INTEREST AND DIVIDEND ON INVESTMENTS- Interest on investments and FHLB dividend income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Income And Expenses [Line Items]
Mortgage-backed securities	$ 50,065	$ 40,281	$ 37,044
PR Government obligations, U.S. Treasury securities and U.S. Government agencies	21,372	16,267	19,788
Total Intesrest income investment securities	72,893	58,547	59,546
Interest on money market investments and interest-bearing cash accounts	2,662	3,388	13,353
Total interest income and dividends on investments	75,555	61,935	72,899
Taxable [Member]
Other Income And Expenses [Line Items]
Mortgage-backed securities	31,398	9,404	7,812
PR Government obligations, U.S. Treasury securities and U.S. Government agencies	5,513	1,032	165
Other investment securities (including FHLB dividends)	1,456	1,999	2,714
Interest on money market investments and interest-bearing cash accounts	2,661	3,386	13,205
Exempt [Member]
Other Income And Expenses [Line Items]
Mortgage-backed securities	18,667	30,877	29,232
PR Government obligations, U.S. Treasury securities and U.S. Government agencies	15,859	15,235	19,623
Interest on money market investments and interest-bearing cash accounts	$ 1	$ 2	$ 148