Assets and Liabilities Recorded at Fair Value on Recurring Basis (Detail) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Assets
Derivative assets	$ 4,013	$ 8,051
Asset-backed Securities \| Fair Value, Measurements, Recurring \| Level 3 \| Acacia
Liabilities
ABS issued	273,325
Asset-backed Securities \| Fair Value, Measurements, Recurring \| Acacia
Liabilities
ABS issued	273,325
Fair Value, Measurements, Recurring
Assets
Commercial real estate loans	12,698
Trading securities	296,978
Available-for-sale securities	740,623
Derivative assets	4,013
Liabilities
Derivative liabilities	82,639
Fair Value, Measurements, Recurring \| Level 1
Assets
Derivative assets	276
Liabilities
Derivative liabilities	1,425
Fair Value, Measurements, Recurring \| Level 2
Assets
Derivative assets	3,737
Liabilities
Derivative liabilities	81,214
Fair Value, Measurements, Recurring \| Level 3
Assets
Commercial real estate loans	12,698
Trading securities	296,978
Available-for-sale securities	$ 740,623

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

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 Trading Securities which consist of all investments in certain debt and equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for which an entity has elected the fair value option. Trading generally reflects active and frequent buying and selling, and trading securities are generally used with the objective of generating profits on short-term differences in price, but this category of investments may also include items which are not intended to be sold in the near term or for which the fair value option has been elected.

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