v3.25.2
Description of the Business and Significant Accounting Policies - Narrative (Details)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended
Mar. 02, 2020
claim
Feb. 29, 2020
claim
Jun. 29, 2025
USD ($)
$ / shares
Sep. 29, 2024
USD ($)
Jun. 30, 2024
USD ($)
Jun. 29, 2025
USD ($)
$ / shares
Jun. 30, 2024
USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Percentage of park attendance and revenue during peak period           70.00%  
Net income (loss) attributable to Six Flags Entertainment Corporation     $ (99,648)   $ 55,553 $ (319,366) $ (77,914)
Net income (loss) per share of common stock - basic (in dollars per share) | $ / shares     $ (0.99)     $ (3.18)  
Change in Accounting Principle, Depreciation              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
(Decrease) increase in depreciation     $ (15,000)     $ 14,000  
Net income (loss) attributable to Six Flags Entertainment Corporation     $ 14,000     $ (13,000)  
Net income (loss) per share of common stock - basic (in dollars per share) | $ / shares     $ 0.14     $ (0.13)  
Securities Class Action Lawsuits              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Settlement amount awarded       $ 40,000      
Insurance settlement receivable     $ 40,000     $ 40,000  
Loss contingency payable     $ 40,000     $ 40,000  
Securities Class Action Lawsuits | Pending Litigation | Former Six Flags              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Number of claims filed | claim 2 2