Consolidated Statements of Comprehensive Income (Loss) (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Deferred taxes on unrealized loss on investment securities	$ (1)	$ 38	$ 44
Loss reclassified from AOCI into income, tax	$ 63	$ 76	$ 75

Other Comprehensive Income (Loss), Securities, Available-for-Sale, Cash And Cash Equivalents Unrealized Holding Gain (Loss) Arising During Period, Tax

No definition available.

Name:	save_OtherComprehensiveIncomeLossSecuritiesAvailableForSaleCashAndCashEquivalentsUnrealizedHoldingGainLossArisingDuringPeriodTax
Namespace Prefix:	save_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration