Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Statistical Measurement [Domain] Statistical Measurement [Domain] Property and equipment, net Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment The Investment Center, Inc. The Investment Center, Inc. [Member] The Investment Center, Inc. Award Timing Predetermined Award Timing Predetermined [Flag] Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Commission Revenue Disaggregated by Product Category and Timing of Transfer of Good or Service [Abstract] Commission Revenue Disaggregated by Product Category and Timing of Transfer of Good or Service [Abstract] Commission Revenue Disaggregated by Product Category and Timing of Transfer of Good or Service [Abstract] Entity File Number Entity File Number Financing obligation liabilities Financing Obligation Liabilities Financing Obligation Liabilities Additional Paid-In Capital Additional Paid-in Capital [Member] Fractional shares — investment Fractional Shares [Member] Fractional Shares Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Accrued advisory and commission expenses payable Accrued Commissions And Advisory Fees Payable Balance of accrued commissions, recruiting bonus accruals, and other commissions payable. Tabular List, Table Tabular List [Table Text Block] Fair Value Measurement, Not Measured At Fair Value [Axis] Fair Value Measurement, Not Measured At Fair Value [Axis] Fair Value Measurement, Not Measured At Fair Value Senior unsecured, revolving credit facility Senior Secured, Revolving Credit Facility Due March 2026 [Member] Senior Secured, Revolving Credit Facility Due March 2026 Senior Notes Due 2028 Senior Notes Due April 2028 [Member] Senior Notes Due April 2028 Transaction and fee Transaction And Other Fees Revenue recognized in the period from transaction fees and ticket charges, subscription fees, IRA custodian fees, contract and license fees, conference fees and small or inactive account fees. Dividends Declared [Table Text Block] Dividends Declared [Table Text Block] Recently Issued & Adopted Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Restricted cash Business Combination, Recognizable Identifiable Assets Acquired and Liabilities Assumed, Restricted Cash Business Combination, Recognizable Identifiable Assets Acquired and Liabilities Assumed, Restricted Cash Type of Restructuring [Domain] Type of Restructuring [Domain] Liabilities incurred Business Combination, Consideration Transferred, Liabilities Incurred Debt Securities Debt Securities [Member] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Earnings per share, basic Basic earnings per share Earnings Per Share, Basic Other Other Expenses Adjustment to Compensation: Adjustment to Compensation [Axis] Public Offering Public Offering [Member] Public Offering Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Liabilities Liabilities, Fair Value Disclosure [Abstract] Revenues Revenue from Contract with Customer [Text Block] Cash for liabilities assumed Payments For Liabilities Assumed, Settled At Closing Payments For Liabilities Assumed, Settled At Closing Maturities of securities held-to-maturity Debt Securities, Held-to-Maturity, Maturity [Abstract] Treasury Stock, Valued, Acquired, Excluding Excise Tax Treasury Stock, Valued, Acquired, Excluding Excise Tax Treasury Stock, Valued, Acquired, Excluding Excise Tax Discount Rate Measurement Input, Discount Rate [Member] Dividends payable, date to be paid Dividends Payable, Date to be Paid Issuance of common stock to settle restricted stock units, net, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Security Owned and Sold, Not yet Purchased Fair Value, Security Name [Domain] Security Owned and Sold, Not yet Purchased Fair Value, Security Name [Domain] Measurement Input Type [Domain] Measurement Input Type [Domain] Adjustment to Compensation, Amount Adjustment to Compensation Amount Other assets Increase (Decrease) in Other Operating Assets Share-based compensation Share-Based Payment Arrangement, Noncash Expense Communications and data processing Communications and Information Technology Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Advisor loans, net Financing Receivable, after Allowance for Credit Loss Asset Acquisitions Asset Acquisitions [Member] Asset Acquisitions Income taxes paid Income Taxes Paid Securities owned — trading Debt Securities, Trading, and Equity Securities, FV-NI Cash dividends on common stock Cash dividends on common stock Dividends, Common Stock, Cash Total stockholders' equity ENDING BALANCE Equity, Attributable to Parent Measurement Frequency [Axis] Measurement Frequency [Axis] Insider Trading Policies and Procedures [Line Items] Share-based Payment Arrangement, Expense Share-Based Payment Arrangement, Expense Other Other Sundry Liabilities LPL Financial LLC LPL Financial LLC [Member] LPL Financial LLC Common stock, shares authorized Common Stock, Shares Authorized Payables to broker-dealers and clearing organizations Increase (Decrease) in Payable to Broker-Dealer and Clearing Organization Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Stock Issued During Period, Shares, New Issues Stock Issued During Period, Shares, New Issues Total liabilities and stockholders' equity Liabilities and Equity Fair Value, Recurring Fair Value, Recurring [Member] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Maximum Maximum [Member] Restricted stock awards [Member] Restricted stock awards [Member] Share awards for directors that an entity has not yet issued because the agreed-upon consideration, such as employee services, has not yet been received. Due after Year Four Finite-Lived Intangible Asset, Expected Amortization, after Year Four Amount of amortization for asset, excluding financial asset and goodwill, lacking physical substance with finite life expected to be recognized after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Debt Instrument, Interest Rate, Decrease Debt Instrument, Interest Rate, Increase (Decrease) Accounting Policies [Abstract] Accounting Policies [Abstract] Promotional Promotional Expenses The total expense recognized in the period for promotional items and business development costs. Net Carrying Value Finite-Lived Intangible Assets, Net Restricted Stock [Member] Restricted Stock [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Borrowings [Line Items] Debt Instrument [Line Items] Purchases of other investments Payments to Acquire Other Investments Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Summary of restricted stock awards and restricted stock units activity Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Treasury Stock Treasury Stock, Common [Member] Award Recipient [Axis] Award Recipient [Axis] Award Recipient [Axis] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Advisory Relationships Advisory Relationships [Member] Advisory Relationships Decrease to provisional intangible assets acquired Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Operating lease liabilities Operating Lease, Liability US Government Agencies Debt Securities US Government Agencies Debt Securities [Member] Share Repurchase Program [Line Items] Share Repurchase Program [Line Items] Loans Payable, Fair Value Disclosure Loans Payable, Fair Value Disclosure Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount LIABILITIES: Liabilities [Abstract] Acquisitions Business Combination [Text Block] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Other Acquisitions Other Acquisitions [Member] Other Acquisitions INCOME BEFORE PROVISION FOR INCOME TAXES Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Client payables Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Client Payables Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Client Payables Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Aggregate principal amount of debt issued Proceeds from Issuance of Debt Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Line of Credit Facility [Table] Line of Credit Facility [Table] Debt issuance costs Debt Issuance Costs, Gross Net income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Measurement Input Type [Axis] Measurement Input Type [Axis] U.S. government notes - at amortized cost, Within one year Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Name Measure Name Line of Credit Facility [Abstract] Line of Credit Facility [Abstract] Secured Debt Secured Debt [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Advisor loans, net Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Advisor Loans, Net Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Advisor Loans, Net Fixed Interest Rate (as percent) Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate Consolidation, Less-than-Wholly-Owned Subsidiary, Parent Ownership Interest, Effect of Change [Table] Consolidation, Less-than-Wholly-Owned Subsidiary, Parent Ownership Interest, Effect of Change [Table] Document Fiscal Period Focus Document Fiscal Period Focus Unsecured Debt Unsecured Debt [Member] Accrued advisory and commission expenses payable Changes In Accrued Commissions And Advisory Fees Payable The net change in the balance of accrued commissions, recruiting bonus accruals, and other commissions payable over the reporting period. Award Timing Method Award Timing Method [Text Block] Trailing Trailing [Member] Trailing Award Type [Axis] Award Type [Axis] Liabilities, not measured at fair value Liabilities, Not Measured At Fair Value [Abstract] Liabilities, Not Measured At Fair Value Long-term Debt Corporate long-term debt Corporate Debt and Other Borrowings, Net Long-Term Debt Legal Entity [Axis] Legal Entity [Axis] Business Combination, Pro Forma Information Business Combination, Pro Forma Information [Table Text Block] Total assets Assets Due Year One Finite-Lived Intangible Asset, Expected Amortization, Year One Trading Symbol Trading Symbol Advisor and Financial Institution Relationships Advisor And Financial Institution Relationships [Member] Advisor and financial institution relationships. Weighted-Average Grant-Date Fair Value, Vested Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Unearned Revenue [Abstract] Unearned Revenue [Abstract] Unearned Revenue [Abstract] Components of intangible assets Schedule of Intangible Assets and Goodwill [Table Text Block] Entity Address, City or Town Entity Address, City or Town CASH FLOWS FROM OPERATING ACTIVITIES: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Investment securities Debt Securities 2028, 2030 and 2035 Senior Notes 5.150% Senior Notes Due 2030, 5.750% Senior Notes Due 2035 And 4.900% Senior Notes Due 2028 [Member] 5.150% Senior Notes Due 2030, 5.750% Senior Notes Due 2035 And 4.900% Senior Notes Due 2028 Weighted-average life remaining (in years) Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Fair Value Measurement, Not Measured At Fair Value [Domain] Fair Value Measurement, Not Measured At Fair Value [Domain] Fair Value Measurement, Not Measured At Fair Value [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Restricted stock units (RSUs) [Member] Restricted Stock Units (RSUs) [Member] Uncollateralized Uncollateralized [Member] Held-to-maturity securities - at amortized cost: Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss [Abstract] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Collateral securities Collateral Securities Repledged, Delivered, or Used Total consideration Total consideration Business Combination, Consideration Transferred Assets Assets, Fair Value Disclosure [Abstract] Due Year Four Finite-Lived Intangible Asset, Expected Amortization, Year Four Entity Emerging Growth Company Entity Emerging Growth Company U.S. government notes - at fair value, Total Debt Securities, Held-to-Maturity, Fair Value Cash dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Lease assets obtained in exchange for operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Business combination, recognized identifiable assets acquired and liabilities assumed, assets Total identifiable assets acquired Business Combination, Recognized Asset Acquired, Asset Repayments of revolving credit facilities Repayments of Lines of Credit Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Less: Unamortized Debt Issuance Cost Debt Issuance Costs, Net U.S. government notes - at fair value, After five but within ten years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Level 2 Fair Value, Inputs, Level 2 [Member] Number of uncommitted lines of credit with an unspecified limit Uncommitted Lines Of Credit, Unspecified Limit The number of uncommitted lines of credit with an unspecified limit maintained by the Company. Restricted cash Restricted cash Restricted Cash and Cash Equivalent Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Net Carrying Value Indefinite-Lived Intangible Assets (Excluding Goodwill) Additions and purchase accounting adjustments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Business Combination [Domain] Business Combination [Domain] Net capital Broker-Dealer, Net Capital Share-based Payment Arrangement, Option, Exercise Price Range [Table] Share-Based Payment Arrangement, Option, Exercise Price Range [Table] Operating leases Increase (Decrease) In Right Of Use Assets And Lease Liabilities Net Increase (Decrease) In Right Of Use Assets And Lease Liabilities Net Provision for bad debts Accounts Receivable, Credit Loss Expense (Reversal) Senior Notes Due 2035 Senior Notes Due March 2035 [Member] Senior Notes Due March 2035 Secured, uncommitted lines of credit Secured, Uncommitted Lines of Credit, Due March 2025 [Member] Secured, Uncommitted Lines of Credit, Due March 2025 Other assets Other Assets, Fair Value Disclosure PEO PEO [Member] Maturities of securities held-to-maturity Investments Classified by Contractual Maturity Date [Table Text Block] Assets, not measured at fair value Assets, Not Measured At Fair Value [Abstract] Assets, Not Measured At Fair Value Proceeds from senior unsecured notes Proceeds from Issuance of Senior Long-Term Debt Contingent consideration Contingent Consideration [Member] Contingent Consideration Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Amortization expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Retained Earnings Retained Earnings [Member] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities U.S. government notes - at fair value, After one but within five years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Variable Interest Rate (as percent) Debt Instrument, Interest Rate, Effective Percentage Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] CASH AND EQUIVALENTS, CASH AND EQUIVALENTS SEGREGATED UNDER FEDERAL OR OTHER REGULATIONS AND RESTRICTED CASH — Beginning of period CASH AND EQUIVALENTS, CASH AND EQUIVALENTS SEGREGATED UNDER FEDERAL OR OTHER REGULATIONS AND RESTRICTED CASH — End of period Total cash, cash equivalents, and restricted cash shown in the statement of cash flows Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] PROVISION FOR INCOME TAXES Income Tax Expense (Benefit) Equivalency Rate Measurement Input, Equivalency Rate [Member] Measurement Input, Equivalency Rate Facility Closing Facility Closing [Member] Applicable Margin Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Sale of Stock [Domain] Sale of Stock [Domain] Other assets Total other assets Other Assets Intangible Assets, Net (Excluding Goodwill) Total intangible assets Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Principal payment of financing obligation Payment Of Financing Obligations Payment Of Financing Obligations U.S. government notes - at fair value, Within one year Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Dividends payable, date of record Dividends Payable, Date of Record Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Total liabilities at fair value Liabilities, Fair Value Disclosure Business Combination [Table] Business Combination [Table] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Intangible Assets by Major Class [Table] Schedule of Intangible Assets by Major Class [Table] Schedule of Intangible Assets by Major Class [Table] Commonwealth Financial Network Commonwealth Financial Network [Member] Commonwealth Financial Network Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Goodwill acquired Goodwill, Acquired During Period Proceeds from stock option exercises and other Proceeds from Stock Options Exercised City Area Code City Area Code Dividend payable, amount per share (in USD per share) Dividends Payable, Amount Per Share Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Number of Shares, Beginning Balance Number of Shares, Ending Balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Proceeds from maturity of securities classified as held-to-maturity Proceeds from Sale and Maturity of Held-to-Maturity Securities Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Operating lease liabilities [Extensible List] Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Other Assets and Other Liabilities Other Assets And Other Liabilities Disclosure [Text Block] Other Assets And Other Liabilities Disclosure Senior Notes Due May 2027 Senior Notes Due May 2027 [Member] Senior Notes Due May 2027 Subsequent Event Subsequent Event [Member] Other Liabilities, Noncurrent Total other liabilities Other Liabilities Goodwill Goodwill Goodwill, beginning balance Goodwill, ending balance Goodwill Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Range Long-Term Debt, Measurement Input PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Commonwealth Financial Network. Acquisition Commonwealth Financial Network. Acquisition [Member] Commonwealth Financial Network. Acquisition Remainder of Fiscal Year Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Assets Business Combination, Recognized Asset Acquired, Asset [Abstract] Income Taxes Receivable Income Taxes Receivable Amount pledged with client-owned securities Customer Securities for which Entity has Right to Sell or Repledge, Fair Value of Securities Sold or Repledged Financial Instruments Owned and Pledged as Collateral [Abstract] Financial Instruments Owned and Pledged as Collateral [Abstract] Equity Components [Axis] Equity Components [Axis] Senior Notes Due 2027 Senior Notes Due November 2027 [Member] Senior Notes Due 2027 - High Yield Bond [Member] Fair value adjustments Liabilities, Fair Value Adjustment Organization and Description of the Company Nature of Operations [Text Block] Senior Notes Due 2031 Senior Notes Due 2031 [Member] Senior Notes Due 2031 Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Number of reportable segments Number of Reportable Segments SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION: Supplemental Cash Flow Information [Abstract] Other receivables Business Combination, Recognized Asset Acquired, Receivable, Current Other Performance Measure, Amount Other Performance Measure, Amount Payment of debt issuance costs Payments of Debt Issuance Costs Entity Address, State or Province Entity Address, State or Province Principal payment of finance leases and obligations Finance Lease, Principal Payments Brokerage, clearing and exchange Floor Brokerage, Exchange and Clearance Fees Financial Instruments with Off-Balance-Sheet Credit Risk and Concentrations of Credit Risk Concentration Risk Credit Risk Financial Instruments Off Balance Sheet Risk [Text Block] Description of financial instruments, excluding certain derivatives, with off-balance sheet credit risk (for example, standby letters of credit or financial guarantees), including (1) information about the (shared) activity, region or economic characteristic that identifies the concentration, (2) the face or contract amount of the instrument, (3) the nature and terms of the instrument, including the market risk, cash requirements and accounting policies for it, (4) the maximum amount of loss due to credit risk that would be incurred if the counterparties failed completely to perform according to the terms of the contracts, and any security or collateral that proved to be of no value, (5) the entity's policy of requiring collateral or other security to support financial instruments subject to credit risk, information about access to collateral or other security, and a brief description of the security supporting those financial instruments, and (6) the policy of entering into and a brief description of master netting arrangements to mitigate the credit risk, and the extent to which such arrangements would reduce the maximum amount of loss due to credit risk. NET (DECREASE) INCREASE IN CASH AND EQUIVALENTS, CASH AND EQUIVALENTS SEGREGATED UNDER FEDERAL OR OTHER REGULATIONS AND RESTRICTED CASH Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation Individual: Individual [Axis] Receivables from others Increase (Decrease) in Other Receivables Additional paid-in capital Additional Paid in Capital, Common Stock Entities [Table] Entities [Table] Entity [Domain] Entity [Domain] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Senior Notes Due 2028 Senior Notes Due November 2028 [Member] Senior Notes Due November 2028 Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Operating lease assets Operating Lease, Right-of-Use Asset Equity awards liability Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Liabilities, Equity Awards Liability Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Liabilities, Equity Awards Liability Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Less: required net capital Broker-Dealer, Minimum Net Capital Required, Parent, Aggregate Indebtedness Standard Entity Interactive Data Current Entity Interactive Data Current Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Acquisition related costs Business Combination, Acquisition-Related Cost, Expense Principal Transaction Revenue, Description of Reporting Category [Axis] Principal Transaction Revenue, Description of Reporting Category [Axis] Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Mutual funds Mutual funds Mutual Fund [Member] Stock option exercises and other, shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Equity [Abstract] Asset Acquisition, Contingent Consideration, Liability Asset Acquisition, Contingent Consideration, Liability Segment Information Segment Reporting Disclosure [Text Block] Marketable Securities Marketable Securities Mutual funds U.S. treasury obligations US Treasury Securities [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] 2035 Senior Notes 2035 Senior Notes [Member] 2035 Senior Notes Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Financial instruments not measured at fair value Fair Value, Not Measured At Fair Value [Member] Fair Value, Not Measured At Fair Value Other liabilities Business Combination, Recognized Liability Assumed, Other Liability, Noncurrent Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Securities borrowed Securities Borrowed [Member] Securities Borrowed Contingent consideration Business Combination, Contingent Consideration, Liability Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Number of uncommitted lines of credit with a specified limit Uncommitted Lines Of Credit, Specified Limit Uncommitted Lines Of Credit, Specified Limit Amortization of intangible assets Amortization of Intangible Assets Other Other Assets, Miscellaneous Forecasted Growth Rates Measurement Input, Forecasted Growth Rate [Member] Measurement Input, Forecasted Growth Rate Sales-based Sales Based [Member] Sales Based Advisor loans, net Increase (Decrease) in Other Loans Deferred Income Tax Assets, Net Deferred Income Tax Assets, Net U.S. treasury obligations Mutual Funds [Member] An investment vehicle that is made up of a pool of funds collected from many investors for the purpose of investing in securities such as stocks, bonds, money market instruments and similar assets. Mutual funds are operated by money managers, who invest the fund's capital and attempt to produce capital gains and income for the fund's investors. Senior Notes Due 2029 Senior Notes Due 2029 [Member] Senior Notes Due 2029 Depreciation and amortization Depreciation, Depletion and Amortization Financial Guarantee Insurance Contracts, Claim Liability Financial Guarantee Insurance Contracts, Claim Liability [Table Text Block] Entity Central Index Key Entity Central Index Key PEO Name PEO Name Total net revenues Revenues Sale of stock, consideration received on transaction Sale of Stock, Consideration Received on Transaction Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] Compensation And Benefits Compensation And Benefits [Member] Compensation And Benefits Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Revolving Credit Facility Revolving Credit Facility [Member] Balance - Beginning of period Balance - End of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Monte-Carlo Simulation Model Valuation Technique, Option Pricing Model [Member] Other Assets And Other Liabilities [Abstract] Other Assets And Other Liabilities Arrangement Duration Trading Arrangement Duration Debt Securities, Trading, and Equity Securities, FV-NI Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block] Deferred Revenue, Revenue Recognized Deferred Revenue, Revenue Recognized Cash equivalents segregated under federal or other regulations Cash Equivalents Segregated Under Federal Or Other Regulations [Member] Cash Equivalents Segregated Under Federal Or Other Regulations Self-insurance liability, beginning balance Self-insurance liability, ending balance Self-Insurance Liabilities Self-Insurance Liabilities Exercise Price Award Exercise Price Business Combination, Series of Individually Immaterial Business Combinations Business Combination, Series of Individually Immaterial Business Combinations [Member] Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Stockholders' Equity Share-Based Payment Arrangement [Text Block] Other intangibles Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Cash and equivalents Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent ASSETS Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Due Year Three Finite-Lived Intangible Asset, Expected Amortization, Year Three Debt Instrument [Axis] Debt Instrument [Axis] Weighted-Average Grant-Date Fair Value, Forfeited Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Fair Value Measurements Fair Value Disclosures [Text Block] Business Combination [Line Items] Business Combination [Line Items] Payables to clients Increase Decrease Payables To Clients The net change during the reporting period in payables to clients, includes amounts payable on cash and margin transactions, including interest on certain client balances. Credit Facility [Domain] Credit Facility [Domain] Gross Carrying Value Finite-Lived Intangible Assets, Gross STOCKHOLDERS' EQUITY: Equity, Attributable to Parent [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Broker-Dealer, Revolving Credit Facility Broker-Dealer, Revolving Credit Facility [Member] Broker-Dealer, Revolving Credit Facility 4.900% Senior Notes Due 2028 4.900% Senior Notes Due 2028 [Member] 4.900% Senior Notes Due 2028 Number of States in which Entity Operates Number of States in which Entity Operates Entity Address, Address Line One Entity Address, Address Line One Fair Value Disclosure, Measurement of Contingent Consideration Using Monte-Carlo Simulation Model Fair Value Disclosure, Measurement Of Contingent Consideration Using Monte-Carlo Simulation Model [Table Text Block] Fair Value Disclosure, Measurement Of Contingent Consideration Using Monte-Carlo Simulation Model Treasury stock purchases Treasury stock purchased Treasury Stock, Value, Acquired, Cost Method Unearned revenue Deferred Revenue Stated rate Debt Instrument, Interest Rate, Stated Percentage Securities sold, but not yet purchased Financial Instruments Sold, Not yet Purchased, at Fair Value Business combination, contingent consideration arrangements, change in range of outcomes, contingent consideration, liability, value, high Business Combination, Contingent Consideration, Change in Range of Outcomes, Liability, Maximum, Increase (Decrease) Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Deferred compensation plan Deferred Compensation Plan [Member] Deferred Compensation Plan U.S. government notes - at amortized cost, After five but within ten years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 5 through 10 Fair Value as of Grant Date Award Grant Date Fair Value Entity Registrant Name Entity Registrant Name Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest [Abstract] Clearing Corporation [Axis] Clearing Corporation [Axis] Clearing Corporation [Axis] Deferred compensation Deferred Compensation Liability, Current and Noncurrent Total Fair Value Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Long-term and Other Borrowings Schedule of Long-Term Debt Instruments [Table Text Block] Compensation and benefits Labor and Related Expense Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Stock Issued During Period, Shares, Stock Options Exercised, Including Adjustments To Additional Paid In Capital Stock Issued During Period, Shares, Stock Options Exercised, Including Adjustments To Additional Paid In Capital Stock Issued During Period, Shares, Stock Options Exercised, Including Adjustments To Additional Paid In Capital Other asset-based Other Asset Based Fees [Member] Other Asset Based Fees Costs and Expenses, Total Costs and Expenses Forfeited Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Document Quarterly Report Document Quarterly Report Total assets at fair value Assets, Fair Value Disclosure Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Asset-based Revenue disaggregated by Product and Service [Abstract] Asset-based Revenue disaggregated by Product and Service [Abstract] Asset-based Revenue disaggregated by Product and Service [Abstract] Options Clearing Corporation [Member] Options Clearing Corporation [Member] Options Clearing Corporation [Member] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Weighted-Average Grant-Date Fair Value, Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Restatement Determination Date: Restatement Determination Date [Axis] Cash Payments to Acquire Businesses, Gross Non-PEO NEO Non-PEO NEO [Member] Unearned revenue Business Combination, Recognized Liability Assumed, Deferred Revenue, Current Number of business combinations Number of Business Combinations Number of Business Combinations Fractional shares - investment Fractional Shares Investment Fractional Shares Investment Increase in consideration transferred Business Combination, Increase In Consideration Transferred Business Combination, Increase In Consideration Transferred Interest Expense, Debt Interest Expense, Debt Liabilities Business Combination, Recognized Liability Assumed, Liability [Abstract] Sale of Stock [Axis] Sale of Stock [Axis] Name Trading Arrangement, Individual Name Award Type [Domain] Award Type [Domain] 5.750% Senior Notes Due 2035 5.750% Senior Notes Due 2035 [Member] 5.750% Senior Notes Due 2035 Equity Awards Adjustments Equity Awards Adjustments [Member] Other Other Noncash Income (Expense) Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Other Other Income Compensation Amount Outstanding Recovery Compensation Amount Debt instrument, face amount Debt Instrument, Face Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Other liabilities: Other Liabilities, Unclassified [Abstract] Sponsorship Programs [Member] Sponsorship Programs [Member] LPL receives compensation from certain financial product manufacturers and is paid in connection with programs that support LPL marketing and sales force education and training efforts referred to as, Sponsorship Programs [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Stock units vested and undistributed Stock units vested and undistributed Stock units vested and undistributed Senior Notes Due 2034 Senior Notes Due 2034 [Member] Senior Notes Due 2034 Share Repurchase Program [Axis] Share Repurchase Program [Axis] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Prefunded acquisition Pre-Funded Acquisition Pre-Funded Acquisition Name Awards Close in Time to MNPI Disclosures, Individual Name Weighted-Average Grant-Date Fair Value, Beginning Balance Weighted-Average Grant-Date Fair Value, Ending Balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value U.S. government notes - at amortized cost, After one but within five years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five Restructuring Type [Axis] Restructuring Type [Axis] Change in estimated fair value of contingent consideration Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Advisory Advisory Revenue Amount of fees charged on the LPL corporate RIA platform provided through LPL Financial to clients of LPL advisors based on the value of their advisory assets. Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] REVENUES: Revenues [Abstract] Share-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Retained earnings Treasury Stock, Value Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] Term Loan A Term Loan A [Member] Term Loan A Service and fee Service And Fee Revenue Service And Fee Revenue Major Types of Trading Securities and Assets [Domain] Financial Instruments [Domain] Financial Instruments [Domain] Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Available Line of Credit Facility, Remaining Borrowing Capacity Senior Notes Due 2028 Senior Notes Due 2028 [Member] Senior Notes Due 2028 Investment Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Other [Member] Other Investment [Member] Other Investment [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Minimum Minimum [Member] Referral fee Capitalized Advisor Referral Fee Capitalized Advisor Referral Fee Goodwill, Measurement Period Adjustment Purchase accounting adjustments Goodwill, Measurement Period Adjustment Company Selected Measure Name Company Selected Measure Name Net income Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax Senior Notes Senior Notes [Member] Corporate Debt and Other Borrowings, Net Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Losses paid Self- Insurance Liabilities, Losses Paid Self- Insurance Liabilities, Losses Paid Trading securities - at fair value: Debt Securities, Trading, and Equity Securities, FV-NI [Abstract] Disaggregation of Revenue - Reporting Category [Table Text Block] Disaggregation of Revenue - Reporting Category [Table Text Block] Disaggregation of Revenue - Reporting Category [Table Text Block] Cash paid for amounts included in the measurement of operating lease liabilities Operating Lease, Payments Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Business combination, recognized identifiable assets acquired and liabilities assumed, liabilities Total liabilities assumed Business Combination, Recognized Liability Assumed, Liability Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10 Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10 Advisory and commission Commissions And Advisory Fees Gross commissions and advisory fees that are earned and paid out to customers based on the sale of various products and services, production bonuses for achieving production levels, share-based compensation expense for stock options and warrants granted to customers, and deferred commissions for customers as part of a non-qualified deferred compensation plan. All Executive Categories All Executive Categories [Member] Collateral Held [Domain] Collateral Held [Domain] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Common stock, $0.001 par value; 600,000,000 shares authorized; 136,822,289 and 136,637,544 shares issued at June 30, 2026 and December 31, 2025, respectively Common Stock, Value, Issued Goodwill [Roll Forward] Goodwill [Roll Forward] Short-term Investments Short-Term Investments Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Weighted-average shares outstanding, diluted Diluted weighted-average number of shares outstanding Weighted Average Number of Shares Outstanding, Diluted Asset-based Asset Based Fees Asset Based Fees Revenue recognized in the period for fees from cash sweep programs, sponsorship programs, omnibus processing and networking services. Employees, officers and directors [Member] Employees, officers and directors [Member] Employees and officers [Member] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Finite-lived intangible assets acquired Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived Business Combination [Axis] Business Combination [Axis] Entity Small Business Entity Small Business Federal Or Other Regulations Federal Or Other Regulations [Member] Federal Or Other Regulations Percentage of voting interests acquired Business Combination, Voting Equity Interest Acquired, Percentage Incremental costs associated with issuance Payments of Stock Issuance Costs Other Borrowings Other Long-Term Debt Document Transition Report Document Transition Report Operating lease assets [Extensible List] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Other assets Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent Fair Value Disclosure of Asset and Liability Not Measured at Fair Value Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table Text Block] Stock option exercises and other Stock Issued During Period, Value, Stock Options Exercised, Including Adjustments To Additional Paid In Capital Stock Issued During Period, Value, Stock Options Exercised, Including Adjustments To Additional Paid In Capital Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Receivables from clients Increase Decrease Receivables From Clients The net change during the reporting period in receivables from brokerage clients. Brokerage client balances include margin loans to clients stated, net of allowance for doubtful accounts. Proceeds from revolving credit facilities Proceeds from Lines of Credit Number of Acquisitions Number Of Acquisitions Number Of Acquisitions Accrued advisory and commission expenses payable Business Combination, Recognizable Identifiable Assets Acquired and Liabilities Assumed, Accrued Advisory And Commission Expenses Payable Business Combination, Recognizable Identifiable Assets Acquired and Liabilities Assumed, Accrued Advisory And Commission Expenses Payable Payment of contingent consideration Payment for Contingent Consideration Liability, Financing Activities Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Statement, Scenario [Axis] Scenario [Axis] Weighted-Average Price Paid Per Share Shares Acquired, Average Cost Per Share Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] Share-Based Payment Arrangement, Option, Exercise Price Range [Line Items] Fourth Amendment Agreement Term Loan B Fourth Amendment Agreement Term Loan B [Member] Fourth Amendment Agreement Term Loan B Credit Agreement entered on March 10, 2017[Member] Document Type Document Type Level 3 Fair Value, Inputs, Level 3 [Member] Earnings per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Product and Service [Axis] Product and Service [Axis] Asset Acquisition [Domain] Asset Acquisition [Domain] Proceeds from Issuance of Common Stock Proceeds from Issuance of Common Stock All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Disaggregation of Revenue - Product and Service [Table Text Block] Disaggregation of Revenue - Product and Service [Table Text Block] Disaggregation of Revenue - Product and Service [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Brokers and Dealers [Abstract] Broker-Dealer [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Asset Acquisition, Consideration Transferred Asset Acquisition, Consideration Transferred Point-in-time [Member] Transferred at Point in Time [Member] Name Forgone Recovery, Individual Name Product Sponsor Relationships Product Sponsor Relationships [Member] Product sponsor relationships. Finite-lived intangible assets acquired Finite-Lived Intangible Assets Acquired Statistical Measurement [Axis] Statistical Measurement [Axis] Capitalized interest Interest Paid, Capitalized, Investing Activity Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Share Repurchase Program, Authorized, Amount Share Repurchase Program, Authorized, Amount Other receivables, net Other Receivables, Net, Current Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Recordkeeping Revenues [Member] Recordkeeping Revenues [Member] Recordkeeping Revenues [Member] Tax payments related to settlement of restricted stock units Payment, Tax Withholding, Share-Based Payment Arrangement Net Capital and Regulatory Requirements Broker-Dealer Disclosure [Text Block] Concentration Risk Credit Risk Financial Instruments Off Balance Sheet Risk [Abstract] Concentration Risk Credit Risk Financial Instruments Off Balance Sheet Risk [Abstract] Concentration risk credit risk financial instruments off balance sheet risk. Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-Maturity [Table] Asset Acquisition, Consideration Transferred, Contingent Consideration Asset Acquisition, Consideration Transferred, Contingent Consideration Entity Information [Line Items] Entity Information [Line Items] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Collateral security (Fair value) Customer Securities for which Entity has Right to Sell or Repledge, Fair Value Total other liabilities Other Liabilities, Fair Value Disclosure Ownership Interest Percentage In Subsidiary Ownership Interest Percentage In Subsidiary Ownership interest percentage in subsidiary. Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Outstanding Long-Term Line of Credit Level 1 Fair Value, Inputs, Level 1 [Member] Total revenue Business Combination, Pro Forma Information, Pro Forma Revenue Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items] Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items] Accounts payable and accrued liabilities Business Combination, Recognized Liability Assumed, Accounts Payable, Current Obligations Obligations, Fair Value Disclosure Earnings per share, diluted Diluted earnings per share Earnings Per Share, Diluted Forecast Forecast [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Interest Income Interest Income, Operating Title of 12(b) Security Title of 12(b) Security NONCASH DISCLOSURES: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Security Owned and Sold, Not yet Purchased, at Fair Value [Axis] Security Owned and Sold, Not yet Purchased, at Fair Value [Axis] Cash and equivalents segregated under federal or other regulations Cash segregated under federal and other regulations Cash and Securities Segregated under Federal and Other Regulations Sale of stock, number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction Dividends [Axis] Dividends [Axis] Treasury stock, shares BEGINNING BALANCE, treasury shares ENDING BALANCE, treasury shares Treasury Stock, Common, Shares Earnings Per Share [Abstract] Earnings Per Share [Abstract] Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Corporate debt, net Long-Term Senior Debt, Net Net carrying amount of senior long-term debt, after unamortized (discount) premium and det issuance costs. Includes senior term loan B and senior unsecured notes. Prepaid assets Prepaid Expense Broker-dealer revolving credit facility Broker-Dealer, Revolving Credit Facility Due July 2024 [Member] Broker-Dealer, Revolving Credit Facility Due July 2024 Broker-Dealer, Net Capital Requirement, SEC Regulation Broker-Dealer, Net Capital Requirement, SEC Regulation [Table Text Block] Financial Instruments Owned and Pledged as Collateral [Line Items] Financial Instruments Owned and Pledged as Collateral [Line Items] Other liabilities: Nonfinancial Liabilities Fair Value Disclosure [Abstract] Cash equivalents Cash Equivalents Not Subject To Segregation [Member] Cash Equivalents Not Subject To Segregation Treasury stock purchases, shares Shares Purchased Treasury Stock, Shares, Acquired Due Year Two Finite-Lived Intangible Asset, Expected Amortization, Year Two Award Timing Disclosures [Line Items] O 2024 Q3 Dividends O 2024 Q3 Dividends [Member] O 2024 Q3 Dividends Senior Notes Due 2030 Senior Notes Due March 2030 [Member] Senior Notes Due 2030 Measurement Frequency [Domain] Measurement Frequency [Domain] Payables to broker-dealers and clearing organizations Payables to broker-dealers and clearing organizations Broker-Dealer, Payable to Other Broker-Dealer and Clearing Organization Stockholders' Equity Note Disclosure [Text Block] Equity [Text Block] Trade Names [Member] Trade Names [Member] NET INCOME Net income Net Income (Loss) Attributable to Parent Dividends [Domain] Dividends [Domain] Subsequent Event [Table] Subsequent Event [Table] Expiration Date Trading Arrangement Expiration Date Senior Notes Due 2030 Senior Notes Due June 2030 [Member] Senior Notes Due June 2030 Advisors and Financial Institutions [Member] Advisors and Financial Institutions [Member] Advisors and financial institutions. Increase (Decrease) in Other Operating Liabilities Increase (Decrease) in Other Operating Liabilities Secured, uncommitted lines of credit Secured, Uncommitted Lines of Credit, No Maturity, Two [Member] Secured, Uncommitted Lines of Credit, No Maturity, Two Fixed Income [Member] Fixed Income Securities [Member] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Excess net capital Broker-Dealer, Excess Net Capital, 1500 Percent, Aggregate Indebtedness Standard Other investments Other Investments [Member] Property and equipment, net Property, Plant and Equipment, Net Taxes payable Taxes Payable Repurchase of common stock Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Base Rate Base Rate [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Deferred compensation Deferred Compensation Asset Deferred Compensation Asset Intangible Assets [Line Items] Intangible Assets [Line Items] Intangible Assets [Line Items] Loan forgiveness Loan Forgiveness Forgiven portion of previously issued loans to certain shareholders, net of interest incurred. Entity Current Reporting Status Entity Current Reporting Status Clearing Corporation [Domain] Clearing Corporation [Domain] [Domain] for Clearing Corporation [Axis] Receivables from: Receivables [Abstract] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Collateral Held [Axis] Collateral Held [Axis] Total cash funded at close Payments to Acquire Businesses, At Close Payments to Acquire Businesses, At Close Customer Relationships Customer Relationships [Member] Capital Unit [Line Items] Capital Unit [Line Items] Line of Credit Line of Credit [Member] Retained earnings Retained Earnings (Accumulated Deficit) Other assets: Other Assets, Unclassified [Abstract] Unsecured, uncommitted lines of credit Unsecured, Uncommitted Lines of Credit Due September 2021, Two [Member] Unsecured, Uncommitted Lines of Credit Due September 2021, Two Number of Asset Acquisitions Number of Asset Acquisitions Number of Asset Acquisitions Schedule of Trading Securities and Other Trading Assets, Major Types of Trading Securities and Assets [Axis] Financial Instrument [Axis] Financial Instrument [Axis] Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Noncash Item [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Executive Category: Executive Category [Axis] Over time [Member] Transferred over Time [Member] Advisor Relationships Advisor Relationships [Member] Advisor Relationships Document and Entity Information [Abstract] Document and Entity Information [Abstract] Purchases of securities classified as held-to-maturity Payments to Acquire Held-to-Maturity Securities Current Fiscal Year End Date Current Fiscal Year End Date Technology Technology-Based Intangible Assets [Member] Schedule of other assets and other liabilities Schedule of Other Assets and Other Liabilities [Table Text Block] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Finite-Lived Intangible Assets Finite-Lived Intangible Assets, Net [Abstract] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Commission Commission Brokerage Commissions Revenue Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] 5.150% Senior Notes Due 2030 5.150% Senior Notes Due 2030 [Member] 5.150% Senior Notes Due 2030 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Investment securities - held-to-maturity securities Total held-to-maturity securities U.S. government notes - at amortized cost, Total Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss Professional services Professional Fees Statement [Table] Statement [Table] Investment securities Business Combination, Recognized Asset Acquired, Investment in Debt and Equity Securities, Current Business Combination Business Combination [Table Text Block] Deferred income taxes Deferred Income Tax Expense (Benefit) Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] CASH FLOWS FROM FINANCING ACTIVITIES: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Disaggregation of Revenue - Timing of Transfer of Good or Service [Table Text Block] Disaggregation of Revenue - Timing of Transfer of Good or Service [Table Text Block] Disaggregation of Revenue - Timing of Transfer of Good or Service [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Cash for post-combination expenses Payments For Post-Combination Expenses Payments For Post-Combination Expenses Self-Insurance Liability [Roll Forward] Self-Insurance Liability [Roll Forward] Self-Insurance Liability BEGINNING BALANCE, shares ENDING BALANCE, shares Shares, Issued Balance Long-TermSeniorDebtGross Amount, before unamortized (discount) premium and debt issuance costs, of long-term senior debt. Includes senior secured term loan B and senior unsecured notes. Variable Rate [Domain] Variable Rate [Domain] Disaggregation of Revenue - Reporting Category & Timing of Transfer of Good or Service [Table Text Block] Disaggregation of Revenue - Reporting Category & Timing of Transfer of Good or Service [Table Text Block] Disaggregation of Revenue - Reporting Category & Timing of Transfer of Good or Service [Table Text Block] Financial assets and financial liabilities measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Total number of uncommitted lines of credit Number Of Uncommitted Lines Of Credit Number of uncommitted lines of credit mainted by the Company. Fractional shares - repurchase obligation Fractional Shares Repurchase Obligation Fractional Shares Repurchase Obligation Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI Net assets acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag Sale of stock, price per share (in dollars per share) Sale of Stock, Price Per Share Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-Maturity Securities [Line Items] Authorized shares Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Payments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales Termination Date Trading Arrangement Termination Date Net cash (used in) provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Receivables from brokers, dealers and clearing organizations Receivable from Broker-Dealer and Clearing Organization Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Issuance of common stock to settle restricted stock units Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Weighted-average shares outstanding, basic Basic weighted-average number of shares outstanding Weighted Average Number of Shares Outstanding, Basic Indefinite-lived Intangible Assets Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract] Basic and diluted earnings per share computations Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Share Repurchase Program [Table] Share Repurchase Program [Table] National Securities Clearing Corporation [Member] National Securities Clearing Corporation [Member] National Securities Clearing Corporation [Member] Business Combination, Number of Businesses Acquired Business Combination, Number of Businesses Acquired Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Future amortization expense Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Commission Revenue disaggregated by Investment Product Category [Abstract] Commission Revenue disaggregated by Investment Product Category [Abstract] Commission Revenue disaggregated by Investment Product Category [Abstract] Receivables from clients, net Receivable from Customer in Brokerage Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Name of Reporting Category [Domain] Name of Reporting Category [Domain] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Amortization of debt issuance costs Amortization of Debt Issuance Costs Entity Tax Identification Number Entity Tax Identification Number Scenario [Domain] Scenario [Domain] Probability Weighted Expected Return Method Valuation Technique, Discounted Cash Flow [Member] Asset Acquisition [Axis] Asset Acquisition [Axis] Fair Value Disclosure 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Receivables From Brokers, Dealers And Clearing Organizations Business Combination, Recognizable Identifiable Assets Acquired and Liabilities Assumed, Receivables From Brokers, Dealers And Clearing Organizations Share Repurchase Program [Abstract] Stock Issued During Period, Value, New Issues Stock Issued During Period, Value, New Issues Statement [Line Items] Statement [Line Items] Equity, Capital Unit or Share [Table] Equity, Capital Unit or Share [Table] Variable Rate [Axis] Variable Rate [Axis] Debt issuance costs, net Unamortized Debt Issuance Expense Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalent Subsequent Event [Line Items] Subsequent Event [Line Items] Unsecured, uncommitted lines of credit Unsecured, Uncommitted Lines of Credit Due September 2021, One [Member] Unsecured, Uncommitted Lines of Credit Due September 2021, One Common Stock Common Stock [Member] Vested Number of 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