GOODWILL AND OTHER INTANGIBLES - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2019	Feb. 15, 2016	Jun. 30, 2012
Finite Lived Intangible Assets [Line Items]
Goodwill	$ 28,100,000		$ 28,100,000			$ 28,100,000
Amortization expense			1,425,000	$ 1,551,000
Goodwill and Intangible Asset Impairment			0
Core Deposits [Member]
Finite Lived Intangible Assets [Line Items]
Finite Lived Intangible Assets Gross	51,664,000		51,664,000			51,664,000
Amortization expense	200,000	$ 200,000	400,000	400,000
Net carrying amount	3,086,000		$ 3,086,000			3,488,000
Remaining amortization period			4 years 7 months 6 days		5 years 1 month 6 days
Customer Relationships [Member] | Credit Card [Member]
Finite Lived Intangible Assets [Line Items]
Finite Lived Intangible Assets Gross	24,465,000		$ 24,465,000			24,465,000
Amortization expense	500,000	500,000	900,000	1,000,000.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles								$ 24,500,000
Net carrying amount	2,668,000		$ 2,668,000			3,615,000
Remaining amortization period			1 year 4 months 24 days		1 year 10 months 24 days
Customer Relationships [Member] | Insurance Customer Intangible [Member]
Finite Lived Intangible Assets [Line Items]
Finite Lived Intangible Assets Gross	1,067,000		$ 1,067,000			1,067,000
Amortization expense	38,000	$ 38,000	76,000	$ 76,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles							$ 1,100,000
Net carrying amount	$ 394,000		$ 394,000			$ 470,000
Remaining amortization period			2 years 6 months		3 years