REGULATORY MATTERS - Summary of Commitments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commercial Letters Of Credit [Member]
Other Commitments [Line Items]
Financial instruments whose contract amounts represent credit risk	$ 69,664	$ 46,728
Standby letters of credit [Member] [Member]
Other Commitments [Line Items]
Financial instruments whose contract amounts represent credit risk	2,865	2,691
Commercial lines of credit [Member]
Other Commitments [Line Items]
Financial instruments whose contract amounts represent credit risk	455,344	471,732
Unused personal lines of credit [Member]
Other Commitments [Line Items]
Financial instruments whose contract amounts represent credit risk	722,510	710,607
Construction undisbursed funds [Member]
Other Commitments [Line Items]
Financial instruments whose contract amounts represent credit risk	$ 160,905	$ 77,649