| Summary of Significant Accounting Policies | Summary of Significant Accounting Policies a. Basis of Presentation The consolidated financial statements include our accounts and the accounts of our wholly owned subsidiaries. We also consolidate the partnerships that own Six Flags Over Texas ("SFOT") and Six Flags Over Georgia (including Six Flags White Water Atlanta) ("SFOG", and together with SFOT, the "Partnership Parks") as subsidiaries in our consolidated financial statements as we have determined that we have the power to direct the activities of those entities that most significantly impact the entities' economic performance and we have the obligation to absorb losses and receive benefits from the entities that can be potentially significant to these entities. The equity interests owned by non-affiliated parties in the Partnership Parks are reflected in the accompanying consolidated balance sheets as redeemable noncontrolling interests. The portion of earnings or loss attributable to non-affiliated parties in the Partnership Parks is reflected as net income attributable to noncontrolling interests in the accompanying consolidated statements of operations. See Note 6 for further discussion. Intercompany transactions and balances have been eliminated in consolidation. b. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect 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 could differ from those estimates. We evaluate our estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which we believe to be reasonable under the circumstances. We adjust such estimates and assumptions when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. c. Fair Value Measurement Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 820, Fair Value Measurement , defines fair value as the exchange prices 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 guidance also specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. In accordance with FASB ASC Topic 820, Fair Value Measurement , these two types of inputs have created the following fair value hierarchy: • Level 1: quoted prices in active markets for identical assets; • Level 2: inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the instrument; and • Level 3: inputs to the valuation methodology are unobservable for the asset or liability. The fair value of a financial instrument is the amount at which the instrument could be exchanged in a current transaction between willing parties. We use a market approach for our recurring fair value measurements, and we endeavor to use the best information available. Accordingly, valuation techniques that maximize the use of observable impacts are favored. We present the estimated fair values and classifications of our financial instruments in accordance with FASB Accounting Standards Consideration ("ASC") Topic 820, Fair Value Measurement. The following methods and assumptions were used to estimate the fair value of each class of financial instruments: • The carrying values of cash and cash equivalents, accounts receivable, notes receivable, accounts payable and accrued liabilities approximate fair value because of the short maturity of these instruments. • The measurement of the fair value of long-term debt is based on market prices that generally are observable for similar liabilities at commonly quoted intervals and is considered a Level 2 fair value measurement. Refer to Note 7 for additional information. d. Cash Equivalents Cash equivalents consists of short-term highly liquid investments with a remaining maturity as of the date of purchase of three months or less, which are readily convertible into cash. For purposes of the consolidated statements of cash flows, we consider all highly liquid debt instruments with remaining maturities as of their date of purchase of three months or less to be cash equivalents. Cash equivalents were not significant as of December 31, 2018 and 2017 . e. Inventories Inventories are stated at lower of weighted average cost or net realizable value and primarily consist of products purchased for resale, including merchandise, food and miscellaneous supplies. Products are removed from inventory at weighted average cost. We have recorded a nominal valuation allowance for slow moving inventory as of December 31, 2018 and $0.3 million as of December 31, 2017 . f. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets include $22.9 million and $21.1 million of spare parts inventory for existing rides and attractions as of December 31, 2018 and 2017 , respectively. These items are expensed as the repair or maintenance of rides and attractions occur. g. Advertising Costs Production costs of commercials and programming are charged to operations in the year first aired. The costs of other advertising, promotion, and marketing programs are charged to operations when incurred with the exception of direct-response advertising which is charged to the period it will benefit. As of December 31, 2018 and 2017 , we had $1.6 million and $1.9 million in prepaid advertising, respectively. The amounts capitalized are included in prepaid expenses. Advertising and promotions expense was $68.4 million , $63.7 million and $62.8 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. h. Debt Issuance Costs We capitalize costs related to the issuance of debt. Debt issuance costs directly related to our Revolving Loan are presented within other assets as debt issuance costs in our consolidated balance sheets. Debt issuance costs directly related to our Amended and Restated Term Loam B and our senior unsecured notes are presented within noncurrent liabilities as a reduction of long-term debt in our consolidated balance sheets. The amortization of such costs is recognized as interest expense using the interest method over the term of the respective debt issue. Amortization related to deferred debt issuance costs was $4.0 million , $4.1 million and $4.5 million for the years ended December 31, 2018 , 2017 and 2016 respectively. See Note 7 for further discussion. i. Property and Equipment Property and equipment additions are recorded at cost and the carrying value is depreciated using the straight-line method over the estimated useful lives of the assets. Maintenance and repair costs that do not improve service potential or extend economic life are charged directly to expense as incurred, while betterments and renewals are generally capitalized as property and equipment. When an item is retired or otherwise disposed of, the cost and applicable accumulated depreciation are removed and the resulting gain or loss is recognized. See Note 4 for further detail of the components of our property and equipment. The estimated useful lives of the assets are as follows: Rides and attractions 5 - 25 years Land improvements 10 - 15 years Buildings and improvements Approximately 30 years Furniture and equipment 5 - 10 years j. Goodwill and Indefinite-Lived Intangible Assets Goodwill and intangible assets with indefinite useful lives are tested for impairment annually, or more frequently if events or circumstances indicate that the assets might be impaired. We identify our reporting unit and determine the carrying value of the reporting unit by assigning the assets and liabilities, including the existing goodwill and intangible assets, to the reporting unit. We then determine the fair value of the reporting unit and compare it to the carrying amount of the reporting unit. All of our parks are operated in a similar manner and have comparable characteristics in that they produce and distribute similar services and products using similar processes, have similar types of customers, are subject to similar regulations and exhibit similar economic characteristics. As such, we are a single reporting unit. For each year, the fair value of the single reporting unit exceeded our carrying amount (provided that, we have one reporting unit at the same level for which our Holdings common stock is traded, we believe our market capitalization is the best indicator of our reporting unit's fair value). In September 2012, the FASB amended FASB ASC Topic 350, Intangibles - Goodwill and Other , which permits entities to perform a qualitative analysis on indefinite-lived intangible assets to determine if it is more likely than not that the fair value of the intangible asset was less than its carrying amount as a basis for determining whether it was necessary to perform a quantitative impairment test. We adopted this amendment in September 2012 and have performed a qualitative analysis on our indefinite-lived intangible assets during the fourth quarter of each year. The fair value of indefinite-lived intangible assets is generally determined based on a discounted cash flow analysis. An impairment loss occurs to the extent that the carrying value exceeds the fair value. For goodwill, if the fair value of the reporting unit were to be less than the carrying amount, an impairment loss would be recognized to the extent that the carrying amount of the reporting unit exceeds its fair value. k. Valuation of Long-Lived Assets We review long-lived assets, including finite-lived intangible assets subject to amortization, for impairment upon the occurrence of events or changes in circumstances that would indicate that the carrying value of the asset or group of assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset or group of assets to the future net cash flows expected to be generated by the asset or group of assets. If such assets are not considered to be fully recoverable, any impairment to be recognized is measured by the amount by which the carrying amount of the asset or group of assets exceeds its respective fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. l. Revenue Recognition FASB ASC 606, Revenue from Contracts with Customers (together with the series of Accounting Standards Updates described in the first paragraph under "Recently Adopted Accounting Pronouncements" below, "Topic 606") is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects consideration to which the entity expects to be entitled in exchange for those goods or services. We recognize revenue upon admission into our parks, provision of our services or when products are delivered to our guests. Revenues are presented in the accompanying consolidated statements of operations net of sales taxes collected from our guests and remitted or payable to government taxing authorities. In contrast to our season pass and other multi-use offerings (such as our all season dining pass program, which enables season pass holders and members to eat meals and snacks any day they visit the park for one upfront payment) that expire at the end of each operating season, the membership program continues on a month-to-month basis after the initial twelve -month membership term and can be canceled any time after the initial term pursuant to the terms of the membership program. Guests enrolled in the membership program can visit our parks an unlimited number of times anytime they are open as long as the guest remains enrolled in the membership program. For season passes, memberships in the initial twelve-month term and other multi-use admissions, we estimate a redemption rate based on historical experience and other factors and assumptions we believe to be customary and reasonable and recognize a pro-rata portion of the revenue as the guest attends our parks. We review the estimated redemption rate regularly and on an ongoing basis and revise it as necessary throughout the year. Amounts received for multi-use admissions in excess of redemptions are recognized in deferred revenue. For active memberships after the initial twelve-month term, we recognize revenue monthly as payments are received. As of December 31, 2018 , deferred revenue was primarily comprised of (i) advance sales of season passes, all season dining passes and other admissions for the 2019 operating season, (ii) unredeemed portions of the membership program that will be recognized in 2019, and (iii) sponsorship, international agreements and other fee-based revenue that will be recognized in 2019. We have entered into international agreements to assist third parties in the planning, design, development and operation of Six Flags-branded parks outside of North America. These agreements typically consist of a brand licensing agreement, project services agreement, and management services agreement. Under Topic 606, we treat these agreements as one contract because each was negotiated with a single commercial objective. We have identified three distinct promises within the agreement with each third party partner as brand licensing, project services, and management services. Each of these promises is its own performance obligation and distinct as the third party could benefit from each service on its own with other readily available resources and each service is separately identifiable from other services in the context of the contract. We recognize revenue under our international agreements over the relevant service period of each performance obligation based on its relative stand-alone selling price, as determined by our best estimate of selling price. We review the service period of each performance obligation on an ongoing basis and revise it as necessary throughout the year. Revisions to the relevant service periods of the performance obligations may result in revisions to revenue in future periods and are recognized in the period in which the change is identified. On January 1, 2018, we adopted Topic 606 using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting under FASB ASC 605, Revenue Recognition ("Topic 605"). See Note 3 for additional information. m. Accounts Receivable, Net Accounts receivable are reported at net realizable value and consist primarily of amounts due from guests for the sale of group outings and multi-use admission products, including season passes and the membership program. We are not exposed to a significant concentration of credit risk, however, based on the age of the receivables, our historical experience and other factors and assumptions we believe to be customary and reasonable, we do record an allowance for doubtful accounts. As of December 31, 2018 and 2017 , we have recorded an allowance for doubtful accounts of $7.4 million and $4.2 million , respectively. The allowance for doubtful accounts is primarily comprised of estimated defaults under our membership plans. n. Derivative Instruments and Hedging Activities We account for derivatives and hedging activities in accordance with FASB ASC Topic 815, Derivatives and Hedging . This accounting guidance establishes accounting and reporting standards for derivative instruments, including certain derivative instruments embedded in other contracts, and for hedging activities. It requires an entity to recognize all derivatives as either assets or liabilities in the consolidated balance sheet and measure those instruments at fair value. If certain conditions are met, a derivative may be specifically designated as a hedge for accounting purposes. The accounting for changes in the fair value of a derivative (e.g., gains and losses) depends on the intended use of the derivative and the resulting designation. We formally document all relationships between hedging instruments and hedged items, as well as our risk-management objective and our strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as cash flow hedges to forecasted transactions. We also assess, both at the hedge's inception and on an ongoing basis, whether the derivatives that are used in hedging transactions are highly effective in offsetting changes in cash flows of hedged items. Change in the fair value of a derivative that is effective and that is designated and qualifies as a cash-flow hedge are recorded in other comprehensive income (loss) until operations are affected by the variability in cash flows of the designated hedged item, at which point they are reclassified to interest expense. Change in fair value of a derivative that is not designated as a hedge are recorded in other income (expense), net in the consolidated statements of operations on a current basis. As of December 31, 2017, the interest rate swap agreements expired and all related amounts previously held as derivative assets and liabilities on the consolidated balance sheets and previously recorded in accumulated other comprehensive income were realized in earnings. o. Commitments and Contingencies We are involved in various lawsuits and claims that arise in the normal course of business. Amounts associated with lawsuits or claims are reserved for matters in which it is believed that losses are probable and can be reasonably estimated. In addition to matters in which it is believed that losses are probable, disclosure is also provided for matters in which the likelihood of an unfavorable outcome is at least reasonably possible but for which a reasonable estimate of loss or range of loss is not possible. Legal fees are expensed as incurred. See Note 14 for further discussion. p. Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, including net operating loss and other tax carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date. We have a valuation allowance of $115.2 million and $113.5 million as of December 31, 2018 and 2017 , respectively, due to uncertainties related to our ability to utilize some of our deferred tax assets, primarily consisting of certain state net operating loss and other tax carryforwards, before they expire. The valuation allowance was based on our estimates of taxable income by jurisdiction in which we operate and the period over which our deferred tax assets were recoverable. For the foreseeable future, we project taxable income that will allow for the utilization of all of our federal net operating loss carryforwards before they expire. Our liability for income taxes is finalized as auditable tax years pass their respective statutes of limitations in the various jurisdictions in which we are subject to tax. However, these jurisdictions may audit prior years for which the statute of limitations is closed for the purpose of making an adjustment to our taxable income in a year for which the statute of limitations has not closed. Accordingly, taxing authorities of these jurisdictions may audit prior years of the group and its predecessors for the purpose of adjusting net operating loss carryforwards to years for which the statute of limitations has not closed. We classify interest and penalties attributable to income taxes as part of income tax expense. As of December 31, 2018 and 2017 , we had no accrued interest and penalties liability. Because we do not permanently reinvest foreign earnings, United States deferred income taxes have been provided on unremitted foreign earnings to the extent that such foreign earnings are expected to be taxable upon repatriation. On December 22, 2017, the Tax Act was signed into law. The Tax Act contained significant changes to corporate taxation, including reduction of the corporate tax rate from 35% to 21% effective January 1, 2018, limitation of the tax deduction for interest expense, limitation of the deduction for net operating losses and elimination of net operating loss carrybacks, one time taxation of offshore earnings at reduced rates, elimination of U.S. tax on foreign earnings (subject to certain important exceptions), new taxes concerning global intangible low-tax income (GILTI), immediate deductions for certain new investments instead of deductions for depreciation expense over time, and modifying or repealing many business deductions and credits including the limitation on deductions for certain executive compensation arrangements under Section 162(m) of the Internal Revenue Code. All corporation taxation aspects of the Tax Act are included in our year ended December 31, 2017 tax provision. See Note 10 for further discussion. q. Earnings Per Common Share Basic earnings per common share is computed by dividing net income attributable to Holdings' common stockholders by the weighted average number of common shares outstanding for the period. Diluted earnings per common share is computed by dividing net income attributable to Holdings' common stockholders by the weighted average number of common shares outstanding during the period including the effect of all dilutive common stock equivalents using the treasury stock method. In periods for which there is a net loss, diluted loss per common share is equal to basic loss per common share, since the effect of including any common stock equivalents would be antidilutive. r. Stock-Based Compensation Pursuant to the Six Flags Entertainment Corporation Long-Term Incentive Plan (the "Long-Term Incentive Plan"), Holdings may grant stock options, stock appreciation rights, restricted stock, restricted stock units, unrestricted stock, deferred stock units, performance and cash-settled awards and dividend equivalents to select employees, officers, directors and consultants of Holdings and its affiliates. We recognize the fair value of each grant as compensation expense on a straight-line basis over the vesting period using the graded vesting terms of the respective grant. The fair value of stock option grants is estimated on the date of grant using the Black-Scholes option pricing valuation model. The fair value of stock, restricted stock units and restricted stock awards is the quoted market price of Holdings' stock on the date of grant. See Note 9 for further discussion of stock-based compensation and related disclosures. s. Comprehensive Income Comprehensive income consists of net income, changes in the foreign currency translation adjustment, changes in the fair value of derivatives that are designated as hedges and changes in the net actuarial gains (losses) and amortization of prior service costs on our defined benefit retirement plan. t. Redeemable Noncontrolling Interest We record the carrying amount of our redeemable noncontrolling interests at their fair value at the date of issuance. We recognize the changes in their redemption value immediately as they occur and adjust the carrying value of these redeemable noncontrolling interests to equal the redemption value at the end of each reporting period, if greater than the redeemable noncontrolling interest carrying value. This method would view the end of the reporting period as if it were also the redemption date for the redeemable noncontrolling interests. We conduct an annual review to determine if the fair value of the redeemable units is less than the redemption amount. If the fair value of the redeemable units is less than the redemption amount, there would be a charge to earnings per share allocable to common stockholders. The redemption amount at the end of each reporting period did not exceed the fair value of the redeemable units. u. Acquisition of Park Assets On May 22, 2018, we entered into an asset purchase agreement with Premier Parks, LLC and its affiliates to acquire the lease rights to operate five parks owned by EPR Properties, LLC (the "five new parks"). We completed the transaction on June 1, 2018. In connection with the purchase agreement, we entered into operating leases with EPR Properties, LLC, under which we are the tenant. The five new parks were previously operated by Premier Parks, LLC of Oklahoma City and its affiliates. These acquisitions expanded our portfolio of parks in North America to twenty-five . The financial results of the five new parks since the acquisition date are included in our consolidated statements of operations. Assets acquired and liabilities assumed, consisting primarily of working capital, are reflected in our consolidated financial statements. We paid $19.1 million in cash to Premier Parks, LLC for the five new parks, which reflects the $23.0 million purchase price, less net working capital and other adjustments. We recorded $29.4 million of goodwill in connection with the acquisition, which is attributable to the excess of the purchase price over the net working capital liabilities we assumed. v. Recently Adopted Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers ("ASU 2014-09"). The amendments in ASU 2014-09 provide for a single, principles-based model for revenue recognition that replaces the existing revenue recognition guidance. In August 2015, the FASB issued Accounting Standards Update 2015-14, Revenue from Contracts with Customers - Deferral of the Effective Date ("ASU 2015-14"), to defer the effective date of ASU 2014-09 for one year. The new guidance became effective for annual and interim periods beginning after December 15, 2017 and replaced most existing revenue recognition guidance under U.S. GAAP. In March and April 2016, the FASB issued Accounting Standards Update No. 2016-08 and No. 2016-10, Revenue from Contracts with Customers (Topic 606)and Principal versus Agent Considerations and Identifying Performance Obligations and Licensing, respectively (together, "ASU 2016-08/10"). The amendments in ASU 2016-08/10 state that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The effective date and transition requirements for the amendments in ASU 2016-08/10 are the same as the effective date and transition requirements in ASU 2015-14. ASU 2016 08/10 permits the use of either a retrospective or cumulative effect transition method, and early adoption is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. On January 1, 2018, we adopted Topic 606 using the modified retrospective transition method applied to those contracts with customers which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting under FASB ASC 605, Revenue Recognition ("Topic 605"). Refer to Note 3 for additional information. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). The amendments in ASU 2016-15 address eight classification issues related to the statement of cash flows: • debt repayment or debt extinguishment costs; • settlement of zero-coupon bonds; • contingent consideration payments made after a business combination; • proceeds from insurance claims; • proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; • distribution received from equity method investees; • beneficial interests in securitization transactions; and • separately identifiable cash flows and application of the predominance principle. On January 1, 2018, we adopted ASU 2016-15 using a retrospective transition method to each period presented. The adoption of ASU 2016-15 did not result in a material impact to the presentation of our condensed consolidated statement of cash flows. In November 2016, the FASB issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash ("ASU 2016-18"). The amendments in ASU 2016-18 require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The accounting effects of ASU 2016-18 did not result in a material impact to the presentation of our consolidated statement of cash flows. In March 2017, the FASB issued Accounting Standards Update No. 2017-07, Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost ("ASU 2017-07"). The amendments in ASU 2017-07 require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The amendments in ASU 2017-07 also require that an employer disaggregate the service cost component from the other components of net benefit cost. ASU 2017-07 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The amendments in ASU 2017-07 should be applied retrospectively for the presentation of the service cost component and the other components of net periodic pension cost and net periodic post-retirement benefit cost in the consolidated statements of operations. On January 1, 2018, we adopted ASU 2017-07 using a retrospective transition method to each period presented. Accordingly, the service cost component of net periodic pension cost allocated to our park employees and corporate employees was included within "Operating expenses" and "Selling, general and administrative expenses," respectively, while the other cost components were included in "Other net periodic pension benefit" in the condensed consolidated statements of operations. Certain prior year amounts in the consolidated statements of operations were reclassified to conform to current year presentation in connection with the adoption of ASU 2017-07. For the years ended December 31, 2017 and 2016, the Company reclassified $2.7 million and $0.7 million , respectively, from "Operating expenses" to "Other net periodic pension benefit." This amount represents the non-service cost component of net periodic pension costs allocable to our park level employees. For the years ended December 31, 2017 and 2016, the Company reclassified $0.6 million and $1.2 million , respectively, from "Selling, general an |
