Financial Instruments with Off-Balance-Sheet Risk and Credit Risk	12 Months Ended
Dec. 31, 2015
Risks And Uncertainties [Abstract]
Financial Instruments with Off-Balance-Sheet Risk and Credit Risk	Note 13. Financial Instruments with Off-Balance-Sheet Risk and Credit Risk: Financial Instruments The Company’s trading and investment activities include equity securities, convertible debt securities, corporate debt securities, bank loans, and listed equity options that are primarily traded in United States markets. The Company also invests in non-registered investment funds that trade and invest in public and non-public debt and equity securities. As of December 31, 2015 and 2014, the Company had not entered into any transactions involving financial instruments that would expose the Company to significant related off-balance-sheet risk. In addition, as part of its market making activities, the Company sells equity and debt securities it does not currently own (financial instruments sold, not yet purchased—see Note 3 Financial Instruments). When the Company sells a security short and borrows the security to make a delivery, a gain, limited to the price at which the Company sold the security short, or a loss, unlimited in size, will be realized upon the termination of the short sale. Market Risk The securities industry is subject to numerous risks, including the risk of loss associated with the underwriting, ownership, and trading of securities, and the risk of reduced revenues in periods of reduced demand for security offerings and activity in secondary trading markets. Changing economic and market trends may negatively impact the liquidity and value of the Company’s investments and the level of security offerings underwritten by the Company, which may adversely affect the Company’s revenues and profitability. Market risk is primarily caused by movements in market prices of the Company’s trading and investment securities and changes in value of the underlying securities of the investment funds in which the Company invests. The Company’s trading securities and investments are also subject to interest rate volatility and possible illiquidity in markets in which the Company trades or invests. The Company seeks to manage market risk through monitoring procedures. The Company’s principal transactions are primarily long and short equity and convertible debt transactions. Positions taken and commitments made by the Company, including those made in connection with investment banking activities, may result in substantial amounts of exposure to individual issuers and businesses, including non-investment grade issuers, securities with low trading volumes and those not readily marketable. These issuers and securities may expose the Company to a higher degree of risk than associated with investment grade instruments. Credit Risk The Company’s broker-dealer subsidiaries clear all of their securities transactions through clearing brokers on a fully disclosed basis. Pursuant to the terms of the agreements between the Company’s broker-dealer subsidiaries and their clearing brokers, the clearing brokers have the right to charge the Company for losses that result from a counterparty’s failure to fulfill its contractual obligations. As the right to charge our broker-dealer subsidiaries has no maximum amount and applies to all trades executed through the clearing brokers, the Company believes there is no maximum amount assignable to this right. At December 31, 2015 and 2014, the Company has recorded no liabilities, and during the years ended December 31, 2015, 2014 and 2013, the Company did not incur any significant costs, with regard to this right. In addition, the Company has the right to pursue collection from the counterparties who do not perform under their contractual obligations. The Company monitors the credit standing of the clearing brokers and all counterparties with which it conducts business. The Company attempts to limit its credit spread risk by offsetting long or short positions in various related securities. Through indemnification provisions in agreements with clearing organizations, customer activities may expose the Company to off-balance-sheet credit risk. Financial instruments may have to be purchased or sold at prevailing market prices in the event a customer fails to settle a trade on its original terms or in the event cash and securities in customer margin accounts are not sufficient to fully cover customer obligations. The Company seeks to manage the risks associated with customer activities through customer screening and selection procedures as well as through requirements on customers to maintain margin collateral in compliance with various regulations and clearing organization policies. Credit risk from the Company’s securities lending operations arises if a lender or borrower defaults on an outstanding securities loan or borrow transaction and the cash or securities the Company is holding is insufficient to cover the amount they owe the Company for that receivable. The Company assigns credit limits and collateral posting thresholds for each counterparty and these limits and thresholds are reviewed periodically. The Company’s equity and debt securities held for trading and investment purposes include non-investment grade securities of privately held issuers with no ready markets. The concentration and illiquidity of these investments expose the Company to a higher degree of risk than associated with readily marketable securities.

Note 13. Financial Instruments with Off-Balance-Sheet Risk and Credit Risk:

Financial Instruments

The Company’s trading and investment activities include equity securities, convertible debt securities, corporate debt securities, bank loans, and listed equity options that are primarily traded in United States markets. The Company also invests in non-registered investment funds that trade and invest in public and non-public debt and equity securities. As of December 31, 2015 and 2014, the Company had not entered into any transactions involving financial instruments that would expose the Company to significant related off-balance-sheet risk.

In addition, as part of its market making activities, the Company sells equity and debt securities it does not currently own (financial instruments sold, not yet purchased—see Note 3 Financial Instruments). When the Company sells a security short and borrows the security to make a delivery, a gain, limited to the price at which the Company sold the security short, or a loss, unlimited in size, will be realized upon the termination of the short sale.

Market Risk

The securities industry is subject to numerous risks, including the risk of loss associated with the underwriting, ownership, and trading of securities, and the risk of reduced revenues in periods of reduced demand for security offerings and activity in secondary trading markets. Changing economic and market trends may negatively impact the liquidity and value of the Company’s investments and the level of security offerings underwritten by the Company, which may adversely affect the Company’s revenues and profitability.

Market risk is primarily caused by movements in market prices of the Company’s trading and investment securities and changes in value of the underlying securities of the investment funds in which the Company invests. The Company’s trading securities and investments are also subject to interest rate volatility and possible illiquidity in markets in which the Company trades or invests. The Company seeks to manage market risk through monitoring procedures. The Company’s principal transactions are primarily long and short equity and convertible debt transactions.

Positions taken and commitments made by the Company, including those made in connection with investment banking activities, may result in substantial amounts of exposure to individual issuers and businesses, including non-investment grade issuers, securities with low trading volumes and those not readily marketable. These issuers and securities may expose the Company to a higher degree of risk than associated with investment grade instruments.

Credit Risk

The Company’s broker-dealer subsidiaries clear all of their securities transactions through clearing brokers on a fully disclosed basis. Pursuant to the terms of the agreements between the Company’s broker-dealer subsidiaries and their clearing brokers, the clearing brokers have the right to charge the Company for losses that result from a counterparty’s failure to fulfill its contractual obligations. As the right to charge our broker-dealer subsidiaries has no maximum amount and applies to all trades executed through the clearing brokers, the Company believes there is no maximum amount assignable to this right. At December 31, 2015 and 2014, the Company has recorded no liabilities, and during the years ended December 31, 2015, 2014 and 2013, the Company did not incur any significant costs, with regard to this right. In addition, the Company has the right to pursue collection from the counterparties who do not perform under their contractual obligations. The Company monitors the credit standing of the clearing brokers and all counterparties with which it conducts business. The Company attempts to limit its credit spread risk by offsetting long or short positions in various related securities.

Through indemnification provisions in agreements with clearing organizations, customer activities may expose the Company to off-balance-sheet credit risk. Financial instruments may have to be purchased or sold at prevailing market prices in the event a customer fails to settle a trade on its original terms or in the event cash and securities in customer margin accounts are not sufficient to fully cover customer obligations. The Company seeks to manage the risks associated with customer activities through customer screening and selection procedures as well as through requirements on customers to maintain margin collateral in compliance with various regulations and clearing organization policies.

Credit risk from the Company’s securities lending operations arises if a lender or borrower defaults on an outstanding securities loan or borrow transaction and the cash or securities the Company is holding is insufficient to cover the amount they owe the Company for that receivable. The Company assigns credit limits and collateral posting thresholds for each counterparty and these limits and thresholds are reviewed periodically.

The Company’s equity and debt securities held for trading and investment purposes include non-investment grade securities of privately held issuers with no ready markets. The concentration and illiquidity of these investments expose the Company to a higher degree of risk than associated with readily marketable securities.