Receivables and Payables (Details) (USD $)	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Receivables from brokers, dealers and clearing organizations
Broker-dealers	$ 807,740,000		$ 807,740,000		$ 246,560,000
Clearing organizations	408,854,000		408,854,000		413,000
Securities borrowed	618,100,000		618,100,000		618,662,000
Allowance for doubtful accounts	(351,000)		(351,000)		(384,000)
Total	1,834,343,000		1,834,343,000		865,251,000
Payables to brokers, dealers and clearing organizations
Broker-dealers	776,696,000		776,696,000		403,432,000
Clearing organizations	32,000		32,000		108,526,000
Securities loaned	630,508,000		630,508,000		628,000,000
Total	1,407,236,000		1,407,236,000		1,139,958,000
Receivables from customers
Customers	1,142,046,000		1,142,046,000		607,286,000
Allowance for doubtful accounts	(1,168,000)		(1,168,000)		(1,030,000)
Total	1,140,878,000		1,140,878,000		606,256,000
Payables to customers
Total	1,478,360,000		1,478,360,000		272,027,000
Securities Borrowed and Loaned
Fair value of securities borrowed	591,000,000		591,000,000
Interest earned	6,328,000	1,159,000	9,680,000	1,326,000
Interest incurred	(5,003,000)	(779,000)	(7,420,000)	(843,000)
Interest earned incurred, net	$ 1,325,000	$ 380,000	$ 2,260,000	$ 483,000

The gross amounts of interest incurred on cash received from counterparties as collateral for securities loaned.

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The net amount of interest earned and incurred on securities borrowed and securities loaned transactions.

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The gross amount of interest earned on cash provided to counterparties as collateral for securities borrowed.

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Amounts payable to clearing organizations on open transactions, and floor-brokerage payables.

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Represents the allowance for doubtful accounts on receivables from brokers, dealers and clearing organizations.

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Represents the allowance for doubtful accounts on receivables from customers.

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Gross amount due from customers for fees and charges arising from transactions related to the entity's brokerage activities and operations.

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This is the amount of cash advanced as security in return for borrowing securities from another party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 6
-Article 9

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The amount of cash received as security in return for loaning securities to another party.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Amount due from correspondent brokers if the broker dealer clears transactions on behalf of or through correspondents.

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Amount due to correspondent brokers if the broker-dealer clears transactions on behalf of or through correspondents.

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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.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-BRD
-Chapter 4
-Paragraph 80
-Subparagraph Exhibit 4-8, 4
-IssueDate 2006-05-01
-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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-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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Amounts payable to customers at the balance sheet date. The term customers generally excludes other broker-dealers; persons who are principal officers, directors, and stockholders; and persons whose securities or funds are part of the regulatory net capital of the broker-dealer. Another broker-dealer's account can be classified as a customer if the account is carried as an omnibus account in compliance with certain regulations. The accounts of principal officers, directors and stockholders may be combined in the customer captions if they are not material and the combination is disclosed in the oath that is required to accompany the annual audited FOCUS Report.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Rule 15c3
-Number 240
-Article 15c3
-Section 1
-Subsection c
-Paragraph 1

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-BRD
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-IssueDate 2006-05-01
-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)
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-IssueDate 2006-05-01
-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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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.

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Amount due from customers for fees and charges arising from transactions related to the entity's brokerage activities and operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-BRD
-Chapter 4
-Paragraph 35
-IssueDate 2006-05-01
-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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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. This item represents the aggregate of securities borrowed from broker-dealers or institutions (a) to deliver them in place of securities not available because of short-sales or late or ineffective deliveries; (b) to lend them in connection with finder or conduit transactions; and (c) to be used for other purposes permitted under federal regulations.

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