Long-term Incentive Compensation Plans	9 Months Ended
Long-term Incentive Compensation Plans	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Long-term Incentive Compensation Plans	Long-term Incentive Compensation Plans AB maintains several unfunded, non-qualified long-term incentive compensation plans, under which the company grants awards of restricted AB Holding Units and options to buy AB Holding Units to its employees and members of the Board of Directors, who are not employed by AB or by any of AB’s affiliates (“Eligible Directors”). AB funds its restricted AB Holding Unit awards either by purchasing AB Holding Units on the open market or purchasing newly-issued AB Holding Units from AB Holding, and then holding all of these AB Holding Units in a consolidated rabbi trust until distributing them to employees or retiring them. In accordance with the AB Holding Partnership Agreement, when AB purchases newly-issued AB Holding Units from AB Holding, AB Holding is required to use the proceeds it receives from AB to purchase the equivalent number of newly-issued AB Units, thus increasing its percentage ownership interest in AB. AB Holding Units held in the consolidated rabbi trust are corporate assets in the name of the trust and are available to the general creditors of AB. During the three and nine months ended September 30, 2015, AB purchased 3.0 million and 3.8 million AB Holding Units for $82.1 million and $103.4 million, respectively (on a trade date basis). These amounts reflect open-market purchases of 3.0 million and 3.7 million AB Holding Units for $82.1 million and $101.1 million, respectively, with the remainder relating to purchases of AB Holding Units from employees to allow them to fulfill statutory tax withholding requirements at the time of distribution of long-term incentive compensation awards. During the three and nine months ended September 30, 2014, AB purchased approximately 0.1 million and 0.2 million AB Holding Units for $1.3 million and $5.4 million, respectively (on a trade date basis). These amounts reflect purchases from employees to allow them to fulfill statutory tax withholding requirements at the time of distribution of long-term incentive compensation awards. Each quarter, AB implements plans to repurchase AB Holding Units pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended (“Exchange Act”). A Rule 10b5-1 plan allows a company to repurchase its shares at times when it otherwise might be prevented from doing so because of self-imposed trading blackout periods or because it possesses material non-public information. Each broker selected by AB has the authority under the terms and limitations specified in the plan to repurchase AB Holding Units on AB’s behalf in accordance with the terms of the plan. Repurchases are subject to regulations promulgated by the SEC as well as certain price, market volume and timing constraints specified in the plan. The plan adopted during the third quarter of 2015 expired at the close of business on October 21, 2015. AB may adopt additional Rule 10b5-1 plans in the future to engage in open-market purchases of AB Holding Units to help fund anticipated obligations under its incentive compensation award program and for other corporate purposes. During the first nine months of 2015 and 2014, AB granted to employees and Eligible Directors 0.3 million and 0.8 million restricted AB Holding Unit awards, respectively. AB used AB Holding Units repurchased during the period and newly-issued AB Holding Units to fund the restricted AB Holding Unit awards. During the first nine months of 2015 and 2014, AB Holding issued 0.5 million and 0.8 million AB Holding Units, respectively, upon exercise of options to buy AB Holding Units. AB Holding used the proceeds of $9.0 million and $12.8 million, respectively, received from employees as payment in cash for the exercise price to purchase the equivalent number of newly-issued AB Units.

The entire disclosure for compensation costs, including compensated absences accruals, compensated absences liability, deferred compensation arrangements and income statement compensation items. Deferred compensation arrangements may include a description of an arrangement with an individual employee, which is generally an employment contract between the entity and a selected officer or key employee containing a promise by the employer to pay certain amounts at designated future dates, usually including a period after retirement, upon compliance with stipulated requirements. This type of arrangement is distinguished from broader based employee benefit plans as it is usually tailored to the employee. Disclosure also typically includes the amount of related compensation expense recognized during the reporting period, the number of shares (units) issued during the period under such arrangements, and the carrying amount as of the balance sheet date of the related liability.