Commitments and Contingencies - Fixed Maintenance Reserve Payments (Details) (Aircraft and Related Flight Equipment [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2014
Aircraft and Related Flight Equipment [Member]
Fixed Maintenance Reserve Payments [Line Items]
Fixed maintenance reserve payments, future estimated payments due, the remainder of 2014	$ 5.5
Fixed maintenance reserve payments, future estimated payments due, 2015	7.6
Fixed maintenance reserve payments, future estimated payments due, 2016	8.0
Fixed maintenance reserve payments, future estimated payments due, 2017	7.4
Fixed maintenance reserve payments, future estimated payments due, 2018	5.8
Fixed maintenance reserve payments, future estimated payments due, 2019 and beyond	$ 18.4

Fixed Maintenance Reserve Payments, Future Estimated Payments Due, Due After Five Years

No definition available.

Name:	save_FixedMaintenanceReservePaymentsFutureEstimatedPaymentsDueDueAfterFiveYears
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fixed Maintenance Reserve Payments, Future Estimated Payments Due, Due Within Five Years

No definition available.

Name:	save_FixedMaintenanceReservePaymentsFutureEstimatedPaymentsDueDueWithinFiveYears
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fixed Maintenance Reserve Payments, Future Estimated Payments Due, Due Within Four Years

No definition available.

Name:	save_FixedMaintenanceReservePaymentsFutureEstimatedPaymentsDueDueWithinFourYears
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fixed Maintenance Reserve Payments, Future Estimated Payments Due, Due Within Three Years

No definition available.

Name:	save_FixedMaintenanceReservePaymentsFutureEstimatedPaymentsDueDueWithinThreeYears
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fixed Maintenance Reserve Payments, Future Estimated Payments Due, Due Within Two Years

No definition available.

Name:	save_FixedMaintenanceReservePaymentsFutureEstimatedPaymentsDueDueWithinTwoYears
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fixed Maintenance Reserve Payments, Future Estimated Payments Due, Within Twelve Months

No definition available.

Name:	save_FixedMaintenanceReservePaymentsFutureEstimatedPaymentsDueWithinTwelveMonths
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	save_FixedMaintenanceReservePaymentsLineItems
Namespace Prefix:	save_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration