Debt and Other Obligations - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Debt Instrument [Line Items]
Amortization of deferred financing costs	$ 2,106	$ 2,192
Interest Expense, Other	218	74
Total	23,878	24,971
Fixed-rate senior term loans
Debt Instrument [Line Items]
Interest expense, term loans	2,813	3,945
Fixed-rate junior term loans
Debt Instrument [Line Items]
Interest expense, term loans	0	523
Fixed-rate term loans
Debt Instrument [Line Items]
Interest expense, term loans	7,613	6,202
2015-1 EETC Class A
Debt Instrument [Line Items]
Interest expense, term loans	3,549	3,838
2015-1 EETC Class B
Debt Instrument [Line Items]
Interest expense, term loans	795	880
2015-1 EETC Class C
Debt Instrument [Line Items]
Interest expense, term loans	1,209	1,335
2017-1 EETC Class AA
Debt Instrument [Line Items]
Interest expense, term loans	1,887	1,989
2017-1 EETC Class A
Debt Instrument [Line Items]
Interest expense, term loans	680	717
2017-1 EETC Class B
Debt Instrument [Line Items]
Interest expense, term loans	644	754
2017-1 EETC Class C
Debt Instrument [Line Items]
Interest expense, term loans	1,092	1,080
Revolving credit facilities
Debt Instrument [Line Items]
Interest expense, term loans	1,159	1,413
Finance Lease Obligations [Member]
Debt Instrument [Line Items]
Interest expense, term loans	$ 113	$ 29

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
-Topic 230
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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