PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities [Abstract]
Net income	$ 58,614	$ 45,353	$ 29,220
Adjustments [Abstract]
Stock based compensation	1,639	1,272	853
Net cash from operating activities	96,271	5,627	30,484
Cash flows from investing activities [Abstract]
Cash paid in business combination	0	(687)	0
Net cash from investing activities	(159,841)	(156,228)	(213,493)
Cash flows from financing activities [Abstract]
Issuance of common stock	0	0	51,392
Payments to tax authorities for stock-based compensation	(625)	(319)	0
Payments to repurchase common stock	(9,227)	(293)	0
Cash dividends on common stock	(5,385)	(2,528)	(1,079)
Net cash from financing activities	250,084	292,809	95,119
Net change in cash and cash equivalents	186,514	142,208	(87,890)
Beginning cash and cash equivalents	300,307	158,099	245,989
Ending cash and cash equivalents	486,821	300,307	158,099
South Plains Financial, Inc. [Member]
Cash flows from operating activities [Abstract]
Net income	58,614	45,353	29,220
Adjustments [Abstract]
Equity in undistributed subsidiary income	(15,401)	(28,682)	(25,241)
Amortization of debt issuance costs	186	47	0
Stock based compensation	1,639	1,272	853
Change in other assets	(1,765)	(342)	(1,601)
Change in other liabilities	317	131	541
Net cash from operating activities	43,590	17,779	3,772
Cash flows from investing activities [Abstract]
Cash paid in business combination	0	0	(76,100)
Net cash from investing activities	0	0	(76,100)
Cash flows from financing activities [Abstract]
Proceeds from long-term borrowings	0	49,070	0
Repayments of long-term borrowings	0	0	(7,530)
Issuance of common stock	0	0	51,392
Payments to tax authorities for stock-based compensation	(625)	(319)	(351)
Payments to repurchase common stock	(9,227)	(293)	0
Share based liability conversion	0	0	11,450
Cash dividends on common stock	(5,385)	(2,528)	(1,079)
Net cash from financing activities	(15,237)	45,930	53,882
Net change in cash and cash equivalents	28,353	63,709	(18,446)
Beginning cash and cash equivalents	67,890	4,181	22,627
Ending cash and cash equivalents	$ 96,243	$ 67,890	$ 4,181