Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2019

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, 2019 and December 31, 2018 were as follows:

	June 30, 2019				December 31, 2018				Fair Value Level Hierarchy
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
	(in millions)
Fixed-rate senior term loans	$	364.0	$	382.4	$	382.4	$	373.6	Level 3
Fixed-rate junior term loans	26.8		27.4		31.1		31.1		Level 3
Fixed-rate term loans	672.7		700.4		625.1		600.1		Level 3
2015-1 EETC Class A	363.6		382.7		378.6		374.8		Level 2
2015-1 EETC Class B	76.0		78.2		80.0		78.1		Level 2
2015-1 EETC Class C	103.8		105.9		109.5		107.9		Level 2
2017-1 EETC Class AA	235.4		240.7		242.5		228.8		Level 2
2017-1 EETC Class A	78.5		78.9		80.8		76.6		Level 2
2017-1 EETC Class B	77.2		77.8		83.7		79.1		Level 2
2017-1 EETC Class C	85.5		87.6		85.5		84.2		Level 2
Revolving credit facility	160.0		160.0		135.3		135.3		Level 3
Total long-term debt	$	2,243.5	$	2,322.0	$	2,234.5	$	2,169.6

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:

	Fair Value Measurements as of June 30, 2019
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	1,110.8	$	1,110.8	$	—	$	—
Short-term investment securities	104.2		104.2		—		—
Total assets	$	1,215.0	$	1,215.0	$	—	$	—
Total liabilities	$	—	$	—	$	—	$	—

	Fair Value Measurements as of December 31, 2018
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	1,004.7	$	1,004.7	$	—	$	—
Short-term investment securities	102.8		102.8		—		—
Total assets	$	1,107.5	$	1,107.5	$	—	$	—
Total liabilities	$	—	$	—	$	—	$	—