Business Description Organization and Basis of Presentation (Policies)	6 Months Ended
Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The interim condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the interim results, have been made. The preparation of the condensed consolidated financial statements requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the interim reporting periods. Actual results could differ from those estimates. The condensed consolidated statement of financial condition as of December 31, 2023 was derived from audited financial statements. Certain disclosures included in the annual financial statements have been condensed or omitted from these financial statements as they are not required for interim financial statements under principles generally accepted in the United States of America ("GAAP") and the rules of the SEC.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include AB and its majority-owned and/or controlled subsidiaries, and the consolidated entities that are considered to be variable interest entities (“VIEs”) and/or voting interest entities (“VOEs”) in which AB has a controlling financial interest. Non-controlling interests on the condensed consolidated statements of financial condition include the portion of consolidated company-sponsored investment funds in which we do not have direct equity ownership. All significant inter-company transactions and balances among the consolidated entities have been eliminated.
Subsequent Events	Subsequent Events We have evaluated subsequent events through the date that these financial statements were filed with the SEC and did not identify any subsequent events that would require disclosure in these financial statements. (1) On April 1, 2024 AB and Societe Generale, a leading European bank, completed their transaction to form a jointly owned equity research provider and cash equity trading partner for institutional investors. AB has deconsolidated the Bernstein Research Services business and contributed the business to the joint venture. For further discussion, see Note 17 Divestiture.
Recently Adopted Accounting Pronouncements and Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements During the three and six months ended June 30, 2024, there have been no recently adopted accounting pronouncements. Accounting Pronouncements Not Yet Adopted In December 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This amendment is expected to enhance the transparency and decision usefulness of income tax disclosures by requiring public business entities, on an annual basis, to disclose specific categories in the rate reconciliation, additional information for reconciling items that meet a quantitative threshold and certain information about income taxes paid. This revised guidance is effective for financial statements issued for fiscal years beginning after December 15, 2024. The revised guidance will not have a material impact on our financial condition or results of operations. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which required disclosure of incremental segment information on an annual and interim basis. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, and requires retrospective application to all prior periods presented in the financial statements. We are currently evaluating the impacts of the new standard.
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures Effective April 1, 2024, AB and Societe Generale ("SocGen") completed their previously announced transaction to form a global joint venture with two joint venture holding companies, one outside of North America and one within North America ("NA JV", and together the "JVs"). AB owns a majority interest in the NA JV while SocGen owns a majority interest in the joint venture outside of North America. On April 1, 2024, we deconsolidated our Bernstein Research Services ("BRS") business and contributed the BRS business to the JVs. We have recorded our subsequent investment in each of the JVs under the equity method of accounting under ASC 323 Investments – Equity Method and Joint Ventures, as we retained the ability to exercise significant influence over the operating and financial policies of the JVs but did not retain a controlling interest. Our investments in companies over which we have the ability to exercise significant influence are accounted for under the equity method and are recorded at cost plus our share of earnings and losses. As of June 30, 2024, we owned 66.7% of the NA JV and 49.0% of the joint venture outside of North America and our combined carrying value in the two investments was $295.4 million. The structure of the Board of Directors of the NA JV, which includes two independent directors, in addition to four directors from AB and three directors from SocGen, precludes AB’s control of the Board thereby permitting deconsolidation of the BRS business. In addition, we periodically assess our investments in our joint ventures for impairment if certain events or changes in circumstances occur including, but not limited to, ongoing operating losses, projected decreases in earnings or a significant business disruption. The significant assumptions used to estimate fair value include revenue growth and profitability, capital spending and a discount rate. By their nature, these assumptions and projections are uncertain. If we were to determine the current fair value of our investment was less than the carrying value of the investment, and we determined the shortfall was other than temporary, we would recognize an impairment to the investment in the amount by which the carrying value exceeds its fair value. For further discussion, see Note17 – Divestiture.
Reclassification	Reclassification During the second quarter of 2024, amounts previously presented on the condensed consolidated statement of financial condition as "long-term incentive compensation-related" investments are now presented as "other" investments. Prior period amounts previously presented as such have been reclassified to conform to the current periods presentation.

Business Description Organization and Basis of Presentation (Policies)

6 Months Ended

Jun. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The interim condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the interim results, have been made. The preparation of the condensed consolidated financial statements requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the interim reporting periods. Actual results could differ from those estimates. The condensed consolidated statement of financial condition as of December 31, 2023 was derived from audited financial statements. Certain disclosures included in the annual financial statements have been condensed or omitted from these financial statements as they are not required for interim financial statements under principles generally accepted in the United States of America ("GAAP") and the rules of the SEC.

Principles of Consolidation

The condensed consolidated financial statements include AB and its majority-owned and/or controlled subsidiaries, and the consolidated entities that are considered to be variable interest entities (“VIEs”) and/or voting interest entities (“VOEs”) in which AB has a controlling financial interest. Non-controlling interests on the condensed consolidated statements of financial condition include the portion of consolidated company-sponsored investment funds in which we do not have direct equity ownership. All significant inter-company transactions and balances among the consolidated entities have been eliminated.

Subsequent Events

We have evaluated subsequent events through the date that these financial statements were filed with the SEC and did not identify any subsequent events that would require disclosure in these financial statements.

(1) On April 1, 2024 AB and Societe Generale, a leading European bank, completed their transaction to form a jointly owned equity research provider and cash equity trading partner for institutional investors. AB has deconsolidated the Bernstein Research Services business and contributed the business to the joint venture. For further discussion, see Note 17 Divestiture.

Recently Adopted Accounting Pronouncements and Accounting Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

During the three and six months ended June 30, 2024, there have been no recently adopted accounting pronouncements.

Accounting Pronouncements Not Yet Adopted

In December 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This amendment is expected to enhance the transparency and decision usefulness of income tax disclosures by requiring public business entities, on an annual basis, to disclose specific categories in the rate reconciliation, additional information for reconciling items that meet a quantitative threshold and certain information about income taxes paid. This revised guidance is effective for financial statements issued for fiscal years beginning after December 15, 2024. The revised guidance will not have a material impact on our financial condition or results of operations.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which required disclosure of incremental segment information on an annual and interim basis. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, and requires retrospective application to all prior periods presented in the financial statements. We are currently evaluating the impacts of the new standard.

Investments in Unconsolidated Joint Ventures

Effective April 1, 2024, AB and Societe Generale ("SocGen") completed their previously announced transaction to form a global joint venture with two joint venture holding companies, one outside of North America and one within North America ("NA JV", and together the "JVs"). AB owns a majority interest in the NA JV while SocGen owns a majority interest in the joint venture outside of North America.

On April 1, 2024, we deconsolidated our Bernstein Research Services ("BRS") business and contributed the BRS business to the JVs. We have recorded our subsequent investment in each of the JVs under the equity method of accounting under ASC 323 Investments – Equity Method and Joint Ventures, as we retained the ability to exercise significant influence over the operating and financial policies of the JVs but did not retain a controlling interest. Our investments in companies over which we have the ability to exercise significant influence are accounted for under the equity method and are recorded at cost plus our share of earnings and losses. As of June 30, 2024, we owned 66.7% of the NA JV and 49.0% of the joint venture outside of North America and our combined carrying value in the two investments was $295.4 million. The structure of the Board of Directors of the NA JV, which includes two independent directors, in addition to four directors from AB and three directors from SocGen, precludes AB’s control of the Board thereby permitting deconsolidation of the BRS business.

In addition, we periodically assess our investments in our joint ventures for impairment if certain events or changes in circumstances occur including, but not limited to, ongoing operating losses, projected decreases in earnings or a significant business disruption. The significant assumptions used to estimate fair value include revenue growth and profitability, capital spending and a discount rate. By their nature, these assumptions and projections are uncertain. If we were to determine the current fair value of our investment was less than the carrying value of the investment, and we determined the shortfall was other than temporary, we would recognize an impairment to the investment in the amount by which the carrying value exceeds its fair value. For further discussion, see Note17 – Divestiture.

Reclassification

During the second quarter of 2024, amounts previously presented on the condensed consolidated statement of financial condition as "long-term incentive compensation-related" investments are now presented as "other" investments. Prior period amounts previously presented as such have been reclassified to conform to the current periods presentation.