Acquisition - Narrative (Details) - USD ($) $ in Thousands, shares in Millions		9 Months Ended
	Jul. 01, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Business Acquisition [Line Items]
Contingent consideration liability		$ 273,145		$ 38,260
Cash acquired from acquisition		40,800	$ 2,800
Goodwill		3,719,880		$ 3,091,763
CarVal Investors, L.P.
Business Acquisition [Line Items]
Percentage of interests acquired	100.00%
Assets under management	$ 12,200,000
Equity interest contributed to affiliate	100.00%
Business combination, equity interest issued (in shares)	3.2
Fair value of AB Holding Units issued	$ 132,800
Business combination, liabilities incurred	$ 419,400
Percentage of equity interest acquiree	100.00%
Contingent consideration liability	$ 227,100	227,100
Business combination, contingent consideration, performance term	6 years
Business combination, excess purchase price over fair value	$ 156,100
Cash acquired from acquisition	40,800
Deferred tax asset	4,823
Goodwill	627,593	$ 627,600
Business combination, recognized identifiable assets acquired and liabilities assumed, finite-lived intangibles	$ 303,000
CarVal Investors, L.P. | Minimum | Investment Management Contracts and Investor Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted verage useful life	5 years
CarVal Investors, L.P. | Maximum | Investment Management Contracts and Investor Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted verage useful life	10 years