PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION, Condensed Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Interest expense	$ (13,272)	$ (15,946)	$ (28,367)
Other expense	(17,883)	(17,818)	(14,592)
Income before income taxes	73,121	56,603	36,701
Income tax (benefit)	14,507	11,250	7,481
Net income	58,614	45,353	29,220
South Plains Financial, Inc. [Member]
Income Statement [Abstract]
Dividends	48,250	20,500	10,000
Other income	26	115	64
ESOP Contribution	0	0	(1,800)
Interest expense	(4,936)	(3,390)	(3,562)
Other expense	(1,466)	(1,572)	(2,221)
Income before income taxes	41,874	15,653	2,481
Income tax (benefit)	(1,339)	(1,018)	(1,498)
Equity in undistributed subsidiary income	15,401	28,682	25,241
Net income	$ 58,614	$ 45,353	$ 29,220