Spirit Airlines (SAVEQ) 10-Q 24 Apr 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 17, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Entity Registrant Name	SPIRIT AIRLINES, INC.
Entity Central Index Key	0001498710
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		68,438,785

Condensed Statements of Operati

Condensed Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating revenues:
Revenues	$ 855,796	$ 704,138
Operating expenses:
Aircraft fuel	229,636	204,646
Salaries, wages and benefits	203,901	155,096
Landing fees and other rents	59,649	49,630
Aircraft rent	45,782	50,191
Depreciation and amortization	50,726	39,373
Distribution	35,719	30,631
Maintenance, materials and repairs	31,604	29,710
Special charges	0	89,168
Loss on disposal of assets	1,913	848
Other operating	109,062	93,642
Total operating expenses	767,992	742,935
Operating income (loss)	87,804	(38,797)
Other (income) expense:
Interest expense	24,971	17,849
Capitalized interest	(2,557)	(2,252)
Interest income	(6,924)	(4,066)
Other expense	233	133
Special charges, non-operating	0	9,201
Total other (income) expense	15,723	20,865
Income (loss) before income taxes	72,081	(59,662)
Provision (benefit) for income taxes	16,005	(14,740)
Net income (loss)	$ 56,076	$ (44,922)
Basic earnings (loss) per share	$ 0.82	$ (0.66)
Diluted earnings (loss) per share	$ 0.82	$ (0.66)
Passenger [Member]
Operating revenues:
Revenues	$ 838,065	$ 689,141
Other [Member]
Operating revenues:
Revenues	$ 17,731	$ 14,997

Condensed Statements of Compreh

Condensed Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 56,076	$ (44,922)
Unrealized gain (loss) on short-term investment securities, net of deferred taxes of $39 and ($8)	130	(23)
Interest rate derivative loss reclassified into earnings, net of taxes of $27 and $21	47	58
Other comprehensive income	177	35
Comprehensive income (loss)	$ 56,253	$ (44,887)

Condensed Statements of Compr_2

Condensed Statements of Comprehensive Income (Parenthetical) (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Tax effect of the unrealized gain (loss) on short-term investment securities	$ 39	$ (8)
Loss reclassified from AOCI into earnings, tax	$ 27	$ 21

Condensed Balance Sheets (unaud

Condensed Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 1,122,139	$ 1,004,733
Short-term investment securities	103,491	102,789
Accounts receivable, net	70,946	47,660
Aircraft maintenance deposits, net	129,838	106,901
Prepaid expenses and other current assets	90,346	83,383
Total current assets	1,516,760	1,345,466
Property and equipment:
Flight equipment	3,322,618	3,257,215
Ground property and equipment	201,579	191,661
Less accumulated depreciation	(369,405)	(332,864)
Total property and equipment	3,154,792	3,116,012
Operating lease right-of-use assets	1,046,262	0
Pre-delivery deposits on flight equipment	264,419	236,775
Long-term aircraft maintenance deposits	118,359	138,738
Deferred heavy maintenance, net	280,118	249,010
Other long-term assets	43,229	79,456
Total assets	6,423,939	5,165,457
Current liabilities:
Accounts payable	26,713	39,320
Air traffic liability	403,001	291,981
Current maturities of long-term debt and finance leases	173,413	163,557
Current maturities of operating leases	128,138	0
Other current liabilities	395,404	339,677
Total current liabilities	1,126,669	834,535
Long-term debt and finance leases, less current maturities	2,039,619	2,024,774
Operating leases, less current maturities	895,056	0
Deferred income taxes	366,854	355,141
Deferred gains and other long-term liabilities	18,085	22,503
Shareholders’ equity:
Common stock	7	7
Additional paid-in-capital	374,896	371,225
Treasury stock, at cost	(72,239)	(67,016)
Retained earnings	1,676,008	1,625,481
Accumulated other comprehensive income (loss)	(1,016)	(1,193)
Total shareholders’ equity	1,977,656	1,928,504
Total liabilities and shareholders’ equity	$ 6,423,939	$ 5,165,457

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities:
Net income (loss)	$ 56,076	$ (44,922)
Adjustments to reconcile net income to net cash provided by operations:
Losses reclassified from other comprehensive income	74	79
Share-based compensation	3,671	3,075
Amortization of deferred gains and losses and debt issuance costs	2,289	1,624
Depreciation and amortization	50,726	39,373
Deferred income tax expense (benefit)	11,647	(20,266)
Loss on disposal of assets	1,913	848
Special charges, non-operating	0	9,201
Changes in operating assets and liabilities:
Accounts receivable	(23,285)	(2,983)
Aircraft maintenance deposits, net	(2,559)	14,844
Long-term deposits and other assets	20,735	3,512
Deferred heavy maintenance, net	(44,161)	(50,712)
Accounts payable	(13,543)	6,227
Air traffic liability	111,020	93,483
Other liabilities	30,712	117,779
Other	(164)	(27)
Net cash provided by operating activities	205,151	171,135
Investing activities:
Purchase of available-for-sale investment securities	(26,476)	(30,853)
Proceeds from the maturity of available-for-sale investment securities	26,085	30,504
Pre-delivery deposits on flight equipment, net of refunds	(37,913)	(41,580)
Capitalized interest	(2,276)	(1,500)
Assets under construction for others	(262)	0
Purchase of property and equipment	(63,109)	(237,221)
Net cash used in investing activities	(103,951)	(280,650)
Financing activities:
Proceeds from issuance of long-term debt	59,706	227,128
Proceeds from stock options exercised	0	2
Payments on debt obligations	(37,901)	(18,650)
Payments on finance lease obligations	(239)	(197)
Reimbursement for assets under construction for others	262	0
Repurchase of common stock	(5,223)	(959)
Debt issuance costs	(399)	(201)
Net cash provided by financing activities	16,206	207,123
Net increase in cash and cash equivalents	117,406	97,608
Cash and cash equivalents at beginning of period	1,004,733	800,849
Cash and cash equivalents at end of period	1,122,139	898,457
Cash payments for:
Interest, net of capitalized interest	19,167	8,569
Income taxes paid, net of refunds	816	679
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	47,577	0
Operating cash flows for finance leases	210	0
Financing cash flows for finance leases	29	0
Non-cash transactions:
Capital expenditures funded by finance lease borrowings	1,492	237,042
Capital expenditures funded by operating lease borrowings	$ 128,191	$ 0

Condensed Statements of Shareho

Condensed Statements of Shareholders' Equity Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Restatement Adjustment [Member]Retained Earnings [Member]
Beginning balance at Dec. 31, 2017	$ 1,762,574	$ 7	$ 360,153	$ (65,854)	$ 1,469,732	$ (1,464)
Share-based compensation	3,075		3,075
Repurchase of common stock	(959)			(959)
Proceeds from options exercised	2		2
Changes in comprehensive income	35					35
Net income (loss)	(44,922)
Ending balance at Mar. 31, 2018	1,719,805	7	363,230	(66,813)	1,424,810	(1,429)
Beginning balance at Dec. 31, 2018	1,928,504	7	371,225	(67,016)	1,625,481	(1,193)
Share-based compensation	3,671		3,671
Repurchase of common stock	(5,223)			(5,223)
Proceeds from options exercised	0		0
Changes in comprehensive income	177					177
Net income (loss)	56,076
Ending balance at Mar. 31, 2019	$ 1,977,656	$ 7	$ 374,896	$ (72,239)	$ 1,676,008	$ (1,016)
Ending balance (Accounting Standards Update 2016-02) at Mar. 31, 2019							$ (5,549)

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements include the accounts of Spirit Airlines, Inc. ("the Company"). These unaudited condensed financial statements reflect all normal recurring adjustments which management believes are necessary to fairly present the financial position, results of operations and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements of the Company and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 filed with the Securities and Exchange Commission on February 13, 2019. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect both the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from these estimates.

Recent Accounting Developments

Recent Accounting Developments	3 Months Ended
	Mar. 31, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Developments	Recent Accounting Developments Recently Adopted Accounting Pronouncements Leases The Company adopted ASU No. 2016-02, "Leases (Topic 842)," effective January 1, 2019. The Company adopted Topic 842 utilizing the modified retrospective adoption method with an effective date of January 1, 2019 and elected the package of transition practical expedients for expired or existing contracts, which does not require reassessment of: (1) whether any of the Company's contracts are or contain leases, (2) lease classification and (3) initial direct costs. Therefore, the condensed financial statements for 2019 are presented under the new standard, while the comparative periods presented are not adjusted and continue to be reported in accordance with the Company's historical accounting policy. This standard requires all lessees to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, for all leases with a term greater than 12 months. The adoption of the new lease standard had a significant impact on the Company's condensed balance sheets due to the recognition of $1.0 billion of right-of-use assets for operating leases, $128.1 million of current maturities of operating leases and $895.1 million of operating leases, less current maturities. In addition, the Company recognized a $5.5 million cumulative effect adjustment, net of tax, to retained earnings. This adjustment was driven by the recognition of unamortized deferred gains and losses related to aircraft sale-leaseback transactions entered into in prior periods. Prior to the adoption of Topic 842, gains and losses on sale-leaseback transactions were generally deferred and recognized in income over the lease term. The accounting for finance leases is substantially unchanged. The adoption of Topic 842 did not have a significant impact on the Company's lease classification or a material impact on its statements of operations and liquidity. Additionally, adoption of Topic 842 did not have a material impact on the Company’s debt-covenant compliance under its current agreements. Refer to Note 9, Leases for information regarding the Company's adoption of Topic 842 and the Company's undiscounted future lease payments and the timing of those payments. Recently Issued Accounting Pronouncements Not Yet Adopted Cloud Computing Arrangements In August 2018, the FASB issued ASU No. 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software". This new standard requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in Accounting Standards Codification ("ASC") 350-40, "Accounting for Internal-Use Software", to determine which implementation costs to capitalize as assets and amortize over the term of the hosting arrangement or expense as incurred. This new standard is effective for public business entities in fiscal years beginning after December 15, 2019. Early adoption is permitted, including during an interim period. Entities have the option to apply this standard prospectively to all implementation costs incurred after the date of adoption or retrospectively. The Company is evaluating this new standard, but does not expect it to have a significant impact on its financial statement presentation or results. Accounting for Credit Losses

Revenue Disaggregation

Revenue Disaggregation	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue Disaggregation	Revenue Operating revenues is comprised of passenger revenues, which includes fare and non-fare revenues, and other revenues. The following table shows disaggregated operating revenues for the first quarter of 2019 and 2018. Three Months Ended March 31, 2019 2018 (in thousands) Operating revenues: Fare $ 416,345 $ 342,695 Non-fare 421,720 346,446 Total passenger revenues 838,065 689,141 Other 17,731 14,997 Total operating revenues $ 855,796 $ 704,138 The Company is managed as a single business unit that provides air transportation for passengers. Operating revenues by geographic region as defined by the Department of Transportation (DOT) area are summarized below: Three Months Ended March 31, 2019 2018 (in thousands) DOT—Domestic $ 753,100 $ 647,807 DOT—Latin America 102,696 56,331 Total $ 855,796 $ 704,138 The Company defers the amount for award travel obligation as part of loyalty deferred revenue within air traffic liability (ATL) on the Company's condensed balance sheets and recognizes loyalty travel awards in passenger revenue as the mileage credits are used for travel. As of March 31, 2019 and December 31, 2018 , the Company had ATL balances of $403.0 million and $292.0 million , respectively. The remaining ATL balance as of March 31, 2019

Special Charges

Special Charges	3 Months Ended
	Mar. 31, 2019
Special Charges and Credits [Abstract]
Special Charges	Special Charges Special Charges, Operating During the three months ended March 31, 2019 , the Company had no special charges, operating in the statement of operations. During the first quarter of 2018, the Company negotiated and amended the collective bargaining agreement with the Air Line Pilots Association, International ("ALPA"), under the guidance of the National Mediation Board ("NMB"). In connection with the amended agreement, the Company recorded a one-time ratification incentive of $80.7 million , including payroll taxes, and an $8.5 million adjustment related to other contractual provisions. These amounts totaling $89.2 million were recorded in special charges within operating expenses in the condensed statement of operations for the three months ended March 31, 2018 . Special Charges, Non-Operating During the three months ended March 31, 2019 , the Company had no special charges, non-operating within other (income) expense in the statement of operations. During the three months ended March 31, 2018 , the Company recorded $9.2 million in special charges, non-operating within other (income) expense in the statement of operations. On March 28, 2018, the Company entered into an aircraft purchase agreement for the purchase of 14 A319 aircraft previously operated under operating leases by the Company. The aggregate gross purchase price for the 14 aircraft was $285.0 million , and the price for each aircraft at the time of the sale was comprised of a cash payment net of the amount of maintenance reserves and security deposits for such aircraft held by the applicable lessor pursuant to the lease for such aircraft. The contract was deemed a lease modification which resulted in a change of classification from operating leases to finance leases for the 14 aircraft. During the first quarter of 2018, the finance lease assets were recorded at the lower of cost or fair value of the aircraft within flight equipment on the condensed balance sheets. During the second quarter of 2018, the purchase of the 14

Earnings (Loss) per Share

Earnings (Loss) per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings per Share	Earnings (Loss) per Share The following table sets forth the computation of basic and diluted earnings (loss) per common share: Three Months Ended March 31, 2019 2018 (in thousands, except per share amounts) Numerator Net income (loss) $ 56,076 $ (44,922 ) Denominator Weighted-average shares outstanding, basic 68,380 68,222 Effect of dilutive stock awards 136 — Adjusted weighted-average shares outstanding, diluted 68,516 68,222 Earnings (loss) per share Basic earnings (loss) per common share $ 0.82 $ (0.66 ) Diluted earnings (loss) per common share $ 0.82 $ (0.66 ) Anti-dilutive weighted-average shares 159 324

Short-term Investment Securitie

Short-term Investment Securities	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Short-term Investment Securities The Company's short-term investment securities are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of 12 months or less. These securities are stated at fair value within current assets on the Company's condensed balance sheets. Realized gains and losses on sales of investments, if any, are reflected in non-operating income (expense) in the condensed statements of operations. As of March 31, 2019 and December 31, 2018 , the Company had $103.5 million and $102.8 million in short-term available-for-sale investment securities, respectively. During the three months ended March 31, 2019 , these investments earned interest income at a weighted-average fixed rate of approximately 2.5% . For the three months ended March 31, 2019 , an unrealized gain of $130 thousand , net of deferred taxes of $39 thousand , was recorded within accumulated other comprehensive income ("AOCI") related to these investment securities. For the three months ended March 31, 2018 , an unrealized loss of $23 thousand , net of deferred taxes of $8 thousand , was recorded within AOCI related to these investment securities. The Company has not recognized any realized gains or losses related to these securities as the Company has not transacted any sale of these securities. As of March 31, 2019 and December 31, 2018 , $56 thousand and $74 thousand

Accrued Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2019
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Other current liabilities as of March 31, 2019 and December 31, 2018 consist of the following: March 31, 2019 December 31, 2018 (in thousands) Federal excise and other passenger taxes and fees payable $ 90,504 $ 60,604 Salaries and wages 79,359 82,900 Airport obligations 65,291 52,029 Aircraft maintenance 65,126 59,805 Fuel 28,378 25,368 Aircraft and facility lease obligations 20,630 15,149 Interest payable 19,344 18,086 Other 26,772 25,736 Other current liabilities $ 395,404 $ 339,677

Financial Instruments and Risk

Financial Instruments and Risk Management	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments and Risk Management	Financial Instruments and Risk Management As part of the Company’s risk management program, the Company from time to time uses a variety of financial instruments to reduce its exposure to fluctuations in the price of jet fuel and interest rates. The Company does not hold or issue derivative financial instruments for trading purposes. The Company may be exposed to credit losses in the event of nonperformance by counterparties to these financial instruments. The Company periodically reviews and seeks to mitigate exposure to the financial deterioration and nonperformance of any counterparty by monitoring the absolute exposure levels, each counterparty's credit ratings and the historical performance of the counterparties relating to hedge transactions. The credit exposure related to these financial instruments is limited to the fair value of contracts in a net receivable position at the reporting date. The Company also maintains security agreements that require the Company to post collateral if the value of selected instruments falls below specified mark-to-market thresholds. The Company records financial derivative instruments at fair value, which includes an evaluation of each counterparty's credit risk. As of March 31, 2019 , the Company did not hold any derivatives with requirements to post collateral. Fuel Derivative Instruments From time to time, the Company may enter into fuel derivative contracts in order to mitigate the risk of future volatility in fuel prices. The Company's fuel derivative contracts, if any, generally consist of United States Gulf Coast jet fuel swaps ("jet fuel swaps") and United States Gulf Coast jet fuel options ("jet fuel options"). Both jet fuel swaps and jet fuel options are used at times to protect the refining price risk between the price of crude oil and the price of refined jet fuel, and to manage the risk of increasing fuel prices. Fair value of the instruments is determined using standard option valuation models. The Company accounts for any fuel derivative contracts at fair value and recognizes them in the balance sheet in prepaid expenses and other current assets or other current liabilities. The Company did not enter into any fuel derivative instruments during the three months ended March 31, 2019 and 2018 and did not have any outstanding fuel derivatives as of March 31, 2019 and December 31, 2018 . Historically, the Company has not elected hedge accounting on any fuel derivative instruments entered into and, as a result, changes in the fair value of fuel derivative contracts, if any, were recorded in aircraft fuel expense. Interest Rate Swaps From time to time, the Company may enter into interest rate swaps to fix the benchmark interest rate component of interest payments or for other reasons. These instruments limit the Company's exposure to changes in the benchmark interest rate in the period from the trade date through the date of maturity. Interest rate swaps may be designated as cash flow hedges. The Company generally accounts for interest rate swaps at fair value and recognizes them in the balance sheet in prepaid expenses and other current assets or other current liabilities with changes in fair value recorded within AOCI. As of March 31, 2019 and December 31, 2018 , the Company did not have any outstanding interest rate swaps. Realized gains and losses from cash flow hedges are recorded in the statement of cash flows as a component of cash flows from operating activities. Subsequent to the issuance of each debt instrument, amounts remaining in AOCI are amortized over the life of the fixed-rate debt instrument. During the three months ended March 31, 2019 and 2018 , there were no unrealized gains or losses recorded within AOCI related to these instruments as they settled in 2015. For the three months ended March 31, 2019 , the Company reclassified interest rate swap losses of $47 thousand , net of tax of $27 thousand , into earnings. For the three months ended March 31, 2018 , the Company reclassified interest rate swap losses of $58 thousand , net of tax of $21 thousand , into earnings. As of March 31, 2019 and December 31, 2018 , $1.1 million and $1.1 million

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	Leases The Company leases aircraft, engines, airport terminal, maintenance and training facilities, aircraft hangars, commercial real estate, and office and computer equipment, among other items. Certain of these leases include provisions for variable lease payments which are based on several factors, including, but not limited to, relative leased square footage, enplaned passengers, and airports’ annual operating budgets. Due to the variable nature of the rates, these leases are not recorded on the Company's balance sheet as a right-of-use asset and lease liability. Lease terms are generally 8 years to 18 years for aircraft and up to 30 years for other leased equipment and property. The Company adopted Topic 842 utilizing the modified retrospective adoption method with an effective date of January 1, 2019. The Company made the election to not apply the recognition requirements in Topic 842 to short-term leases (i.e., leases of twelve months or less). Instead, a lessee may recognize the lease payments in profit or loss on a straight-line basis over the lease term. The Company elected this accounting policy for all classes of underlying assets. In addition, in accordance with Topic 842, variable lease payments in the period in which the obligation for those payments is incurred are not included in the recognition of a lease liability or right-of-use asset. Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Right-of-use assets and liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. When available, the Company uses the rate implicit in the lease to discount lease payments to present value. However, the Company's leases generally do not provide a readily determinable implicit rate. Therefore, the Company estimates the incremental borrowing rate to discount lease payments based on information available at lease commencement. The Company uses publicly available data for instruments with similar characteristics when calculating its incremental borrowing rates. The Company has options to extend certain of its operating leases for an additional period of time and options to early terminate several of its operating leases. The lease term consists of the noncancellable period of the lease and the periods covered by options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. The Company's lease agreements do not contain any residual value guarantees. The Company has elected to not separate non-lease components from the associated lease component for all underlying classes of assets with lease and non-lease components. As of March 31, 2019 , the Company had 50 aircraft financed under operating leases, with lease term expirations between 2021 and 2031 . In addition, as of March 31, 2019 , the Company had 11 spare engines financed under operating leases with lease term expiration dates ranging from 2019 to 2027 . One of the Company's leased aircraft has variable rent payments, which fluctuate based on changes in London Interbank Offered Rate ("LIBOR"). The Company entered into sale leaseback transactions with third-party aircraft lessors for some of these aircraft and engine leases. Upon adoption of Topic 842, the Company recognized a $5.5 million cumulative effect adjustment, net of tax, to retained earnings driven by the recognition of unamortized deferred gains and losses related to aircraft sale-leaseback transactions entered into in prior periods. Prior to the adoption of Topic 842, gains and losses on sale-leaseback transactions were generally deferred and recognized in income over the lease term. Under Topic 842, gains and losses on sale-leaseback transactions, subject to adjustment for off-market terms, are recognized immediately. Some of the Company’s aircraft and engine master lease agreements provide that the Company pays maintenance reserves to aircraft lessors to be held as collateral in advance of the Company’s required performance of major maintenance activities. A majority of these maintenance reserve payments are calculated based on a utilization measure, such as flight hours or cycles, while some maintenance reserve payments are fixed, time-based contractual amounts. Maintenance reserve payments that are probable of being recovered when the Company performs qualifying maintenance are recorded in aircraft maintenance deposits on the Company's condensed balance sheet. Fixed maintenance reserve payments that are not probable of being recovered are considered lease payments and are included in the right-of-use asset and lease liability. Maintenance reserve payments that are based on a utilization measure and are not probable of being recovered are considered variable lease payment that are recognized when they are probable of being incurred and are not included in the right-of-use asset and lease liability. Fixed maintenance reserve payments for the Company's aircraft and related flight equipment, including estimated amounts for contractual price escalations, are expected to be $4.3 million for the remainder of 2019 , $5.6 million in 2020 , $5.7 million in 2021 , $4.9 million in 2022 , $4.1 million in 2023 , and $8.8 million in 2024 and beyond . Some of the master lease agreements do not require that the Company pay maintenance reserves so long as the Company's cash balance does not fall below a certain level. As of March 31, 2019 , the Company is in full compliance with those requirements and does not anticipate having to pay reserves related to these master leases in the future. Under the terms of the lease agreements, the Company will continue to operate and maintain the aircraft. Payments under the majority of the lease agreements are fixed for the term of the lease. The lease agreements contain standard termination events, including termination upon a breach of the Company's obligations to make rental payments and upon any other material breach of the Company's obligations under the leases, and standard maintenance and return condition provisions. These return provisions are evaluated at inception of the lease and throughout the lease terms and are accounted for as either fixed or variable lease payments (depending on the nature of the lease return condition) when it is probable that such amounts will be incurred. When determining probability and estimated cost of lease return obligations, there are various other factors that need to be considered such as the contractual terms of the lease, the ability to swap engines or other aircraft components, current condition of the aircraft, the age of the aircraft at lease expiration, utilization of engines and other components, the extent of repairs needed at return, return locations, current configuration of the aircraft and cost of repairs and materials at the time of return. As a result of the different factors listed above, management assesses the need to accrue lease return costs throughout the lease as facts and circumstances warrant an assessment. The Company expects lease return costs and unrecoverable maintenance deposits will increase as individual aircraft lease agreements approach their respective termination dates and the Company begins to accrue the estimated cost of return conditions for the corresponding aircraft. Upon a termination of the lease due to a breach by the Company, the Company would be liable for standard contractual damages, possibly including damages suffered by the lessor in connection with remarketing the aircraft or while the aircraft is not leased to another party. Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the Company's aircraft and spare engine lease agreements recognized on a straight-line basis. Aircraft rent expense also includes maintenance reserves paid to aircraft lessors in advance of the performance of major maintenance activities that are not probable of being reimbursed and probable lease return condition obligations. The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's condensed balance sheets as of March 31, 2019 . The table does not include commitments that are contingent on events or other factors that are currently uncertain or unknown. Finance Leases Operating Leases Aircraft and Spare Engine Leases Property Facility Leases Other Total Operating and Finance Lease Obligations (in thousands) remainder of 2019 $ 894 $ 142,701 $ 2,088 $ 434 $ 146,117 2020 780 185,414 2,394 517 189,105 2021 606 183,572 1,903 — 186,081 2022 578 175,571 1,562 — 177,711 2023 202 151,177 1,055 — 152,434 2024 and thereafter — 477,187 4,749 — 481,936 Total minimum lease payments $ 3,060 $ 1,315,622 $ 13,751 $ 951 $ 1,333,384 Less amount representing interest 310 303,429 3,658 43 307,440 Present value of minimum lease payments $ 2,750 $ 1,012,193 $ 10,093 $ 908 $ 1,025,944 Less current portion 1,053 125,429 2,165 544 129,191 Long-term portion $ 1,697 $ 886,764 $ 7,928 $ 364 $ 896,753 Commitments related to the Company's noncancellable short-term operating leases not recorded on the Company's condensed balance sheets are expected to be $0.2 million for the remainder of 2019 and $0.0 million in 2020 and beyond . The majority of the Company's finance lease obligations relate to leased computer and office equipment. Payments under the Company's finance lease agreements are fixed for terms ranging from 3 to 5 years . Accounting for finance leases is substantially unchanged under Topic 842. Finance lease assets are recorded within property and equipment and the related liabilities are recorded within current maturities of long-term debt and finance leases and long-term debt and finance leases, less current maturities in the Company's condensed balance sheets. The table below presents information for lease costs related to the Company's finance and operating leases: Three Months Ended March 31, 2019 (in thousands) Finance lease cost Amortization of leased assets $ 210 Interest of lease liabilities 29 Operating lease cost Operating lease cost (1) 49,715 Short-term lease cost (1) 3,449 Variable lease cost (1) 28,117 Total lease cost $ 81,520 (1) Expenses are classified within aircraft rent and landing fees and other rents on the Company's condensed statement of operations. The table below presents lease-related terms and discount rates as of March 31, 2019 : March 31, 2019 Weighted-average remaining lease term Operating leases 8.0 years Finance leases 3.5 years Weighted-average discount rate Operating leases 6.72 % Finance leases 6.12 %
Leases	Leases The Company leases aircraft, engines, airport terminal, maintenance and training facilities, aircraft hangars, commercial real estate, and office and computer equipment, among other items. Certain of these leases include provisions for variable lease payments which are based on several factors, including, but not limited to, relative leased square footage, enplaned passengers, and airports’ annual operating budgets. Due to the variable nature of the rates, these leases are not recorded on the Company's balance sheet as a right-of-use asset and lease liability. Lease terms are generally 8 years to 18 years for aircraft and up to 30 years for other leased equipment and property. The Company adopted Topic 842 utilizing the modified retrospective adoption method with an effective date of January 1, 2019. The Company made the election to not apply the recognition requirements in Topic 842 to short-term leases (i.e., leases of twelve months or less). Instead, a lessee may recognize the lease payments in profit or loss on a straight-line basis over the lease term. The Company elected this accounting policy for all classes of underlying assets. In addition, in accordance with Topic 842, variable lease payments in the period in which the obligation for those payments is incurred are not included in the recognition of a lease liability or right-of-use asset. Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Right-of-use assets and liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. When available, the Company uses the rate implicit in the lease to discount lease payments to present value. However, the Company's leases generally do not provide a readily determinable implicit rate. Therefore, the Company estimates the incremental borrowing rate to discount lease payments based on information available at lease commencement. The Company uses publicly available data for instruments with similar characteristics when calculating its incremental borrowing rates. The Company has options to extend certain of its operating leases for an additional period of time and options to early terminate several of its operating leases. The lease term consists of the noncancellable period of the lease and the periods covered by options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. The Company's lease agreements do not contain any residual value guarantees. The Company has elected to not separate non-lease components from the associated lease component for all underlying classes of assets with lease and non-lease components. As of March 31, 2019 , the Company had 50 aircraft financed under operating leases, with lease term expirations between 2021 and 2031 . In addition, as of March 31, 2019 , the Company had 11 spare engines financed under operating leases with lease term expiration dates ranging from 2019 to 2027 . One of the Company's leased aircraft has variable rent payments, which fluctuate based on changes in London Interbank Offered Rate ("LIBOR"). The Company entered into sale leaseback transactions with third-party aircraft lessors for some of these aircraft and engine leases. Upon adoption of Topic 842, the Company recognized a $5.5 million cumulative effect adjustment, net of tax, to retained earnings driven by the recognition of unamortized deferred gains and losses related to aircraft sale-leaseback transactions entered into in prior periods. Prior to the adoption of Topic 842, gains and losses on sale-leaseback transactions were generally deferred and recognized in income over the lease term. Under Topic 842, gains and losses on sale-leaseback transactions, subject to adjustment for off-market terms, are recognized immediately. Some of the Company’s aircraft and engine master lease agreements provide that the Company pays maintenance reserves to aircraft lessors to be held as collateral in advance of the Company’s required performance of major maintenance activities. A majority of these maintenance reserve payments are calculated based on a utilization measure, such as flight hours or cycles, while some maintenance reserve payments are fixed, time-based contractual amounts. Maintenance reserve payments that are probable of being recovered when the Company performs qualifying maintenance are recorded in aircraft maintenance deposits on the Company's condensed balance sheet. Fixed maintenance reserve payments that are not probable of being recovered are considered lease payments and are included in the right-of-use asset and lease liability. Maintenance reserve payments that are based on a utilization measure and are not probable of being recovered are considered variable lease payment that are recognized when they are probable of being incurred and are not included in the right-of-use asset and lease liability. Fixed maintenance reserve payments for the Company's aircraft and related flight equipment, including estimated amounts for contractual price escalations, are expected to be $4.3 million for the remainder of 2019 , $5.6 million in 2020 , $5.7 million in 2021 , $4.9 million in 2022 , $4.1 million in 2023 , and $8.8 million in 2024 and beyond . Some of the master lease agreements do not require that the Company pay maintenance reserves so long as the Company's cash balance does not fall below a certain level. As of March 31, 2019 , the Company is in full compliance with those requirements and does not anticipate having to pay reserves related to these master leases in the future. Under the terms of the lease agreements, the Company will continue to operate and maintain the aircraft. Payments under the majority of the lease agreements are fixed for the term of the lease. The lease agreements contain standard termination events, including termination upon a breach of the Company's obligations to make rental payments and upon any other material breach of the Company's obligations under the leases, and standard maintenance and return condition provisions. These return provisions are evaluated at inception of the lease and throughout the lease terms and are accounted for as either fixed or variable lease payments (depending on the nature of the lease return condition) when it is probable that such amounts will be incurred. When determining probability and estimated cost of lease return obligations, there are various other factors that need to be considered such as the contractual terms of the lease, the ability to swap engines or other aircraft components, current condition of the aircraft, the age of the aircraft at lease expiration, utilization of engines and other components, the extent of repairs needed at return, return locations, current configuration of the aircraft and cost of repairs and materials at the time of return. As a result of the different factors listed above, management assesses the need to accrue lease return costs throughout the lease as facts and circumstances warrant an assessment. The Company expects lease return costs and unrecoverable maintenance deposits will increase as individual aircraft lease agreements approach their respective termination dates and the Company begins to accrue the estimated cost of return conditions for the corresponding aircraft. Upon a termination of the lease due to a breach by the Company, the Company would be liable for standard contractual damages, possibly including damages suffered by the lessor in connection with remarketing the aircraft or while the aircraft is not leased to another party. Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the Company's aircraft and spare engine lease agreements recognized on a straight-line basis. Aircraft rent expense also includes maintenance reserves paid to aircraft lessors in advance of the performance of major maintenance activities that are not probable of being reimbursed and probable lease return condition obligations. The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's condensed balance sheets as of March 31, 2019 . The table does not include commitments that are contingent on events or other factors that are currently uncertain or unknown. Finance Leases Operating Leases Aircraft and Spare Engine Leases Property Facility Leases Other Total Operating and Finance Lease Obligations (in thousands) remainder of 2019 $ 894 $ 142,701 $ 2,088 $ 434 $ 146,117 2020 780 185,414 2,394 517 189,105 2021 606 183,572 1,903 — 186,081 2022 578 175,571 1,562 — 177,711 2023 202 151,177 1,055 — 152,434 2024 and thereafter — 477,187 4,749 — 481,936 Total minimum lease payments $ 3,060 $ 1,315,622 $ 13,751 $ 951 $ 1,333,384 Less amount representing interest 310 303,429 3,658 43 307,440 Present value of minimum lease payments $ 2,750 $ 1,012,193 $ 10,093 $ 908 $ 1,025,944 Less current portion 1,053 125,429 2,165 544 129,191 Long-term portion $ 1,697 $ 886,764 $ 7,928 $ 364 $ 896,753 Commitments related to the Company's noncancellable short-term operating leases not recorded on the Company's condensed balance sheets are expected to be $0.2 million for the remainder of 2019 and $0.0 million in 2020 and beyond . The majority of the Company's finance lease obligations relate to leased computer and office equipment. Payments under the Company's finance lease agreements are fixed for terms ranging from 3 to 5 years . Accounting for finance leases is substantially unchanged under Topic 842. Finance lease assets are recorded within property and equipment and the related liabilities are recorded within current maturities of long-term debt and finance leases and long-term debt and finance leases, less current maturities in the Company's condensed balance sheets. The table below presents information for lease costs related to the Company's finance and operating leases: Three Months Ended March 31, 2019 (in thousands) Finance lease cost Amortization of leased assets $ 210 Interest of lease liabilities 29 Operating lease cost Operating lease cost (1) 49,715 Short-term lease cost (1) 3,449 Variable lease cost (1) 28,117 Total lease cost $ 81,520 (1) Expenses are classified within aircraft rent and landing fees and other rents on the Company's condensed statement of operations. The table below presents lease-related terms and discount rates as of March 31, 2019 : March 31, 2019 Weighted-average remaining lease term Operating leases 8.0 years Finance leases 3.5 years Weighted-average discount rate Operating leases 6.72 % Finance leases 6.12 %

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Aircraft-Related Commitments and Financing Arrangements The Company’s contractual purchase commitments consist primarily of aircraft and engine acquisitions through manufacturers. As of March 31, 2019 , the Company's aircraft orders consisted of the following: Airbus Third-Party Lessor A320ceo A320neo A320neo Total remainder of 2019 1 8 1 10 2020 17 17 2021 18 18 1 43 1 45 As of March 31, 2019 , the Company has no contractual aircraft purchase commitments beyond 2021. The Company also has two spare engine orders for V2500 SelectTwo engines with International Aero Engines ("IAE") and seven spare engine orders for PurePower PW1100G-JM engines with Pratt & Whitney. Spare engines are scheduled for delivery from 2019 through 2023 . Purchase commitments for these aircraft and engines, including estimated amounts for contractual price escalations and pre-delivery payments, are expected to be $466.6 million for the remainder of 2019 , $865.7 million in 2020 , $775.7 million in 2021 , $17.6 million in 2022 , $8.3 million in 2023 , and $0.0 million in 2024 and beyond . As of March 31, 2019 , the Company had secured debt financing commitments of $35.0 million for 1 aircraft, being delivered in May 2019. In addition, the Company has secured financing for one aircraft leased directly from a third-party lessor, which was delivered in April 2019. Aircraft rent commitments for this 1 leased aircraft are approximately $3.0 million for the remainder of 2019 , $4.1 million in 2020 , $4.1 million in 2021 , $4.1 million in 2022 , $4.1 million in 2023 , and $29.4 million in 2024 and beyond . As of March 31, 2019 , the Company does not have financing commitments in place for the remaining 43 Airbus aircraft on firm order, which are scheduled for delivery in the remainder of 2019 through 2021 . Interest commitments related to the secured debt financing of 61 delivered aircraft as of March 31, 2019 are $64.9 million for the remainder of 2019 , $77.4 million in 2020 , $70.3 million in 2021 , $63.4 million in 2022 , $53.2 million in 2023 , and $154.2 million in 2024 and beyond . For principal commitments related to these financed aircraft, refer to Note 12, Debt and Other Obligations. As of March 31, 2019 , principal and interest commitments related to the Company's future secured debt financing of 1 undelivered aircraft under bank debt are $2.2 million for the remainder of 2019 , $4.7 million in 2020 , $4.7 million in 2021 , $3.5 million in 2022 , $3.6 million in 2023 , and $26.2 million in 2024 and beyond . The Company is contractually obligated to pay the following minimum guaranteed payments for its reservation system and other miscellaneous subscriptions and services as of March 31, 2019 : $9.3 million for the remainder of 2019 , $14.4 million in 2020 , $11.3 million in 2021 , $11.2 million in 2022 , $11.3 million in 2023 , and $56.0 million thereafter . During the first quarter of 2018, the Company entered into a contract renewal with its reservation system provider which expires in 2028. Litigation The Company is subject to commercial litigation claims and to administrative and regulatory proceedings and reviews that may be asserted or maintained from time to time. The Company believes the ultimate outcome of such lawsuits, proceedings and reviews will not, individually or in the aggregate, have a material adverse effect on its financial position, liquidity or results of operations. Credit Card Processing Arrangements The Company has agreements with organizations that process credit card transactions arising from the purchase of air travel, baggage charges, and other ancillary services by customers. As is standard in the airline industry, the Company's contractual arrangements with credit card processors permit them, under certain circumstances, to retain a holdback or other collateral, which the Company records as restricted cash, when future air travel and other future services are purchased via credit card transactions. The required holdback is the percentage of the Company's overall credit card sales that its credit card processors hold to cover refunds to customers if the Company fails to fulfill its flight obligations. The Company's credit card processors do not require the Company to maintain cash collateral provided that the Company satisfies certain liquidity and other financial covenants. Failure to meet these covenants would provide the processors the right to place a holdback resulting in a commensurate reduction of unrestricted cash. As of March 31, 2019 and December 31, 2018 , the Company was in compliance with such liquidity and other financial covenants in its credit card processing agreements and the processors were holding back no remittances. The maximum potential exposure to cash holdbacks by the Company's credit card processors, based upon advance ticket sales and $9 Fare Club memberships as of March 31, 2019 and December 31, 2018 , was $455.5 million and $321.0 million , respectively. Employees The Company has 5 union-represented employee groups that together represented approximately 79% of all employees at March 31, 2019 . The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of March 31, 2019 . Employee Groups Representative Amendable Date Percentage of Workforce Pilots Air Line Pilots Association, International ("ALPA") February 2023 26% Flight Attendants Association of Flight Attendants ("AFA-CWA") May 2021 45% Dispatchers Professional Airline Flight Control Association ("PAFCA") October 2023 1% Ramp Service Agents International Association of Machinists and Aerospace Workers ("IAMAW") June 2020 4% Passenger Service Agents Transport Workers Union of America ("TWU") NA 3% In August 2015 , the Company's collective bargaining agreement with its pilots, represented by ALPA, became amendable. In February 2018, the pilot group voted to approve a new five -year agreement with the Company. In connection with the new agreement, the Company recorded a one-time ratification incentive of $80.7 million , including payroll taxes, and an $8.5 million adjustment related to other contractual provisions. These amounts totaling $89.2 million were recorded in special charges within operating expenses in the condensed statement of operations for the three months ended March 31, 2018 . For additional information, refer to Note 4, Special Charges. In June 2018, the NMB notified the Company that the TWU filed an application seeking a representation election for the Company's passenger service agents. The NMB determined that a representation election would be held and the voting period for the election took place through September 4, 2018. The Company’s passenger service agents voted to be represented by the TWU, but the representation applies only to the Company’s Fort Lauderdale station where the Company has direct employees in the passenger service classification. The Company and the TWU began meeting in late October 2018 to negotiate an initial collective bargaining agreement. As of March 31, 2019 , the Company continued to negotiate with the TWU. The Company is self-insured for health care claims, up to a stop loss amount for eligible participating employees and qualified dependent medical claims, subject to deductibles and limitations. The Company’s liabilities for claims incurred but not reported are determined based on an estimate of the ultimate aggregate liability for claims incurred. The estimate is calculated from actual claim rates and adjusted periodically as necessary. The Company has accrued $5.1 million and $4.4 million in health care claims as of March 31, 2019 and December 31, 2018

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Under ASC 820, "Fair Value Measurements and Disclosures", disclosures relating to how fair value is determined for assets and liabilities are required, and a hierarchy for which these assets and liabilities must be grouped is established, based on significant levels of inputs, as follows: Level 1 —Quoted prices in active markets for identical assets or liabilities. Level 2 —Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes several valuation techniques in order to assess the fair value of the Company’s financial assets and liabilities. Fuel Derivative Instruments From time to time, the Company may enter into fuel derivative contracts in order to mitigate the risk of future volatility in fuel prices. The Company’s fuel derivative contracts generally consist of jet fuel swaps and jet fuel options. These instruments are valued using energy and commodity market data, which is derived by combining raw inputs with quantitative models and processes to generate forward curves and volatilities. The Company utilizes the market approach to measure fair value for its fuel derivative instruments, if any. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. The Company has not historically elected hedge accounting on its fuel derivative instruments, if any. As a result, the Company would record the fair value adjustment of any fuel derivatives in the accompanying statement of operations within aircraft fuel and on the balance sheet within prepaid expenses and other current assets or other current liabilities, depending on whether the net fair value of the derivatives is in an asset or liability position as of the respective date. Fair values of any fuel derivative instruments are determined using standard option valuation models. The Company also considers counterparty risk and its own credit risk in its determination of all estimated fair values. The Company offsets fair value amounts recognized for any derivative instruments executed with the same counterparty under a master netting arrangement. The Company determines fair value of any jet fuel options utilizing an option pricing model based on inputs that are either readily available in public markets or can be derived from information available in publicly quoted markets. The Company has consistently applied these valuation techniques in all periods presented and believes it has obtained the most accurate information available for the types of derivative contracts it may hold. The fair value of the Company's jet fuel swaps, if any, are determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets; therefore, the Company categorizes these instruments as Level 2. Due to the fact that certain inputs utilized to determine the fair value of jet fuel options are unobservable (principally implied volatility), the Company categorizes these derivatives as Level 3. Implied volatility of a jet fuel option is the volatility of the price of the underlying commodity that is implied by the market price of the option based on an option pricing model. Thus, it is the volatility that when used in a particular pricing model yields a theoretical value for the option equal to the current market price of that option. Implied volatility, a forward-looking measure, differs from historical volatility because the latter is calculated from known past returns. At each balance sheet date, the Company substantiates and adjusts unobservable inputs. The Company routinely assesses the valuation model's sensitivity to changes in implied volatility. As of March 31, 2019 and December 31, 2018 , the Company had no outstanding jet fuel derivatives. Long-Term Debt The estimated fair value of the Company's term loan debt agreements has been determined to be Level 3 as certain inputs used to determine the fair value of these agreements are unobservable. The Company utilizes a discounted cash flow method to estimate the fair value of the Level 3 long-term debt. The estimated fair value of the Company's publicly and non-publicly held EETC debt agreements has been determined to be Level 2 as the Company utilizes quoted market prices in markets with low trading volumes to estimate the fair value of its Level 2 long-term debt. The carrying amounts and estimated fair values of the Company's long-term debt at March 31, 2019 and December 31, 2018 were as follows: March 31, 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 $ 373.2 $ 384.0 $ 382.4 $ 373.6 Level 3 Fixed-rate junior term loans 29.0 29.5 31.1 31.1 Level 3 Fixed-rate term loans 649.5 665.6 625.1 600.1 Level 3 2015-1 EETC Class A 378.6 386.2 378.6 374.8 Level 2 2015-1 EETC Class B 80.0 80.8 80.0 78.1 Level 2 2015-1 EETC Class C 109.5 110.3 109.5 107.9 Level 2 2017-1 EETC Class AA 235.4 231.3 242.5 228.8 Level 2 2017-1 EETC Class A 78.5 76.3 80.8 76.6 Level 2 2017-1 EETC Class B 77.2 75.8 83.7 79.1 Level 2 2017-1 EETC Class C 85.5 86.3 85.5 84.2 Level 2 Revolving credit facility 160.0 160.0 135.3 135.3 Level 3 Total long-term debt $ 2,256.4 $ 2,286.1 $ 2,234.5 $ 2,169.6 Cash and Cash Equivalents Cash and cash equivalents at March 31, 2019 and December 31, 2018 are comprised of liquid money market funds and cash, and are categorized as Level 1 instruments. The Company maintains cash with various high-quality financial institutions. Short-term Investment Securities Short-term investment securities at March 31, 2019 and December 31, 2018 are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of 12 months or less. The Company's short-term investment securities are categorized as Level 1 instruments, as the Company uses quoted market prices in active markets when determining the fair value of these securities. For additional information, refer to Note 6, Short-term Investment Securities. Assets and liabilities measured at gross fair value on a recurring basis are summarized below: Fair Value Measurements as of March 31, 2019 Total Level Level Level (in millions) Cash and cash equivalents $ 1,122.1 $ 1,122.1 $ — $ — Short-term investment securities 103.5 103.5 — — Total assets $ 1,225.6 $ 1,225.6 $ — $ — Total liabilities $ — $ — $ — $ — Fair Value Measurements as of December 31, 2018 Total Level Level Level (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 $ — $ — $ — $ — The Company had no transfers of assets or liabilities between any of the above levels during the periods ended March 31, 2019 and December 31, 2018 .

Debt and Other Obligations

Debt and Other Obligations	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt and Other Obligations	Debt and Other Obligations As of March 31, 2019 , the Company had outstanding non-public and public debt instruments. During the three months ended March 31, 2019 , the Company issued additional debt through a fixed-rate term facility and a previously existing revolving credit facility described below. Fixed-rate term loans During 2018, the Company entered into a facility agreement, which as of March 31, 2019 , provided $35.0 million for an Airbus A320 aircraft delivered during the first quarter of 2019. The loan extended under the facility agreement is secured by a first-priority security interest on the individual aircraft. This loan has a term life of 12 years and amortizes on a mortgage-style basis, which requires quarterly principal and interest payments. Revolving credit facility During the fourth quarter of 2018, the Company entered into a revolving credit facility for up to $160 million secured by the collateral assignment of certain of the Company's rights under the purchase agreement with Airbus, related to 43 Airbus A320neo aircraft scheduled to be delivered between August 2019 and December 2021. The final maturity of the facility is December 30, 2020. As of March 31, 2019 , the Company had drawn $160.0 million on the facility which is included in long-term debt and finance leases, less current maturities on the Company's condensed balance sheets. The revolving credit facility bears variable interest based on LIBOR. Long-term debt is comprised of the following: As of Three Months Ended March 31, March 31, 2019 December 31, 2018 2019 2018 (in millions) (weighted-average interest rates) Fixed-rate senior term loans due through 2027 $ 373.2 $ 382.4 4.10 % 4.10 % Fixed-rate junior term loans due through 2022 29.0 31.1 6.90 % 6.90 % Fixed-rate loans due through 2031 649.5 625.1 3.67 % 3.83 % Fixed-rate class A 2015-1 EETC due through 2028 378.6 378.6 4.10 % 4.10 % Fixed-rate class B 2015-1 EETC due through 2024 80.0 80.0 4.45 % 4.45 % Fixed-rate class C 2015-1 EETC due through 2023 109.5 109.5 4.93 % N/A Fixed-rate class AA 2017-1 EETC due through 2030 235.4 242.5 3.38 % 3.38 % Fixed-rate class A 2017-1 EETC due through 2030 78.5 80.8 3.65 % 3.65 % Fixed-rate class B 2017-1 EETC due through 2026 77.2 83.7 3.80 % 3.80 % Fixed-rate class C 2017-1 EETC due through 2023 85.5 85.5 5.11 % N/A Revolving credit facility due in 2020 160.0 135.3 3.88 % N/A Long-term debt 2,256.4 2,234.5 Less current maturities 172.3 162.8 Less unamortized discounts, net 46.0 47.7 Total $ 2,038.1 $ 2,024.0 The Company's debt financings are collateralized by first priority security interest in the individual aircraft being financed with the exception of the Company's revolving credit facility secured by the Company's rights under the purchase agreement with Airbus related to certain A320neo aircraft. During the three months ended March 31, 2019 and March 31, 2018 , the Company made scheduled principal payments of $37.9 million and $18.7 million on its outstanding debt obligations, respectively. At March 31, 2019 , long-term debt principal payments for the next five years and thereafter are as follows: March 31, 2019 (in millions) remainder of 2019 $ 135.8 2020 212.8 2021 283.3 2022 161.9 2023 300.5 2024 and beyond 1,162.1 Total debt principal payments $ 2,256.4 Interest Expense Interest expense related to long-term debt and finance leases consists of the following: Three Months Ended March 31, 2019 2018 (in thousands) Fixed-rate senior term loans $ 3,945 $ 4,317 Fixed-rate junior term loans 523 667 Fixed-rate term loans 6,202 4,911 Class A 2015-1 EETC 3,838 4,142 Class B 2015-1 EETC 880 1,012 Class C 2015-1 EETC 1,335 — Class AA 2017-1 EETC 1,989 682 Class A 2017-1 EETC 717 246 Class B 2017-1 EETC 754 283 Class C 2017-1 EETC 1,080 — Revolving credit facility 1,413 — Amortization of deferred financing costs 2,192 1,491 Commitment and other fees 74 77 Finance leases 29 21 Total $ 24,971 $ 17,849

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of accounting	The accompanying unaudited condensed financial statements include the accounts of Spirit Airlines, Inc. ("the Company"). These unaudited condensed financial statements reflect all normal recurring adjustments which management believes are necessary to fairly present the financial position, results of operations and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements of the Company and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018
Use of estimates	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect both the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from these estimates.
Recent Accounting Developments	Recently Adopted Accounting Pronouncements Leases The Company adopted ASU No. 2016-02, "Leases (Topic 842)," effective January 1, 2019. The Company adopted Topic 842 utilizing the modified retrospective adoption method with an effective date of January 1, 2019 and elected the package of transition practical expedients for expired or existing contracts, which does not require reassessment of: (1) whether any of the Company's contracts are or contain leases, (2) lease classification and (3) initial direct costs. Therefore, the condensed financial statements for 2019 are presented under the new standard, while the comparative periods presented are not adjusted and continue to be reported in accordance with the Company's historical accounting policy. This standard requires all lessees to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, for all leases with a term greater than 12 months. The adoption of the new lease standard had a significant impact on the Company's condensed balance sheets due to the recognition of $1.0 billion of right-of-use assets for operating leases, $128.1 million of current maturities of operating leases and $895.1 million of operating leases, less current maturities. In addition, the Company recognized a $5.5 million cumulative effect adjustment, net of tax, to retained earnings. This adjustment was driven by the recognition of unamortized deferred gains and losses related to aircraft sale-leaseback transactions entered into in prior periods. Prior to the adoption of Topic 842, gains and losses on sale-leaseback transactions were generally deferred and recognized in income over the lease term. The accounting for finance leases is substantially unchanged. The adoption of Topic 842 did not have a significant impact on the Company's lease classification or a material impact on its statements of operations and liquidity. Additionally, adoption of Topic 842 did not have a material impact on the Company’s debt-covenant compliance under its current agreements. Refer to Note 9, Leases for information regarding the Company's adoption of Topic 842 and the Company's undiscounted future lease payments and the timing of those payments. Recently Issued Accounting Pronouncements Not Yet Adopted Cloud Computing Arrangements In August 2018, the FASB issued ASU No. 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software". This new standard requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in Accounting Standards Codification ("ASC") 350-40, "Accounting for Internal-Use Software", to determine which implementation costs to capitalize as assets and amortize over the term of the hosting arrangement or expense as incurred. This new standard is effective for public business entities in fiscal years beginning after December 15, 2019. Early adoption is permitted, including during an interim period. Entities have the option to apply this standard prospectively to all implementation costs incurred after the date of adoption or retrospectively. The Company is evaluating this new standard, but does not expect it to have a significant impact on its financial statement presentation or results. Accounting for Credit Losses
Sale Leaseback Transactions	m
Leases	Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the Company's aircraft and spare engine lease agreements recognized on a straight-line basis. Aircraft rent expense also includes maintenance reserves paid to aircraft lessors in advance of the performance of major maintenance activities that are not probable of being reimbursed and probable lease return condition obligations.

Revenue Disaggregation (Tables)

Revenue Disaggregation (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Schedule of Revenue Disaggregation	Operating revenues by geographic region as defined by the Department of Transportation (DOT) area are summarized below: Three Months Ended March 31, 2019 2018 (in thousands) DOT—Domestic $ 753,100 $ 647,807 DOT—Latin America 102,696 56,331 Total $ 855,796 $ 704,138 The Company defers the amount for award travel obligation as part of loyalty deferred revenue within air traffic liability (ATL) on the Company's condensed balance sheets and recognizes loyalty travel awards in passenger revenue as the mileage credits are used for travel. As of March 31, 2019 and December 31, 2018 , the Company had ATL balances of $403.0 million and $292.0 million , respectively. The remaining ATL balance as of March 31, 2019 Three Months Ended March 31, 2019 2018 (in thousands) Operating revenues: Fare $ 416,345 $ 342,695 Non-fare 421,720 346,446 Total passenger revenues 838,065 689,141 Other 17,731 14,997 Total operating revenues $ 855,796 $ 704,138

Earnings (Loss) per Share (Tabl

Earnings (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per common share	The following table sets forth the computation of basic and diluted earnings (loss) per common share: Three Months Ended March 31, 2019 2018 (in thousands, except per share amounts) Numerator Net income (loss) $ 56,076 $ (44,922 ) Denominator Weighted-average shares outstanding, basic 68,380 68,222 Effect of dilutive stock awards 136 — Adjusted weighted-average shares outstanding, diluted 68,516 68,222 Earnings (loss) per share Basic earnings (loss) per common share $ 0.82 $ (0.66 ) Diluted earnings (loss) per common share $ 0.82 $ (0.66 ) Anti-dilutive weighted-average shares 159 324

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2019
Payables and Accruals [Abstract]
Accrued liabilities included in other current liabilities	Other current liabilities as of March 31, 2019 and December 31, 2018 consist of the following: March 31, 2019 December 31, 2018 (in thousands) Federal excise and other passenger taxes and fees payable $ 90,504 $ 60,604 Salaries and wages 79,359 82,900 Airport obligations 65,291 52,029 Aircraft maintenance 65,126 59,805 Fuel 28,378 25,368 Aircraft and facility lease obligations 20,630 15,149 Interest payable 19,344 18,086 Other 26,772 25,736 Other current liabilities $ 395,404 $ 339,677

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Schedule of Operating Lease Maturities	The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's condensed balance sheets as of March 31, 2019 . The table does not include commitments that are contingent on events or other factors that are currently uncertain or unknown. Finance Leases Operating Leases Aircraft and Spare Engine Leases Property Facility Leases Other Total Operating and Finance Lease Obligations (in thousands) remainder of 2019 $ 894 $ 142,701 $ 2,088 $ 434 $ 146,117 2020 780 185,414 2,394 517 189,105 2021 606 183,572 1,903 — 186,081 2022 578 175,571 1,562 — 177,711 2023 202 151,177 1,055 — 152,434 2024 and thereafter — 477,187 4,749 — 481,936 Total minimum lease payments $ 3,060 $ 1,315,622 $ 13,751 $ 951 $ 1,333,384 Less amount representing interest 310 303,429 3,658 43 307,440 Present value of minimum lease payments $ 2,750 $ 1,012,193 $ 10,093 $ 908 $ 1,025,944 Less current portion 1,053 125,429 2,165 544 129,191 Long-term portion $ 1,697 $ 886,764 $ 7,928 $ 364 $ 896,753
Schedule of Finance Lease Maturities	The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's condensed balance sheets as of March 31, 2019 . The table does not include commitments that are contingent on events or other factors that are currently uncertain or unknown. Finance Leases Operating Leases Aircraft and Spare Engine Leases Property Facility Leases Other Total Operating and Finance Lease Obligations (in thousands) remainder of 2019 $ 894 $ 142,701 $ 2,088 $ 434 $ 146,117 2020 780 185,414 2,394 517 189,105 2021 606 183,572 1,903 — 186,081 2022 578 175,571 1,562 — 177,711 2023 202 151,177 1,055 — 152,434 2024 and thereafter — 477,187 4,749 — 481,936 Total minimum lease payments $ 3,060 $ 1,315,622 $ 13,751 $ 951 $ 1,333,384 Less amount representing interest 310 303,429 3,658 43 307,440 Present value of minimum lease payments $ 2,750 $ 1,012,193 $ 10,093 $ 908 $ 1,025,944 Less current portion 1,053 125,429 2,165 544 129,191 Long-term portion $ 1,697 $ 886,764 $ 7,928 $ 364 $ 896,753
Schedule of Lease Cost	The table below presents information for lease costs related to the Company's finance and operating leases: Three Months Ended March 31, 2019 (in thousands) Finance lease cost Amortization of leased assets $ 210 Interest of lease liabilities 29 Operating lease cost Operating lease cost (1) 49,715 Short-term lease cost (1) 3,449 Variable lease cost (1) 28,117 Total lease cost $ 81,520
Schedule of Lease Weighted-Average Terms And Discount Rates	The table below presents lease-related terms and discount rates as of March 31, 2019 : March 31, 2019 Weighted-average remaining lease term Operating leases 8.0 years Finance leases 3.5 years Weighted-average discount rate Operating leases 6.72 % Finance leases 6.12 %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Operating Aircraft Leases	As of March 31, 2019 , the Company's aircraft orders consisted of the following: Airbus Third-Party Lessor A320ceo A320neo A320neo Total remainder of 2019 1 8 1 10 2020 17 17 2021 18 18 1 43 1 45
Employee groups and status of the collective bargaining agreements	The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of March 31, 2019 . Employee Groups Representative Amendable Date Percentage of Workforce Pilots Air Line Pilots Association, International ("ALPA") February 2023 26% Flight Attendants Association of Flight Attendants ("AFA-CWA") May 2021 45% Dispatchers Professional Airline Flight Control Association ("PAFCA") October 2023 1% Ramp Service Agents International Association of Machinists and Aerospace Workers ("IAMAW") June 2020 4% Passenger Service Agents Transport Workers Union of America ("TWU") NA 3%

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2019 and December 31, 2018 were as follows: March 31, 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 $ 373.2 $ 384.0 $ 382.4 $ 373.6 Level 3 Fixed-rate junior term loans 29.0 29.5 31.1 31.1 Level 3 Fixed-rate term loans 649.5 665.6 625.1 600.1 Level 3 2015-1 EETC Class A 378.6 386.2 378.6 374.8 Level 2 2015-1 EETC Class B 80.0 80.8 80.0 78.1 Level 2 2015-1 EETC Class C 109.5 110.3 109.5 107.9 Level 2 2017-1 EETC Class AA 235.4 231.3 242.5 228.8 Level 2 2017-1 EETC Class A 78.5 76.3 80.8 76.6 Level 2 2017-1 EETC Class B 77.2 75.8 83.7 79.1 Level 2 2017-1 EETC Class C 85.5 86.3 85.5 84.2 Level 2 Revolving credit facility 160.0 160.0 135.3 135.3 Level 3 Total long-term debt $ 2,256.4 $ 2,286.1 $ 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 March 31, 2019 Total Level Level Level (in millions) Cash and cash equivalents $ 1,122.1 $ 1,122.1 $ — $ — Short-term investment securities 103.5 103.5 — — Total assets $ 1,225.6 $ 1,225.6 $ — $ — Total liabilities $ — $ — $ — $ — Fair Value Measurements as of December 31, 2018 Total Level Level Level (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 $ — $ — $ — $ —

Debt and Other Obligations (Tab

Debt and Other Obligations (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt is comprised of the following: As of Three Months Ended March 31, March 31, 2019 December 31, 2018 2019 2018 (in millions) (weighted-average interest rates) Fixed-rate senior term loans due through 2027 $ 373.2 $ 382.4 4.10 % 4.10 % Fixed-rate junior term loans due through 2022 29.0 31.1 6.90 % 6.90 % Fixed-rate loans due through 2031 649.5 625.1 3.67 % 3.83 % Fixed-rate class A 2015-1 EETC due through 2028 378.6 378.6 4.10 % 4.10 % Fixed-rate class B 2015-1 EETC due through 2024 80.0 80.0 4.45 % 4.45 % Fixed-rate class C 2015-1 EETC due through 2023 109.5 109.5 4.93 % N/A Fixed-rate class AA 2017-1 EETC due through 2030 235.4 242.5 3.38 % 3.38 % Fixed-rate class A 2017-1 EETC due through 2030 78.5 80.8 3.65 % 3.65 % Fixed-rate class B 2017-1 EETC due through 2026 77.2 83.7 3.80 % 3.80 % Fixed-rate class C 2017-1 EETC due through 2023 85.5 85.5 5.11 % N/A Revolving credit facility due in 2020 160.0 135.3 3.88 % N/A Long-term debt 2,256.4 2,234.5 Less current maturities 172.3 162.8 Less unamortized discounts, net 46.0 47.7 Total $ 2,038.1 $ 2,024.0
Schedule of Maturities of Long-term Debt	At March 31, 2019 , long-term debt principal payments for the next five years and thereafter are as follows: March 31, 2019 (in millions) remainder of 2019 $ 135.8 2020 212.8 2021 283.3 2022 161.9 2023 300.5 2024 and beyond 1,162.1 Total debt principal payments $ 2,256.4
Schedule of Interest Expense, Long-term Debt	Interest expense related to long-term debt and finance leases consists of the following: Three Months Ended March 31, 2019 2018 (in thousands) Fixed-rate senior term loans $ 3,945 $ 4,317 Fixed-rate junior term loans 523 667 Fixed-rate term loans 6,202 4,911 Class A 2015-1 EETC 3,838 4,142 Class B 2015-1 EETC 880 1,012 Class C 2015-1 EETC 1,335 — Class AA 2017-1 EETC 1,989 682 Class A 2017-1 EETC 717 246 Class B 2017-1 EETC 754 283 Class C 2017-1 EETC 1,080 — Revolving credit facility 1,413 — Amortization of deferred financing costs 2,192 1,491 Commitment and other fees 74 77 Finance leases 29 21 Total $ 24,971 $ 17,849

Recent Accounting Developments

Recent Accounting Developments Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 1,046,262		$ 0
Current maturities of operating leases	128,138		0
Operating leases, less current maturities	895,056		$ 0
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	1,000,000
Current maturities of operating leases	128,100
Operating leases, less current maturities	$ 895,100
Restatement Adjustment [Member] | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ (5,500)

Revenue Disaggregation (Details

Revenue Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Air traffic liability	$ 403,001		$ 291,981
Total operating revenues	855,796	$ 704,138
DOT—Domestic [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	753,100	647,807
DOT—Latin America [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	102,696	56,331
Passenger [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	838,065	689,141
Fare [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	416,345	342,695
Non Fare [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	421,720	346,446
Other [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 17,731	$ 14,997

Special Charges (Details)

Special Charges (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)aircraft
Property, Plant and Equipment [Line Items]
Special charges, non-operating	$ 0	$ 9,201
Special Charges [Abstract]
Special charges	$ 0	89,168
Airbus A319 [Member]
Special Charges [Abstract]
Purchase price		$ 285,000
Airbus A319 [Member] | Capital Lease Obligations [Member]
Special Charges [Abstract]
Number of aircrafts purchased | aircraft		14
Pilots [Member]
Special Charges [Abstract]
Ratification Incentive		$ 80,700
Adjustments for contractual provisions		8,500
Special charges		$ 89,200

Earnings (Loss) per Share (Deta

Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator
Net income (loss)	$ 56,076	$ (44,922)
Denominator
Weighted-average shares outstanding, basic (in shares)	68,380	68,222
Effect of dilutive stock awards (in shares)	136	0
Adjusted weighted-average shares outstanding, diluted (in shares)	68,516	68,222
Earnings (loss) per share
Basic earnings per common share (in dollars per share)	$ 0.82	$ (0.66)
Diluted earnings per common share (in dollars per share)	$ 0.82	$ (0.66)
Anti-dilutive weighted-average shares (in shares)	159	324

Short-term Investment Securit_2

Short-term Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Short-term investment securities	$ 103,491		$ 102,789
Unrealized gain (loss), net of deferred taxes	130	$ (23)
Tax effect of the unrealized gain (loss) on short-term investment securities	39	$ (8)
Accumulated other comprehensive income (loss)	$ (1,016)		(1,193)
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Weighted-average fixed rate	2.50%
Accumulated other comprehensive income (loss)	$ 56		$ 74

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Federal excise and other passenger taxes and fees payable	$ 90,504	$ 60,604
Salaries and wages	79,359	82,900
Airport obligations	65,291	52,029
Aircraft maintenance	65,126	59,805
Fuel	28,378	25,368
Aircraft and facility lease obligations	20,630	15,149
Interest payable	19,344	18,086
Other	26,772	25,736
Other current liabilities	$ 395,404	$ 339,677

Financial Instruments and Ris_2

Financial Instruments and Risk Management - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Derivative [Line Items]
Interest rate derivative losses reclassified into earnings	$ 47	$ 58
Loss reclassified from AOCI into earnings, tax	27	21
Accumulated other comprehensive loss	1,016		$ 1,193
Interest Rate Swap [Member]
Derivative [Line Items]
Accumulated other comprehensive loss	1,100		$ 1,100
Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Interest rate derivative losses reclassified into earnings	47	58
Loss reclassified from AOCI into earnings, tax	$ 27	$ 21

Leases Narrative (Details)

Leases Narrative (Details) $ in Thousands	Mar. 31, 2019USD ($)aircraft_engineaircraft	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Lease Not Yet Commenced, Amount	$ 200
Lessee, Operating Lease, Lease Not Yet Commenced, Amount, Year Two	0
Stockholders' Equity Attributable to Parent	$ 1,977,656		$ 1,928,504	$ 1,719,805	$ 1,762,574
Minimum
Lessee, Lease, Description [Line Items]
Finance leases, term	3 years
Maximum
Lessee, Lease, Description [Line Items]
Finance leases, term	5 years
Spare Engines
Lessee, Lease, Description [Line Items]
Number of leased assets financed under operating leases | aircraft_engine	11
Aircraft | A320 Family
Lessee, Lease, Description [Line Items]
Number of leased assets financed under operating leases | aircraft	50
Fixed Maintenance Reserve Payments, Aircraft and Related Flight Equipment
Lessee, Lease, Description [Line Items]
Committed expenditures, remainder of 2019	$ 4,300
Committed expenditures, 2020	5,600
Committed expenditures, 2021	5,700
Committed expenditures, 2022	4,900
Committed expenditures, 2023	4,100
Committed expenditures, 2024 and beyond	$ 8,800
Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft financed under operating leases with a variable rate | aircraft	1
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Operating leases, term	8 years
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Operating leases, term	18 years
Other Leased Equipment and Property | Maximum
Lessee, Lease, Description [Line Items]
Operating leases, term	30 years
Retained Earnings [Member]
Lessee, Lease, Description [Line Items]
Stockholders' Equity Attributable to Parent	$ 1,676,008		$ 1,625,481	$ 1,424,810	$ 1,469,732
Accounting Standards Update 2016-02 | Restatement Adjustment [Member]
Lessee, Lease, Description [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ (5,500)
Accounting Standards Update 2016-02 | Restatement Adjustment [Member] | Retained Earnings [Member]
Lessee, Lease, Description [Line Items]
Stockholders' Equity Attributable to Parent	$ (5,549)

Leases Finance and Operating Le

Leases Finance and Operating Lease Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finance Leases
remainder of 2019	$ 894
2020	780
2021	606
2022	578
2023	202
2024 and thereafter	0
Total minimum lease payments	3,060
Less amount representing interest	310
Present value of minimum lease payments	2,750
Less current portion	1,053
Long-term portion	1,697
Operating Leases
Less current portion	128,138	$ 0
Long-term portion	895,056	$ 0
Total Operating and Finance Lease Obligations
remainder of 2019	146,117
2020	189,105
2021	186,081
2022	177,711
2023	152,434
2024 and thereafter	481,936
Total minimum lease payments	1,333,384
Less amount representing interest	307,440
Present value of minimum lease payments	1,025,944
Less current portion	129,191
Long-term portion	896,753
Aircraft and Spare Engine
Operating Leases
remainder of 2019	142,701
2020	185,414
2021	183,572
2022	175,571
2023	151,177
2024 and thereafter	477,187
Total minimum lease payments	1,315,622
Less amount representing interest	303,429
Present value of minimum lease payments	1,012,193
Less current portion	125,429
Long-term portion	886,764
Property Facility
Operating Leases
remainder of 2019	2,088
2020	2,394
2021	1,903
2022	1,562
2023	1,055
2024 and thereafter	4,749
Total minimum lease payments	13,751
Less amount representing interest	3,658
Present value of minimum lease payments	10,093
Less current portion	2,165
Long-term portion	7,928
Other
Operating Leases
remainder of 2019	434
2020	517
2021	0
2022	0
2023	0
2024 and thereafter	0
Total minimum lease payments	951
Less amount representing interest	43
Present value of minimum lease payments	908
Less current portion	544
Long-term portion	$ 364

Leases Lease Costs (Details)

Leases Lease Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Finance Lease, Cost [Abstract]
Amortization of leased assets	$ 210
Interest of lease liabilities	29
Operating lease cost	49,715
Short-term lease cost	3,449
Variable lease cost	28,117
Total lease cost	$ 81,520

Leases Weighted Average Lease T

Leases Weighted Average Lease Terms and Discount Rates (Details)	Mar. 31, 2019
Weighted-average remaining lease term
Operating leases	8 years
Finance leases	3 years 6 months
Weighted-average discount rate
Operating leases	6.72%
Finance leases	6.12%

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Future Aircraft Operating Leases (Details)	Mar. 31, 2019aircraft
Long-term Purchase Commitment [Line Items]
remainder of 2019	10
2020	17
2021	18
Future Aircraft To Be Received	45
Airbus [Member] | A320 [Member]
Long-term Purchase Commitment [Line Items]
remainder of 2019	1
2020
2021
Future Aircraft To Be Received	1
Airbus [Member] | A-320-Neo [Member]
Long-term Purchase Commitment [Line Items]
remainder of 2019	8
2020	17
2021	18
Future Aircraft To Be Received	43
Third Party Lessor [Member] | A-320-Neo [Member]
Long-term Purchase Commitment [Line Items]
remainder of 2019	1
2020
Future Aircraft To Be Received	1
Number of Aircraft with Secured Lease Financing Commitments Scheduled for Delivery	1

Commitments and Contingencies_2

Commitments and Contingencies - Aircraft-Related Commitments and Financing Arrangements (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)aircraft	Mar. 31, 2019USD ($)aircraft_engineaircraft
Secured Debt [Member]
Interest Commitments
Interest commitments, remainder of 2019		$ 64.9
Interest commitments, 2020		77.4
Interest commitments, 2021		70.3
Interest commitments, 2022		63.4
Interest commitments, 2023		53.2
Interest commitments, 2024 and beyond		154.2
Principal and Interest Commitments
Principal and interest commitments related to future secured debt, remainder of 2019		2.2
Principal and interest commitments related to future secured debt, 2020		4.7
Principal and interest commitments related to future secured debt, 2021		4.7
Principal and interest commitments related to future secured debt, 2022		3.5
Principal and interest commitments related to future secured debt, 2023		3.6
Principal and interest commitments related to future secured debt, 2024 and beyond		$ 26.2
2019 [Member] | Airbus [Member]
Aircraft rent commitments
Number of aircraft with secured debt financing commitments scheduled for delivery | aircraft		1
2019-2021 [Member] [Member] | Airbus [Member]
Aircraft rent commitments
Number of aircraft without secured financing commitments scheduled for delivery | aircraft		43
Aircraft and Related Flight Equipment [Member]
Committed Expenditures
Committed expenditures, remainder of 2019		$ 466.6
Committed expenditures, 2020		865.7
Committed expenditures, 2021		775.7
Committed expenditures, 2022		17.6
Committed expenditures, 2023		8.3
Committed expenditures, 2024 and beyond		0
Face amount, commitment for future issuance		35
Fixed Maintenance Reserve Payments, Aircraft and Related Flight Equipment
Committed Expenditures
Committed expenditures, remainder of 2019		4.3
Committed expenditures, 2020		5.6
Committed expenditures, 2021		5.7
Committed expenditures, 2022		4.9
Committed expenditures, 2023		4.1
Committed expenditures, 2024 and beyond		8.8
Non-aircraft Related Commitments [Member]
Committed Expenditures
Committed expenditures, remainder of 2019		9.3
Committed expenditures, 2020		14.4
Committed expenditures, 2021		11.3
Committed expenditures, 2022		11.2
Committed expenditures, 2023		11.3
Committed expenditures, 2024 and beyond		$ 56
V2500 SelectTWO Engine [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of spare aircraft engines ordered | aircraft_engine		2
PurePower PW1100G-JM Engine [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of spare aircraft engines ordered | aircraft_engine		7
A-320-Neo [Member] | Third Party Lessor [Member]
Aircraft rent commitments
Aircraft rent commitments, remainder of 2019		$ 3
Aircraft rent commitments, 2020		4.1
Aircraft rent commitments, 2021		4.1
Aircraft rent commitments, 2022		4.1
Aircraft rent commitments, 2023		4.1
Aircraft rent commitments, 2024 and beyond		$ 29.4
Airbus A319 [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Purchase price	$ 285
Airbus A319 [Member] | Capital Lease Obligations [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of aircrafts purchased | aircraft	14
A320 and A321 [Member]
Aircraft rent commitments
Number of delivered aircraft with secured debt financing commitments | aircraft		61
A320 [Member] | 2019 [Member] | Equipment Notes, 2017-1 [Member]
Aircraft rent commitments
Number of aircraft with secured debt financing commitments scheduled for delivery | aircraft		1

Commitments and Contingencies_3

Commitments and Contingencies - Credit Card Processing Arrangements (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Restricted cash holdbacks	$ 0	$ 0
Maximum Potential Exposure to Cash Holdbacks from Credit Card Processors	$ 455,500,000	$ 321,000,000

Commitments and Contingencies_4

Commitments and Contingencies - Employees (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2018	Mar. 31, 2019USD ($)employee_group	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)
Liability for Claims and Claims Adjustment Expense [Line Items]
Special charges		$ 0	$ 89,168
Air Line Pilots Association, International [Member]
Concentration Risk [Line Items]
Term of collective bargaining agreement	5 years
Health Insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Accrued health care claims		$ 5,100		$ 4,400
Pilots [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Ratification Incentive			80,700
Adjustments for contractual provisions			8,500
Special charges			$ 89,200
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member]
Concentration Risk [Line Items]
Number of union-represented employee groups | employee_group		5
Company's employees covered under collective bargaining agreements (as a percent)		79.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Air Line Pilots Association, International [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		26.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Association of Flight Attendants [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		45.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Professional Airline Flight Control Association [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		1.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | International Association Of Machinists And Aerospace Workers (IAM) [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		4.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Transport Workers Union [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		3.00%

Fair Value Measurements - Long-

Fair Value Measurements - Long-term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Carrying Value	$ 2,256.4	$ 2,234.5
Senior Loans [Member]
Debt Instrument [Line Items]
Carrying Value	373.2	382.4
Junior Loans [Member]
Debt Instrument [Line Items]
Carrying Value	29	31.1
Fixed Rate Loan [Member]
Debt Instrument [Line Items]
Carrying Value	649.5	625.1
Equipment Notes, Series A 2015-1 [Member]
Debt Instrument [Line Items]
Carrying Value	378.6	378.6
Equipment Notes, Series B 2015-1 [Member]
Debt Instrument [Line Items]
Carrying Value	80	80
Equipment Notes, Series C 2015-1 [Member]
Debt Instrument [Line Items]
Carrying Value	109.5	109.5
Equipment Notes, Series AA 2017-1 [Member]
Debt Instrument [Line Items]
Carrying Value	235.4	242.5
Equipment Notes, Series A 2017-1 [Member]
Debt Instrument [Line Items]
Carrying Value	78.5	80.8
Equipment Notes, Series B 2017-1 [Member]
Debt Instrument [Line Items]
Carrying Value	77.2	83.7
Equipment Notes, Series C 2017-1 [Member]
Debt Instrument [Line Items]
Carrying Value	85.5	85.5
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Carrying Value	160	135.3
Estimated Fair Value [Member]
Debt Instrument [Line Items]
Estimated Fair Value	2,286.1	2,169.6
Estimated Fair Value [Member] | Level 3 [Member] | Senior Loans [Member]
Debt Instrument [Line Items]
Estimated Fair Value	384	373.6
Estimated Fair Value [Member] | Level 3 [Member] | Junior Loans [Member]
Debt Instrument [Line Items]
Estimated Fair Value	29.5	31.1
Estimated Fair Value [Member] | Level 3 [Member] | Fixed Rate Loan [Member]
Debt Instrument [Line Items]
Estimated Fair Value	665.6	600.1
Estimated Fair Value [Member] | Level 3 [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Estimated Fair Value	160	135.3
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series A 2015-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	386.2	374.8
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series B 2015-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	80.8	78.1
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series C 2015-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	110.3	107.9
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series AA 2017-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	231.3	228.8
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series A 2017-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	76.3	76.6
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series B 2017-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	75.8	79.1
Estimated Fair Value [Member] | Level 2 [Member] | Equipment Notes, Series C 2017-1 [Member]
Debt Instrument [Line Items]
Estimated Fair Value	$ 86.3	$ 84.2

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 1,122.1	$ 1,004.7
Short-term investment securities	103.5	102.8
Total assets	1,225.6	1,107.5
Total liabilities	0	0
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,122.1	1,004.7
Short-term investment securities	103.5	102.8
Total assets	1,225.6	1,107.5
Total liabilities	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Short-term investment securities	0	0
Total assets	0	0
Total liabilities	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Short-term investment securities	0	0
Total assets	0	0
Total liabilities	$ 0	$ 0

Debt and Other Obligations (Det

Debt and Other Obligations (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)aircraft	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 2,256.4		$ 2,234.5
Less current maturities	172.3		162.8
Less unamortized discounts, net	46		47.7
Total	2,038.1		2,024
Repayments of debt obligations	$ 37.9	$ 18.7
Future Aircraft To Be Received | aircraft	45
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt	$ 160		135.3
Weighted-average interest rate	3.88%
Senior Loans [Member]
Debt Instrument [Line Items]
Long-term debt	$ 373.2		382.4
Weighted-average interest rate	4.10%	4.10%
Junior Loans [Member]
Debt Instrument [Line Items]
Long-term debt	$ 29		31.1
Weighted-average interest rate	6.90%	6.90%
Fixed Rate Loan [Member]
Debt Instrument [Line Items]
Principal amount	$ 35
Long-term debt	$ 649.5		625.1
Weighted-average interest rate	3.67%	3.83%
Equipment Notes, Series A 2015-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 378.6		378.6
Weighted-average interest rate	4.10%	4.10%
Equipment Notes, Series B 2015-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 80		80
Weighted-average interest rate	4.45%	4.45%
Equipment Notes, Series C 2015-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 109.5		109.5
Weighted-average interest rate	4.93%
Equipment Notes, Series AA 2017-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 235.4		242.5
Weighted-average interest rate	3.38%	3.38%
Equipment Notes, Series A 2017-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 78.5		80.8
Weighted-average interest rate	3.65%	3.65%
Equipment Notes, Series B 2017-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 77.2		83.7
Weighted-average interest rate	3.80%	3.80%
Equipment Notes, Series C 2017-1 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 85.5		$ 85.5
Weighted-average interest rate	5.11%
Capital Addition Purchase Commitments [Member]
Debt Instrument [Line Items]
Debt financing commitments	$ 35
Fixed Rate Loan [Member] | Maximum
Debt Instrument [Line Items]
Long-term Debt, Term	12 years
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 160
Airbus [Member] | A-320-Neo [Member]
Debt Instrument [Line Items]
Future Aircraft To Be Received | aircraft	43
Airbus [Member] | A-320-Neo [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Future Aircraft To Be Received | aircraft	43
Airbus [Member] | A320 [Member]
Debt Instrument [Line Items]
Future Aircraft To Be Received | aircraft	1

Debt and Other Obligations - Fu

Debt and Other Obligations - Future Maturities (Details) $ in Millions	Mar. 31, 2019USD ($)
Debt Disclosure [Abstract]
remainder of 2019	$ 135.8
2020	212.8
2021	283.3
2022	161.9
2023	300.5
2024 and beyond	1,162.1
Total debt principal payments	$ 2,256.4

Debt and Other Obligations - In

Debt and Other Obligations - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Debt Instrument [Line Items]
Amortization of deferred financing costs	$ 2,192	$ 1,491
Interest Expense, Other	74	77
Total	24,971	17,849
Senior Loans [Member]
Debt Instrument [Line Items]
Interest expense, term loans	3,945	4,317
Junior Loans [Member]
Debt Instrument [Line Items]
Interest expense, term loans	523	667
Fixed Rate Loan [Member]
Debt Instrument [Line Items]
Interest expense, term loans	6,202	4,911
Equipment Notes, Series A 2015-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	3,838	4,142
Equipment Notes, Series B 2015-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	880	1,012
Equipment Notes, Series C 2015-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	1,335	0
Equipment Notes, Series AA 2017-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	1,989	682
Equipment Notes, Series A 2017-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	717	246
Equipment Notes, Series B 2017-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	754	283
Equipment Notes, Series C 2017-1 [Member]
Debt Instrument [Line Items]
Interest expense, term loans	1,080	0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest expense, term loans	1,413	0
Finance Lease Obligations [Member]
Debt Instrument [Line Items]
Interest expense, term loans	$ 29	$ 21