DEBT SECURITIES - Investment Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 359,169		$ 437,537
Held to Maturity Gross Unrecognized gains	4,819		4,068
Held to Maturity Gross Unrecognized losses	21,137		14,490
Held to Maturity Fair value	342,851		427,115
Allowance for credit losses, Held-to-Maturity securities	$ 2,250		$ 8,286
Held to Maturity Weighted-average yield	4.80%		4.71%
Interest receivable	$ 68,783		$ 69,730
Held-to-maturity Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Interest receivable	2,800		5,500
Municipal Bonds [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Due Withing One Year	3,159		1,202
Held to Maturity Gross Unrecognized gain Due Within One Year	15		0
Held to Maturity Gross Unrecognized losses Due Within One Year	23		15
Held to Maturity Fair value Due Within One Year	3,151		1,187
Allowance for credit losses Due within one year	$ 46		$ 2
Held to Maturity Weighted-average yield Due withing One Year	9.30%		5.20%
Held to Maturity Amortized Cost After 1 to 5 years	$ 51,133		$ 42,530
Held to Maturity Gross Unrecognized gains After 1 to 5 years	1,052		886
Held to Maturity Gross Unrecognized losses After 1 to 5 years	1,111		1,076
Held to Maturity Fair value After 1 to 5 years	51,074		42,340
Allowance for credit losses After 1 to 5 years	$ 1,320		$ 656
Held to Maturity Weighted-average yield After 1 to 5 years	7.71%		6.34%
Held to Maturity Amortized Cost After 5 to 10 years	$ 35,831		$ 55,956
Held to Maturity Gross Unrecognized gains After 5 to 10 years	3,540		3,182
Held to Maturity Gross Unrecognized losses After 5 to 10 years	271		360
Held to Maturity Fair value After 5 to 10 years	39,100		58,778
Allowance for credit losses After 5 to 10 years	$ 605		$ 3,243
Held to Maturity Weighted-average yield After 5 to 10 years	7.05%		6.29%
Held to Maturity Amortized Cost After 10 years	$ 16,595		$ 66,022
Held to Maturity Gross Unrecognized gains After 10 years	212		0
Held to Maturity Gross Unrecognized losses After 10 years	0		1,318
Held to Maturity Fair value After 10 years	16,807		64,704
Allowance for credit losses After 10 years	$ 279		$ 4,385
Held to Maturity Weighted-average yield After 10 years	8.75%		7.10%
Held To Maturity Securities Amortized	$ 106,718		$ 165,710
Held to Maturity Gross Unrecognized gains	4,819		4,068
Held to Maturity Gross Unrecognized losses	1,405		2,769
Held to Maturity Fair value	110,132		167,009
Allowance for credit losses, Held-to-Maturity securities	$ 2,250	$ 8,401	$ 8,286	$ 8,257	$ 8,885	$ 8,571
Held to Maturity Weighted-average yield	7.70%		6.62%
Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 150,650		$ 166,739
Held to Maturity Gross Unrecognized gains	0		0
Held to Maturity Gross Unrecognized losses	12,034		7,156
Held to Maturity Fair value	138,616		159,583
Allowance for credit losses, Held-to-Maturity securities	$ 0		$ 0
Held to Maturity Weighted-average yield	3.84%		3.78%
Commercial MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 1 to 5 years	$ 9,489		$ 9,621
Held to Maturity Gross Unrecognized gains After 1 to 5 years	0		0
Held to Maturity Gross Unrecognized losses After 1 to 5 years	516		396
Held to Maturity Fair value After 1 to 5 years	8,973		9,225
Allowance for credit losses After 1 to 5 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 1 to 5 years	3.48%		3.48%
Held to Maturity Amortized Cost After 10 years	$ 92,312		$ 95,467
Held to Maturity Gross Unrecognized gains After 10 years	0		0
Held to Maturity Gross Unrecognized losses After 10 years	7,182		4,169
Held to Maturity Fair value After 10 years	85,130		91,298
Allowance for credit losses After 10 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 10 years	3.15%		3.15%
Held To Maturity Securities Amortized	$ 101,801		$ 105,088
Held to Maturity Gross Unrecognized gains	0		0
Held to Maturity Gross Unrecognized losses	7,698		4,565
Held to Maturity Fair value	94,103		100,523
Allowance for credit losses, Held-to-Maturity securities	$ 0		$ 0
Held to Maturity Weighted-average yield	3.18%		3.18%
MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 252,451		$ 271,827
Held to Maturity Gross Unrecognized gains	0		0
Held to Maturity Gross Unrecognized losses	19,732		11,721
Held to Maturity Fair value	232,719		260,106
Allowance for credit losses, Held-to-Maturity securities	$ 0		$ 0
Held to Maturity Weighted-average yield	3.57%		3.55%
Unisured Portion Of Government Deposits [Member] | Asset Pledged as Collateral [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 179,900		$ 190,100
Held to Maturity Fair value	174,900		189,400
FHLMC [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 5 to 10 years	17,580		21,443
Held to Maturity Gross Unrecognized gains After 5 to 10 years	0		0
Held to Maturity Gross Unrecognized losses After 5 to 10 years	1,131		746
Held to Maturity Fair value After 5 to 10 years	16,449		20,697
Allowance for credit losses After 5 to 10 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 5 to 10 years	3.03%		3.03%
Held to Maturity Amortized Cost After 10 years	$ 18,740		$ 19,362
Held to Maturity Gross Unrecognized gains After 10 years	0		0
Held to Maturity Gross Unrecognized losses After 10 years	1,689		888
Held to Maturity Fair value After 10 years	17,051		18,474
Allowance for credit losses After 10 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 10 years	4.34%		4.21%
Held To Maturity Securities Amortized	$ 36,320		$ 40,805
Held to Maturity Gross Unrecognized gains	0		0
Held to Maturity Gross Unrecognized losses	2,820		1,634
Held to Maturity Fair value	33,500		39,171
Allowance for credit losses, Held-to-Maturity securities	$ 0		$ 0
Held to Maturity Weighted-average yield	3.70%		3.59%
GNMA [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 16,786		$ 19,131
Held to Maturity Gross Unrecognized gains After 10 years	0		0
Held to Maturity Gross Unrecognized losses After 10 years	1,414		943
Held to Maturity Fair value After 10 years	15,372		18,188
Allowance for credit losses After 10 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 10 years	3.35%		3.35%
FNMA [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 68,388		$ 72,347
Held to Maturity Gross Unrecognized gains After 10 years	0		0
Held to Maturity Gross Unrecognized losses After 10 years	5,902		3,155
Held to Maturity Fair value After 10 years	62,486		69,192
Allowance for credit losses After 10 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 10 years	4.17%		4.14%
CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA: [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 29,156		$ 34,456
Held to Maturity Gross Unrecognized gains After 10 years	0		0
Held to Maturity Gross Unrecognized losses After 10 years	1,898		1,424
Held to Maturity Fair value After 10 years	27,258		33,032
Allowance for credit losses After 10 years	$ 0		$ 0
Held to Maturity Weighted-average yield After 10 years	3.49%		3.49%