.8	$	—	$	2.3
Total liabilities	$	—	$	—	$	—	$	—

	Fair Value Measurements as of December 31, 2019
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	979.0	$	979.0	$	—	$	—
Short-term investment securities	105.3		105.3		—		—
Assets held for sale	2.3						2.3
Total assets	$	1,086.6	$	1,084.3	$	—	$	2.3
Total liabilities	$	—	$	—	$	—	$	—

Schedule of assets held for sale activity

	Assets Held for Sale Activity for the Six Months Ended June 30, 2020
	(in millions)
Balance at December 31, 2019	$	2.3
Purchases	—
Sales	—
Total realized or unrealized gains (losses) included in earnings, net	$	—
Balance at March 31, 2020	$	2.3
Purchases	—
Sales	—
Total realized or unrealized gains (losses) included in earnings, net	—
Balance at June 30, 2020	$	2.3