| Summary of Significant Accounting Policies | Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements include the accounts of Spirit Airlines, Inc. ("Spirit") and its consolidated subsidiaries (the "Company"). Spirit is an ultra low-cost, low-fare airline that provides affordable travel opportunities principally throughout the domestic United States, the Caribbean and Latin America and is headquartered in Miramar, Florida. Spirit manages operations on a system-wide basis due to the interdependence of its route structure in the various markets served. As only one service is offered (i.e., air transportation), management has concluded there is only one reportable segment. Use of Estimates The preparation of financial statements in accordance with generally accepted accounting principles in the United States of America requires the Company's management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. The Company's estimates and assumptions are based on historical experience and changes in the business environment. However, actual results may differ from estimates under different conditions, sometimes materially. Critical accounting policies and estimates are defined as those that both (i) are most important to the portrayal of the Company's financial condition and results and (ii) require management's most subjective judgments. The Company's most critical accounting policies and estimates are described below. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of less than three months at the date of acquisition to be cash equivalents. Investments included in this category primarily consist of cash and money market funds. Cash and cash equivalents are stated at cost, which approximates fair value. Restricted Cash The Company's restricted cash is comprised of cash held in account subject to account control agreements to be used for the payment of interest and fees on the Company's 8.00% senior secured notes and cash pledged as collateral against the Company's secured letters of credit. 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 twelve months or less. These securities are stated at fair value within current assets on the Company's consolidated balance sheet. For all short-term investments, at each reset period or upon reinvestment, the Company accounts for the transaction as proceeds from the maturity of short-term investment securities for the security relinquished, and purchase of short-term investment securities for the security purchased, in the Company's consolidated statements of cash flows. Realized gains and losses on sales of investments, if any, are reflected in non-operating income (expense) in the consolidated statements of operations. Unrealized gains and losses on investment securities are reflected as a component of accumulated other comprehensive income. Accounts Receivable Accounts receivable primarily consist of amounts due from credit card processors associated with the sales of tickets, amounts due from the Internal Revenue Service related to federal excise fuel tax and amounts expected to be received related to the CARES Employee Retention credit . The Company records an allowance for amounts not expected to be collected. The Company estimates the allowance based on historical write-offs and aging trends as well as an estimate of the expected lifetime credit losses. The allowance for doubtful accounts was immaterial as of December 31, 2021 and 2020. In addition, the provision for doubtful accounts and write-offs for 2021, 2020 and 2019 were each immaterial. Income Tax Receivable Income tax receivable consists of amounts due from tax authorities for recovery of income taxes paid in prior periods. Property and Equipment Property and equipment is stated at cost, less accumulated depreciation and amortization. Depreciation of operating property and equipment is computed using the straight-line method applied to each unit of property. Residual values for new aircraft, new engines, major spare rotable parts, avionics and assemblies are generally estimated to be 10%. Property under finance leases and related obligations are initially recorded at an amount equal to the present value of future minimum lease payments computed using the Company's incremental borrowing rate or, when known, the interest rate implicit in the lease. Amortization of property under finance leases is recorded on a straight-line basis over the lease term and is included in depreciation and amortization expense. The depreciable lives used for the principal depreciable asset classifications are: Estimated Useful Life Aircraft, engines and flight simulators 25 Spare rotables and flight assemblies 7 to 25 years Other equipment and vehicles 5 to 7 years Internal use software 3 to 10 years Finance leases Lease term or estimated useful life of the asset Leasehold improvements Lesser of lease term or estimated useful life of the improvement Buildings Lesser of lease term or 30 years As of December 31, 2021, the Company had 106 aircraft, 20 spare engines and 1 flight simulator capitalized within flight equipment with depreciable lives of 25 years. As of December 31, 2021, the Company had 67 aircraft financed through operating leases with lease terms from 8 to 18 years. In addition, the Company had 12 spare engines financed through operating leases with lease terms from 6 months to 18 years. The following table illustrates the components of depreciation and amortization expense: Year Ended December 31, 2021 2020 2019 (in thousands) Depreciation $ 193,079 $ 179,470 $ 155,326 Amortization of heavy maintenance 91,929 88,927 63,364 Amortization of capitalized software 12,203 10,191 6,574 Total depreciation and amortization $ 297,211 $ 278,588 $ 225,264 The Company capitalizes certain internal and external costs associated with the acquisition and development of internal-use software for new products, and enhancements to existing products, that have reached the application development stage and meet recoverability tests. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software, and labor cost for employees who are directly associated with, and devote time, to internal-use software projects. Capitalized computer software, included as a component of ground and other equipment in the accompanying consolidated balance sheets, net of amortization, was $32.6 million and $24.3 million at December 31, 2021 and 2020, respectively. The Company records amortization of capitalized software on a straight-line basis within depreciation and amortization expense in the accompanying consolidated statements of operations. The Company placed in service internal-use software of $20.5 million, $21.5 million and $5.9 million, during the years ended 2021, 2020 and 2019, respectively. Operating Lease Right-of-Use Asset and Liabilities 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, periods covered by options to extend the lease if the Company is reasonably certain to exercise the option, periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the option and periods covered by an option to extend or not terminate the lease in which the exercise of the option is controlled by the lessor. The Company's lease agreements do not contain any residual value guarantees. The Company elected to not separate non-lease components from the associated lease component for all underlying classes of assets with lease and non-lease components. The Company elected not to apply the recognition requirements in Topic 842 to short-term leases (i.e., leases of 12 months or less) but instead recognize these lease payments in income 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 are not included in the recognition of a lease liability or right-of-use asset. Pre-Delivery Deposits on Flight Equipment The Company is required to make pre-delivery deposit payments ("PDPs") towards the purchase price of each new aircraft and engine prior to the scheduled delivery date. These deposits are initially classified as pre-delivery deposits on flight equipment on the Company's consolidated balance sheets until the aircraft or engine is delivered, at which time the related PDPs are deducted from the final purchase price of the aircraft or engine and are reclassified to flight equipment on the Company's consolidated balance sheets. In addition, the Company capitalizes the interest that is attributable to the outstanding PDP balances as a percentage of the related debt on which interest is incurred. Capitalized interest represents interest cost incurred during the acquisition period of a long-term asset, and is the amount which theoretically could have been avoided had the Company not paid PDPs for the related aircraft or engines. Related interest is capitalized and included within pre-delivery deposits on flight equipment through the acquisition period until delivery is taken of the aircraft or engine and the asset is ready for service. Once the aircraft or engine is delivered, the capitalized interest is also reclassified into flight equipment on the Company's consolidated balance sheets along with the related PDPs as they are included in the cost of the aircraft or engine. Capitalized interest for 2021, 2020 and 2019 is primarily related to the interest incurred on long-term debt. Measurement of Asset Impairments The Company records impairment charges on long-lived assets used in operations when events and circumstances indicate that the assets may be impaired, the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets, and the net book value of the assets exceeds their estimated fair value. In making these determinations, the Company uses certain assumptions, including, but not limited to: (i) estimated fair value of the assets; and (ii) estimated, undiscounted future cash flows expected to be generated by these assets, which are based on additional assumptions such as asset utilization, length of service the asset will be used in the Company’s operations, and estimated salvage values. The Company has assessed whether any impairment of its long-lived assets existed and has determined that no charges were deemed necessary under applicable accounting standards as of December 31, 2021. The Company's assumptions about future conditions important to its assessment of potential impairment of its long-lived assets, including the impact of the COVID-19 pandemic to its business, are subject to uncertainty, and the Company will continue to monitor these conditions in future periods as new information becomes available, and will update its analyses accordingly. Passenger Revenues Fare revenues. Tickets sold are initially deferred within air traffic liability ("ATL") on the Company's consolidated balance sheet. Passenger fare revenues are recognized at time of departure when transportation is provided. Generally, all tickets sold by the Company are nonrefundable. An unused ticket expires at the date of scheduled travel and is recognized as revenue at the date of scheduled travel. As of December 31, 2021 and 2020, the Company had ATL balances of $382.3 million and $402.0 million, respectively. As of December 31, 2021, substantially all of the ATL balance as of December 31, 2020 had been recognized. Substantially all of the Company's ATL balance as of December 31, 2021 is expected to be recognized within 12 months. Non-fare revenues. Certain ancillary items such as bags, seats and other travel-related fees, are deemed part of the single performance obligation of providing passenger transportation. These ancillary items are recognized in non-fare revenues within passenger revenues, at the time of departure, in the Company's disaggregated revenue table within Note 4, Revenue Disaggregation. The following table summarizes the primary components of the Company's non-fare revenue and the revenue recognition method utilized for each service or product: Year Ended December 31, Non-fare revenue Recognition method 2021 2020 2019 (in thousands) Baggage Time of departure $ 663,228 $ 404,896 $ 734,243 Passenger usage fee Time of departure 610,762 358,561 669,177 Advance seat selection Time of departure 215,682 125,213 228,876 Other Varies 263,203 120,638 238,454 Non-fare revenue $ 1,752,875 $ 1,009,308 $ 1,870,750 Changes and cancellations. Customers may elect to change or cancel their itinerary prior to the date of departure. For changes, a service charge is recognized at time of departure of newly scheduled travel and is deducted from the face value of the original purchase price of the ticket, and the original ticket becomes invalid. For cancellations, a service charge is assessed and the amount remaining after deducting the service charge is called a credit shell which prior to 2020 had an expiration of 60 days from the date the credit shell was created. During 2020, in response to the COVID-19 pandemic, the Company increased the expiration period on some of its credit shells from 60 days to up to 21 months or more in some cases and waived change and cancellation fees for the Guests who booked travel through the first quarter of 2021. On July 28, 2021, the Company began issuing credit shells with an expiration period of 90 days. Credit shells issued prior to July 28, 2021 expired on December 31, 2021. The Company expects that the level of requests for credit shells and refunds in the upcoming months will decrease with some fluctuation as the effects of COVID-19 continue to evolve. As the COVID-19 pandemic continues to evolve, the Company will evaluate any continued impact to travel plans and may decide to extend credit shell expiration dates and/or waive change and cancellation fees in the future. Credit shells can be used towards the purchase of a new ticket and the Company’s other service offerings. Both service charge and credit shell amounts are recorded as deferred revenue and amounts expected to expire unused are estimated based on historical experience. Estimating the amount of credits that will go unused involves some level of subjectivity and judgment. Assumptions used to generate breakage estimates can be impacted by several factors including, but not limited to, changes to the Company's ticketing policies, changes to the Company’s refund, exchange, and credit shell policies, and economic factors. Given the unusually high amount of cancellations in the current year and the related increase in credit shells provided, the Company experienced variability in the amount of breakage revenue recognized throughout the year and expects some variability in the amount of breakage revenue recorded in future periods, as the estimates of the portion of those funds that will expire unused may differ from historical experience. Refer to Note 4, Revenue Disaggregation for additional information about breakage revenue recognized in 2021. Other Revenues Other revenues primarily consist of the marketing component of the sale of frequent flyer miles to the Company's credit card partner and commissions revenue from the sale of various items such as hotels and rental cars. Frequent Flyer Program The Company operates the Free Spirit loyalty program, which attracts members and partners and builds customer loyalty for the Company by offering a variety of awards, benefits and services. In January 2021, the Company launched a new, more expansive frequent flyer program, “Free Spirit Program”, with extended point expiration, additional benefits based on status tiers, and other changes. Free Spirit loyalty program members earn and accrue points for dollars spent on Spirit for flights and other non-fare services as well as services from non-air partners such as retail merchants, hotels or car rental companies or by making purchases with credit cards issued by partner banks and financial services providers. Points are redeemable by customers in future periods for air travel on Spirit. To reflect the mileage credits earned, the program includes two types of transactions that are considered revenue arrangements with multiple performance obligations: (1) points earned with travel and (2) points sold to its co-branded credit card partner. Passenger ticket sales earning points. Passenger ticket sales earning points provide customers with (1) points earned and (2) air transportation. The Company values each performance obligation on a stand-alone basis and allocates the consideration to each performance obligation based on their relative fair value. To value the point credits earned, the Company considers the quantitative value a passenger receives by redeeming points for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV"). The Company defers revenue for the points when earned and recognizes loyalty travel awards in passenger revenue as the points are redeemed and services are provided. The Company records the air transportation portion of the passenger ticket sales in air traffic liability and recognizes passenger revenue when transportation is provided or if the ticket goes unused, at the date of scheduled travel. Sale of points. Customers may earn points based on their spending with the Company's co-branded credit card company with which the Company has an agreement to sell points. The contract to sell points under this agreement has multiple performance obligations, as discussed below. The Company's co-branded credit card agreement provides for joint marketing where cardholders earn points for making purchases using co-branded cards. During 2020, the Company extended its agreement with the administrator of the FREE SPIRIT affinity credit card program through March 31, 2024. The Company accounts for this agreement consistently with the accounting method that allocates the consideration received to the individual products and services delivered. The value is allocated based on the relative stand-alone selling prices of those products and services, which generally consists of (i) points to be awarded, (ii) airline benefits and (iii) advertising and marketing efforts. The Company determined the estimate of the stand-alone selling prices by considering discounted cash flow analysis using multiple inputs and assumptions, including: (1) the expected number of points awarded and number of points redeemed, (2) the estimated stand-alone selling price of the award travel obligation and airline benefits, and (3) the cost of advertising and marketing efforts undertaken by the Company. Based on the terms of the program, the Company updated its estimates of the allocation of future revenues to the performance obligations described above. The Company defers the amount for award travel obligation as part of loyalty deferred revenue within ATL on the consolidated balance sheet and recognizes loyalty travel awards in passenger revenue as the points are used for travel. Revenue allocated to advertising and the remaining performance obligations, primarily marketing components, is recorded in other revenue over time as points are delivered. Total unrecognized revenue from future FREE SPIRIT loyalty program was $42.7 million and $31.6 million at December 31, 2021 and 2020, respectively. The current portion of this balance is recorded within air traffic liability and the long-term portion of this balance is recorded within deferred gains and other long-term liabilities in the accompanying consolidated balance sheets. The following table illustrates total cash proceeds received from the sale of points and the portion of such proceeds recognized in non-ticket revenue immediately as marketing component: Consideration received from credit card loyalty programs Portion of proceeds recognized immediately as marketing component Year Ended (in thousands) December 31, 2021 $ 48,035 $ 23,681 December 31, 2020 33,201 25,918 December 31, 2019 48,136 37,151 Mileage breakage. For points that the Company estimates are not likely to be redeemed ("breakage"), the Company recognizes the associated value proportionally during the period in which the remaining points are redeemed. Management uses statistical models to estimate breakage based on historical redemption patterns. A change in assumptions as to the period over which points are expected to be redeemed, the actual redemption activity for points or the estimated fair value of points expected to be redeemed could have an impact on revenues in the year in which the change occurs and in future years. Current activity of frequent flyer program. Points are combined in one homogeneous pool and are not separately identifiable. As such, revenue is comprised of points that were part of the frequent flyer deferred revenue balance at the beginning of the period as well as points that were issued during the period. Airframe and Engine Maintenance The Company accounts for heavy maintenance and major overhaul under the deferral method whereby the cost of heavy maintenance and major overhaul is deferred and amortized until the earlier of the end of the useful life of the related asset, the end of the remaining lease term or the next scheduled heavy maintenance event. Amortization of heavy maintenance and major overhaul costs charged to depreciation and amortization expense was $91.9 million, $88.9 million and $63.4 million for the years ended 2021, 2020 and 2019, respectively. During the years ended 2021, 2020 and 2019, the Company deferred $74.1 million, $75.2 million and $176.0 million, respectively, of costs for heavy maintenance, net of reimbursements. As of December 31, 2021 and 2020, the Company had a deferred heavy maintenance balance of $633.9 million and $570.6 million, and accumulated heavy maintenance amortization of $303.9 million and $222.7 million, respectively. The Company outsources certain routine, non-heavy maintenance functions under contracts that require payment on a utilization basis, such as flight hours. Costs incurred for maintenance and repair under flight hour maintenance contracts, where labor and materials price risks have been transferred to the service provider, are expensed based on contractual payment terms. All other costs for routine maintenance of the airframes and engines are charged to expense as performed. The table below summarizes the components of the Company’s maintenance cost: Year Ended December 31, 2021 2020 2019 (in thousands) Flight hour-based maintenance expense $ 81,591 $ 52,092 $ 78,253 Non-flight hour-based maintenance expense 77,911 59,135 65,322 Total maintenance, materials and repairs $ 159,502 $ 111,227 $ 143,575 Leased Aircraft Return Costs The Company's aircraft lease agreements often contain provisions that require the Company to return aircraft airframes, engines and other aircraft components to the lessor in a certain condition or pay an amount to the lessor based on the airframe and engine's actual return condition. Lease return costs include all costs that would be incurred at the return of the aircraft, including costs incurred to repair the airframe and engines to the required condition as stipulated by the lease. Lease return costs are recognized beginning when it is probable that such costs will be incurred and they can be estimated. When determining the probability to accrue lease return costs, there are various estimated cost and factors which need to be considered such as the contractual terms of the lease agreement, current condition of the aircraft, the age of the aircraft at lease expiration, projected number of hours run on the engine at the time of return, and the number of projected cycles run on the airframe at the time of return, among others. Management assesses the need to accrue lease return costs periodically throughout the year or whenever facts and circumstances warrant an assessment. Lease return costs will generally be estimable closer to the end of the lease term but may be estimable earlier in the lease term depending on the contractual terms of the lease agreement and the timing of maintenance events for a particular aircraft. Aircraft Maintenance Deposits Some of the Company's aircraft and engine master lease agreements provide that the Company pay 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. These lease agreements generally provide that maintenance reserves are reimbursable to the Company upon completion of the maintenance event. 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 December 31, 2021, the Company was in full compliance with such requirements and does not anticipate having to pay reserves related to these master leases in the foreseeable future. Maintenance reserve payments are reflected as aircraft maintenance deposits in the accompanying consolidated balance sheets. The Company makes certain assumptions to determine the recoverability of maintenance deposits. These assumptions are based on various factors such as the estimated time between the maintenance events, the date the aircraft is due to be returned to the lessor, the cost of future maintenance events and the utilization of the aircraft before it is returned to the lessor. When it is not probable the Company will recover amounts currently on deposit with a lessor, such amounts are expensed as supplemental rent. Aircraft Fuel Aircraft fuel expense includes jet fuel and associated into-plane costs, taxes, and oil, and realized and unrealized gains and losses associated with fuel derivative contracts, if any. Advertising The Company expenses advertising and the production costs of advertising as incurred. Marketing and advertising expenses of $7.1 million, $5.5 million and $6.3 million for the years ended 2021, 2020 and 2019, respectively, were recorded within distribution expense in the consolidated statements of operations. Income Taxes The Company accounts for income taxes using the asset and liability method. The Company records a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will be not realized. As of December 31, 2021 and 2020, the Company recorded a valuation allowance of $5.1 million and $2.9 million, respectively. For additional information, refer to Note 17, Income Taxes. Stock-Based Compensation The Company recognizes cost of employee services received in exchange for awards of equity instruments based on the fair value of each instrument at the date of grant. For the majority of awards, compensation expense is recognized on a straight-line basis over the period during which an employee is required to provide service in exchange for an award. Certain awards have performance conditions that must be achieved prior to vesting and are expensed based on the expected achievement at each reporting period. The Company has issued and outstanding restricted stock awards, performance share awards and market share awards. Restricted stock awards are valued at the fair value of the shares on the date of grant. The fair value of performance share awards based on a market condition and the market share awards are estimated through the use of a Monte Carlo simulation model. The fair value of performance share awards based on a performance condition is based on the fair value of the shares on the date of grant. The performance share awards based on a performance condition are evaluated at each report date and adjustments are made to stock-based compensation expense based on the number of shares deemed probable of issuance upon vesting. For additional information, refer to Note 12, Stock-Based Compensation. Concentrations of Risk The Company’s business may be adversely affected by increases in the price of aircraft fuel, the volatility of the price of aircraft fuel, or both. Aircraft fuel, one of the Company’s largest expenditures, represented approximately 28%, 19% and 30% of total operating expenses in 2021, 2020 and 2019, respectively. The Company’s operations are largely concentrated in the southeast United States with Fort Lauderdale being the highest volume fueling point in the system. Gulf Coast Jet indexed fuel is the basis for a substantial majority of the Company’s fuel consumption. Any disruption to the oil production or refinery capacity in the Gulf Coast, as a result of weather or any other disaster, or disruptions in supply of jet fuel, dramatic escalations in the costs of jet fuel and/or the failure of fuel providers to perform under fuel arrangements for other reasons could have a material adverse effect on the Company’s financial condition and results of operations. The Company’s operations will continue to be vulnerable to weather conditions (including hurricane season or snow and severe winter weather), which could disrupt service or create air traffic control problems. These events may result in decreased revenue and/or increased costs. The Company relies on a single vendor for the delivery of additional aircraft. Due to the relatively small size of the Company's fleet and high utilization rate, the unavailability of aircraft and or reduced capacity, resulting from delivery delays or performance issues from this vendor, could have a material adverse effect on the Company’s business, results of operations and financial condition. As of December 31, 2021, the Company had five union-represented employee groups that together represented approximately 81% of all employees. A strike or other significant labor dispute with the Company’s unionized employees is likely to adversely affect the Company’s ability to conduct business. Additional disclosures are included in Note 18, Commitments and Contingencies. |
