Loans - Additional Information (Detail) (USD $)	Jun. 30, 2011 Covered under Loss Sharing Agreements with FDIC Westernbank Puerto Rico ASC Subtopic 310 30	Dec. 31, 2010 Covered under Loss Sharing Agreements with FDIC Westernbank Puerto Rico ASC Subtopic 310 30	Jun. 30, 2011 Covered under Loss Sharing Agreements with FDIC Westernbank Puerto Rico ASC Subtopic 310 20	Dec. 31, 2010 Covered under Loss Sharing Agreements with FDIC Westernbank Puerto Rico ASC Subtopic 310 20	Jun. 30, 2010 Covered under Loss Sharing Agreements with FDIC Westernbank Puerto Rico ASC Subtopic 310 20	Jun. 30, 2011 Acquired loans in an FDIC assisted transaction Westernbank Puerto Rico	Dec. 31, 2010 Acquired loans in an FDIC assisted transaction Westernbank Puerto Rico	Apr. 30, 2010 Acquired loans in an FDIC assisted transaction Westernbank Puerto Rico	Jun. 30, 2011 Acquired loans in an FDIC assisted transaction Westernbank Puerto Rico Consumer	Dec. 31, 2010 Acquired loans in an FDIC assisted transaction Westernbank Puerto Rico Consumer	Jun. 30, 2011 Non Covered Loans		Dec. 31, 2010 Non Covered Loans		Jun. 30, 2011 Covered under Loss Sharing Agreements with FDIC		Dec. 31, 2010 Covered under Loss Sharing Agreements with FDIC		Jun. 30, 2011 Covered under Loss Sharing Agreements with FDIC Consumer	Jun. 30, 2011 Consumer	Dec. 31, 2010 Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on which the accrual of interest income had been discontinued											$ 1,652,465,000	[1]	$ 1,571,853,000	[2]	$ 14,979,000	[3]	$ 25,975,000	[3]	$ 827,000	$ 49,000,000	$ 60,000,000
Unpaid principal balance of acquired loans								8,100,000,000
Outstanding principal balance of covered loans	$ 6,800,000,000	$ 7,700,000,000	$ 400,000,000	$ 300,000,000	$ 300,000,000	$ 4,265,065,000	$ 4,539,928,000		$ 122,903,000	$ 154,400,000

[1] For purposes of this table non-performing loans exclude $400 million in non-performing loans held-for-sale.

[2] For purposes of this table non-performing loans exclude $672 million in non-performing loans held-for-sale.

[3] Covered loans accounted for under ASC Subtopic 310-30 are excluded from the above table as they are considered to be performing due to the application of the accretion method, in which these loans will accrete interest income over the remaining life of the loans using estimated cash flow analyses.