Defined Contribution 401(k) Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 defined_contribution_plan	Dec. 31, 2011	Dec. 31, 2010
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, number of plans	3
Defined contribution 401(k) plan, matching contributions made in period	$ 6,600,000	$ 4,900,000	$ 4,800,000
Spirit Airlines, Inc. Employee Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, requisite service period	60 days
Defined contribution 401(k) plan, requisite service period, hours	1000 hours
Defined contribution 401(k) plan, requisite age	21 years
Defined contribution plan, employer matching contribution, percent of match	50.00%
Spirit Airlines, Inc. Pilots’ Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, requisite service period	60 days
Defined contribution 401(k) plan, requisite service period, hours	1000 hours
Defined contribution 401(k) plan, requisite age	21 years
Defined contribution plan, employer matching contribution, percent of match	100.00%
Defined contribution 401(k) plan, IRS elective deferral limit	17,000
Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, requisite service period	60 days
Defined contribution 401(k) plan, requisite service period, hours	1000 hours
Defined contribution 401(k) plan, requisite age	21 years
Defined contribution 401(k) plan, IRS elective deferral limit	$ 13,000
Maximum | Spirit Airlines, Inc. Employee Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	3.00%
Maximum | Spirit Airlines, Inc. Pilots’ Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	8.00%
Pilots | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution plan, employer matching contribution, percent of match	100.00%
Pilots | Maximum | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	8.00%
Other Employees | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution plan, employer matching contribution, percent of match	50.00%
Other Employees | Maximum | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	3.00%