| Document and Entity Information | Jul. 27, 2022 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001498710 |
| Document Type | 8-K |
| Document Period End Date | Jul. 27, 2022 |
| Entity Registrant Name | Spirit Airlines, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-35186 |
| Entity Tax Identification Number | 38-1747023 |
| Entity Address, Address Line One | 2800 Executive Way |
| Entity Address, City or Town | Miramar |
| Entity Address, State or Province | FL |
| Entity Address, Postal Zip Code | 33025 |
| City Area Code | (954) |
| Local Phone Number | 447-7920 |
| Written Communications | false |
| Soliciting Material | true |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.0001 par value |
| Trading Symbol | SAVE |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
