SEGMENT INFORMATION - revenues and selected balance sheet data by geography based on the location (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 804,208	$ 766,469	$ 707,277
Total assets	18,793,071	12,611,266
Deposits	15,317,383	9,348,429
Brokered certificates of deposit	216,172	435,089
Puerto Rico [Member]
Segment Reporting Information [Line Items]
Total revenues	678,370	628,489	581,269
Total assets	16,091,112	10,059,890	9,797,267
Total gross loans held for investment portfolio	9,367,032	6,695,953	6,586,033
Deposits	12,338,934	6,422,864	6,208,531
Brokered certificates of deposit	109,000	243,400	441,100
United States [Member]
Segment Reporting Information [Line Items]
Total revenues	88,799	100,213	86,991
Total assets	2,117,966	2,048,260	1,940,633
Total gross loans held for investment portfolio	1,993,797	1,879,346	1,834,088
Deposits	1,622,481	1,661,657	1,519,362
Brokered certificates of deposit	107,100	191,700	114,500
Virgin Islands [Member]
Segment Reporting Information [Line Items]
Total revenues	37,039	37,767	39,017
Total assets	583,993	503,116	505,661
Total gross loans held for investment portfolio	466,749	466,383	481,188
Deposits	$ 1,355,968	$ 1,263,908	$ 1,266,821