Changes in the accretable yield for the acquired loans in the Westernbank FDIC-assisted transaction (Detail) (Westernbank Puerto Rico [Member], Acquired Loans In An F D I C Assisted Transaction [Member], Covered Under Loss Sharing Agreements With F D I C [Member], A S C Subtopic 31030 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Accretable yield
Beginning Balance	$ 1,280,758	$ 1,379,612	$ 1,309,205	$ 1,451,669
Accretion	(66,017)	(68,529)	(224,998)	(196,055)
Change In Expected Cash Flows	97,780	(1,465)	228,314	54,004
Ending Balance	1,312,521	1,309,618	1,312,521	1,309,618
Carrying amount of loans
Beginning Balance	2,610,664	3,012,866	2,827,947	3,491,759
Accretion	66,017	68,529	224,998	196,055
Collections	(148,248)	(190,346)	(524,512)	(796,765)
Ending Balance	2,528,433	2,891,049	2,528,433	2,891,049
Less: Allowance for loan losses	(85,640)	(108,874)	(85,640)	(108,874)	(93,915)
Carrying amount, net of allowance	2,442,793	2,782,175	2,442,793	2,782,175	2,734,032
Performing Financing Receivable Member
Accretable yield
Beginning Balance	1,271,202	1,365,670	1,297,725	1,446,381
Accretion	(62,958)	(69,146)	(212,826)	(190,607)
Change In Expected Cash Flows	95,920	4,879	219,265	45,629
Ending Balance	1,304,164	1,301,403	1,304,164	1,301,403
Carrying amount of loans
Beginning Balance	2,387,911	2,653,071	2,509,075	3,051,964
Accretion	62,958	69,146	212,826	190,607
Collections	(124,265)	(166,611)	(395,297)	(686,965)
Ending Balance	2,326,604	2,555,606	2,326,604	2,555,606
Less: Allowance for loan losses	(52,812)	(49,744)	(52,812)	(49,744)	(57,594)
Carrying amount, net of allowance	2,273,792	2,505,862	2,273,792	2,505,862	2,451,481
Nonperforming Financing Receivable Member
Accretable yield
Beginning Balance	9,556	13,942	11,480	5,288
Accretion	(3,059)	617	(12,172)	(5,448)
Change In Expected Cash Flows	1,860	(6,344)	9,049	8,375
Ending Balance	8,357	8,215	8,357	8,215
Carrying amount of loans
Beginning Balance	222,753	359,795	318,872	439,795
Accretion	3,059	(617)	12,172	5,448
Collections	(23,983)	(23,735)	(129,215)	(109,800)
Ending Balance	201,829	335,443	201,829	335,443
Less: Allowance for loan losses	(32,828)	(59,130)	(32,828)	(59,130)	(36,321)
Carrying amount, net of allowance	$ 169,001	$ 276,313	$ 169,001	$ 276,313	$ 282,551