Debt and Other Obligations (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of long-term debt instruments

Long-term debt is comprised of the following:

	As of				Year Ended December 31,
	2018		2017		2018		2017
	(in millions)				(weighted-average interest rates)
Fixed-rate senior term loans due through 2027	$	382.4	$	417.9	4.10	%	4.10	%
Fixed-rate junior term loans due through 2022	31.1		39.3		6.90	%	6.90	%
Fixed-rate loans due through 2030	625.1		518.0		3.88	%	3.83	%
Fixed-rate class A 2015-1 EETC due through 2028	378.6		408.6		4.10	%	4.10	%
Fixed-rate class B 2015-1 EETC due through 2024	80.0		92.0		4.45	%	4.45	%
Fixed-rate class C 2015-1 EETC due through 2023	109.5		—		4.93	%	N/A
Fixed-rate class AA 2017-1 EETC due through 2030	242.5		37.5		3.38	%	3.38	%
Fixed-rate class A 2017-1 EETC due through 2030	80.8		12.5		3.65	%	3.65	%
Fixed-rate class B 2017-1 EETC due through 2026	83.7		13.8		3.80	%	3.80	%
Fixed-rate class C 2017-1 EETC due through 2023	85.5		—		5.11	%	N/A
Revolving credit facility due in 2020	135.3		—		3.72	%	N/A
Long-term debt	$	2,234.5	$	1,539.6
Less current maturities	162.8		115.4
Less unamortized discount, net	47.7		36.7
Total	$	2,024.0	$	1,387.5

Schedule of maturities of long-term debt

At December 31, 2018, long-term debt principal payments for the next five years and thereafter are as follows:

	December 31, 2018
	(in millions)
2019	$	171.3
2020	303.6
2021	162.1
2022	159.5
2023	298.0
2024 and beyond	1,140.0
Total debt principal payments	$	2,234.5

Schedule of interest expense on long-term debt and capital leases

Interest expense related to long-term debt and capital leases consists of the following:

	Year Ended December 31,
	2018		2017
	(in thousands)
Fixed-rate senior term loans	$	16,869	$	18,328
Fixed-rate junior term loans	2,475		3,035
Fixed-rate term loans	19,615		8,610
Class A 2015-1 EETC	16,138		17,230
Class B 2015-1 EETC	3,781		4,446
Class C 2015-1 EETC	3,575		—
Class AA 2017-1 EETC	6,026		54
Class A 2017-1 EETC	2,172		19
Class B 2017-1 EETC	2,420		22
Class C 2017-1 EETC	2,478		—
Revolving credit facility	793		—
Capital leases	104		154
Commitment fees	262		124
Amortization of deferred financing costs	7,069		5,280
Total	$	83,777	$	57,302