Long-Term Incentive Compensation Plans - Summary of Changes in Unvested Restricted AB Holding Units (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2024 $ / shares shares
AB Holding Units
Unvested, beginning balance (in shares) | shares	13,447,555
Granted (in shares) | shares	5,922,324
Vested (in shares) | shares	(6,740,540)
Forfeited (in shares) | shares	(210,088)
Unvested, ending balance (in shares) | shares	12,419,251
Weighted Average Grant Date Fair Value per AB Holding Unit
Unvested, Beginning Weighted Average Grant Date Fair Value per AB Holding Unit (in dollars per share) | $ / shares	$ 35.02
Granted, Weighted Average Grant Date Fair Value per AB Holding Unit (in dollars per share) | $ / shares	35.29
Vested, Weighted Average Grant Date Fair Value per AB Holding Unit (in dollars per share) | $ / shares	36.26
Forfeited, Weighted Average Grant Date Fair Value per AB Holding Unit (in dollars per share) | $ / shares	35.15
Unvested, Ending Weighted Average Grant Date Fair Value per AB Holding Unit (in dollars per share) | $ / shares	$ 34.47