Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Mar. 03, 2026	Jun. 30, 2025
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Financial Statement Error Correction [Flag]	true
Document Financial Statement Restatement Recovery Analysis [Flag]	false
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	true
Amendment Flag	false
Document Period End Date	Dec. 31, 2025
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Entity Information [Line Items]
Entity Registrant Name	South Plains Financial, Inc.
Entity Central Index Key	0001163668
Entity File Number	001-38895
Entity Tax Identification Number	75-2453320
Entity Incorporation, State or Country Code	TX
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Public Float			$ 442.0
Entity Contact Personnel [Line Items]
Entity Address, Address Line One	5219 City Bank Parkway
Entity Address, City or Town	Lubbock
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	79407
Entity Phone Fax Numbers [Line Items]
City Area Code	806
Local Phone Number	792-7101
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, par value $1.00 per share
Trading Symbol	SPFI
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		16,331,422