REGULATORY MATTERS - Actual Capital Amounts and Ratios (Detail) $ in Thousands	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Parent Company [Member]
Common equity Tier 1 (Ratio)
Total risk-based	$ 618,025	$ 446,571
Common equity Tier 1	438,109	352,481
Tier I risk-based	453,409	367,727
Tier I leverage	$ 453,409	$ 367,727
Total risk-based, Ratio	19.1	15.8
Common equity Tier 1, Ratio	13.50%	12.50%
Tier I risk-based, Ratio	14.0	13.0
Tier I leverage, Ratio	9.2	10.3
Subsidiaries [Member]
Common equity Tier 1 (Ratio)
Total risk-based	$ 549,273	$ 439,538
Common equity Tier 1	513,453	425,630
Tier I risk-based	513,453	425,630
Tier I leverage	$ 513,453	$ 425,630
Total risk-based, Ratio	16.9	15.6
Common equity Tier 1, Ratio	15.80%	15.10%
Tier I risk-based, Ratio	15.8	15.1
Tier I leverage, Ratio	10.4	11.8