BORROWING ARRANGEMENTS - Debentures and Trust Preferred Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($)
Debentures and Trust Preferred Securities [Member] | SPFCT III [Member]
BORROWING ARRANGEMENTS [Abstract]
Variable Rate Basis	SPFCT III   2004   $ 10,000       $ 10,310      2034    3-mo. CME Term SOFR + 291bps; 6.77%
Issued date	Dec. 31, 2004
Stated maturity date	Dec. 31, 2034
Term of variable rate	3 months
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	spfi:ChicagoMercantileExchangeTermSecuredOvernightFinancingRateSOFRRateMember
Basis spread on variable rate	2.91%
Interest rate	6.77%
Debentures and Trust Preferred Securities [Member] | SPFCT IV [Member]
BORROWING ARRANGEMENTS [Abstract]
Variable Rate Basis	SPFCT IV   2005    20,000      20,619      2035    3-mo. CME Term SOFR + 165bps; 5.37%
Issued date	Dec. 31, 2005
Stated maturity date	Dec. 31, 2035
Term of variable rate	3 months
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	spfi:ChicagoMercantileExchangeTermSecuredOvernightFinancingRateSOFRRateMember
Basis spread on variable rate	1.65%
Interest rate	5.37%
Debentures and Trust Preferred Securities [Member] | SPFCT V [Member]
BORROWING ARRANGEMENTS [Abstract]
Variable Rate Basis	SPFCT V   2007    15,000      15,464      2037    3-mo. CME Term SOFR + 176bps; 5.48%
Issued date	Dec. 31, 2007
Stated maturity date	Dec. 31, 2037
Term of variable rate	3 months
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	spfi:ChicagoMercantileExchangeTermSecuredOvernightFinancingRateSOFRRateMember
Basis spread on variable rate	1.76%
Interest rate	5.48%
Trust Preferred Securities [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of TPS	$ 45,000
Trust Preferred Securities [Member] | SPFCT III [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of TPS	10,000
Trust Preferred Securities [Member] | SPFCT IV [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of TPS	20,000
Trust Preferred Securities [Member] | SPFCT V [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of TPS	15,000
Debentures [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of debentures	46,393
Debentures [Member] | SPFCT III [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of debentures	10,310
Debentures [Member] | SPFCT IV [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of debentures	20,619
Debentures [Member] | SPFCT V [Member]
BORROWING ARRANGEMENTS [Abstract]
Amount of debentures	$ 15,464