995300 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 995301 - Statement - Condensed Consolidated Statements of Financial Condition (Unaudited) link:presentationLink link:calculationLink link:definitionLink 995302 - Statement - Condensed Consolidated Statements of Financial Condition (Unaudited) (Parentheticals) link:presentationLink link:calculationLink link:definitionLink 995303 - Statement - Condensed Consolidated Statements of Operations (Unaudited) link:presentationLink link:calculationLink link:definitionLink 995304 - Statement - Condensed Consolidated Statements of Changes In Equity (Unaudited) link:presentationLink link:calculationLink link:definitionLink 995305 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited) link:presentationLink link:calculationLink link:definitionLink 995306 - Disclosure - Organization and Basis of Presentation link:presentationLink link:calculationLink link:definitionLink 995307 - Disclosure - New Accounting Standards link:presentationLink link:calculationLink link:definitionLink 995308 - Disclosure - Asset Acquisition link:presentationLink link:calculationLink link:definitionLink 995309 - Disclosure - Receivables from, Payables to, and Deposits with Broker-Dealers and Clearing Organizations link:presentationLink link:calculationLink link:definitionLink 995310 - Disclosure - Fair Value Measurements link:presentationLink link:calculationLink link:definitionLink 995311 - Disclosure - Property, Office Facilities, and Equipment, Net link:presentationLink link:calculationLink link:definitionLink 995312 - Disclosure - Software, Net link:presentationLink link:calculationLink link:definitionLink 995313 - Disclosure - Leases link:presentationLink link:calculationLink link:definitionLink 995314 - Disclosure - Goodwill and Other Intangible Assets, Net link:presentationLink link:calculationLink link:definitionLink 995315 - Disclosure - Investments, Cost link:presentationLink link:calculationLink link:definitionLink 995316 - Disclosure - Long-Term Debt link:presentationLink link:calculationLink link:definitionLink 995317 - Disclosure - Deferred Contract Incentive link:presentationLink link:calculationLink link:definitionLink 995318 - Disclosure - Revenue Recognition link:presentationLink link:calculationLink link:definitionLink 995319 - Disclosure - Income Taxes link:presentationLink link:calculationLink link:definitionLink 995320 - Disclosure - Capital Requirements link:presentationLink link:calculationLink link:definitionLink 995321 - Disclosure - Financial Instruments with Off-Balance Sheet Risk link:presentationLink link:calculationLink link:definitionLink 995322 - Disclosure - Earnings Per Common Share link:presentationLink link:calculationLink link:definitionLink 995323 - Disclosure - Commitments, Contingencies, and Other link:presentationLink link:calculationLink link:definitionLink 995324 - Disclosure - Segment Reporting link:presentationLink link:calculationLink link:definitionLink 995325 - Disclosure - Employee Benefit Plans link:presentationLink link:calculationLink link:definitionLink 995326 - Disclosure - Related Party Disclosures link:presentationLink link:calculationLink link:definitionLink 995327 - Disclosure - Subsequent Events link:presentationLink link:calculationLink link:definitionLink 995328 - Disclosure - Insider Trading Arrangements link:presentationLink link:calculationLink link:definitionLink 996329 - Disclosure - New Accounting Standards (Policies) link:presentationLink link:calculationLink link:definitionLink 996330 - Disclosure - Asset Acquisition (Tables) link:presentationLink link:calculationLink link:definitionLink 996331 - Disclosure - Receivables from, Payables to, and Deposits with Broker-Dealers and Clearing Organizations (Tables) link:presentationLink link:calculationLink link:definitionLink 996332 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 996333 - Disclosure - Property, Office Facilities, and Equipment, Net (Tables) link:presentationLink link:calculationLink link:definitionLink 996334 - Disclosure - Software, Net (Tables) link:presentationLink link:calculationLink link:definitionLink 996335 - Disclosure - Leases (Tables) link:presentationLink link:calculationLink link:definitionLink 996336 - Disclosure - Long-Term Debt (Tables) link:presentationLink link:calculationLink link:definitionLink 996337 - Disclosure - Revenue Recognition (Tables) link:presentationLink link:calculationLink link:definitionLink 996338 - Disclosure - Financial Instruments with Off-Balance Sheet Risk (Tables) link:presentationLink link:calculationLink link:definitionLink 996339 - Disclosure - Earnings Per Common Share (Tables) link:presentationLink link:calculationLink link:definitionLink 996340 - Disclosure - Commitments, Contingencies, and Other (Tables) link:presentationLink link:calculationLink link:definitionLink 996341 - Disclosure - Segment Reporting (Tables) link:presentationLink link:calculationLink link:definitionLink 996342 - Disclosure - Employee Benefit Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 996343 - Disclosure - Organization and Basis of Presentation (Details) link:presentationLink link:calculationLink link:definitionLink 996344 - Disclosure - Asset Acquisition (Details) link:presentationLink link:calculationLink link:definitionLink 996345 - Disclosure - Asset Acquisition - Schedule of Purchase Price (Details) link:presentationLink link:calculationLink link:definitionLink 996346 - Disclosure - Receivables from, Payables to, and Deposits with Broker-Dealers and Clearing Organizations (Details) link:presentationLink link:calculationLink link:definitionLink 996347 - Disclosure - Receivables from, Payables to, and Deposits with Broker-Dealers and Clearing Organizations - Schedule of Amounts Receivable from, Payables to, and Deposits with Broker-Dealers and Clearing Organizations (Details) link:presentationLink link:calculationLink link:definitionLink 996348 - Disclosure - Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Details) link:presentationLink link:calculationLink link:definitionLink 996349 - Disclosure - Fair Value Measurements - Schedule of U.S. Government Securities with the Market Values and Maturity Dates (Details) link:presentationLink link:calculationLink link:definitionLink 996350 - Disclosure - Fair Value Measurements - Schedule of Financial Assets and Liabilities not Measured at Fair Value (Details) link:presentationLink link:calculationLink link:definitionLink 996351 - Disclosure - Property, Office Facilities, and Equipment, Net (Details) link:presentationLink link:calculationLink link:definitionLink 996352 - Disclosure - Property, Office Facilities, and Equipment, Net - Schedule of Property, Office Facilities, and Equipment (Details) link:presentationLink link:calculationLink link:definitionLink 996353 - Disclosure - Software, Net (Details) link:presentationLink link:calculationLink link:definitionLink 996354 - Disclosure - Software, Net - Schedule of Software (Details) link:presentationLink link:calculationLink link:definitionLink 996355 - Disclosure - Software, Net - Schedule of Future Amortization of Software Assets (Details) link:presentationLink link:calculationLink link:definitionLink 996356 - Disclosure - Leases (Details) link:presentationLink link:calculationLink link:definitionLink 996357 - Disclosure - Leases - Schedule of Lease Cost (Details) link:presentationLink link:calculationLink link:definitionLink 996358 - Disclosure - Leases - Schedule of Future Annual Minimum Payments (Details) link:presentationLink link:calculationLink link:definitionLink 996359 - Disclosure - Goodwill and Other Intangible Assets, Net (Details) link:presentationLink link:calculationLink link:definitionLink 996360 - Disclosure - Investments, Cost (Details) link:presentationLink link:calculationLink link:definitionLink 996361 - Disclosure - Long-Term Debt (Details) link:presentationLink link:calculationLink link:definitionLink 996362 - Disclosure - Long-Term Debt - Schedule of Future Remaining Annual Minimum Principal Payments (Details) link:presentationLink link:calculationLink link:definitionLink 996363 - Disclosure - Deferred Contract Incentive (Details) link:presentationLink link:calculationLink link:definitionLink 996364 - Disclosure - Revenue Recognition (Details) link:presentationLink link:calculationLink link:definitionLink 996365 - Disclosure - Revenue Recognition - Schedule of Recognition of Revenue from Contracts with Customers (Details) link:presentationLink link:calculationLink link:definitionLink 996366 - Disclosure - Income Taxes (Details) link:presentationLink link:calculationLink link:definitionLink 996367 - Disclosure - Capital Requirements (Details) link:presentationLink link:calculationLink link:definitionLink 996368 - Disclosure - Financial Instruments with Off-Balance Sheet Risk (Details) link:presentationLink link:calculationLink link:definitionLink 996369 - Disclosure - Financial Instruments with Off-Balance Sheet Risk - Schedule of Securities Borrowing and Lending Activity (Details) link:presentationLink link:calculationLink link:definitionLink 996370 - Disclosure - Earnings Per Common Share (Details) link:presentationLink link:calculationLink link:definitionLink 996371 - Disclosure - Earnings Per Common Share - Schedule of Basic and Diluted Earnings Per Common Share (Details) link:presentationLink link:calculationLink link:definitionLink 996372 - Disclosure - Commitments, Contingencies, and Other (Details) link:presentationLink link:calculationLink link:definitionLink 996373 - Disclosure - Commitments, Contingencies, and Other - Schedule of Early Termination Fee Upon Occurrence Pursuant (Details) link:presentationLink link:calculationLink link:definitionLink 996374 - Disclosure - Segment Reporting (Details) link:presentationLink link:calculationLink link:definitionLink 996375 - Disclosure - Segment Reporting - Schedule of Other Segment Items (Details) link:presentationLink link:calculationLink link:definitionLink 996376 - Disclosure - Employee Benefit Plans (Details) link:presentationLink link:calculationLink link:definitionLink 996377 - Disclosure - Employee Benefit Plans - Schedule of Plan Awards Granted and the Related Fair Values (Details) link:presentationLink link:calculationLink link:definitionLink 996378 - Disclosure - Related Party Disclosures (Details) link:presentationLink link:calculationLink link:definitionLink 996379 - Disclosure - Subsequent Events (Details) link:presentationLink link:calculationLink link:definitionLink