SEGMENT INFORMATION - Information about Reportable Segments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Interest income	$ 862,614	$ 794,708	$ 692,982
Interest expense	(67,321)	(64,779)	(92,660)
Net interest income	795,293	729,929	600,322
Provision for credit losses - (benefit) expense	(25,679)	61,720	(168,717)
Non-interest income	123,092	121,164	111,226
Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	862,614	794,708	692,982
Net (charge) credit for transfer of funds	0	0	0
Interest expense	(67,321)	(64,779)	(92,660)
Net interest income	795,293	729,929	600,322
Provision for credit losses - (benefit) expense	27,696	(65,698)	170,985
Non-interest income	123,092	121,164	111,226
Direct non-interest expenses	287,821	296,780	258,864
Segment income	602,868	620,011	281,699
Average earnings assets	18,516,894	19,235,941	14,201,505
Mortgage Banking Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	98,920	104,638	76,025
Non-interest income	15,950	24,278	22,069
Mortgage Banking Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	130,185	144,203	128,043
Net (charge) credit for transfer of funds	(31,265)	(39,565)	(52,018)
Interest expense	0	0	0
Net interest income	98,920	104,638	76,025
Provision for credit losses - (benefit) expense	(7,643)	(16,030)	22,518
Non-interest income	15,950	24,278	22,069
Direct non-interest expenses	23,049	29,125	33,054
Segment income	99,464	115,821	42,522
Average earnings assets	2,233,245	2,506,365	2,241,753
Consumer Retail Banking Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	442,624	281,703	220,678
Non-interest income	78,457	69,774	50,962
Consumer Retail Banking Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	302,631	271,127	240,725
Net (charge) credit for transfer of funds	173,917	38,859	18,771
Interest expense	(33,924)	(28,283)	(38,818)
Net interest income	442,624	281,703	220,678
Provision for credit losses - (benefit) expense	57,123	20,322	54,094
Non-interest income	78,457	69,774	50,962
Direct non-interest expenses	162,663	165,357	131,133
Segment income	301,295	165,798	86,413
Average earnings assets	2,918,800	2,551,278	2,202,595
Commercial And Corporate Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	109,822	191,917	135,591
Non-interest income	18,189	16,032	12,606
Commercial And Corporate Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	205,888	201,684	155,254
Net (charge) credit for transfer of funds	(96,066)	(9,767)	(19,663)
Interest expense	0	0	0
Net interest income	109,822	191,917	135,591
Provision for credit losses - (benefit) expense	(20,241)	(67,544)	74,607
Non-interest income	18,189	16,032	12,606
Direct non-interest expenses	37,131	36,219	28,631
Segment income	111,121	239,274	44,959
Average earnings assets	3,626,107	3,793,945	3,039,786
Treasury And Investments Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	39,600	59,331	87,879
Non-interest income	(74)	227	13,708
Treasury And Investments Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	104,215	67,841	55,003
Net (charge) credit for transfer of funds	(43,838)	14,687	59,074
Interest expense	(20,777)	(23,197)	(26,198)
Net interest income	39,600	59,331	87,879
Provision for credit losses - (benefit) expense	(434)	(136)	2,774
Non-interest income	(74)	227	13,708
Direct non-interest expenses	3,702	4,093	3,449
Segment income	36,258	55,601	95,364
Average earnings assets	7,300,208	7,827,326	4,232,144
United States Operations Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	80,485	65,967	54,025
Non-interest income	2,860	3,963	4,630
United States Operations Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	94,782	82,194	84,169
Net (charge) credit for transfer of funds	(2,748)	(4,214)	(6,164)
Interest expense	(11,549)	(12,013)	(23,980)
Net interest income	80,485	65,967	54,025
Provision for credit losses - (benefit) expense	(3,073)	(975)	12,592
Non-interest income	2,860	3,963	4,630
Direct non-interest expenses	33,365	33,902	33,782
Segment income	53,053	37,003	12,281
Average earnings assets	2,069,030	2,126,528	2,026,619
Virgin Islands Operations Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	23,842	26,373	26,124
Non-interest income	7,710	6,890	7,251
Virgin Islands Operations Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest income	24,913	27,659	29,788
Net (charge) credit for transfer of funds	0	0	0
Interest expense	(1,071)	(1,286)	(3,664)
Net interest income	23,842	26,373	26,124
Provision for credit losses - (benefit) expense	1,964	(1,335)	4,400
Non-interest income	7,710	6,890	7,251
Direct non-interest expenses	27,911	28,084	28,815
Segment income	1,677	6,514	160
Average earnings assets	$ 369,504	$ 430,499	$ 458,608