REVENUE FROM CONTRACTS WITH CUSTOMERS (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Net interest income	$ 729,929	$ 600,322	$ 567,081
Noninterest Income	121,164	111,226	90,572
Total Revenues	851,093	711,548	657,653
Other non-interest income	48,937	41,834	39,909
Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	35,284	24,612	23,916
Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	11,945	9,364	10,186
Total Revenues	3,300	3,300	3,000
Other non-interest income		5,000
Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	8,464	5,844	5,635
Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	28,064	19,765	20,905
Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	9,977	8,994	8,789
Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	27,430	42,647	21,141
Mortgage Banking Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income	104,638	76,025	68,803
Noninterest Income	24,278	22,069	16,825
Total Revenues	128,916	98,094	85,628
Mortgage Banking Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Mortgage Banking Segment [Member] | Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Mortgage Banking Segment [Member] | Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Mortgage Banking Segment [Member] | Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Mortgage Banking Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	771	342	216
Mortgage Banking Segment [Member] | Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	23,507	21,727	16,609
Consumer Retail Banking Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income	281,703	220,678	244,535
Noninterest Income	69,774	50,962	51,729
Total Revenues	351,477	271,640	296,264
Consumer Retail Banking Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	20,083	13,286	14,534
Consumer Retail Banking Segment [Member] | Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	11,166	8,754	9,621
Consumer Retail Banking Segment [Member] | Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	6,279	4,516	4,120
Consumer Retail Banking Segment [Member] | Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	26,360	18,218	19,014
Consumer Retail Banking Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	4,185	2,900	3,012
Consumer Retail Banking Segment [Member] | Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	1,701	3,288	1,428
Commercial And Corporate Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income	191,917	135,591	91,266
Noninterest Income	16,032	12,606	11,714
Total Revenues	207,949	148,197	102,980
Commercial And Corporate Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	11,807	8,026	5,811
Commercial And Corporate Segment [Member] | Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Commercial And Corporate Segment [Member] | Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	1,079	478	466
Commercial And Corporate Segment [Member] | Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	83	62	104
Commercial And Corporate Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	2,640	2,260	2,690
Commercial And Corporate Segment [Member] | Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	423	1,780	2,643
Treasury And Investments Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income	59,331	87,879	73,626
Noninterest Income	227	13,708	(225)
Total Revenues	59,558	101,587	73,401
Treasury And Investments Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Treasury And Investments Segment [Member] | Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Treasury And Investments Segment [Member] | Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Treasury And Investments Segment [Member] | Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	0	0
Treasury And Investments Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	0	184	0
Treasury And Investments Segment [Member] | Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	227	13,524	(225)
United States Operations Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income	65,967	54,025	62,539
Noninterest Income	3,963	4,630	2,807
Total Revenues	69,930	58,655	65,346
United States Operations Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	555	553	631
United States Operations Segment [Member] | Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	114	52	67
United States Operations Segment [Member] | Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	51	41	0
United States Operations Segment [Member] | Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	19	16	43
United States Operations Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	1,825	1,800	1,558
United States Operations Segment [Member] | Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	1,399	2,168	508
Virgin Islands Operations Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income	26,373	26,124	26,312
Noninterest Income	6,890	7,251	7,722
Total Revenues	33,263	33,375	34,034
Virgin Islands Operations Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	2,839	2,747	2,940
Virgin Islands Operations Segment [Member] | Insurance commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	665	558	498
Virgin Islands Operations Segment [Member] | Merchant-related income [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	1,055	809	1,049
Virgin Islands Operations Segment [Member] | Credit and debit card fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	1,602	1,469	1,744
Virgin Islands Operations Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	556	1,508	1,313
Virgin Islands Operations Segment [Member] | Not inscope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Noninterest Income	$ 173	$ 160	$ 178