Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Revenue subject to contracts with customers	$ 3,688,518	$ 3,430,316	$ 3,315,390
Dividend and interest income	50,923	104,421	98,226
Investment (losses) gains	(16,401)	38,659	2,653
Other revenues	104,703	97,559	98,676
Total revenues	3,724,186	3,575,637	3,419,760
Less: Interest expense	15,650	57,205	52,399
Net revenues	3,708,536	3,518,432	3,367,361
Expenses:
Employee compensation and benefits	1,494,198	1,442,783	1,378,811
Promotion and servicing:
Amortization of deferred sales commissions	27,355	15,029	21,343
Trade execution, marketing, T&E and other	189,787	219,860	222,630
General and administrative:
General and administrative	485,544	484,750	448,996
Real estate charges	5,526	3,324	7,160
Contingent payment arrangements	1,855	(510)	(2,219)
Interest on borrowings	6,180	13,035	10,359
Amortization of intangible assets	21,372	28,759	27,781
Total expenses	2,801,100	2,694,995	2,542,047
Operating income	907,436	823,437	825,314
Income tax	45,653	41,754	45,816
Net income	861,783	781,683	779,498
Net (loss) income of consolidated entities attributable to non-controlling interests	(4,169)	29,641	21,910
Net income attributable to AB Unitholders	$ 865,952	$ 752,042	$ 757,588
Net income per AB Unit:
Basic (in dollars per share)	$ 3.19	$ 2.78	$ 2.79
Diluted (in dollars per share)	$ 3.19	$ 2.78	$ 2.78
Investment advisory and services fees
Revenues:
Revenue subject to contracts with customers	$ 2,595,436	$ 2,472,044	$ 2,362,211
Bernstein research services
Revenues:
Revenue subject to contracts with customers	459,744	407,911	439,432
Distribution related
Revenues:
Revenue subject to contracts with customers	529,781	455,043	418,562
Promotion and servicing:
Distribution-related payments	$ 569,283	$ 487,965	$ 427,186