Long-Term Incentive Compensation Plans - Schedule of Grant Details of Restricted AB Holding Units (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Units Awarded (in shares)	5,922,324
Weighted average grant date fair value (in dollars per share)	$ 35.29
Employment and Separation Agreements
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Units Awarded (in shares)	1,200,000	500,000	500,000
Compensation Expense	$ 17.6	$ 30.1	$ 35.0
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Units Awarded (in shares)	29,952	30,102	30,870
Weighted average grant date fair value (in dollars per share)	$ 34.06	$ 33.89	$ 38.55
Compensation Expense	$ 1.0	$ 1.0	$ 1.2
Minimum | Employment and Separation Agreements
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)	$ 28.46	$ 27.86	$ 34.86
Maximum | Employment and Separation Agreements
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)	$ 37.26	$ 38.58	$ 49.90