Consolidated Company-Sponsored Investment Funds - Summary of Balance Sheet Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Total assets	$ 10,510,088	$ 9,697,840
Liabilities	5,927,996	5,483,958
Redeemable non-controlling interest	421,169	102,359
Partners' capital attributable to AB Unitholders	4,160,923	4,111,523	$ 4,017,101
Total liabilities, redeemable non-controlling interest and capital	10,510,088	9,697,840
Consolidated company-sponsored investment funds
Variable Interest Entity [Line Items]
Cash and cash equivalents	90,326	36,506
Investments	613,025	302,582
Other assets	30,461	12,244
Total assets	733,812	351,332
Liabilities	87,000	30,620
Redeemable non-controlling interest	421,169	102,359
Partners' capital attributable to AB Unitholders	225,643	218,353
Total liabilities, redeemable non-controlling interest and capital	733,812	351,332
VIEs
Variable Interest Entity [Line Items]
Cash and cash equivalents	90,326	36,370
Investments	613,025	242,541
Other assets	30,461	4,859
Total assets	733,812	283,770
Liabilities	87,000	7,741
Redeemable non-controlling interest	421,169	82,753
Partners' capital attributable to AB Unitholders	225,643	193,276
Total liabilities, redeemable non-controlling interest and capital	733,812	283,770
VOEs
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	136
Investments	0	60,041
Other assets	0	7,385
Total assets	0	67,562
Liabilities	0	22,879
Redeemable non-controlling interest	0	19,606
Partners' capital attributable to AB Unitholders	0	25,077
Total liabilities, redeemable non-controlling interest and capital	$ 0	$ 67,562