ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Reclassification Adjustments Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unrealized gains/(losses) on investments available-for-sale Affected line item in the Statements of Income:
Investment securities gains	$ 467	$ 77	$ 190
Income before taxes	467	77	190
Tax expense	120	20	50
Net income	347	57	140
Amortization of defined benefit pension plan items Affected line item in the Statements of Income:
Recognized actuarial loss	(874)	(1,059)	(1,000)
Income before taxes	(874)	(1,059)	(1,000)
Tax benefit	(223)	(277)	(261)
Net loss	$ (651)	$ (782)	$ (739)