Amendment Flag Current Fiscal Year End Date Document Period End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Registrant Name Entity Central Index Key Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Document Type Summary of Significant Accounting Policies [Abstract] Accumulated other comprehensive income (loss) Adjustments to reconcile net income to net cash provided by operating activities: Additional allocation of equity in net income attributable to AllianceBernstein resulting from assumed dilutive effect of compensatory options Out-of-the-money options from the diluted net income per unit (in units) ASSETS Total assets Assets Basis of Presentation Cash and cash equivalents as of beginning of period Cash and cash equivalents as of end of period Cash and Cash Equivalents, at Carrying Value Change in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and contingencies (See Note 7) Unallocated Holding Units Remaining in the Consolidated Rabbi Trust (in holding units) Deferred Compensation Plans Computation of income tax [Abstract] Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Deferred compensation liability for the full dollar value of the awards One-time, non-cash deferred compensation charge Subsequent Cash Distribution, Declaration Date Subsequent Cash Distribution, Distribution Declared (in dollars per unit) Subsequent Cash Distribution, Amount Subsequent Cash Distribution, Date of Record Subsequent Cash Distribution, Distribution Date Cash Distributions [Abstract] Due to AllianceBernstein Due from AllianceBernstein Net Income Per Unit [Abstract] Net Income Per Unit Earnings Per Share [Text Block] Net income per unit: Effective tax rate (in hundredths) Multiplied by: federal tax (in hundredths) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate Investment in AllianceBernstein Computation of equity in net income attributable to AllianceBernstein Unitholders [Abstract] Investment in AllianceBernstein Investment in AllianceBernstein, beginning of period Investment in AllianceBernstein, end of period Equity Method Investments Multiplied by: weighted average equity ownership interest (in hundredths) Equity Method Investment, Ownership Percentage Net income attributable to AllianceBernstein Unitholders Investment in AllianceBernstein [Abstract] General Partner: 100,000 general partnership units issued and outstanding General Partner: units outstanding (in shares) General Partners' Capital Account, Units Outstanding General partnership: units issued (in shares) Condensed Statements of Income (unaudited) [Abstract] Income Taxes Income Tax Disclosure [Text Block] Income Taxes [Abstract] Equity in net income attributable to AllianceBernstein Unitholders Equity in net income attributable to AllianceBernstein Unitholders Changes in components for calculation of income tax [Abstract] Income taxes Decrease (increase) in due from AllianceBernstein Increase (Decrease) in Accounts Receivable, Related Parties Increase in due to AllianceBernstein Changes in assets and liabilities: Decrease (increase) in other assets Increase (Decrease) in Other Operating Assets (Decrease) in other liabilities Investment in AllianceBernstein Investments in and Advances to Affiliates, Schedule of Investments [Text Block] Liabilities: Total liabilities Liabilities LIABILITIES AND PARTNERS' CAPITAL Total liabilities and partners' capital Liabilities and Equity Limited partners: units issued (in shares) Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract] Limited partners: 105,073,342 and 105,073,342 limited partnership units issued and outstanding Limited partners: units outstanding (in shares) Units Outstanding [Abstract] Limited partners or members ownership interest in Company (in hundredths) General partnership interest (in hundredths) Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Loss Contingencies [Table] Damages sought Loss Contingencies by Nature of Contingency [Axis] Loss Contingencies [Line Items] Loss Contingency, Nature [Domain] Business Description And Organization Nature of Operations [Text Block] Net income - diluted Net Income (Loss) Attributable to Parent, Diluted Cash flows from financing activities: Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Diluted (in dollars per share) Diluted net income per unit (in dollars per unit) Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Cash flows from investing activities: Cash flows from operating activities: Basic (in dollars per share) Basic net income per unit (in dollars per unit) Net Income Net income Net income Net income - basic Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Business Description And Organization [Abstract] Other assets Income tax benefit (expense) Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Less: reclassification adjustment for gains (losses) included in net income Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax Change in unrealized gains on investments Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax Amortization of prior service cost Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Benefit Cost, before Tax Amortization of transition asset Recognized actuarial loss Other liabilities Holding Units held by AllianceBernstein to fund deferred compensation plans Foreign currency translation adjustments Other comprehensive income (loss), before taxes: Unrealized gains arising during period Unrealized gains on investments: Other comprehensive income (loss), before taxes Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Changes in employee benefit related items: Total partners' capital Partners' Capital Partners' capital: Change in Holding Units held by AllianceBernstein for deferred compensation plans Investments in AllianceBernstein with proceeds from exercise of compensatory options to buy Holding Units Investment in AllianceBernstein with proceeds from exercise of compensatory options to buy holding units Cash distributions to unitholders Payments of Ordinary Dividends Investment in AllianceBernstein from distributions paid to AllianceBernstein consolidated rabbi trust Investment in AllianceBernstein from distributions paid to AllianceBernstein consolidated rabbi trust Payments to Acquire Businesses and Interest in Affiliates Capital contributions receivable from AllianceBernstein Cash distributions received from AllianceBernstein Cash distributions received from AllianceBernstein Proceeds from exercise of compensatory options to buy Holding Units Proceeds from Stock Options Exercised Capital contributions receivable from AllianceBernstein Receivable from Shareholders or Affiliates for Issuance of Capital Stock Revision Investment in Affiliate Net Income Per Unit Computation of Effective Income Tax Rate and Changes in Components of Income Tax Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Changes in Holding Units Outstanding Deferred Compensation Plans [Abstract] Vesting period of awards Open-Market Purchases of Holding Units (in units) Options exercised (in units) Units Outstanding, beginning of period (in units) Units Outstanding, end of period (in units) Shares, Outstanding Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Condensed Statements of Cash Flows (unaudited) [Abstract] Condensed Statements of Financial Condition (unaudited) [Abstract] Condensed Statement of Comprehensive Income (unaudited) [Abstract] Units issued (in units) Units forfeited (in units) Dollar Amount Paid for Holding Units Acquired Stock Repurchased During Period, Value Holding Units Purchased in Period (in units) Stock Repurchased During Period, Shares Restricted Holding Unit Awards to Employees (in units) Stock Issued During Period, Shares, Share-based Compensation, Gross Weighted average units outstanding - diluted (in units) Weighted Average Limited Partnership Units Outstanding, Diluted Dilutive effect of compensatory options (in units) Weighted average units outstanding - basic (in units) The amount of qualifying revenue (primarily investment advisory fees and certain equity commissions) reported by an equity method investment of the entity. Equity Method Investment, Summarized Financial Information, Qualifying Revenue The percentage change in the sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations. Increase (decrease) in income tax Decrease in income taxes (in hundredths) The percentage change in the amount of net income (loss) reported by an equity method investment of the entity. Increase (decrease) in net income attributable to equity method investment Decrease in net income attributable to AllianceBernstein Unitholders (in hundredths) The percentage change in the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Increase (decrease) in equity in net income attributable to equity method investments Decrease in equity in net income attributable to AllianceBernstein Unitholders (in hundredths) Alleged realized losses in portfolio. Realized losses in portfolio Realized losses in the portfolio Portfolio amount of client owned U.S. mortgage-backed securities. Portfolio amount of client seeking damages Portfolio amount of client seeking damages (in pounds) The maximum value (monetary amount) of the award the plaintiff seeks in the legal matter. Alleged Damages Maximum [Member] Alleged Damages - Maximum The minimum value (monetary amount) of the award the plaintiff seeks in the legal matter. Alleged Damages Minimum [Member] Alleged Damages - Minimum The percentage change in the amount of qualifying revenue (primarily investment advisory fees and certain equity commissions) reported by an equity method investment of the entity. Increase (decrease) in qualifying revenue of equity method investment Decrease in AllianceBernstein qualifying revenue (in hundredths) Tax rate attributable to operating income for unincorporated business entities operating in New York City, before credits paid for unincorporated business entities by a subsidiary. New York City unincorporated business tax rate New York City unincorporated business tax (in hundredths) Holdings proportional share of the units held by AllianceBernstein in its Consolidated Rabbi Trust which are excluded from weighted average units outstanding. Proportional share of Companys units held by related party in consolidated rabbi trust Proportional share of the Holding Units held by AllianceBernstein in its consolidated rabbi trust (in hundredths) The amount paid for holding units purchased on the open market for issuance to employees under the plan. Share Based Compensation Arrangement By Holding Unit Payment Award Amount Paid For Holding Units Purchased On Open Market Dollar Amount Paid for Open-Market Purchases of Holding Units The percentage of awarded deferred incentive compensation expense to be recognized in each year. Deferred Incentive Compensation Expense Percentage To Be Recognized Percentage of unrecognized deferred incentive compensation expense recognized (in hundredths) Amount of reclassification from a liability to Partner's Capital as equity-based awards as a result of shares issued during the period. Reclassified liability to partners' capital Maximum amount of award an employee was able to allocate to deferred cash. Deferred cash maximum per employee Maximum percentage of award an employee was able to allocate to deferred cash. Employee allocation percentage maximum Employee allocation percentage maximum (in hundredths) Describes policy to determining cash distributions, cash distributions per unit based on cash flow received from operations, payments on borrowings and purchase of assets in the ordinary course of business. Cash Distributions [Policy Text Block] Cash Distributions Economic interest in AllianceBernstein owned by specific named entity as a General Partner and Limited Partner in Holding and AllianceBernstein, expressed as a percentage of total. Limited Liability Company Llc Or Limited Partnership Lp Members Or Limited Partners Economic Interest In Company AXA and its subsidiaries economic interest in Company (in hundredths) AXA's ownership percentage of the issued and outstanding units representing assignments of beneficial ownership of limited partnership interests in Holdings. Limited Liability Company Llc Or Limited Partnership Lp Members Or Limited Partners Ownership Interest In Holding Company AXA and its subsidiaries ownership interest in Holding company (in hundredths) Schedule of Limited Partnership Ownership Interest By Partners [Line Items] Partners in a limited partnership. Limited Partnership Interest Partners [Domain] Represents holders of ownership interest in Company that are otherwise unaffiliated with Company. Unaffiliated Holders [Member] Represents the holding Company, AllianceBernstein Holdings, that has an ownership interest in Company. Holdings [Member] International group of insurance and related financial services companies and certain other subsidiaries. AXA And Its Subsidiaries [Member] Pertinent data on partners in a limited partnership. Limited Partnership Interest By Partner [Axis] Schedule of Limited Partnership Ownership Interest By Partners [Table] Ownership structure of AllianceBernstein, expressed as a percentage of general and limited partnership interests. Ownership Interest by Limited Partners [Table Text Block] Ownership Interest by Limited Partners Entire disclosure of an entity's capital units or capital shares. Capital Units [Text Block] Units Outstanding Schedule of net income per unit [Abstract] Represents Holdings proportionate share of net changes in accumulated other comprehensive income (loss) of equity method investments during the period. Change in accumulated other comprehensive income (loss) Changes in accumulated other comprehensive (loss) income Document and Entity Information [Abstract]