FAIR VALUE - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Securities available for sale:
Investment securities available for sale	$ 1,597,847	$ 1,923,268
Liabilities:
Fair value of notes payable		15,968
Derivatives, included in liabilities:
Total	1,604,611	1,948,347
Medium term notes [Member]
Liabilities:
Fair value of notes payable		15,968
Embedded written options on stock index deposits and notes payable [Member]
Derivatives, included in liabilities:
Derivatives, included in liabilities		899
Forward Contracts [Member]
Derivatives, included in liabilities:
Derivatives, included in liabilities	190	168
Equity Securities [Member]
Securities available for sale:
Investment securities available for sale	40	41
U.S. Treasury securities [Member]
Securities available for sale:
Investment securities available for sale	7,495	476,992
Non-callable U.S. agency debt [Member]
Securities available for sale:
Investment securities available for sale		301,585
Callable U.S. agency debt and MBS [Member]
Securities available for sale:
Investment securities available for sale	1,472,277	859,818
Puerto Rico Government obligations [Member]
Securities available for sale:
Investment securities available for sale	63,346	222,613
Private label MBS [Member]
Securities available for sale:
Investment securities available for sale	54,689	61,206
Corporate bonds [Member]
Securities available for sale:
Investment securities available for sale		1,013
Interest Rate Cap [Member]
Derivatives, included in assets:
Derivatives, included in assets	318	378
Derivatives, included in liabilities:
Derivatives, included in liabilities	6,238	6,767
Purchased options used to manage exposure to the stock market on embedded stock index options [Member]
Derivatives, included in assets:
Derivatives, included in assets		899
Forward contracts [Member]
Derivatives, included in assets:
Derivatives, included in assets	18
Level 1 [Member]
Derivatives, included in liabilities:
Total	7,535	778,618
Level 1 [Member] \| Equity Securities [Member]
Securities available for sale:
Investment securities available for sale	40	41
Level 1 [Member] \| U.S. Treasury securities [Member]
Securities available for sale:
Investment securities available for sale	7,495	476,992
Level 1 [Member] \| Non-callable U.S. agency debt [Member]
Securities available for sale:
Investment securities available for sale		301,585
Level 2 [Member]
Derivatives, included in liabilities:
Total	1,538,644	1,104,266
Level 2 [Member] \| Medium term notes [Member]
Liabilities:
Fair value of notes payable		15,968
Level 2 [Member] \| Embedded written options on stock index deposits and notes payable [Member]
Derivatives, included in liabilities:
Derivatives, included in liabilities		899
Level 2 [Member] \| Forward Contracts [Member]
Derivatives, included in liabilities:
Derivatives, included in liabilities	190	168
Level 2 [Member] \| Callable U.S. agency debt and MBS [Member]
Securities available for sale:
Investment securities available for sale	1,472,277	859,818
Level 2 [Member] \| Puerto Rico Government obligations [Member]
Securities available for sale:
Investment securities available for sale	59,603	219,369
Level 2 [Member] \| Interest Rate Cap [Member]
Derivatives, included in assets:
Derivatives, included in assets	318	378
Derivatives, included in liabilities:
Derivatives, included in liabilities	6,238	6,767
Level 2 [Member] \| Purchased options used to manage exposure to the stock market on embedded stock index options [Member]
Derivatives, included in assets:
Derivatives, included in assets		899
Level 2 [Member] \| Forward contracts [Member]
Derivatives, included in assets:
Derivatives, included in assets	18
Level 3 [Member]
Derivatives, included in liabilities:
Total	58,432	65,463
Level 3 [Member] \| Puerto Rico Government obligations [Member]
Securities available for sale:
Investment securities available for sale	3,743	3,244
Level 3 [Member] \| Private label MBS [Member]
Securities available for sale:
Investment securities available for sale	54,689	61,206
Level 3 [Member] \| Corporate bonds [Member]
Securities available for sale:
Investment securities available for sale		$ 1,013

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

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- Definition

Derivative instrument obligations meeting the definition of a liability which the Company is a party to as of the balance sheet date.

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- Definition

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