| Document and Entity Information | Jun. 26, 2024 |
| Cover [Abstract] | |
| Entity Registrant Name | Six Flags Entertainment Corp |
| Amendment Flag | false |
| Entity Central Index Key | 0000701374 |
| Document Type | 8-K |
| Document Period End Date | Jun. 26, 2024 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 1-13703 |
| Entity Tax Identification Number | 13-3995059 |
| Entity Address, Address Line One | 1000 Ballpark Way |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | Arlington |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 76011 |
| City Area Code | (972) |
| Local Phone Number | 595-5000 |
| Written Communications | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, $0.025 par value per share |
| Trading Symbol | SIX |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
