INVESTMENT SECURITIES - Investment Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Fair value	$ 111,162	$ 110,374
Allowance for Credit Losse, Held-to-maturity securities	9,268	0
Municipal Bonds [Member] | Puerto Rico [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Matury Amortized Due Withing One Year	321	321
Held to Maturity Gross Unrecognized gain Due Within One Year	0	0
Held to Maturity Gross Unrecognized losses Due Within One Year	3	6
Held to Maturity Fair value Due Within One Year	318	$ 315
Allowance for credit losses Withing One Year	$ 99
Held to Maturity Weighted-average yield Due withing One Year	5.65%	5.84%
Held to Maturity Amortized Cost After 1 to 5 years	$ 8,122	$ 8,264
Held to Maturity Gross Unrecognized gains After 1 to 5 years	0	0
Held to Maturity Gross Unrecognized losses After 1 to 5 years	675	736
Held to Maturity Fair value After 1 to 5 years	7,447	$ 7,528
Allowance for credit losses After 1 to 5 years	$ 78
Held to Maturity Weighted-average yield After 1 to 5 years	4.99%	5.18%
Held to Maturity Amortized Cost After 5 to 10 years	$ 56,511	$ 56,511
Held to Maturity Gross Unrecognized gains After 5 to 10 years	0	0
Held to Maturity Gross Unrecognized losses After 5 to 10 year	8,118	8,646
Held to Maturity Fair value After 5 to 10 years	48,393	$ 47,865
Allowance for credit losses After 5 to 10 years	$ 2,999
Held to Maturity Weighted-average yield After 5 to 10 years	5.42%	5.77%
Held to Maturity Weighted-average yield	5.31%	5.56%
Held to Maturity Amortized Cost After 10 years	$ 73,580	$ 73,579
Held to Maturity Gross Unrecognized gains After 10	0	0
Held to Maturity Gross Unrecognized losses After 10	18,576	18,913
Held to Maturity Fair value After 10 years	55,004	$ 54,666
Allowance for credit losses After 10 years	$ 6,092
Held to Maturity Weighted-average yield After 10 years	5.25%	5.44%
Held to Maturity Amortized cost	$ 138,534	$ 138,675
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Fair value	111,162	110,374
Allowance for Credit Losse, Held-to-maturity securities	9,268	0
Held to Maturity Gross Unrecognized losses	$ 27,372	$ 28,301