0000001 - Document - Document and Entity Information Document link:presentationLink link:calculationLink link:definitionLink 9952151 - Statement - Condensed Consolidated Statements of Income (Unaudited) link:presentationLink link:calculationLink link:definitionLink 9952152 - Statement - Condensed Consolidated Statements of Financial Condition (Unaudited) link:presentationLink link:calculationLink link:definitionLink 9952153 - Statement - Condensed Consolidated Statements of Financial Condition (Unaudited) (Parentheticals) link:presentationLink link:calculationLink link:definitionLink 9952154 - Statement - Condensed Consolidated Statements of Stockholders' Equity (Unaudited) link:presentationLink link:calculationLink link:definitionLink 9952155 - Statement - Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952156 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited) link:presentationLink link:calculationLink link:definitionLink 9952157 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited) cash, cash equivalent and restricted cash reconciliation link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - Organization and Description of the Company link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - Revenue link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - Acquisitions (Notes) link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - Fair Value Measurements link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - Investment Securities link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - Goodwill and Other Intangible Assets link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - Other Assert and Other Liabilities link:presentationLink link:calculationLink link:definitionLink 9952166 - Disclosure - Corporate Debt and Other Borrowings, Net link:presentationLink link:calculationLink link:definitionLink 9952167 - Disclosure - Commitments and Contingencies link:presentationLink link:calculationLink link:definitionLink 9952168 - Disclosure - Stockholders' Equity link:presentationLink link:calculationLink link:definitionLink 9952169 - Disclosure - Share-Based Compensation link:presentationLink link:calculationLink link:definitionLink 9952170 - Disclosure - Earnings per Share link:presentationLink link:calculationLink link:definitionLink 9952171 - Disclosure - Net Capital and Regulatory Requirements link:presentationLink link:calculationLink link:definitionLink 9952172 - Disclosure - Financial Instruments with Off-Balance-Sheet Credit Risk and Concentrations of Credit Risk link:presentationLink link:calculationLink link:definitionLink 9952173 - Disclosure - Segment Information link:presentationLink link:calculationLink link:definitionLink 9952174 - Disclosure - Subsequent Events link:presentationLink link:calculationLink link:definitionLink 9952175 - Disclosure - Equity link:presentationLink link:calculationLink link:definitionLink 9955511 - Disclosure - Summary of Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 9955512 - Disclosure - Revenue (Tables) link:presentationLink link:calculationLink link:definitionLink 9955513 - Disclosure - Acquisitions (Tables) link:presentationLink link:calculationLink link:definitionLink 9955514 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 9955515 - Disclosure - Investment Securities (Tables) link:presentationLink link:calculationLink link:definitionLink 9955516 - Disclosure - Goodwill and Other Intangible Assets (Tables) link:presentationLink link:calculationLink link:definitionLink 9955517 - Disclosure - Other Assert and Other Liabilities (Tables) link:presentationLink link:calculationLink link:definitionLink 9955518 - Disclosure - Corporate Debt and Other Borrowings, Net (Tables) link:presentationLink link:calculationLink link:definitionLink 9955519 - Disclosure - Commitment and Contingencies (Tables) link:presentationLink link:calculationLink link:definitionLink 9955520 - Disclosure - Stockholders' Equity (Tables) link:presentationLink link:calculationLink link:definitionLink 9955521 - Disclosure - Share-Based Compensation (Tables) link:presentationLink link:calculationLink link:definitionLink 9955522 - Disclosure - Earnings per Share (Tables) link:presentationLink link:calculationLink link:definitionLink 9955523 - Disclosure - Net Capital and Regulatory Requirements (Tables) link:presentationLink link:calculationLink link:definitionLink 9955524 - Disclosure - Equity (Tables) link:presentationLink link:calculationLink link:definitionLink 9955525 - Disclosure - Organization and Description of the Company Consolidation, Parent Ownership Interest (Details) link:presentationLink link:calculationLink link:definitionLink 9955526 - Disclosure - Revenue - Asset-based Revenue disaggregated by Product and Service (Details) link:presentationLink link:calculationLink link:definitionLink 9955527 - Disclosure - Revenue - Commission Revenue Disaggregated by Product Category (Details) link:presentationLink link:calculationLink link:definitionLink 9955528 - Disclosure - Revenue - Commission Revenue Disaggregated by Product Category and Timing of Transfer of Good or Service (Details) link:presentationLink link:calculationLink link:definitionLink 9955529 - Disclosure - Revenue - Transaction and Fee Revenue Disaggregated by Timing of Transfer of Good or Service (Details) link:presentationLink link:calculationLink link:definitionLink 9955530 - Disclosure - Revenue - Unearned Revenue Recognized (Details) link:presentationLink link:calculationLink link:definitionLink 9955531 - Disclosure - Acquisitions - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955532 - Disclosure - Acquisitions - Consideration Paid (Details) link:presentationLink link:calculationLink link:definitionLink 9955533 - Disclosure - Acquisitions - Assets Acquired and Liabilities Assumed (Details) link:presentationLink link:calculationLink link:definitionLink 9955534 - Disclosure - Acquisitions - Pro Forma Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955535 - Disclosure - Fair Value Measurements - Fair Value Disclosure, Measurement of Contingent Consideration Using Monte-Carlo Simulation Model (Details) link:presentationLink link:calculationLink link:definitionLink 9955536 - Disclosure - Fair Value Measurements - Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) link:presentationLink link:calculationLink link:definitionLink 9955537 - Disclosure - Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring and Nonrecurring Basis (Details) link:presentationLink link:calculationLink link:definitionLink 9955538 - Disclosure - Fair Value Measurements - Not Measured at Fair Value (Details) link:presentationLink link:calculationLink link:definitionLink 9955539 - Disclosure - Investment Securities - Summary (Details) link:presentationLink link:calculationLink link:definitionLink 9955540 - Disclosure - Investment Securities (Details 1) link:presentationLink link:calculationLink link:definitionLink 9955541 - Disclosure - Goodwill and Other Intangible Assets - Goodwill (Details) link:presentationLink link:calculationLink link:definitionLink 9955542 - Disclosure - Goodwill and Other Intangible Assets - Intangible Assets (Components) (Details) link:presentationLink link:calculationLink link:definitionLink 9955543 - Disclosure - Goodwill and Other Intangible Assets (Future Amortization Expense) (Details) link:presentationLink link:calculationLink link:definitionLink 9955544 - Disclosure - Other Assert and Other Liabilities - Schedule of Other Assets and Other Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9955545 - Disclosure - Corporate Debt and Other Borrowings, Net (Long-Term Borrowings Outstanding) (Details) link:presentationLink link:calculationLink link:definitionLink 9955546 - Disclosure - Corporate Debt and Other Borrowings, Net (Other Borrowings Outstanding) (Details) link:presentationLink link:calculationLink link:definitionLink 9955547 - Disclosure - Corporate Debt and Other Borrowings, Net - Textuals (Details) link:presentationLink link:calculationLink link:definitionLink 9955548 - Disclosure - Commitments and Contingencies (Legal) (Details) link:presentationLink link:calculationLink link:definitionLink 9955549 - Disclosure - Commitments and Contingencies (Other Commitments) (Details) link:presentationLink link:calculationLink link:definitionLink 9955550 - Disclosure - Commitments and Contingencies - Self insurance Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9955551 - Disclosure - Stockholders' Equity (Dividends Paid) (Details) link:presentationLink link:calculationLink link:definitionLink 9955552 - Disclosure - Stockholdes' Equity (Share Repurchases) (Details) link:presentationLink link:calculationLink link:definitionLink 9955553 - Disclosure - Share-Based Compensation - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955554 - Disclosure - Share-Based Compensation - Stock Option and Warrant Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9955555 - Disclosure - Share-Based Compensation - Restricted Stock Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9955556 - Disclosure - Earnings per Share (Details) link:presentationLink link:calculationLink link:definitionLink 9955557 - Disclosure - Earnings per Share (Textuals) (Details) link:presentationLink link:calculationLink link:definitionLink 9955558 - Disclosure - Net Capital and Regulatory Requirements (Details) link:presentationLink link:calculationLink link:definitionLink 9955559 - Disclosure - Segment Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955560 - Disclosure - Subsequent Events - Dividend Declared (Details) link:presentationLink link:calculationLink link:definitionLink 9955561 - Disclosure - Equity (Details) link:presentationLink link:calculationLink link:definitionLink