ACQUISITIONS - Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Liabilities assumed
Goodwill	$ 30,400	$ 30,588	$ 24,191	$ 24,191
Total loans held for investment	1,931,134	1,954,168
Acquisition cost	500
Cash, Securities and Other
Liabilities assumed
Total loans held for investment	271,811	295,948
Construction and Development
Liabilities assumed
Total loans held for investment	151,651	178,716
1-4 Family Residential
Liabilities assumed
Total loans held for investment	602,412	580,872
Non-Owner Occupied CRE
Liabilities assumed
Total loans held for investment	455,715	482,622
Owner Occupied CRE
Liabilities assumed
Total loans held for investment	212,401	212,426
Commercial. and Industrial.
Liabilities assumed
Total loans held for investment	237,144	203,584
PPP Loans
Liabilities assumed
Total loans held for investment	16,700	46,800
Simmons Bank
Liabilities assumed
Total loans held for investment	$ 323,600	356,700
Teton Financial Services
Business Acquisition [Line Items]
Cash consideration		11,501
Common stock issued		39,818
Total fair value of consideration transferred		51,319
Assets acquired
Cash and cash equivalents		132,498
Available-for-sale securities, at fair value		18,058
Coorespondant bank stock, at cost		928
Mortgage loans held for sale		840
Loans, net		251,418
Premises and equipment		17,758
Accrued interest receivable		923
Accounts receivable		95
Other receivable		520
Core deposit intangible		1,962
Other assets		468
Assets held for sale		120
Total assets acquired		425,588
Liabilities assumed
Deposits		379,198
Accrued interest payable		26
Other liabilities		1,283
Deferred tax liabilities/(assets), net		(29)
Total liabilities assumed		380,478
Net assets acquired		45,110
Goodwill		6,209
Teton Financial Services | Provisional Estimates
Business Acquisition [Line Items]
Cash consideration		11,501
Common stock issued		39,818
Total fair value of consideration transferred		51,319
Assets acquired
Cash and cash equivalents		132,498
Available-for-sale securities, at fair value		18,058
Coorespondant bank stock, at cost		928
Mortgage loans held for sale		840
Loans, net		252,275
Premises and equipment		17,758
Accrued interest receivable		923
Accounts receivable		95
Other receivable		520
Core deposit intangible		1,264
Other assets		226
Assets held for sale		115
Total assets acquired		425,500
Liabilities assumed
Deposits		379,227
Accrued interest payable		26
Other liabilities		1,283
Deferred tax liabilities/(assets), net		42
Total liabilities assumed		380,578
Net assets acquired		44,922
Goodwill		6,397
Teton Financial Services | Measurement Period Adjustments
Assets acquired
Loans, net		(857)
Core deposit intangible		698
Other assets		242
Assets held for sale		5
Total assets acquired		88
Liabilities assumed
Deposits		(29)
Deferred tax liabilities/(assets), net		(71)
Total liabilities assumed		(100)
Net assets acquired		188
Goodwill		$ (188)
Core deposit
Liabilities assumed
Estimated life	10 years