Debt (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) financial_institution line_of_credit	Dec. 31, 2014 USD ($)
Short-term Debt [Line Items]
Short-term debt outstanding	$ 583,946,000	$ 488,988,000
Commercial Paper [Member]
Short-term Debt [Line Items]
Short-term debt outstanding	$ 583,900,000	$ 489,000,000
Weighted average interest rates on short-term debt outstanding	0.50%	0.30%
Average daily borrowings	$ 387,900,000	$ 335,000,000
Weighted average interest rates on average daily borrowings	0.30%	0.20%
Credit facility original principal	$ 1,000,000,000
Credit Facility [Member]
Short-term Debt [Line Items]
Revolving credit facility description	AB has a $1.0 billion committed, unsecured senior revolving credit facility (“Credit Facility”) with a group of commercial banks and other lenders. The Credit Facility provides for possible increases in the principal amount by up to an aggregate incremental amount of $250 million; any such increase is subject to the consent of the affected lenders. The Credit Facility is available for AB’s and Sanford C. Bernstein & Co., LLC's ("SCB LLC") business purposes, including the support of AB’s $1.0 billion commercial paper program. Both AB and SCB LLC can draw directly under the Credit Facility and management may draw on the Credit Facility from time to time. AB has agreed to guarantee the obligations of SCB LLC under the Credit Facility.
Maturity date	Oct. 22, 2019
Credit facility original principal	$ 1,000,000,000
Amounts outstanding under credit facility	0	$ 0
Incremental increases in principal	$ 250,000,000
Credit Facility [Member] | SCB LLC [Member]
Short-term Debt [Line Items]
Revolving credit facility description	In addition, SCB LLC has five uncommitted lines of credit with four financial institutions. Two of these lines of credit permit us to borrow up to an aggregate of approximately $200 million, with AB named as an additional borrower, while three lines have no stated limit.
Number of uncommitted lines of credit | line_of_credit	3
Number of financial institutions offering lines of credit | financial_institution	3
Number of financial institutions with stated limits | line_of_credit	2
Incremental increases in principal	$ 200,000,000
Number of financial institutions with no stated limits | line_of_credit	1
Uncommitted Lines of Credit [Member]
Short-term Debt [Line Items]
Short-term debt outstanding	$ 0	0
Average daily borrowings	$ 3,900,000	$ 5,500,000
Weighted average interest rates on average daily borrowings	1.20%	1.10%