Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2022	Feb. 01, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-35186
Entity Registrant Name	Spirit Airlines, Inc.
Entity Incorporation, State or Country Code	DE
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
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	SAVE
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2.6
Entity Common Stock, Shares Outstanding		109,124,750
Documents Incorporated by Reference	Portions of the registrant's Proxy Statement for the registrant's 2023 Annual Meeting of Stockholders are incorporated by reference into Part III of this Form 10-K to the extent stated herein. The Proxy Statement will be filed within 120 days of the registrant's fiscal year ended December 31, 2022.
Entity Central Index Key	0001498710
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2022