Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions			3 Months Ended														12 Months Ended
		Feb. 14, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	[3]	Mar. 31, 2016	[3]	Dec. 31, 2015	[3]	Sep. 30, 2015	[3]	Jun. 30, 2015	[3]	Mar. 31, 2015	[3]	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Distribution Made to Limited Liability Company (LLC) Member [Line Items]
Subsequent cash distribution, declaration date																	Feb. 14, 2017
Subsequent cash distribution, distribution declared (in dollars per unit)	[1],[2]		$ 0.67	$ 0.45	$ 0.40		$ 0.40		$ 0.50		$ 0.43		$ 0.48		$ 0.45
Subsequent cash distribution, distribution date																	Mar. 09, 2017
Subsequent cash distribution, date of record																	Feb. 24, 2017
Total cash distributions per unit paid to unitholders (in dollars per unit)																	$ 1.75	$ 1.93	$ 1.89
Long-Term Incentive Compensation Plans [Abstract]
AB Holding units purchased in period (in units)																	10.5	8.5
Dollar amount paid for AB holding units acquired																	$ 236,600	$ 218,300
Open-market purchases of AB holding units (in units)																	7.9	5.8
Dollar amount paid for open-market purchases of AB holding units																	$ 176,100	$ 151,100
Restricted AB holding unit awards to employees (in units)																	6.1	7.0
Options to buy AB holding units outstanding, number (in units)																	0.4	0.5
Proceeds from exercise of compensatory options to buy AB holding units																	$ 6,108	$ 9,233	$ 18,955
Employees and Eligible Directors [Member]
Long-Term Incentive Compensation Plans [Abstract]
Restricted AB holding unit awards to employees (in units)																	7.0	7.4
Subsequent Event [Member]
Distribution Made to Limited Liability Company (LLC) Member [Line Items]
Subsequent cash distribution, distribution declared (in dollars per unit)		$ 0.67

[1] Cash distributions reflect the impact of AB’s non-GAAP adjustments.

[2] Declared and paid during the following quarter.

[3] Certain prior-period amounts have been revised, see Note 2 for a discussion of the revision.