INTEREST AND DIVIDEND ON INVESTMENTS- Interest on investments and FHLB dividend income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income And Expenses [Line Items]
Mortgage-backed securities	$ 44,909	$ 45,521	$ 35,532
PR Government obligations, U.S. Treasury securities and U.S. Government agencies	6,803	6,647	8,253
Total Intesrest income investment securities	52,881	53,527	45,294
Interest on money market investments	1,892	1,927	1,827
Total interest and dividends on investments	54,773	55,454	47,121
Taxable [Member]
Other Income And Expenses [Line Items]
Mortgage-backed securities	16,303	19,566	23,989
PR Government obligations, U.S. Treasury securities and U.S. Government agencies	1,357	1,218	1,468
Other investment securities (including FHLB dividends)	1,169	1,359	1,503
Interest on money market investments	1,734	1,231	1,137
Taxable [Member] | Equity Securities [Member]
Other Income And Expenses [Line Items]
Equity Securities	0	0	6
Exempt [Member]
Other Income And Expenses [Line Items]
Mortgage-backed securities	28,606	25,955	11,543
PR Government obligations, U.S. Treasury securities and U.S. Government agencies	5,446	5,429	6,785
Interest on money market investments	$ 158	$ 696	$ 690