Activity in Allowance for Loan Losses Related to ASC 310-30 Acquired Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of period	$ 683,368	$ 803,264	$ 730,607	$ 815,308
Provision for loan losses	249,408	119,199	473,264	219,922
Charge-offs	(132,181)	(189,995)	(270,566)	(334,684)
Balance at end of period	635,219	766,030	635,219	766,030
Westernbank Puerto Rico [Member] | Acquired Loans In An F D I C Assisted Transaction [Member] | Nonperforming Financing Receivable Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of period	91,573	94,559	95,407	83,477
Provision for loan losses	17,568	28,221	31,608	39,591
Charge-offs	(17,946)	(28,809)	(35,820)	(29,097)
Balance at end of period	$ 91,195	$ 93,971	$ 91,195	$ 93,971