Summary of Significant Accounting Policies - Additional Information (Details)			1 Months Ended		3 Months Ended				12 Months Ended
	Feb. 06, 2024 $ / shares	Jul. 01, 2022 USD ($)	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($) reportingUnit $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares
Business Acquisition [Line Items]
Repledged securities			$ 267,100,000		$ 122,400,000	$ 267,100,000			$ 122,400,000	$ 267,100,000
Collateral advances, allowance			0		0	0			0	0
U.S. Treasury bills pledged as collateral			0		0	0			$ 0	0
Number of reporting units | reportingUnit									1
Goodwill			3,598,591,000		3,598,591,000	3,598,591,000			$ 3,598,591,000	3,598,591,000
Held for sale asset disposal group					159,800,000				159,800,000
Contingent payment arrangements			247,309,000		252,690,000	247,309,000			252,690,000	247,309,000
Impairment of contingent consideration payable									0	0
Intangible assets, net of accumulated amortization			310,203,000		264,555,000	310,203,000			264,555,000	310,203,000
Finite-lived intangible assets subject to amortization, net			295,000,000		249,400,000	295,000,000			249,400,000	295,000,000
Indefinite-lived intangible assets not subject to amortization			15,200,000		15,200,000	15,200,000			15,200,000	15,200,000
Finite-lived intangible assets			327,900,000		328,400,000	327,900,000			328,400,000	327,900,000
Accumulated amortization of intangible assets			32,900,000		79,000,000	$ 32,900,000			79,000,000	32,900,000
Amortization of intangible assets									46,854,000	26,564,000	$ 5,697,000
2023					46,000,000				46,000,000
2024					46,000,000				46,000,000
2025					46,000,000				46,000,000
2026					25,000,000				25,000,000
2027					25,000,000				25,000,000
Impairment of finite-lived intangible assets					$ 0				$ 0	5,600,000	1,000,000
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]					General and administrative	General and administrative		General and administrative
Deferred sales commission amortization period US fund (in years)									1 year
Deferred sales commission amortization period non US funds (in years)									4 years
Assets held for sale			551,351,000		$ 564,776,000	$ 551,351,000			$ 564,776,000	551,351,000
Liabilities held for sale			$ 107,952,000		$ 153,342,000	107,952,000			$ 153,342,000	$ 107,952,000
Period over which receivables from brokers and dealers for sale of shares of company-sponsored mutual funds generally are realized									3 days
Maximum percentage of award an employee can elect to allocate to deferred cash					50.00%				50.00%
Maximum amount of deferred cash					$ 250,000				$ 250,000
Granted to employees and Eligible Directors | shares			5,000,000	3,800,000					5,600,000	4,700,000
Options exercised (in Shares) | shares									0	5,774
Proceeds from stock options exercised									$ 0	$ 178,000	3,402,000
Net foreign currency transaction gains (losses)									$ 4,500,000	$ 10,200,000	$ 8,500,000
Cash distributions per unit paid to the General Partner and Unitholders (in dollars per unit) | $ / shares									$ 2.92	$ 3.87	$ 3.86
Subsequent Event
Business Acquisition [Line Items]
Cash distribution, distribution declared (in dollars per unit) | $ / shares	$ 0.85
Deferred Sales Commissions
Business Acquisition [Line Items]
Impairment of finite-lived intangible assets									$ 0	$ 0
AB Holding | AB
Business Acquisition [Line Items]
General partnership interest in Company (percent)									1.00%
Director
Business Acquisition [Line Items]
Long-term incentive awards vesting periods									3 years
Employees based outside of the United States
Business Acquisition [Line Items]
Maximum percentage of award an employee can elect to allocate to deferred cash					100.00%				100.00%
Maximum amount of deferred cash					$ 100,000				$ 100,000
CarVal
Business Acquisition [Line Items]
Goodwill		$ 666,130,000			666,100,000				666,100,000
Contingent payment arrangements		$ 228,900,000	$ 232,100,000		238,500,000	232,100,000			238,500,000	$ 232,100,000
Business combination, contingent consideration, performance term		6 years
Business combination, finite-lived intangibles		$ 303,000,000					$ 303,000,000
Sanford C Bernstein Inc Acquisition
Business Acquisition [Line Items]
Goodwill					2,800,000,000				2,800,000,000
Various smaller acquisitions
Business Acquisition [Line Items]
Goodwill					291,900,000				291,900,000
Autonomous LLC
Business Acquisition [Line Items]
Transaction costs					28,400,000				28,400,000
Autonomous LLC | Contingent Payment Arrangement Expense
Business Acquisition [Line Items]
Transaction costs					14,100,000				14,100,000
Autonomous LLC | Compensation and Benefits Expense
Business Acquisition [Line Items]
Transaction costs					$ 14,300,000				$ 14,300,000
Ramius Alternative Solutions LLC
Business Acquisition [Line Items]
Impairment of contingent consideration payable								$ 600,000
Impairment of finite-lived intangible assets						$ 5,600,000		$ 1,000,000
Minimum
Business Acquisition [Line Items]
Intangible assets acquired, estimated useful life					5 years				5 years
Minimum | Employee
Business Acquisition [Line Items]
Long-term incentive awards vesting periods									3 years
Minimum | CarVal | Investment Management Contracts and Investor Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years					5 years
Maximum
Business Acquisition [Line Items]
Intangible assets acquired, estimated useful life					20 years				20 years
Maximum | Employee
Business Acquisition [Line Items]
Long-term incentive awards vesting periods									4 years
Maximum | CarVal | Investment Management Contracts and Investor Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		10 years					10 years
Furniture
Business Acquisition [Line Items]
Useful life (in years)					8 years				8 years
Equipment | Minimum
Business Acquisition [Line Items]
Useful life (in years)					3 years				3 years
Equipment | Maximum
Business Acquisition [Line Items]
Useful life (in years)					6 years				6 years