Business Description, Organization and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2026
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, 2025 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.
Reclassification	Reclassification During 2026, amounts previously presented on the condensed consolidated statements of income as "contingent payment arrangements" are now presented as part of "amortization of intangible assets." Prior period amounts previously presented as such have been reclassified to conform to the current periods presentation.
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.
Accounting Pronouncements Not Yet Adopted	Accounting Pronouncements Not Yet Adopted In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This amendment is expected to improve financial reporting by requiring that public business entities disclose additional information about specific expense categories in the notes to financial statements at interim and annual reporting periods. This information is not generally presented in the financial statements today. The amendments in this update do not change or remove current expense disclosure requirements. This ASU is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The amendments in this update should be applied either prospectively to financial statements issued for reporting periods after the effective date of this update or retrospectively to any or all periods presented in the financial statements. We are currently evaluating the impacts of the new standard.