REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	$ 797,110	$ 795,293	$ 729,929
Non-interest income (loss)	132,694	123,092	121,164
Total Revenues	929,804	918,385	851,093
Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	38,042	37,823	35,284
Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	12,763	13,743	11,945
Total Revenues	2,500	3,200	3,300
Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	43,909	40,416	36,508
Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	12,942	11,093	9,997
Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	25,038	20,017	27,430
Mortgage Banking Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	78,710	98,920	104,638
Non-interest income (loss)	11,400	15,950	24,278
Total Revenues	90,110	114,870	128,916
Mortgage Banking Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Mortgage Banking Segment [Member] | Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Mortgage Banking Segment [Member] | Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Mortgage Banking Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	288	341	771
Mortgage Banking Segment [Member] | Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	11,112	15,609	23,507
Consumer Retail Banking Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	575,436	442,624	281,703
Non-interest income (loss)	83,241	78,457	69,774
Total Revenues	658,677	521,081	351,477
Consumer Retail Banking Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	21,207	21,906	20,083
Consumer Retail Banking Segment [Member] | Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	11,906	12,733	11,166
Consumer Retail Banking Segment [Member] | Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	40,177	35,683	32,639
Consumer Retail Banking Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	5,592	4,558	4,185
Consumer Retail Banking Segment [Member] | Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	4,359	3,577	1,701
Commercial And Corporate Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	54,658	109,822	191,917
Non-interest income (loss)	21,277	18,189	16,032
Total Revenues	75,935	128,011	207,949
Commercial And Corporate Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	13,289	12,412	11,807
Commercial And Corporate Segment [Member] | Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Commercial And Corporate Segment [Member] | Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	98	1,568	1,161
Commercial And Corporate Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	3,723	3,397	2,641
Commercial And Corporate Segment [Member] | Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	4,167	812	423
Treasury And Investments Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	(13,916)	39,600	59,331
Non-interest income (loss)	2,038	(74)	227
Total Revenues	(11,878)	39,526	59,558
Treasury And Investments Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Treasury And Investments Segment [Member] | Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Treasury And Investments Segment [Member] | Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Treasury And Investments Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	0	0	0
Treasury And Investments Segment [Member] | Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	2,038	(74)	227
United States Operations Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	79,423	80,485	65,967
Non-interest income (loss)	6,697	2,860	3,963
Total Revenues	86,120	83,345	69,930
United States Operations Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	649	607	555
United States Operations Segment [Member] | Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	202	15	114
United States Operations Segment [Member] | Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	99	67	51
United States Operations Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	2,484	2,113	1,844
United States Operations Segment [Member] | Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	3,263	58	1,399
Virgin Islands Operations Segment [Member]
Disaggregation Of Revenue [Line Items]
Net interest income (loss)	22,799	23,842	26,373
Non-interest income (loss)	8,041	7,710	6,890
Total Revenues	30,840	31,552	33,263
Virgin Islands Operations Segment [Member] | Service charges and fees on deposit accounts [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	2,897	2,898	2,839
Virgin Islands Operations Segment [Member] | Insurance Commission Income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	655	995	665
Virgin Islands Operations Segment [Member] | Card and processing income [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	3,535	3,098	2,657
Virgin Islands Operations Segment [Member] | Other service charges and fees [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	855	684	556
Virgin Islands Operations Segment [Member] | Not in scope of Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Non-interest income (loss)	$ 99	$ 35	$ 173