REGULATORY MATTERS - Regulatory Capital (Details) - USD ($)		12 Months Ended
	Dec. 15, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 16, 2021
Common Equity Tier I to RiskWeighted Assets
Dividend restrictions term		2 years
Actual amount		$ 475,154,000	$ 455,391,000
Common Equity Tier One Capital Ratio		15.31	15.45
Capital conversion buffer (as a percent)		2.50%
Minimum Capital Required Basel III (amount)		$ 217,300,000	$ 206,296,000
Minimum Capital RequiredBasel III (ratio)		7.00	7.00
Required to be Considered Well Capitalized, ratio		4.5
Tier I Capital to RiskWeighted Assets
Actual amount		$ 475,154,000	$ 455,391,000
Actual ratio		15.31	15.45
Minimum Capital Required for Capital Adequacy Purposes (amount)		$ 7.0
Minimum Capital Required for Capital Adequacy Purposes (ratio)		6.00%	4.50%
Minimum Capital RequiredBasel III Fully Phasedin (amount)		$ 263,864,000	$ 250,502,000
Minimum Capital RequiredBasel III Fully Phasedin (ratio)		8.50	8.50
Required to be Considered Well Capitalized, ratio		8.0
Total Capital to RiskWeighted Assets
Actual amount		$ 509,766,000	$ 492,328,000
Actual ratio		16.42	16.71
Minimum Capital Required for Capital Adequacy Purposes (ratio)		8.00%
Minimum Capital RequiredBasel III Fully Phasedin (amount)		$ 325,950,000	$ 309,444,000
Minimum Capital RequiredBasel III Fully Phasedin (ratio)		10.50	10.50
Leverage Ratio
Actual amount		$ 475,154,000	$ 455,391,000
Actual ratio		11.22	12.00
Minimum Capital Required for Capital Adequacy Purposes (ratio)		4.00%
Minimum Capital RequiredBasel III Fully Phasedin (amount)		$ 169,470,000	$ 151,797,000
Minimum Capital RequiredBasel III Fully Phasedin (ratio)		4.00	4.00
Regulatory fees in the consolidated statements of income		$ 9,901,000	$ 1,798,000	$ 1,138,000
Subsidiaries [Member]
Common Equity Tier I to RiskWeighted Assets
Actual amount		$ 447,819,000	$ 421,952,000
Common Equity Tier One Capital Ratio		14.43	14.32
Minimum Capital Required Basel III (amount)		$ 217,270,000	$ 206,281,000
Minimum Capital RequiredBasel III (ratio)		7.00	7.00
Required to be Considered Well Capitalized, amount		$ 201,757,000	$ 191,547,000
Required to be Considered Well Capitalized, ratio		6.50	6.50
Tier I Capital to RiskWeighted Assets
Actual amount		$ 447,819,000	$ 421,952,000
Actual ratio		14.43	14.32
Minimum Capital RequiredBasel III Fully Phasedin (amount)		$ 263,836,000	$ 250,484,000
Minimum Capital RequiredBasel III Fully Phasedin (ratio)		8.50	8.50
Required to be Considered Well Capitalized, amount		$ 248,316,000	$ 235,750,000
Required to be Considered Well Capitalized, ratio		8.00	8.00
Total Capital to RiskWeighted Assets
Actual amount		$ 482,431,000	$ 458,886,000
Actual ratio		15.54	15.57
Minimum Capital RequiredBasel III Fully Phasedin (amount)		$ 325,915,000	$ 309,421,000
Minimum Capital RequiredBasel III Fully Phasedin (ratio)		10.50	10.50
Required to be Considered Well Capitalized, amount		$ 310,395,000	$ 294,687,000
Required to be Considered Well Capitalized, ratio		10.00	10.00
Leverage Ratio
Actual amount		$ 447,819,000	$ 421,952,000
Actual ratio		10.58	11.12
Minimum Capital RequiredBasel III Fully Phasedin (amount)		$ 169,381,000	$ 151,772,000
Minimum Capital RequiredBasel III Fully Phasedin (ratio)		4.00	4.00
Required to be Considered Well Capitalized, amount		$ 211,726,000	$ 189,715,000
Required to be Considered Well Capitalized, ratio		5.00	5.00
OCC Consent Order
Leverage Ratio
Civil money penalty					$ 1,000,000.0
FinCEN Consent Order
Leverage Ratio
Civil money penalty	$ 8,000,000.0
Penalty paid (credited)	(1,000,000.0)
OCC and Fincen Consent Order [Member]
Leverage Ratio
Regulatory fees in the consolidated statements of income	$ 8,000,000.0