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], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Accretable yield
Beginning Balance	$ 1,379,612	$ 1,574,850	$ 1,451,669	$ 1,470,259
Accretion	(68,529)	(66,168)	(196,055)	(209,493)
Change In Expected Cash Flows	(1,465)	(37,800)	54,004	210,116
Ending Balance	1,309,618	1,470,882	1,309,618	1,470,882
Carrying amount of loans
Beginning Balance	3,012,866	3,729,489	3,491,759	4,036,471
Accretion	68,529	66,168	196,055	209,493
Collections	(190,346)	(168,448)	(796,765)	(618,755)
Ending Balance	2,891,049	3,627,209	2,891,049	3,627,209
Less: Allowance for loan losses	(108,874)	(103,547)	(108,874)	(103,547)	(95,407)
Carrying amount, net of allowance	2,782,175	3,523,662	2,782,175	3,523,662	3,396,352
Performing Financing Receivable Member
Accretable yield
Beginning Balance	1,365,670	1,550,959	1,446,381	1,428,764
Accretion	(69,146)	(61,540)	(190,607)	(191,989)
Change In Expected Cash Flows	4,879	(29,029)	45,629	223,615
Ending Balance	1,301,403	1,460,390	1,301,403	1,460,390
Carrying amount of loans
Beginning Balance	2,653,071	3,244,957	3,051,964	3,446,451
Accretion	69,146	61,540	190,607	191,989
Collections	(166,611)	(149,583)	(686,965)	(481,526)
Ending Balance	2,555,606	3,156,914	2,555,606	3,156,914
Less: Allowance for loan losses	(49,744)	(64,015)	(49,744)	(64,015)	(48,365)
Carrying amount, net of allowance	2,505,862	3,092,899	2,505,862	3,092,899	3,003,599
Nonperforming Financing Receivable Member
Accretable yield
Beginning Balance	13,942	23,891	5,288	41,495
Accretion	617	(4,628)	(5,448)	(17,504)
Change In Expected Cash Flows	(6,344)	(8,771)	8,375	(13,499)
Ending Balance	8,215	10,492	8,215	10,492
Carrying amount of loans
Beginning Balance	359,795	484,532	439,795	590,020
Accretion	(617)	4,628	5,448	17,504
Collections	(23,735)	(18,865)	(109,800)	(137,229)
Ending Balance	335,443	470,295	335,443	470,295
Less: Allowance for loan losses	(59,130)	(39,532)	(59,130)	(39,532)	(47,042)
Carrying amount, net of allowance	$ 276,313	$ 430,763	$ 276,313	$ 430,763	$ 392,753