Recent Accounting Developments Recent Accounting Developments (Details) $ in Millions	6 Months Ended
Jun. 30, 2017 USD ($)
Adjustments for New Accounting Pronouncements [Line Items]
Income tax deficiency	$ 0.6
Accounting Standards Update 2014-09 [Member]
Adjustments for New Accounting Pronouncements [Line Items]
Expected increase to passenger revenue after adoption	$ 1,000.0

New Accounting Pronouncement or Change in Accounting Principle, Expected Increase (Decrease) in Passenger Revenue

No definition available.

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