Principal Changes in Fair Value as Previously Reported in Form 10-Qs Filed During 2010 and the Revised Amounts Recorded during the Measurement Period (Detail) (Westernbank Puerto Rico, USD $) In Thousands	Apr. 30, 2010
Business Acquisition [Line Items]
Assets	$ 2,337,748
Total assets	8,274,310
Total liabilities	8,274,310
As reported
Business Acquisition [Line Items]
Assets	3,322,561	[1]
Total assets	8,360,198	[1]
Total liabilities	8,360,198	[1]
As reported | Loans
Business Acquisition [Line Items]
Assets	8,554,744	[1]
As reported | Discount
Business Acquisition [Line Items]
Assets	(4,293,756)	[1]
As reported | Net loans
Business Acquisition [Line Items]
Assets	4,260,988	[1]
As reported | Other assets
Business Acquisition [Line Items]
Assets	670,419	[1]
As reported | Goodwill
Business Acquisition [Line Items]
Assets	106,230	[1]
As reported | Deposits
Business Acquisition [Line Items]
Liabilities	2,391,635	[1]
As reported | Note issued to the FDIC
Business Acquisition [Line Items]
Liabilities	5,769,696	[1]
As reported | Equity appreciation instrument
Business Acquisition [Line Items]
Liabilities	52,500	[1]
As reported | Contingent liability on unfunded loan commitments
Business Acquisition [Line Items]
Liabilities	132,442	[1]
As reported | Other liabilities
Business Acquisition [Line Items]
Liabilities	13,925	[1]
As recasted
Business Acquisition [Line Items]
Assets	2,337,748	[2]
Total assets	8,274,310	[2]
Total liabilities	8,274,310	[2]
As recasted | Loans
Business Acquisition [Line Items]
Assets	8,554,744	[2]
As recasted | Discount
Business Acquisition [Line Items]
Assets	(3,354,287)	[2]
As recasted | Net loans
Business Acquisition [Line Items]
Assets	5,200,457	[2]
As recasted | Other assets
Business Acquisition [Line Items]
Assets	649,264	[2]
As recasted | Goodwill
Business Acquisition [Line Items]
Assets	86,841	[2]
As recasted | Deposits
Business Acquisition [Line Items]
Liabilities	2,391,635	[2]
As recasted | Note issued to the FDIC
Business Acquisition [Line Items]
Liabilities	5,770,495	[2]
As recasted | Equity appreciation instrument
Business Acquisition [Line Items]
Liabilities	52,500	[2]
As recasted | Contingent liability on unfunded loan commitments
Business Acquisition [Line Items]
Liabilities	45,755	[2]
As recasted | Other liabilities
Business Acquisition [Line Items]
Liabilities	13,925	[2]
Difference/Change
Business Acquisition [Line Items]
Assets	(984,813)	[3]
Total assets	(85,888)
Total liabilities	(85,888)
Difference/Change | Discount
Business Acquisition [Line Items]
Assets	939,469	[4]
Difference/Change | Net loans
Business Acquisition [Line Items]
Assets	939,469
Difference/Change | Other assets
Business Acquisition [Line Items]
Assets	(21,155)	[5]
Difference/Change | Goodwill
Business Acquisition [Line Items]
Assets	(19,389)
Difference/Change | Note issued to the FDIC
Business Acquisition [Line Items]
Liabilities	799	[6]
Difference/Change | Contingent liability on unfunded loan commitments
Business Acquisition [Line Items]
Liabilities	(86,687)	[7]
Loans
Business Acquisition [Line Items]
Assets	5,200,457
Other assets
Business Acquisition [Line Items]
Assets	44,926
Goodwill
Business Acquisition [Line Items]
Assets	86,841
Deposits
Business Acquisition [Line Items]
Liabilities	2,391,635
Note issued to the FDIC
Business Acquisition [Line Items]
Liabilities	5,770,495
Equity appreciation instrument
Business Acquisition [Line Items]
Liabilities	52,500
Contingent liability on unfunded loan commitments
Business Acquisition [Line Items]
Liabilities	45,755
Other liabilities
Business Acquisition [Line Items]
Liabilities	$ 13,925

[1] Amounts are presented as previously reported.

[2] Amounts reported include retrospective adjustments during the measurement period (ASC Topic 805) related to the Westernbank FDIC-assisted transaction.

[3] This reduction is directly related to the reduction in estimated future credit losses as they are substantially covered by the FDIC under the 80% FDIC loss sharing agreements.

[4] Represents the increase in management's best estimate of fair value mainly driven by lower expected future credit losses on the acquired loan portfolio based on facts and circumstances existent as of the acquisition date but known to management during the measurement period. The main factors that influenced the revised estimated credit losses included review of collateral, revised appraised values, and review of borrower's payment capacity in more thorough due diligence procedures.

[5] Represents revisions to acquisition date estimated fair values of other real estate properties based on new appraisals obtained.

[6] Represents an increase in the premium on the note issued to the FDIC, also influenced by the cash flow streams impacted by the revised loan payment estimates.

[7] Reduction due to revised credit loss estimates and commitments.