Receivables from and Payables to Broker-Dealers, Clearing Organizations, Customers and Related Broker-Dealers (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Receivables from broker-dealers, clearing organizations, customers and related broker-dealers:
Contract values of fails to deliver	$ 693,321	$ 130,675
Receivables from clearing organizations	48,585	48,681
Other receivables from broker-dealers and customers	11,581	8,060
Open derivative contracts	1,160	1,185
Net pending trades	9,216	3,452
Total	763,863	192,053
Payables to broker-dealers, clearing organizations, customers and related broker-dealers:
Contract values of fails to receive	625,014	124,282
Payables to clearing organizations	13,032	5,077
Other payables to broker-dealers and customers	47,821	14,990
Open derivative contracts	297	334
Total	$ 686,164	$ 144,683

Payable for open derivative contracts.

No definition available.

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- Definition

Receivable from net pending trades.

+ References

No definition available.

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- Definition

Receivable from open derivative contracts.

+ References

No definition available.

+ Details

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- Definition

Amount due to other broker-dealers or clearing organizations for executing or clearing trades or orders.

+ References

+ Details

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- Definition

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

+ References

+ Details

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- Definition

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

+ References

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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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- Definition

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.

+ References

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- Definition

Cash and securities on deposit with the expectation that such deposits will be returned with organizations that provide efficient and orderly trade clearance and settlement services for which broker-dealers pay fees. Clearing organizations perform post trade processing and trade comparisons among numerous broker-dealers and act as settlement agents between buying and selling broker-dealers.

+ References

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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.

+ References

+ Details

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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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