INVESTMENT SECURITIES - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014 minimumcreditscore	Sep. 30, 2013	Sep. 30, 2014 minimumcreditscore	Sep. 30, 2013	Dec. 31, 2013
Schedule Of Investments [Line Items]
Proceeds from sale of available-for-sale securities			$ 4,855,000	$ 0
Percentage Of Debt Securities Government And Government Sponsored Agencies	96.00%		96.00%
Minimum Credit Score	700		700
Maximum loan to value ratio	80.00%
Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities			171,016,000	280,694,000
Total investment securities available for sale	1,977,137,000		1,977,137,000		1,978,282,000
Impairement on equity securities	0	0	291,000	(42,000)
Fair value	1,977,137,000		1,977,137,000		1,978,282,000
Amortized cost	2,003,704,000		2,003,704,000		2,049,262,000
Unrealized losses	41,543,000				78,795,000
Weighted average yield	2.52%		2.52%		2.57%
Mortgage Backed Securities Issued By Private Enterprises [Member]
Schedule Of Investments [Line Items]
Amortized cost of private label of mortgage backed security	48,800,000		48,800,000
Puerto Rico Government obligations [Member]
Schedule Of Investments [Line Items]
Total investment securities available for sale	46,400,000		46,400,000
Fair value	46,400,000		46,400,000
Amortized cost	61,100,000		61,100,000
Change in net unrealized gains	$ 4,900,000