v2.4.0.6

Collateralized Transactions Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Collateralized transactions [Abstract]
Customer margin loans outstanding	$ 11,184,098	$ 9,851,018
Securities repledged and deposited for customers	$ 6,500,000	$ 6,400,000
Percentage of securities repledged and deposited for customers	94.00%	94.00%

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- Definition

Margin loans to clients stated net of allowance for doubtful accounts.

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- Definition

Securities acquired through agreements to resell that are shown as repledged and have been deposited in a separate bank account for the exclusive benefit of customers in accordance with SEC Rule 15c3-3.

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No definition available.

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- Definition

Percentage of securities acquired through agreements to resell that are shown as repledged and have been deposited in a separate bank account for the exclusive benefit of customers in accordance with SEC Rule 15c3-3.

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No definition available.

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