Basis of Presentation (Policies)

6 Months Ended

Jun. 30, 2018

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, 2017 filed with the Securities and Exchange Commission on February 13, 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

Revenue from Contracts with Customers

In May 2014, the Financial Accounting Standards Board ("the FASB") issued Accounting Standards Update ("ASU") No. 2014-09, ("ASU 2014-09") "Revenue from Contracts with Customers." The objective of ASU 2014-09 is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The Company adopted this guidance on January 1, 2018 utilizing the full retrospective method of adoption allowed by the standard, in order to provide for comparative results in all periods presented. The most significant impact of this ASU is the elimination of the incremental cost method for frequent flier program accounting, which requires the Company to re-value and record a liability associated with customer flight miles earned as part of the Company’s frequent flier program with a relative fair value approach. The classification and timing of recognition of certain ancillary fees is also impacted by the adoption of ASU 2014-09. While the adoption did not have a significant impact on earnings, the classification of certain revenues, such as bags, seats and other travel-related fees are now deemed part of the single performance obligation of providing passenger transportation. Refer to Note 3, Revenue Recognition for information regarding the Company's adoption of ASU 2014-09 and to Note 4, Revenue Disaggregation for the presentation of passenger revenues disaggregated by fare and non-fare.

Financial Instruments

In January 2016, the FASB issued ASU 2016-01, “Financial Instruments – Overall (Subtopic 825-10).” ASU 2016-01 makes several modifications to Subtopic 825-10 including the elimination of the available-for-sale classification of equity investments, and requires equity investments with readily determinable fair values to be measured at fair value with changes in fair value recognized in net income. ASU 2016-01 is effective for the Company for interim and annual periods beginning January 1, 2018. The Company adopted this guidance on January 1, 2018 with no material impact on the financial statements.

Statement of Cash Flows

In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows." The standard is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2018. The Company adopted this guidance on January 1, 2018 with no material impact on the financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

Leases

In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)." This standard will generally require all leases with durations greater than twelve months to be recognized on the condensed balance sheet and is effective for the Company in the first quarter of 2019, with early adoption permitted. The Company is currently evaluating the new guidance and believes adoption of this standard will have a significant impact on its condensed balance sheets although adoption is not expected to significantly change the recognition, measurement or presentation of lease expenses within the statements of operations and cash flows. Refer to Note 10, Commitments and Contingencies for information regarding the Company's undiscounted future lease payments and the timing of those payments.

Accounting for Credit Losses

In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments - Credit Losses." The standard requires the use of an "expected loss" model on certain types of financial instruments. The standard also amends the impairment model for available-for-sale securities and requires estimated credit losses to be recorded as allowances instead of reductions to the amortized cost of the securities. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2020, with early adoption permitted. The Company is evaluating the new guidance, but does not expect it to have a material impact on its financial statements.

Income Taxes

In March 2018, the FASB issued ASU 2018-05, Income Taxes ("Topic 740") - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118. The standard amends Accounting Standards Codification 740, Income Taxes ("ASC 740") to provide guidance on accounting for the tax effects of the Tax Cuts and Jobs Act ("the Tax Act") pursuant to Staff Accounting Bulletin No. 118. The provisional income tax amounts recorded may be affected as the Company gains a more thorough understanding of the tax law, including those related to the deductibility of acquired assets, state tax treatment and amounts related to employee compensation. The provisional accounting impacts for the Company may change in future reporting periods until the accounting is finalized, which will occur no later than the fourth quarter of 2018. The Company does not expect the guidance to have a material impact on its financial statements.