Receivable from and Payable to Brokers, Dealers, and Clearing Organizations - Schedule of Amounts Receivable from and Payable to Brokers, Dealers and Clearing Organizations (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Receivable/Payable:
Clearing organizations and other, Receivable	$ 1,047,166	$ 738,625
Securities failed to deliver, Receivable	319,808	130,180
Total Receivable	1,366,974	868,805
Clearing organizations and other, Payable	519,581	324,175
Securities failed to receive, Payable	116,333	54,549
Total Payable	$ 635,914	$ 378,724

Receivable from and Payable to Brokers, Dealers, and Clearing Organizations - Schedule of Amounts Receivable from and Payable to Brokers, Dealers and Clearing Organizations (Detail) (USD $)
In Thousands, unless otherwise specified

Jun. 30, 2013

Dec. 31, 2012

Clearing organizations and other, Receivable

$ 1,047,166

$ 738,625

Securities failed to deliver, Receivable

319,808

130,180

Total Receivable

1,366,974

868,805

Clearing organizations and other, Payable

519,581

324,175

Securities failed to receive, Payable

116,333

54,549

Total Payable

$ 635,914

$ 378,724

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- Definition

Other amounts due but not specifically defined in the taxonomy to other broker-dealers or clearing organizations.

+ References

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- Definition

Amounts due that are not specifically identified in the taxonomy and are due from other broker-dealers.

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- Definition

Aggregate amounts payable to broker-dealers and clearing organizations include amounts payable for securities failed to receive, certain deposits received for securities loaned, amounts payable to clearing organizations on open transactions, and floor-brokerage payables. In addition, the net receivable or payable arising from unsettled trades would be reflected in those captions. A broker-dealer that purchases securities, either for its own account or for a customer's account, but does not receive the securities on the settlement date records the amount of money representing the purchase price of the securities, including any accrued interest, as a liability to the selling broker-dealer. This liability is paid when the securities are received by the purchasing broker-dealer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 80

-Subparagraph Exhibit 4-8, 4

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 24, 25

-IssueDate 2006-05-01

-Chapter 7

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 24-31, 35

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Amount receivable from securities failed to deliver, certain deposits for securities borrowed, open transactions, good faith and margin deposits, commissions and floor brokerage items. Also cash and securities [guarantee] on deposit with [commodities] clearing organizations and other entities which provide services necessary to operations of the Company. This item would include, for instance, cash and securities advanced as [refundable] collateral for securities borrowed.

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- Definition

Amount recorded when a Broker Dealer sells securities but does not deliver the securities on settlement date. The amount recorded is the selling price including any accrued interest. This asset is collected upon delivery of the securities.

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- Definition

A broker-dealer that purchases securities but does not receive the securities by the agreed settlement date records the price of the securities and any accrued interest as a liability called Securities Failed-to-Receive to the selling broker. The liability is paid when the securities are received by the purchasing broker dealer.

+ References

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