Carrying amount of loans accounted for pursuant to ASC310-30 (Detail) (Westernbank Puerto Rico [Member], Acquired Loans In An F D I C Assisted Transaction [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	$ 2,733,122	$ 2,827,947	$ 3,157,663	$ 3,491,759
Less: Allowance for loan losses	(90,371)	(93,915)	(91,573)
Carrying amount, net of allowance	2,642,751	2,734,032	3,066,090
Commercial Real Estate Portfolio Segment Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	1,632,157	1,632,672
Commercial And Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	57,491	58,261
Commercial Real Estate Construction Financing Receivable Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	113,531	176,220
Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	894,264	922,361
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	35,679	38,433
Performing Financing Receivable Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	2,469,453	2,509,075	2,758,944	3,051,964
Less: Allowance for loan losses	(56,953)	(57,594)	(52,542)
Carrying amount, net of allowance	2,412,500	2,451,481	2,706,402
Performing Financing Receivable Member | Commercial Real Estate Portfolio Segment Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	1,481,476	1,483,331
Performing Financing Receivable Member | Commercial And Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	55,268	55,192
Performing Financing Receivable Member | Commercial Real Estate Construction Financing Receivable Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	58,975	71,864
Performing Financing Receivable Member | Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	840,490	862,878
Performing Financing Receivable Member | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	33,244	35,810
Nonperforming Financing Receivable Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	263,669	318,872	398,719	439,795
Less: Allowance for loan losses	(33,418)	(36,321)	(39,031)
Carrying amount, net of allowance	230,251	282,551	359,688
Nonperforming Financing Receivable Member | Commercial Real Estate Portfolio Segment Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	150,681	149,341
Nonperforming Financing Receivable Member | Commercial And Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	2,223	3,069
Nonperforming Financing Receivable Member | Commercial Real Estate Construction Financing Receivable Member
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	54,556	104,356
Nonperforming Financing Receivable Member | Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	53,774	59,483
Nonperforming Financing Receivable Member | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount	$ 2,435	$ 2,623