ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Reclassification Adjustments Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Unrealized gains on investments available for sale, affected line items in the Statements of Income
Investment securities gains			$ 178	$ 432
Income before taxes	$ 49	$ 51	178	432
Tax expense	$ (12)	$ (13)	(45)	(110)
Net income			133	322
Amortization of defined benefit pension plan items Affected line item in the Statements of Income:
Recognized actuarial loss			(682)	(656)
Loss before taxes			(682)	(656)
Tax benefit			162	159
Net loss			$ (520)	$ (497)

Amount, before tax and adjustment, of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

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Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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