Credit concentration receivable from major broker dealers.

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Margin deposited with option clearing corporation.

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Distribution on securities received by trust.

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No definition available.

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This item represents a financial instrument (as defined) for which it is not practicable to estimate fair value. Such disclosure may be for an individual financial instrument or a class of financial instruments.

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- Definition

Fair value of loans collateralized by customer securities.

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Fair value of loans collateralized by firm.

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Mortgage loan guarantee period.

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No definition available.

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Pledged securities owned and pledged as collateral amount eligible to be repledged by counterparty carrying value.

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- Definition

Receivables from Brokers-Dealers and Clearing Organizations, Number of Major Broker-Dealers

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Securities owned and pledged as collateral amount not eligible to be repledged by counterparty carrying value.

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No definition available.

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Settlement with Financial Institution, Period to Complete Transactions

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No definition available.

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Amounts due on short-term bank loans secured by customers' securities on the balance sheet date.

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- Definition

Fair value as of the balance sheet date of customer securities accepted as collateral by the entity that it is permitted by contract or custom to sell or re-pledge to counterparties as collateral.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

-Paragraph 1A

-Subparagraph (c)(1)

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- Definition

Fair value as of the balance sheet date of customer securities accepted as collateral by the entity that it has sold or re-pledged to counterparties as collateral.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

-Paragraph 1A

-Subparagraph (c)(2)

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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No definition available.

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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

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The carrying amount (fair value) as of the balance sheet date of securities held that had been pledged by counterparties under financing and lending arrangements, pursuant to which the entity has the right by agreement or custom to sell or re-pledge such securities.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5086-111524

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Collateralized Transactions - Narrative (Details)		3 Months Ended			9 Months Ended
Collateralized Transactions - Narrative (Details)	Sep. 26, 2013 USD ($)	Sep. 30, 2015 USD ($) broker-dealer	Sep. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Sep. 30, 2015 USD ($) broker-dealer	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Bank call loans		$ 147,700,000			$ 147,700,000		$ 59,400,000
Customer securities under customer margin loans available to be pledged		1,400,000,000			1,400,000,000
Customer securities under customer margin loans agreement available to be repledged		150,000,000			150,000,000
Customer securities deposited to secure obligations and margin requirements under option contracts		741,900,000			741,900,000
Outstanding letters of credit		0			0
Carrying value of pledged securities owned that can be sold or re-pledged by the counterparty		752,800,000			752,800,000		518,100,000
Carrying value of securities owned by the Company loaned or pledged		216,600,000			$ 216,600,000		149,100,000
Amount of first interim distribution	$ 9,500,000	$ 437,000		$ 600,000
Receivable from brokers and clearing organizations, number of major broker-dealers \| broker-dealer		2			2
Receivable from brokers and clearing organizations		$ 147,500,000			$ 147,500,000
Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value estimate not practicable warehouse payable		30,856,000			30,856,000		16,683,000
Nonrecurring [Member] \| Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value estimate not practicable warehouse payable		30,856,000			$ 30,856,000		16,683,000
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Settlement with Financial Institution, Period to Complete Transactions					1 day
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Settlement with Financial Institution, Period to Complete Transactions					3 days
Credit Concentration Risk [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Guaranteed mortgages for a period					15 days
Variable interest rate under warehouse facility					1 month LIBOR
Interest expense		280,000	$ 181,000		$ 790,000	$ 400,000
Securities Borrowed Transactions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer securities under customer margin loans agreement available to be repledged		55,300,000			55,300,000		4,400,000
Securities received as collateral under securities borrowed transaction with market value		290,600,000			290,600,000		235,100,000
Reverse Repurchase Agreements [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer securities under customer margin loans agreement available to be repledged		404,700,000			404,700,000		314,100,000
Securities received as collateral under securities borrowed transaction with market value		404,700,000			404,700,000		$ 312,600,000
Corporate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Collateralized loans, collateralized by firm		216,100,000			216,100,000
Other Than Corporate Customer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Collateralized loans, collateralized by customer securities		$ 335,400,000			$ 335,400,000