0000001 - Document - Document and Entity Information link:presentationLink link:calculationLink link:definitionLink 9952151 - Statement - Consolidated Statements of Financial Condition link:presentationLink link:calculationLink link:definitionLink 9952152 - Statement - Consolidated Statements of Financial Condition (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952153 - Statement - Consolidated Statements of Operations link:presentationLink link:calculationLink link:definitionLink 9952154 - Statement - Consolidated Statements of Comprehensive Income link:presentationLink link:calculationLink link:definitionLink 9952155 - Statement - Consolidated Statements of Changes in Shareholders' Equity link:presentationLink link:calculationLink link:definitionLink 9952156 - Statement - Consolidated Statements of Cash Flows link:presentationLink link:calculationLink link:definitionLink 9952157 - Statement - Consolidated Statements of Cash Flows (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - Organization and Basis of Presentation link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - Recent Accounting Pronouncements link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - Acquisitions link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - Receivables from and Payables to Brokers, Dealers and Clearing Organizations link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - Fair Value of Financial Instruments link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - Financial Instruments and Other Inventory Positions link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - Investments link:presentationLink link:calculationLink link:definitionLink 9952166 - Disclosure - 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Disclosure - Shareholders' Equity (Tables) link:presentationLink link:calculationLink link:definitionLink 9955520 - Disclosure - Business Segment and Revenues Information (Tables) link:presentationLink link:calculationLink link:definitionLink 9955521 - Disclosure - Compensation Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 9955522 - Disclosure - Earnings Per Share (Tables) link:presentationLink link:calculationLink link:definitionLink 9955523 - Disclosure - Organization and Basis of Presentation - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955524 - Disclosure - Organization and Basis of Presentation (Details) link:presentationLink link:calculationLink link:definitionLink 9955525 - Disclosure - Recent Accounting Pronouncements (Details) link:presentationLink link:calculationLink link:definitionLink 9955526 - Disclosure - Acquisitions - Acquisition of G Squared Capital Partners (Details) link:presentationLink link:calculationLink link:definitionLink 9955527 - Disclosure - Receivables from and Payables to Brokers, Dealers and Clearing Organizations - Schedule of Receivables from and Payables to Brokers, Dealers and Clearing Organizations (Details) link:presentationLink link:calculationLink link:definitionLink 9955528 - Disclosure - Receivables from and Payables to Brokers, Dealers and Clearing Organizations - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955529 - Disclosure - Fair Value of Financial Instruments - Valuation of Financial Instruments by Pricing Observability Levels (Details) link:presentationLink link:calculationLink link:definitionLink 9955530 - Disclosure - Fair Value of Financial Instruments - Changes in Fair Value Associated with Level III Financial Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 9955531 - Disclosure - Fair Value of Financial Instruments - Information about Significant Unobservable Inputs used in Fair Value Measurement (Details) link:presentationLink link:calculationLink link:definitionLink 9955532 - Disclosure - Fair Value of Financial Instruments - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955533 - Disclosure - Financial Instruments and Other Inventory Positions - Schedule of Financial Instruments and Other Inventory Positions by Type (Details) link:presentationLink link:calculationLink link:definitionLink 9955534 - Disclosure - Financial Instruments and Other Inventory Positions - Schedule of Gross Fair Market Value and Total Absolute Notional Contract Amount (Details) link:presentationLink link:calculationLink link:definitionLink 9955534 - Disclosure - Financial Instruments and Other Inventory Positions - Schedule of Gross Fair Market Value and Total Absolute Notional Contract Amount (Details) link:presentationLink link:calculationLink link:definitionLink 9955535 - Disclosure - Financial Instruments and Other Inventory Positions - Unrealized Gains/(Losses) on Derivative Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 9955535 - Disclosure - Financial Instruments and Other Inventory Positions - Unrealized Gains/(Losses) on Derivative Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 9955536 - Disclosure - Financial Instruments and Other Inventory Positions - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955537 - Disclosure - Investments - Schedule of Investments (Details) link:presentationLink link:calculationLink link:definitionLink 9955538 - Disclosure - Variable Interest Entities - Schedule of Consolidated Variable Interest Entities (Details) link:presentationLink link:calculationLink link:definitionLink 9955539 - Disclosure - Variable Interest Entities - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955540 - Disclosure - Other Assets - Schedule of Other Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955541 - Disclosure - Short-Term Financing - 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Disclosure - Compensation Plans - Incentive Plan Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955548 - Disclosure - Compensation Plans - Restricted Stock Units (Details) link:presentationLink link:calculationLink link:definitionLink 9955549 - Disclosure - Compensation Plans - Stock Options (Details) link:presentationLink link:calculationLink link:definitionLink 9955550 - Disclosure - Compensation Plans - Inducement Plans (Details) link:presentationLink link:calculationLink link:definitionLink 9955551 - Disclosure - Compensation Plans - Stock-Based Compensation Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9955552 - Disclosure - Compensation Plans - Deferred Compensation Plans (Details) link:presentationLink link:calculationLink link:definitionLink 9955553 - Disclosure - Earnings Per Share - Computation of Earnings Per Share (Details) link:presentationLink link:calculationLink link:definitionLink 9955554 - Disclosure - Net Capital Requirements and Other Regulatory Matters - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink