Income Taxes - Summary of Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Computation of equity in net income attributable to AB Unitholders [Abstract]
Multiplied by: weighted average equity ownership interest	36.20%	35.60%	35.40%
Equity in net income attributable to AB Unitholders	$ 416,326,000	$ 308,404,000	$ 266,292,000
Computation of income tax [Abstract]
AB qualifying revenues	$ 2,779,281,000	$ 2,740,137,000	$ 2,640,169,000
Multiplied by: weighted average equity ownership interest for calculating tax	30.50%	30.10%	29.40%
Multiplied by: federal tax	3.50%	3.50%	3.50%
Federal income taxes	$ 29,643,000	$ 28,522,000	$ 27,197,000
State income taxes	840,000	502,000	532,000
Total income taxes	$ 30,483,000	$ 29,024,000	27,729,000
Changes in components for calculation of income tax [Abstract]
Increase in net income attributable to AB Unitholders (percent)	32.60%	15.10%
Increase in equity in net income attributable to AB Unitholders (percent)	35.00%	15.80%
Increase (decrease) in AB qualifying revenue (percent)	1.40%	2.40%
Increase (decrease) in income taxes (percent)	5.00%	4.70%
Unrecognized tax benefits	$ 0	$ 0
Variable Interest Entity, Primary Beneficiary
Computation of equity in net income attributable to AB Unitholders [Abstract]
Net income attributable to AB Unitholders	$ 1,148,623,000	$ 865,952,000	$ 752,042,000