NON-CONSOLIDATED VARIABLE INTEREST ENTITIES (VIEs) AND SERVICING ASSETS - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	Apr. 30, 2004	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Servicing Liabilities At Fair Value [Line Items]
Gain on early extinguishment of debt		$ 0		$ 0	$ 1,605	$ 0
Servicing Asset at Amortized Cost		27,601	$ 28,034	29,690	27,601	29,690	$ 29,037	$ 30,277	$ 30,986
Servicing Asset At Fair Value Amount		$ 45,114			$ 45,114		$ 44,710
Weighted-average yield		1.24%			1.24%		1.22%
Percentage Of Variation In Assumptions					10.00%
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Qualitative Information					These sensitivities are hypothetical and should be used with caution. As the figures indicate, changes in fair value based on a 10% variation in assumptions generally cannot be extrapolated because the relationship between the change in assumption and the change in fair value may not be linear. Also, in this table, the effect of a variation in a particular assumption on the fair value of the MSR is calculated without changing any other assumption. In reality, changes in one factor may result in changes in another (for example, increases in market interest rates may result in lower prepayments), which may magnify or counteract the sensitivities
Debt Securities, Available-for-sale, Allowance for Credit Loss		$ 465	433	664	$ 465	664	$ 458	676	1,105
Junior subordinated debentures		$ 161,700			$ 161,700		$ 183,762
Statutory Trust One [Member]
Servicing Liabilities At Fair Value [Line Items]
Trust preferred securities repurchased			$ 21,400
Trust Preferred Purchase Price Percent			92.50%
Trust Preferred Securities Discount			7.50%
Gain on early extinguishment of debt			$ 1,600
Minimum [Member]
Servicing Liabilities At Fair Value [Line Items]
Percentage Of Variation In Assumptions					10.00%
Maximum [Member]
Servicing Liabilities At Fair Value [Line Items]
Percentage Of Variation In Assumptions					20.00%
Junior Subordinated Debt [Member] | Secured Overnight Financing Rate Sofr Overnight Index Swap Rate [Member]
Servicing Liabilities At Fair Value [Line Items]
Spread on variable rate					0.26161%
Debt Instrument Description Of Variable Rate Basis					3-month CME Term SOFR
Junior Subordinated Debt [Member] | Secured Overnight Financing Rate Sofr Overnight Index Swap Rate [Member] | Statutory Trust One [Member]
Servicing Liabilities At Fair Value [Line Items]
Spread on variable rate					2.75%
Junior Subordinated Debt [Member] | Secured Overnight Financing Rate Sofr Overnight Index Swap Rate [Member] | Statutory Trust Two [Member]
Servicing Liabilities At Fair Value [Line Items]
Spread on variable rate					2.50%
Variable Rate Demand Obligation [Member] | Statutory Trust One [Member]
Servicing Liabilities At Fair Value [Line Items]
Proceeds from Issuance of Trust Preferred Securities	$ 100,000
Proceeds of the issuance, together with proceeds of the purchase	3,100
Principal amount of corporation's junior subordinated deferrable debentures	103,100
Variable Rate Demand Obligation [Member] | Statutory Trust Two [Member]
Servicing Liabilities At Fair Value [Line Items]
Proceeds from Issuance of Trust Preferred Securities	125,000
Proceeds of the issuance, together with proceeds of the purchase	3,900
Principal amount of corporation's junior subordinated deferrable debentures	$ 128,900
Variable Rate Demand Obligation [Member] | Junior Subordinated Debt [Member]
Servicing Liabilities At Fair Value [Line Items]
Debt Instrument, Maturity Date, Description					The Junior Subordinated Deferrable Debentures mature on June 17, 2034, and September 20, 2034, respectively; however, under certain circumstances, the maturity of Junior Subordinated Deferrable Debentures may be shortened (such shortening would result in a mandatory redemption of the variable-rate TRuPs).
Residential MBS [Member]
Servicing Liabilities At Fair Value [Line Items]
Weighted-average yield		1.54%			1.54%		1.52%
Debt Securities, Available-for-sale, Allowance for Credit Loss		$ 83			$ 83		$ 83
Residential MBS [Member] | Private label [Member]
Servicing Liabilities At Fair Value [Line Items]
Weighted-average yield		7.73%			7.73%
Debt Securities, Available-for-sale, Allowance for Credit Loss		$ 100			$ 100		100
Residential MBS [Member] | Secured Overnight Financing Rate Sofr Overnight Index Swap Rate [Member] | Private label [Member]
Servicing Liabilities At Fair Value [Line Items]
Spread on variable rate					0.26161%
Debt Instrument Description Of Variable Rate Basis					3-month CME Term SOFR
Residential MBS [Member] | Private label [Member]
Servicing Liabilities At Fair Value [Line Items]
Servicing Asset at Amortized Cost		7,300			$ 7,300
Servicing Asset At Fair Value Amount		4,900			4,900
Debt Securities, Available-for-sale, Allowance for Credit Loss		83	$ 83	$ 290	83	$ 290	$ 83	$ 290	$ 797
GNMA [Member]
Servicing Liabilities At Fair Value [Line Items]
Principal amount of corporation serviced loans securitized through GNMA		$ 2,100,000			$ 2,100,000