Document And Entity Information	3 Months Ended
	Mar. 31, 2012	Apr. 24, 2012 Common Stock [Member]	Apr. 24, 2012 Nonvoting Common Stock [Member]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Entity Registrant Name	SPIRIT AIRLINES, INC.
Entity Central Index Key	0001498710
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		67,915,431	4,600,797